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Protagonist Therapeutics (NASDAQ: PTGX) jumps on $269.8M 2026 collaboration revenue

(Moderate)
(Neutral)
Form Type
10-Q

Rhea-AI Filing Summary

Protagonist Therapeutics reported a sharp turnaround to profitability for the three and six months ended June 30, 2026, driven by collaboration economics. License and collaboration revenue reached $213.5 million in the quarter and $269.8 million year‑to‑date, largely from its Takeda rusfertide deal and a Janssen ICOTYDE milestone.

Net income was $162.8 million for the quarter and $166.6 million year‑to‑date, compared with losses in 2025, while cash, cash equivalents and marketable securities rose to about $849.5 million as of June 30, 2026. The Takeda opt‑out triggered a $200 million payment and positions Protagonist for royalties of 14–29% plus up to $775 million in sales milestones if rusfertide is approved and commercialized.

ICOTYDE received FDA approval in March 2026 for moderate‑to‑severe plaque psoriasis, earning a $50 million milestone and supporting future royalties of 6–10% and up to $580 million in additional milestones. Management expects research and development spending to increase significantly in the second half of 2026 as programs such as PN‑881, PN‑477, PN‑458 and PN‑8047 advance.

Positive

  • H1 2026 net income of $166.6 million versus a prior‑year loss reflects a substantial profitability inflection driven by collaboration revenue.
  • Cash, cash equivalents and marketable securities of ~$849.5 million as of June 30, 2026 provide significant funding capacity for an expanded clinical and discovery pipeline.
  • The Takeda and JNJ deals create large, diversified potential streams with up to $1.36 billion in combined future milestones plus tiered royalties on ICOTYDE and rusfertide sales.

Negative

  • Management expects research and development expenses to increase significantly in the second half of 2026 as multiple programs move into later‑stage clinical development, which will raise the company’s cash burn.
  • Revenue is highly concentrated in milestone and collaboration payments from Takeda and JNJ and is described as highly variable, depending on partner development progress and commercial execution.

Filing Explained

As of June 30, 2026, equity plans had expanded the share base, while 1.5 million pre-funded warrants remained potential additional shares.

Protagonist Therapeutics filed a Form 10-Q, an unaudited quarterly report, for the period ended June 30, 2026; it reports 2,094,135 shares issued through equity incentive and employee stock purchase plans during the first half, bringing issued and outstanding common shares to $64,672,032 shares at quarter-end from 62,577,897 at year-end, which increases the share base and, absent offsetting changes, reduces existing holders’ percentage ownership.

The stockholders’ equity note also reports 1,500,000 pre-funded warrants still outstanding as of June 30, 2026; none were exercised during the quarter or first half, so these are potential additional shares rather than newly issued shares, subject to a nominal $0.001 exercise price and a 9.99% beneficial-ownership limit.

License & collaboration revenue $213,475,000 Three months ended June 30, 2026
License & collaboration revenue $269,843,000 Six months ended June 30, 2026
Net income $166,632,000 Six months ended June 30, 2026
Cash, cash equivalents & marketable securities $849,500,000 Approximate balance as of June 30, 2026
Takeda opt-out payment recognized $192,400,000 Portion of $200.0M opt-out payment recognized in H1 2026
ICOTYDE FDA approval milestone $50,000,000 Milestone from JNJ earned in March 2026
Accumulated deficit $304,039,000 Cumulative net losses since inception as of June 30, 2026
Common shares outstanding 64,672,032 shares Issued and outstanding as of June 30, 2026
Breakthrough Therapy designation regulatory
"In August 2025, rusfertide was granted Breakthrough Therapy designation by the U.S. Food and Drug Administration"
A breakthrough therapy designation is a regulatory fast-track given to a drug or treatment that shows early signs of providing a major improvement over existing options for a serious condition. Think of it as a VIP lane that can speed up development and more intensive guidance from regulators, which matters to investors because it can shorten time to market, reduce development risk and potentially increase a company’s value — though it does not guarantee approval.
Priority Review regulatory
"The NDA was granted priority review by the FDA, with a Prescription Drug User Fee Act target action date in August 2026"
Priority review is a regulatory fast-track that shortens the time an agency spends evaluating a drug, vaccine or medical device application so a decision comes sooner than normal. For investors, it matters because a faster review is like an express lane to market: it can speed revenue potential and reduce regulatory uncertainty, but it does not guarantee approval and still requires the product to meet safety and effectiveness standards.
tiered royalties financial
"eligible to receive future sales milestone payments and tiered royalties on net product sales at percentages ranging from 6% to 10%"
Tiered royalties are a payment structure where the percentage of earnings paid as royalties changes based on different levels of sales or production. For example, a company might pay a smaller percentage on initial sales and a higher percentage as sales increase beyond certain points. This system encourages higher sales by adjusting payments, making it important for investors to understand how revenue sharing may vary as a product or project grows.
profit and loss sharing arrangement financial
"exercised its right to opt out of the U.S. profit and loss sharing arrangement (50% to the Company and 50% to Takeda)"
cost-based input method financial
"using the cost-based input method for development services, consisting of (i) $192.4 million related to the proportional recognition"
Prescription Drug User Fee Act regulatory
"with a Prescription Drug User Fee Act target action date in August 2026"
A federal program that lets drug makers pay fees to the U.S. regulator to fund and speed up the review of new medicines and label changes. Investors care because it affects how quickly a drug can move from testing to market and how predictable approval timelines and regulatory interactions are — like buying a faster lane at a busy checkpoint that can reduce uncertainty about a product’s commercial timing.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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FAQ

How did Protagonist Therapeutics (PTGX) perform financially in Q2 2026?

Protagonist reported Q2 2026 license and collaboration revenue of $213.5 million and net income of $162.8 million. Results contrast with a loss in Q2 2025 and were driven primarily by Takeda rusfertide economics and ongoing collaboration revenue.

What drove PTGX’s year-to-date 2026 revenue of $269.8 million?

Year‑to‑date license and collaboration revenue was $269.8 million, mainly from the Takeda rusfertide agreement and a $50 million ICOTYDE milestone from JNJ. Protagonist recognized $192.4 million of a $200 million Takeda opt‑out payment using a cost‑based input method.

What is Protagonist Therapeutics’ (PTGX) cash position as of June 30, 2026?

As of June 30, 2026, Protagonist held about $849.5 million in cash, cash equivalents and marketable securities, up from approximately $646.0 million at December 31, 2025. The increase reflects large collaboration inflows, including the Takeda opt‑out payment and the ICOTYDE milestone.

What are the key terms of PTGX’s collaboration with Takeda on rusfertide?

Protagonist received a $300 million upfront payment, a $25 million milestone, and a $200 million opt‑out payment. It may receive another $200 million opt‑out fee, a $75 million approval milestone, up to $775 million in sales milestones, and 14–29% tiered royalties on worldwide net sales.

What is the status of ICOTYDE in Protagonist Therapeutics’ (PTGX) JNJ partnership?

ICOTYDE was approved by the FDA in March 2026 for moderate‑to‑severe plaque psoriasis, triggering a $50 million milestone. Protagonist has earned $387.5 million in non‑refundable payments to date and is eligible for up to $580 million in additional milestones plus 6–10% tiered royalties.

Which pipeline programs is Protagonist Therapeutics (PTGX) advancing beyond ICOTYDE and rusfertide?

Beyond ICOTYDE and rusfertide, Protagonist is developing PN‑881 (oral IL‑17 antagonist, Phase 1), obesity candidates PN‑477 and PN‑458, and oral hepcidin mimetic PN‑8047. Multiple Phase 1 and Phase 2b trials are planned between 2026 and 2027.
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Table of Contents

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended June 30, 2026

or

TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from                      to                    

Commission File No. 001-37852

PROTAGONIST THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

Delaware

  ​ ​ ​

98-0505495

(State or other jurisdiction of
incorporation or organization)

(I.R.S. Employer
Identification No.)

7707 Gateway Boulevard, Suite 140
Newark, California

94560-1160

(Address of registrant’s principal executive offices)

(Zip code)

(510) 474-0170

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Stock, par value $0.00001

PTGX

The Nasdaq Stock Market, LLC

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.   Yes      No  

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).   Yes      No  

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer

Accelerated filer

Smaller reporting company

Non-accelerated filer

Emerging growth company

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.   

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).  Yes      No  

As of July 31, 2026, there were 64,708,285 shares of the registrant’s Common Stock, par value $0.00001 per share, outstanding.

Table of Contents

PROTAGONIST THERAPEUTICS, INC.

FORM 10-Q

TABLE OF CONTENTS

I

Page

PART I

FINANCIAL INFORMATION

Item 1.

Condensed Consolidated Financial Statements (unaudited)

Condensed Consolidated Balance Sheets

1

Condensed Consolidated Statements of Operations

2

Condensed Consolidated Statements of Comprehensive Income (Loss)

3

Condensed Consolidated Statements of Stockholders’ Equity

4

Condensed Consolidated Statements of Cash Flows

6

Notes to Unaudited Condensed Consolidated Financial Statements

7

Item 2.

Management’s Discussion and Analysis of Financial Condition and Results of Operations

18

Item 3.

Quantitative and Qualitative Disclosures About Market Risk

30

Item 4.

Controls and Procedures

31

PART II

OTHER INFORMATION

Item 1.

Legal Proceedings

31

Item 1A.

Risk Factors

31

Item 2.

Unregistered Sales of Equity Securities and Use of Proceeds

33

Item 3.

Defaults Upon Senior Securities

33

Item 4.

Mine Safety Disclosures

33

Item 5.

Other Information

33

Item 6.

Exhibits

33

SIGNATURES

35

Table of Contents

PART I. – FINANCIAL INFORMATION

ITEM 1.FINANCIAL STATEMENTS

PROTAGONIST THERAPEUTICS, INC.

Condensed Consolidated Balance Sheets

(Unaudited)

(In thousands, except share and per share data)

June 30, 

December 31, 

  ​ ​ ​

2026

  ​ ​ ​

2025

Assets

Current assets:

Cash and cash equivalents

$

420,078

$

128,390

Marketable securities

362,498

438,974

Receivable from collaboration partner

13,416

121

Contract asset

3,366

Prepaid expenses and other current assets

7,790

10,089

Total current assets

807,148

577,574

Marketable securities - noncurrent

66,875

78,638

Property and equipment, net

3,456

3,860

Restricted cash - noncurrent

287

287

Operating lease right-of-use asset

6,946

7,829

Other non-current asset

832

Total assets

$

885,544

$

668,188

Liabilities and Stockholders’ Equity

Current liabilities:

  ​

Accounts payable

$

3,459

$

5,339

Accrued expenses and other payables

21,667

28,269

Deferred revenue

9,659

9,550

Operating lease liability

2,396

2,283

Total current liabilities

37,181

45,441

Operating lease liability - noncurrent

6,820

8,040

Total liabilities

44,001

53,481

Commitments and contingencies

Stockholders’ equity:

Preferred stock, $0.00001 par value, 10,000,000 shares authorized; no shares issued and outstanding

Common stock, $0.00001 par value, 180,000,000 shares authorized; 64,672,032 and 62,577,897 shares issued and outstanding as of June 30, 2026 and December 31, 2025, respectively

1

1

Additional paid-in capital

1,146,409

1,084,736

Accumulated other comprehensive (loss) income

(828)

641

Accumulated deficit

(304,039)

(470,671)

Total stockholders’ equity

841,543

614,707

Total liabilities and stockholders’ equity

$

885,544

$

668,188

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

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PROTAGONIST THERAPEUTICS, INC.

Condensed Consolidated Statements of Operations

(Unaudited)

(In thousands, except share and per share data)

Three Months Ended

Six Months Ended

June 30, 

June 30, 

  ​ ​ ​

2026

  ​ ​ ​

2025

  ​ ​ ​

2026

  ​ ​ ​

2025

License and collaboration revenue

$

213,475

$

5,546

$

269,843

$

33,867

Operating expenses:

Research and development

42,061

37,036

88,800

72,929

General and administrative

 

12,648

 

10,551

 

25,925

 

22,289

Total operating expenses

 

54,709

 

47,587

 

114,725

 

95,218

Income (loss) from operations

 

158,766

 

(42,041)

 

155,118

 

(61,351)

Interest income

 

6,429

 

7,406

 

12,305

14,979

Other (expense) income, net

(81)

36

(28)

118

Income (loss) before income tax expense

165,114

(34,599)

167,395

(46,254)

Income tax expense

2,265

172

763

172

Net income (loss)

$

162,849

$

(34,771)

$

166,632

$

(46,426)

Net income (loss) per share, basic

$

2.47

$

(0.55)

$

2.54

$

(0.73)

Net income (loss) per share, diluted

$

2.29

$

(0.55)

$

2.35

$

(0.73)

Weighted-average shares used to compute net income (loss) per share, basic

 

65,935,769

  ​

 

63,510,537

 

65,514,150

  ​

 

63,238,682

Weighted-average shares used to compute net income (loss) per share, diluted

 

71,007,011

  ​

 

63,510,537

 

70,818,718

  ​

 

63,238,682

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

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PROTAGONIST THERAPEUTICS, INC.

Condensed Consolidated Statements of Comprehensive Income (Loss)

(Unaudited)

(In thousands)

Three Months Ended

Six Months Ended

June 30, 

June 30, 

  ​ ​ ​

2026

  ​ ​ ​

2025

  ​ ​ ​

2026

  ​ ​ ​

2025

Net income (loss)

$

162,849

$

(34,771)

$

166,632

$

(46,426)

Other comprehensive (loss) income:

  ​

  ​

Unrealized (loss) gain on marketable securities

(559)

(100)

(1,469)

67

Comprehensive income (loss)

$

162,290

$

(34,871)

$

165,163

$

(46,359)

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

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PROTAGONIST THERAPEUTICS, INC.

Condensed Consolidated Statements of Stockholders’ Equity

(Unaudited)

(In thousands, except share data)

Accumulated

Additional

Other

Total

Common

Paid-In

Comprehensive

Accumulated

Stockholders’

Stock

Capital

Income (Loss)

Deficit

Equity

Three months ended June 30, 2026

  ​

Shares

  ​

Amount

  ​

  ​

  ​

  ​

 

Balance at March 31, 2026

 

64,227,057

  ​

$

1

$

1,122,629

  ​

$

(269)

$

(466,888)

  ​

$

655,473

Issuance of common stock under equity incentive and employee stock purchase plans

444,975

  ​

 

 

9,743

  ​

 

 

  ​

 

9,743

Stock-based compensation expense

 

  ​

 

 

14,037

  ​

 

 

  ​

 

14,037

Other comprehensive loss

 

  ​

 

 

  ​

 

(559)

 

  ​

 

(559)

Net income

 

  ​

 

 

  ​

 

 

162,849

  ​

 

162,849

Balance at June 30, 2026

 

64,672,032

  ​

$

1

$

1,146,409

  ​

$

(828)

$

(304,039)

  ​

$

841,543

Accumulated

Additional

Other

Total

Common

Paid-In

Comprehensive

Accumulated

Stockholders’

Stock

Capital

Income (Loss)

Deficit

Equity

Three months ended June 30, 2025

  ​

Shares

  ​

Amount

  ​

  ​

  ​

  ​

 

Balance at March 31, 2025

61,928,760

  ​

$

1

$

1,041,143

  ​

$

85

$

(352,177)

  ​

$

689,052

Issuance of common stock under equity incentive and employee stock purchase plans

178,812

  ​

 

 

2,925

  ​

 

 

  ​

 

2,925

Stock-based compensation expense

 

  ​

 

 

10,912

  ​

 

 

  ​

 

10,912

Other comprehensive loss

 

  ​

 

 

  ​

 

(100)

 

  ​

 

(100)

Net loss

 

  ​

 

 

  ​

 

 

(34,771)

  ​

 

(34,771)

Balance at June 30, 2025

 

62,107,572

  ​

$

1

$

1,054,980

  ​

$

(15)

$

(386,948)

  ​

$

668,018

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

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PROTAGONIST THERAPEUTICS, INC.

Condensed Consolidated Statements of Stockholders’ Equity

(Unaudited)

(In thousands, except share data)

Accumulated

Additional

Other

Total

Common

Paid-In

Comprehensive

Accumulated

Stockholders’

Stock

Capital

Income (Loss)

Deficit

Equity

Six months ended June 30, 2026

  ​

Shares

  ​

Amount

  ​

  ​

  ​

  ​

 

Balance at December 31, 2025

 

62,577,897

  ​

$

1

$

1,084,736

  ​

$

641

$

(470,671)

  ​

$

614,707

Issuance of common stock under equity incentive and employee stock purchase plans

2,094,135

33,117

33,117

Stock-based compensation expense

 

  ​

 

 

28,556

  ​

 

 

  ​

 

28,556

Other comprehensive loss

 

  ​

 

 

  ​

 

(1,469)

 

  ​

 

(1,469)

Net income

 

  ​

 

 

  ​

 

 

166,632

  ​

 

166,632

Balance at June 30, 2026

 

64,672,032

  ​

$

1

$

1,146,409

  ​

$

(828)

$

(304,039)

  ​

$

841,543

Accumulated

Additional

Other

Total

Common

Paid-In

Comprehensive

Accumulated

Stockholders’

Stock

Capital

Income (Loss)

Deficit

Equity

Six months ended June 30, 2025

  ​

Shares

  ​

Amount

  ​

  ​

  ​

  ​

 

Balance at December 31, 2024

61,035,139

$

1

$

1,015,898

$

(82)

$

(340,522)

$

675,295

Issuance of common stock under equity incentive and employee stock purchase plans

 

1,085,069

  ​

 

 

14,847

  ​

 

 

  ​

 

14,847

Shares withheld for net settlement of tax withholding upon vesting of restricted stock units

(12,636)

(479)

(479)

Stock-based compensation expense

 

  ​

 

 

24,714

  ​

 

 

  ​

 

24,714

Other comprehensive income

 

  ​

 

 

  ​

 

67

 

  ​

 

67

Net loss

 

  ​

 

 

  ​

 

 

(46,426)

  ​

 

(46,426)

Balance at June 30, 2025

 

62,107,572

  ​

$

1

$

1,054,980

  ​

$

(15)

$

(386,948)

  ​

$

668,018

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

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PROTAGONIST THERAPEUTICS, INC.

Condensed Consolidated Statements of Cash Flows

(Unaudited)

(In thousands)

Six Months Ended

June 30, 

  ​ ​ ​

2026

  ​ ​ ​

2025

Cash Flows from Operating Activities

 

  ​

  ​

Net income (loss)

$

166,632

$

(46,426)

Adjustments to reconcile net income (loss) to net cash provided by operating activities:

Stock-based compensation

28,556

24,714

Non-cash lease expense

883

1,137

Depreciation

804

543

Accretion of discount on marketable securities

(2,071)

(4,203)

Other

(4)

5

Changes in operating assets and liabilities:

Receivable from collaboration partner

(13,295)

165,000

Contract asset

(3,366)

(22,287)

Prepaid expenses and other assets

2,299

(2,045)

Accounts payable

(1,897)

1,612

Accrued expenses and other payables

(6,602)

(8,378)

Deferred revenue

109

(10,504)

Income taxes payable

(2,689)

Operating lease liability

(1,107)

104

Other non-current asset

(832)

Net cash provided by operating activities

170,109

96,583

Cash Flows from Investing Activities

Purchase of marketable securities

(203,644)

(281,194)

Proceeds from maturities of marketable securities

289,105

235,957

Proceeds from sale of marketable securities

3,384

7,003

Purchases of property and equipment

(383)

(1,358)

Net cash provided by (used in) investing activities

88,462

(39,592)

Cash Flows from Financing Activities

Proceeds from issuance of common stock upon exercise of stock options and purchases under employee stock purchase plan

33,117

14,847

Tax withholding payments related to net settlement of restricted stock units

(479)

Net cash provided by financing activities

33,117

14,368

Net increase in cash, cash equivalents and restricted cash

291,688

71,359

Cash, cash equivalents and restricted cash, beginning of period

 

128,677

 

97,474

Cash, cash equivalents and restricted cash, end of period

$

420,365

$

168,833

Supplemental Disclosure of Non-Cash Financing and Investing Information:

Purchases of property and equipment in accounts payable and accrued liabilities

$

17

$

103

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

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PROTAGONIST THERAPEUTICS, INC.

Notes to Unaudited Condensed Consolidated Financial Statements

Note 1.Organization and Description of Business

Protagonist Therapeutics, Inc. (the “Company”) is a discovery through late-stage development biopharmaceutical company with a proprietary technology platform that enables de novo discovery of peptide therapeutics. The Company’s programs fall into three broad therapeutic areas: (i) inflammation and immunology (“I&I”), (ii) hematology and (iii) metabolic diseases. The Company’s aim is to develop medicines for biologically and commercially validated targets which demonstrate a strong differentiation compared to existing therapies.

ICOTYDE™ (icotrokinra) was approved in the United States in March 2026 for the treatment of moderate-to-severe plaque psoriasis in adults and pediatric patients 12 years of age or older who weigh at least 40 kg and are candidates for systemic therapy or phototherapy. ICOTYDE is the first and only targeted oral peptide that precisely blocks the Interleukin-23 receptor (“IL-23R”) and is licensed to Janssen Biotech, Inc., a Johnson & Johnson company (“JNJ”). ICOTYDE was jointly discovered by the Company and JNJ scientists, with the Company having primary responsibility for the development of ICOTYDE through Phase 1, and JNJ assuming responsibility for further development and commercialization. In September 2025, JNJ submitted an application to the European Medicines Agency (“EMA”) seeking the first approval of ICOTYDE for the treatment of adults and pediatric patients 12 years of age and older with moderate-to-severe plaque psoriasis. ICOTYDE is in Phase 3 development for psoriatic arthritis and ulcerative colitis, and in Phase 2b/3 for Crohn’s disease.

Rusfertide, a first-in-class investigational injectable mimetic of the natural hormone hepcidin, is currently in development for the treatment of the rare blood disorder polycythemia vera (“PV”). Rusfertide is licensed to Takeda Pharmaceuticals Inc. (“Takeda”). The Company discovered and led development for rusfertide through Phase 3, and Takeda is responsible for further development and commercialization. In August 2025, rusfertide was granted Breakthrough Therapy designation by the U.S. Food and Drug Administration (the “FDA”) for the treatment of erythrocytosis in patients with PV. In December 2025, a New Drug Application (“NDA”) was submitted to the FDA by Takeda and the Company seeking the first approval of rusfertide for the treatment of adults with PV. The NDA was granted priority review by the FDA, with a Prescription Drug User Fee Act target action date in August 2026.

The Company also has a number of clinical and pre-clinical programs addressing biologically and commercially validated targets, including IL-17 oral peptide antagonist PN-881, obesity triple agonist peptide PN-477, obesity dual agonist peptide PN-458, oral small molecule hepcidin functional mimetic PN-8047, and IL-4 and amylin programs.

The Company is headquartered in Newark, California and has one wholly owned subsidiary, Protagonist Pty Limited (“Protagonist Australia”), located in Brisbane, Queensland, Australia.

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Note 2. Summary of Significant Accounting Policies

Basis of Presentation and Consolidation

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”), the instructions to Form 10-Q and Rule 10-01 of Regulation S-X and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP have been condensed or omitted and, accordingly, the condensed consolidated balance sheet as of June 30, 2026 has been derived from the Company’s unaudited consolidated financial statements at that date but does not include all of the information required by GAAP for complete consolidated financial statements. These unaudited interim condensed consolidated financial statements have been prepared on the same basis as the Company’s annual consolidated financial statements and, in the opinion of management, reflect all adjustments (consisting of normal recurring adjustments) that are necessary for a fair presentation of the Company’s condensed consolidated financial statements. The results of operations for the three and six months ended June 30, 2026 are not necessarily indicative of the results to be expected for the year ending December 31, 2026 or for any future period.

The accompanying unaudited condensed consolidated financial statements and related financial information should be read in conjunction with the audited consolidated financial statements and the related notes thereto for the year ended December 31, 2025 included in the Company’s Annual Report on Form 10-K, filed with the SEC on February 25, 2026.

Principles of Consolidation

The accompanying unaudited interim condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiary. All intercompany transactions and balances have been eliminated upon consolidation.

Use of Estimates

The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates, assumptions and judgments that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities as of the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, accruals for research and development activities, stock-based compensation, income taxes, marketable securities and leases. Estimates related to revenue recognition include assumptions used to determine standalone selling price utilized to allocate the transaction price between distinct performance obligations, assumptions used to recognize revenue over time for certain performance obligations for which a cost-based input method is used as the measure of progress, estimates of whether contingent consideration should be included in the transaction price at each reporting period, and estimates related to royalty revenue recognition. Management bases these estimates on historical and anticipated results, trends, and various other assumptions that the Company believes are reasonable under the circumstances, including assumptions as to forecasted amounts and future events. Actual results may differ materially from these estimates.

There has been uncertainty and disruption in the global economy and financial markets due to a number of factors, including but not limited to geopolitical instability and changes in trade policies, including tariffs or other trade restrictions or the threat of such actions and retaliatory actions. The Company’s business may also be impacted by changes or disruptions at the FDA and other government agencies. The Company has taken into consideration any known impacts to its accounting estimates to date and is not aware of any additional specific events or circumstances that would require any additional updates to its estimates or judgments or a revision of the carrying value of its assets or liabilities as of the filing date of this Quarterly Report on Form 10-Q. These estimates may change as new events occur and additional information is obtained. Actual results could differ materially from these estimates under different assumptions or conditions.

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Cash as Reported in Condensed Consolidated Statements of Cash Flows

Cash as reported in the condensed consolidated statements of cash flows includes the aggregate amounts of cash and cash equivalents and restricted cash as presented on the condensed consolidated balance sheets.

Cash as reported in the condensed consolidated statements of cash flows consisted of (in thousands):

June 30, 

  ​ ​ ​

2026

  ​ ​ ​

2025

Cash and cash equivalents

$

420,078

$

168,543

Restricted cash - noncurrent

 

287

 

290

Total cash reported on condensed consolidated statements of cash flows

$

420,365

$

168,833

Restricted cash as of June 30, 2026 and 2025 consists of a cash deposit held as security in connection with a letter of credit related to the Company’s facility lease entered into in March 2017, as subsequently amended, and a cash deposit held as security in connection with the issuance of a bank guarantee in May 2025 to maintain the active status of the Company’s value-added tax registration.

Stock-Based Compensation Expense

The Company has granted stock options, restricted stock units (“RSUs”) and performance stock units (“PSUs”).

Stock-based compensation expense associated with stock options is based on the estimated grant date fair value using the Black-Scholes valuation model, which requires the use of assumptions related to expected stock price volatility, option term, risk-free interest rate and dividend yield. The Company recognizes compensation expense over the vesting period of the awards that are ultimately expected to vest.

Stock-based compensation expense associated with RSUs is based on the fair value of the Company’s common stock on the grant date, which equals the closing market price of the Company’s common stock on the grant date. For RSUs, the Company recognizes compensation expense over the vesting period of the awards that are ultimately expected to vest.

PSUs allow the recipients of such awards to earn fully vested shares of the Company’s common stock upon the achievement of pre-established performance objectives. Stock-based compensation expense associated with PSUs is based on the fair value of the Company’s common stock on the grant date, which equals the closing market price of the Company’s common stock on the grant date and is recognized when the performance objective is expected to be achieved. The Company evaluates the probability of achieving the performance criteria on a quarterly basis. The cumulative effect on current and prior periods of a change in the estimated number of PSUs expected to be earned is recognized as compensation expense or as reduction of previously recognized compensation expense in the period of the revised estimate. No stock-based compensation related to PSUs was recognized for the three and six months ended June 30, 2026 and the three months ended June 30, 2025. The Company recognized $1.8 million of stock-based compensation expense related to PSUs for the six months ended June 30, 2025.

The Company recognizes forfeitures of stock-based awards as they occur.

Total stock-based compensation expense was as follows (in thousands):

Three Months Ended

Six Months Ended

June 30, 

June 30, 

  ​ ​ ​

2026

  ​ ​ ​

2025

  ​ ​ ​

2026

  ​ ​ ​

2025

Research and development

$

7,558

$

6,291

$

15,327

$

14,282

General and administrative

 

6,479

 

4,621

 

13,229

 

10,432

Total stock-based compensation expense

$

14,037

$

10,912

$

28,556

$

24,714

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Significant Accounting Policies

There have been no material changes to the Company’s significant accounting policies during the three and six months ended June 30, 2026, as compared to those disclosed in Note 2. Summary of Significant Accounting Policies included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025.

Recently Issued Accounting Pronouncements Not Yet Adopted as of June 30, 2026

In December 2025, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2025-11 Interim Reporting (Topic 270) – Narrow Scope Improvements (“ASU 2025-11”), which clarifies interim disclosure requirements. ASU 2025-11 also requires entities to disclose events since the end of the last annual reporting period that have a material impact on the entity. This guidance is effective for the Company for interim reporting periods within annual reporting periods beginning on January 1, 2028. Early adoption is permitted. The guidance may be applied either (1) prospectively or (2) retrospectively to any or all prior periods presented in the financial statements. The Company does not expect the adoption of this guidance to have a material effect on its consolidated financial statements and related disclosures.

In November 2024, the FASB issued ASU No. 2024-03 Income Statement – Reporting Comprehensive Income – Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses (“ASU 2024-03”), which requires detailed disclosures about specified categories of expenses (including employee compensation, depreciation, and amortization) included in certain expense captions presented on the face of the income statement. In January 2025, the FASB issued an update to ASU 2024-03 clarifying that all public business entities should initially adopt the disclosure requirements in the first annual reporting period beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. ASU 2024-03 is effective for the Company for fiscal years beginning on January 1, 2027, and for interim periods beginning on January 1, 2028. Early adoption is permitted. The guidance may be applied either (1) prospectively to financial statements issued for reporting periods after the effective date of ASU 2024-03 or (2) retrospectively to all prior periods presented in the financial statements. The Company does not expect the adoption of this guidance to have a material effect on its consolidated financial statements and continues to evaluate disclosure presentation alternatives.

Note 3. License and Collaboration Agreements

JNJ License and Collaboration Agreement

In November 2024, the Company entered into an Amended and Restated License and Collaboration Agreement with JNJ, which amended and restated the License and Collaboration Agreement, effective July 2017, by and between the Company and JNJ, as amended in May 2019 and July 2021 (together, the “JNJ License and Collaboration Agreement”). The JNJ License and Collaboration Agreement relates to the development, manufacture and commercialization of oral IL-23R antagonist drug candidates and enables JNJ to develop collaboration compounds for multiple indications. Under the JNJ License and Collaboration Agreement, JNJ is required to use commercially reasonable efforts to develop at least one collaboration compound for at least two indications.

During the first quarter of 2026, the Company earned a $50.0 million milestone payment upon FDA approval of ICOTYDE for the treatment of moderate-to-severe plaque psoriasis in adults and pediatric patients 12 years of age or older who weigh at least 40 kg and are candidates for systemic therapy or phototherapy. The Company has earned a total of $387.5 million in non-refundable upfront and milestone payments from JNJ under the JNJ License and Collaboration Agreement from inception in 2017 through June 30, 2026.

Upcoming potential development milestones under the JNJ License and Collaboration Agreement include:

$25.0 million upon the acceptance of an NDA filing by the FDA for a second indication;
$45.0 million upon FDA approval of an NDA for a second indication;

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$35.0 million upon the acceptance of an NDA filing by the FDA for a third indication; and
$50.0 million upon FDA approval of an NDA for a third indication.

Pursuant to the agreement, the Company is eligible to receive future sales milestone payments and tiered royalties on net product sales at percentages ranging from 6% to 10%. In addition, the Company remains eligible to receive sales milestones of up to $425.0 million.

Takeda Collaboration Agreement

In January 2024, the Company entered into a worldwide license and collaboration agreement for rusfertide with Takeda, which became effective in March 2024, and was amended in March 2025 (the “Takeda Collaboration Agreement”).

Pursuant to the Takeda Collaboration Agreement, the Company and Takeda agreed to jointly develop and commercialize rusfertide and potentially other specified second-generation injectable hepcidin mimetic compounds (the “Licensed Products”) in the United States (the “Profit-Share Territory”). Takeda was solely and exclusively responsible for the development and commercialization of the Licensed Products in all other countries (the “Takeda Territory”). The Company and Takeda shared the costs of the development, manufacture and commercialization activities for the Licensed Products in the Profit-Share Territory, provided that (i) the Company led, and was solely responsible for its costs associated with, completion of the ongoing Phase 3 VERIFY trial evaluating rusfertide for the treatment of PV; (ii) Takeda led, and was solely responsible for its costs associated with, U.S. regulatory and pre-commercialization activities related to rusfertide in the Profit-Share Territory; and (iii) Takeda led commercialization of rusfertide in the Profit-Share Territory, though the Company held an option to co-detail. Takeda was solely responsible for all costs for the development, manufacture and commercialization of the Licensed Products in the Takeda Territory. The Company granted Takeda a non-transferable, sublicensable and, except for certain specified exceptions, exclusive license to certain intellectual property of the Company to exercise its rights and perform its obligations under the Takeda Collaboration Agreement. In March 2025, the Company and Takeda agreed, pursuant to the provisions of the Takeda Collaboration Agreement, as amended, that Takeda would assume responsibility for leading and implementing the regulatory strategy and associated activities for preparation of the NDA related to rusfertide in PV, which was submitted to the FDA in December 2025. The Company was primarily responsible for clinical development activities through the NDA filing and for conducting ongoing rusfertide long-term extension studies.

Pursuant to the Takeda Collaboration Agreement, the Company received a one-time, non-refundable upfront payment of $300.0 million in April 2024 and a $25.0 million milestone payment in September 2025.

On April 28, 2026, the Company announced that it exercised its right to opt out of the U.S. profit and loss sharing arrangement (50% to the Company and 50% to Takeda) under the Takeda Collaboration Agreement. Following the Company’s exercise of the opt-out right, the Company has agreed to transition applicable development and commercial activities to Takeda, and Takeda has the right to assume sole operational and financial responsibility for such activities in the United States. The opt-out election triggered a $200.0 million payment, with an additional $200.0 million opt-out fee and a separate $75.0 million milestone due upon FDA approval of rusfertide. Following the opt-out, the Company is also eligible to receive up to $775.0 million in sales milestone payments and tiered royalties ranging from 14% to 29% on annual net worldwide sales, with an approximate 21% weighted-average royalty rate at $1.5 billion in annual net sales and a 29% tier applying to incremental annual net sales above $1.5 billion.

Upcoming potential development milestones under the Takeda Collaboration Agreement include:

$75.0 million upon FDA approval of an NDA for rusfertide in PV;
$15.0 million upon first regulatory approval for rusfertide in PV in three European countries, after pricing and reimbursement approval; and
$10.0 million upon first regulatory approval for rusfertide in PV in Japan.

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The Company is obligated to perform certain wind-down activities during the three-month opt-out wind-down period which includes transferring the VERIFY trial and other projects to Takeda, overseeing vendors and development activities until such activities are fully transferred to Takeda, and continuing to perform the rusfertide open label extension. Such costs during the wind-down period (from April 28, 2026 to July 27, 2026) are shared (50%) with Takeda and the Company aims to transfer the majority of the activities to Takeda by July 27, 2026. As agreed upon with Takeda, Protagonist will continue work for the rusfertide open-label extension after the wind-down period until completion, which is expected in the first quarter of 2027. Costs incurred by Protagonist for any remaining wind-down activities and rusfertide open-label extension after July 27, 2026 will be fully reimbursed by Takeda.

The Company initially evaluated the Takeda Collaboration Agreement and concluded that it had elements that were within the scope of ASC Topic 606 and ASC Topic 808. As of the effective date of the Takeda Collaboration Agreement, the Company identified two distinct performance obligations: (i) the rusfertide license delivered upon the effectiveness of the Takeda Collaboration Agreement and (ii) certain development services to be provided prior to the opt-out period, including certain of the Company’s responsibilities to complete the VERIFY Phase 3 clinical trial in PV and associated manufacturing services. Following the completion of the wind-down period on July 27, 2026, the Takeda Collaboration Agreement will no longer meet the definition of a collaborative arrangement under ASC Topic 808.

The Company determined that the initial transaction price totaled $300.0 million, which was comprised of the upfront payment. The Company initially excluded any future estimated milestones or royalties from this transaction price, all of which were either constrained or subject to the sales-and usage-based royalty exception. As part of the Company’s evaluation of this variable consideration constraint, it determined that the potential payments were contingent upon developmental and regulatory milestones that were uncertain and were highly susceptible to factors outside of its control. The Company allocated $254.1 million of the initial transaction price to the license and $45.9 million to the development services based upon the relative standalone selling price of each performance obligation. The estimate of standalone selling price for the license was determined based on discounted cash flows for the expected development and commercialization of rusfertide and included assumptions for forecasted revenues, development timelines and expenses, discount rates, and probabilities of technical and regulatory success. The estimate of standalone selling price for the development services was determined based on forecasted costs and expenses over the expected development period. For the license of rusfertide, the Company determined that Takeda could benefit from the license at the time the license was granted and therefore, the related performance obligation was satisfied at that point in time.

The amount allocated to the license, which represents functional intellectual property that was transferred at a point in time, was satisfied upon transfer of the license to Takeda. The amount allocated to development services will be recognized over time based on a measure of the Company’s efforts toward satisfying the performance obligation relative to the total expected efforts or inputs to satisfy the performance obligation (e.g., costs incurred compared to total budget). As of the opt-out date, the development services performance obligation remained partially unsatisfied.

The exercise of the opt-out right results in a contract modification under ASC Topic 606 because it changes the enforceable rights and obligations of the parties under the Takeda Collaboration Agreement. As a result, the remaining unconstrained consideration was allocated to the remaining development services performance obligation, and the modification was accounted for as part of the existing contract.

Revenue Recognition

For the three months ended June 30, 2026, the Company recognized license and collaboration revenue of $213.5 million. This included $202.5 million under the Takeda Collaboration Agreement using the cost-based input method for development services, consisting of (i) $192.4 million related to the proportional recognition of the $200.0 million opt-out payment, (ii) $5.7 million related to cost reimbursement for post opt-out wind-down services provided by the Company, $3.4 million of which was recorded as a contract asset, and (iii) $4.4 million related to the initial upfront payment and milestones received to date. In addition, the Company recognized revenue during the period of $11.0 million for rusfertide clinical supplies under the Takeda Collaboration Agreement and other revenues. The remaining $7.6 million in revenue related to the $200.0 million opt-out payment under the Takeda Collaboration Agreement was recorded as deferred revenue on the Company’s condensed consolidated balance sheet and is expected to be recognized through the conclusion of the development services performance obligation.

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For the six months ended June 30, 2026, the Company recognized license and collaboration revenue of $269.8 million. This included $205.7 million under the Takeda Collaboration Agreement using the cost-based input method for development services, consisting of (i) $192.4 million related to the proportional recognition of the $200.0 million opt-out payment, (ii) $5.7 million related to cost reimbursement for post opt-out wind-down services provided by the Company, $3.4 million of which was recorded as a contract asset, and (iii) $7.6 million related to the initial upfront payment and milestones received to date. In addition, the Company recognized a $50.0 million milestone payment related to the JNJ License and Collaboration Agreement, which was earned upon FDA approval of ICOTYDE for the treatment of moderate-to-severe plaque psoriasis, and $14.1 million for rusfertide clinical supplies under the Takeda Collaboration Agreement and other revenues.

For the three and six months ended June 30, 2026, the Company recognized $4.4 million and $7.6 million of revenue, respectively, that was included in the deferred revenue balance at the beginning of the period. None of the costs to obtain or fulfill the contracts were capitalized.

Note 4. Fair Value Measurements

Financial assets and liabilities are recorded at fair value. The accounting guidance for fair value provides a framework for measuring fair value, clarifies the definition of fair value and expands disclosures regarding fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value as follows:

Level 1—Inputs are unadjusted quoted prices in active markets for identical assets or liabilities at the measurement date.

Level 2—Inputs (other than quoted market prices included in Level 1) are either directly or indirectly observable for the asset or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life.

Level 3—Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.

In determining fair value, the Company utilizes quoted market prices, broker or dealer quotations, or valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible and considers counterparty credit risk in its assessment of fair value.

The following tables present the fair value of the Company’s financial assets determined using the inputs defined above (in thousands):

June 30, 2026

  ​ ​ ​

Level 1

  ​ ​ ​

Level 2

  ​ ​ ​

Level 3

  ​ ​ ​

Total

Assets:

Money market funds

$

124,167

$

$

 

$

124,167

Certificates of deposit

 

19,906

 

 

 

19,906

U.S. Treasury and agency securities

271,722

271,722

Commercial paper

 

294,306

 

 

 

294,306

Corporate debt securities

77,122

77,122

Total financial assets

$

124,167

$

663,056

  ​

$

 

$

787,223

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December 31, 2025

  ​ ​ ​

Level 1

  ​ ​ ​

Level 2

  ​ ​ ​

Level 3

  ​ ​ ​

Total

Assets:

Money market funds

$

40,774

$

$

 

$

40,774

Certificates of deposit

 

11,391

 

 

 

11,391

U.S. Treasury and agency securities

348,948

348,948

Commercial paper

 

 

77,865

 

 

 

77,865

Corporate debt securities

 

 

159,211

  ​

 

 

 

159,211

Total financial assets

$

40,774

$

597,415

  ​

$

 

$

638,189

The Company’s certificates of deposit, U.S. Treasury and agency securities, including U.S. Treasury bills, commercial paper and corporate debt securities are classified as Level 2 as they were valued based upon quoted market prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-based valuation techniques, for which all significant inputs are observable in the market or can be corroborated by observable market data for substantially the full term of the assets.

The carrying amount of the Company’s remaining financial assets and liabilities, including cash, receivables and payables, approximates their fair value due to their short-term nature.

Note 5. Cash Equivalents and Marketable Securities

Cash equivalents and marketable securities consisted of the following (in thousands):

June 30, 2026

Amortized

Gross Unrealized

 

  ​ ​ ​

Cost

  ​ ​ ​

Gains

  ​ ​ ​

Losses

  ​ ​ ​

Fair Value

Money market funds

$

124,167

$

$

$

124,167

Certificates of deposit

19,918

 

(12)

 

19,906

U.S. Treasury and agency securities

272,197

26

(501)

271,722

Commercial paper

 

294,401

1

(96)

 

294,306

Corporate debt securities

77,226

1

(105)

77,122

Total cash equivalents and marketable securities

$

787,909

$

28

  ​

$

(714)

$

787,223

Classified as:

  ​

  ​

  ​

Cash equivalents

  ​

  ​

  ​

$

357,850

Marketable securities - current

  ​

  ​

  ​

 

362,498

Marketable securities - noncurrent

  ​

  ​

  ​

 

66,875

Total cash equivalents and marketable securities

  ​

  ​

  ​

$

787,223

December 31, 2025

Amortized

Gross Unrealized

 

  ​ ​ ​

Cost

  ​ ​ ​

Gains

  ​ ​ ​

Losses

  ​ ​ ​

Fair Value

Money market funds

$

40,774

$

  ​

$

$

40,774

Certificates of deposit

11,387

4

 

11,391

U.S. Treasury and agency securities

348,250

706

(8)

348,948

Commercial paper

 

77,868

 

4

  ​

 

(7)

 

77,865

Corporate debt securities

159,127

 

93

  ​

 

(9)

 

159,211

Total cash equivalents and marketable securities

$

637,406

$

807

  ​

$

(24)

$

638,189

Classified as:

  ​

  ​

  ​

Cash equivalents

  ​

  ​

  ​

$

120,577

Marketable securities - current

  ​

  ​

  ​

 

438,974

Marketable securities - noncurrent

  ​

  ​

  ​

 

78,638

Total cash equivalents and marketable securities

  ​

  ​

  ​

$

638,189

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All of the Company’s marketable securities are classified as available-for-sale. Current marketable securities of $362.5 million and $439.0 million held as of June 30, 2026 and December 31, 2025, respectively, had contractual maturities of less than one year. Noncurrent marketable securities of $66.9 million and $78.6 million held as of June 30, 2026 and December 31, 2025, respectively, had contractual maturities of at least one year but no more than two years. The Company does not intend to sell its securities that are in an unrealized loss position, and it is not more likely than not that the Company will be required to sell its securities before recovery of their amortized cost basis, which may be at maturity.

During the six months ended June 30, 2026 and 2025, the Company sold $3.4 million and $7.0 million of marketable securities and realized a net gain of $5.0 thousand and a net loss of $5.0 thousand, respectively. The Company evaluated securities with unrealized losses to determine whether such losses, if any, were due to credit-related factors and determined that there were no credit-related losses to be recognized as of June 30, 2026 and December 31, 2025.

Note 6. Balance Sheet Components

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):

June 30, 

December 31, 

2026

2025

Accrued interest receivable

$

2,860

$

4,365

Prepaid clinical and research related expenses

1,249

3,345

Prepaid licenses

764

415

Prepaid insurance

605

1,061

Other

2,312

903

Prepaid expenses and other current assets

$

7,790

$

10,089

Property and Equipment, Net

Property and equipment, net consisted of the following (in thousands):

June 30, 

December 31, 

2026

2025

Laboratory equipment

$

8,053

$

7,748

Furniture and computer equipment

 

1,586

 

1,491

Leasehold improvements

 

2,936

 

2,936

Total property and equipment

 

12,575

 

12,175

Accumulated depreciation

 

(9,119)

 

(8,315)

Property and equipment, net

$

3,456

$

3,860

Accrued Expenses and Other Payables

Accrued expenses and other payables consisted of the following (in thousands):

June 30, 

December 31, 

  ​ ​ ​

2026

2025

Accrued clinical and research related expenses

$

14,978

$

14,798

Accrued employee related expenses

 

5,646

 

12,764

Accrued professional service fees

868

522

Other

 

175

 

185

Total accrued expenses and other payables

$

21,667

$

28,269

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Note 7. Stockholders’ Equity

Pre-Funded Warrants

In August 2023, the Company entered into certain agreements with certain accredited investors and their affiliates (the “Investors”) under which the Company issued pre-funded warrants with an exercise price of $0.001 per share (the “Pre-Funded Warrants”). The Pre-Funded Warrants will expire on the day they are exercised in full. The Pre-Funded Warrants are exercisable at any time prior to expiration except that the Pre-Funded Warrants cannot be exercised by the Investors if, after giving effect thereto, the Investors would beneficially own more than 9.99% of the Company’s common stock, subject to certain exceptions. In accordance with ASC Topic 260, “Earnings Per Share”, outstanding Pre-Funded Warrants are included in the computation of basic net income (loss) per share because the exercise price is negligible, and they are fully vested and exercisable after the original issuance date. No Pre-Funded Warrants were exercised during the three and six months ended June 30, 2026 and 2025. As of June 30, 2026, Pre-Funded Warrants to purchase 1,500,000 shares of common stock remained outstanding.

Note 8. Income Taxes

The Company recorded income tax expense of $2.3 million and $0.8 million for the three and six months ended June 30, 2026, respectively. The Company recorded income tax expense of $0.2 million for both the three and six months ended June 30, 2025. The increases in income tax expense were due to pretax income recorded as compared to pretax losses for the prior year periods. The tax provision for the three and six months ended June 30, 2026 was determined using an estimated annual effective tax rate, adjusted for discrete items, if any.

Note 9. Net Income (Loss) per Share

The computation of basic net income (loss) per share of common stock is based on the weighted-average number of shares of common stock outstanding during each period. The computation of diluted net income (loss) per share of common stock is based on the weighted-average number of shares of common stock outstanding during the period plus, when their effect is dilutive, incremental shares consisting of shares subject to stock options, RSUs, PSUs, the Company’s employee stock purchase plan (“ESPP”), and warrants.

In periods when the Company has net income, the dilutive effect of all potentially outstanding shares is computed using the treasury stock method. In periods in which the Company reports a net loss, all common stock equivalents are deemed anti-dilutive such that basic net loss per share of common stock and diluted net loss per share of common stock are equal.

The following table sets forth the computation of basic and diluted net income (loss) per share (in thousands, except share and per share data):

Three Months Ended

Six Months Ended

June 30, 

June 30, 

  ​ ​ ​

2026

  ​ ​ ​

2025

  ​ ​ ​

2026

  ​ ​ ​

2025

Numerator:

Net income (loss)

$

162,849

$

(34,771)

$

166,632

$

(46,426)

Denominator:

  ​

Weighted-average shares of common stock, basic

 

65,935,769

 

63,510,537

 

65,514,150

  ​

 

63,238,682

Dilutive effect of common stock equivalents

 

5,071,242

 

 

5,304,568

  ​

 

Weighted-average shares of common stock, dilutive

71,007,011

63,510,537

70,818,718

63,238,682

Net income (loss) per share of common stock

Basic net income (loss) per share of common stock

$

2.47

$

(0.55)

$

2.54

  ​

$

(0.73)

Diluted net income (loss) per share of common stock

$

2.29

$

(0.55)

$

2.35

$

(0.73)

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Approximately 0.9 million potentially dilutive shares of common stock (consisting of shares subject to outstanding stock options, RSUs, PSUs and under the ESPP, as applicable) were excluded from the diluted net income per share of common stock computation for the three and six months ended June 30, 2026 because their effect was anti-dilutive. Approximately 9.5 million potentially dilutive shares of common stock (consisting of shares subject to outstanding stock options, RSUs, PSUs, and under the ESPP, as applicable) were excluded from the diluted net loss per share of common stock computation for the three and six months ended June 30, 2025 due to the Company’s net loss for these periods.

Note 10. Segment Reporting

Operating segments are components of an enterprise for which separate financial information is available and which are evaluated by a company’s chief operating decision maker (“CODM”) in deciding how to allocate resources and to assess performance.

The Company operates and manages its business as one operating segment, which primarily focuses on the discovery and development of innovative medicines in areas of unmet medical need. The Company’s Chief Executive Officer serves as the Company’s CODM and manages and allocates resources to the operations of the Company on an entity-wide basis. Managing and allocating resources on an entity-wide basis enables the CODM to assess the overall level of resources available and how to best deploy these resources across functions and research and development projects based on unmet medical need, scientific data, probability of technical and regulatory successful development, market potential and other considerations, and, as necessary, reallocate resources among the Company’s internal research and development portfolio and external opportunities to best support the long-term growth of the Company’s business. The Company’s CODM reviews financial information on an aggregate basis for the purpose of allocating resources and evaluating financial performance, including segment net income (loss), which is also reported on the condensed consolidated statement of operations as consolidated net income (loss).

Segment information was as follows (in thousands):

Three Months Ended

Six Months Ended

June 30, 

June 30, 

  ​ ​ ​

2026

  ​ ​ ​

2025

  ​ ​ ​

2026

  ​ ​ ​

2025

 

 

License and collaboration revenue

$

213,475

$

5,546

$

269,843

$

33,867

Less:

Discovery department expense (1)(2)

(8,521)

(4,952)

(17,027)

(8,698)

Development department expense (1)(2)

(14,432)

(15,504)

(31,905)

(28,409)

General and administrative expenses (1)

(5,745)

(5,890)

(11,440)

(11,425)

Employee wages and benefits - discovery (2)

(2,668)

(2,188)

(5,816)

(4,515)

Employee wages and benefits - development (2)

(4,949)

(4,658)

(10,901)

(10,142)

Employee wages and benefits - general and administrative

(4,357)

(3,483)

(9,080)

(7,315)

Stock-based compensation expense

(14,037)

(10,912)

(28,556)

(24,714)

Other segment items (3)

(81)

36

(28)

118

Interest income

6,429

7,406

12,305

14,979

Income tax expense

(2,265)

(172)

(763)

(172)

Consolidated net income (loss)

$

162,849

$

(34,771)

$

166,632

$

(46,426)

(1) Amounts exclude employee wages and benefits, stock-based compensation and expense allocations.

(2) As of April 1, 2025, the information regularly provided to the CODM was changed to reclassify pre-clinical expenses from development expense to discovery expense. Prior period segment information has been recast to reflect this change.

(3) Other segment items include foreign currency related income (expense) and other miscellaneous income (expense).

The accounting policies of the Company’s operating segment are the same as those described in Note 2. Summary of Significant Accounting Policies. The measure of segment assets is reported as total assets on the Company’s condensed consolidated balance sheets for the periods presented.

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ITEM 2.MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

You should read the following discussion and analysis of our financial condition and results of operations together with our Unaudited Condensed Consolidated Financial Statements and related notes included in Part I, Item 1 of this Quarterly Report on Form 10-Q (the “Quarterly Report”) and with our Audited Consolidated Financial Statements and related notes thereto for the year ended December 31, 2025, included in our Annual Report on Form 10-K filed with the Securities and Exchange Commission (the “SEC”) on February 25, 2026.

Forward-Looking Statements

This Quarterly Report contains certain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). All statements other than statements of historical fact, including statements concerning our plans, objectives, goals, strategies, future events, future revenues or performance, financing needs, expectations, plans or intentions relating to clinical development, product candidates, the regulatory approval process, products and markets, and business trends and other information referred to under the sections entitled “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” are forward-looking statements. These statements are subject to substantial known and unknown risks, uncertainties and other factors that may cause our actual results, outcomes, performance or achievements, or the timing of such results, outcomes, performance or achievements, to be materially different from any results, outcomes, performances or achievements expressed or implied by the forward-looking statements. In some cases, you can identify forward-looking statements by terms such as “anticipates,” “assumes,” “believes,” “commitments,” “could,” “estimates,” “expects,” “forecasts,” “intends,” “may,” “plans,” “potential,” “predicts,” “projects,” “should,” “targets,” “will,” “would,” “seeks” and similar expressions intended to identify forward-looking statements. Forward-looking statements reflect our current views with respect to future events, are based on assumptions, and are subject to risks, uncertainties and other important factors, including, among other things, the potential for our programs; the timing, initiation, progress and expected results of our clinical trials and research and development programs, including enrollment, data, costs and regulatory submissions and approvals; our cash runway; our ability to advance product candidates into, and successfully complete, non-clinical studies and clinical trials; our eligibility for, and any expected benefits of, any U.S. Food and Drug Administration (“FDA”) programs or special designations; the potential for eventual regulatory approval and commercialization of our product candidates; the commercialization of our product candidates, if approved, which for ICOTYDE and rusfertide depends largely on the efforts of our collaboration partners; our ability and the potential to successfully manufacture and supply our product candidates for clinical trials and for commercial use, if approved; the pricing, coverage, and reimbursement of our product candidates, if approved; our potential receipt of milestone payments and royalties under our collaboration agreements; future operating results; our ability and that of our collaboration partners to generate sales, income or cash flow; our estimates regarding expenses, capital requirements, and needs for additional financing and our ability to obtain additional capital; our ability to retain the continued service of our key executives and to identify, hire, and retain additional qualified professionals; developments relating to our competitors and our industry, including competing product candidates and therapies; uncertainty and disruption in the global economy and financial markets due to a number of factors, including but not limited to geopolitical instability, such as the ongoing military conflicts between Russia and Ukraine and in the Middle East and rising tensions between China and Taiwan, elevated and sustained inflation, high oil and other commodity prices and changes in trade policies, including tariffs or other trade restrictions or the threat of such actions and retaliatory actions; the availability of credit; and other factors. Forward-looking statements involve risks, uncertainties and assumptions that are beyond our ability to control or predict, including those risks, uncertainties and assumptions discussed in Part II, Item 1A, of this Quarterly Report, Part 1. Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2025 and in our other filings with the SEC. These statements are based on information available to us as of the date of this Quarterly Report and, while we believe such information provides a reasonable basis for these statements, the information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. Given these risks, uncertainties and other important factors, you should not place undue reliance on these forward-looking statements. Also, forward-looking statements represent our estimates and assumptions only as of the date of this Quarterly Report. Except as required by law, we assume no obligation to update any forward-looking statements publicly, or to update the reasons actual results or

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outcomes could differ materially from those anticipated in any forward-looking statements, whether as a result of new information, future developments, changes in assumptions or otherwise. We caution investors that our business and financial performance are subject to substantial risks and uncertainties.

“Protagonist,” the Protagonist logo and other trademarks, service marks and trade names of Protagonist are registered and unregistered marks of Protagonist Therapeutics, Inc. in the United States and other jurisdictions.

Overview

We are a discovery through late-stage development biopharmaceutical company with a proprietary technology platform that enables de novo discovery of peptide therapeutics. Our development products and discovery programs fall into three broad therapeutic areas: (i) inflammation and immunology (“I&I”), (ii) hematology and (iii) metabolic diseases. Our aim is to develop medicines for biologically and commercially validated targets which demonstrate a strong differentiation compared to existing therapies.

ICOTYDE™ (icotrokinra)

ICOTYDE™ (icotrokinra) was approved in the United States in March 2026 for the treatment of moderate-to-severe plaque psoriasis in adults and pediatric patients 12 years of age or older who weigh at least 40 kg and are candidates for systemic therapy or phototherapy. ICOTYDE is the first and only targeted oral peptide that precisely blocks the Interleukin-23 receptor (“IL-23R”), which underpins the inflammatory response in psoriasis and offers potential in other IL-23-mediated diseases. ICOTYDE is licensed to Janssen Biotech, Inc., a Johnson & Johnson company (“JNJ”), under a license and collaboration agreement initially entered into in 2017. Following ICOTYDE’s joint discovery by Protagonist and JNJ scientists, we were primarily responsible for the development of ICOTYDE through Phase 1, with JNJ assuming responsibility for further development and commercialization. In September 2025, JNJ submitted an application to the European Medicines Agency (“EMA”) seeking the first approval of ICOTYDE for the treatment of adults and pediatric patients 12 years of age or older with moderate-to-severe plaque psoriasis. ICOTYDE is in Phase 3 development for additional indications including psoriatic arthritis, ulcerative colitis and Crohn’s disease.

Rusfertide

Rusfertide is a first-in-class investigational injectable mimetic of the natural hormone hepcidin in development for the treatment of the rare blood disorder polycythemia vera (“PV”). We discovered rusfertide, advanced it into Phase 3 development, and entered into a license and collaboration agreement with Takeda Pharmaceuticals, Inc. (“Takeda”) in January 2024 (the “Takeda Collaboration Agreement”). We remained primarily responsible for clinical development activities through rusfertide’s New Drug Application (“NDA”) filing for the treatment of erythrocytosis in patients with PV, which we and Takeda submitted in December 2025, and Takeda is responsible for further development and commercialization. In March 2026, the FDA accepted the NDA and granted Priority Review status for rusfertide. Rusfertide has also previously received Orphan Drug status, Fast Track designation and, in August 2025, Breakthrough Therapy designation (“BTD”). BTD is a process designed to expedite the development and review of drugs that are intended to treat a serious condition, and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over available therapies. BTD also provides eligibility for priority NDA review, and Orphan Drug status qualifies sponsors for various incentives, including the potential for extended market exclusivity. The NDA for rusfertide is currently under priority review by the FDA, with a Prescription Drug User Fee Act target action date in August 2026. Takeda has disclosed that it expects to launch rusfertide in the second half of 2026, subject to regulatory approval.

IL-17 Program

PN-881. We are developing PN-881, a potential best-in-class oral peptide IL-17 antagonist, for the treatment of immune-mediated skin diseases. PN-881 targets three IL-17 dimers (IL-17 AA, AF and FF), and may offer potential treatment options for plaque psoriasis, psoriatic arthritis, hidradenitis suppurativa, and spondyloarthritis.

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In October 2025, the first human subject was dosed in our Phase 1 trial of PN-881 (ClinicalTrials.gov identifier NCT07153146) evaluating its safety, tolerability, pharmacokinetics and pharmacodynamics in healthy adults. We believe data from our Phase 1 study supports our decision to advance PN-881 into a comprehensive Phase 2b psoriasis program, with initiation expected in early first quarter 2027.

Obesity Program

PN-477. In June 2025, we nominated PN-477, a potential best-in-class novel triple GLP-1, GIP and GCG receptor agonist peptide with oral (“PN-477o”) and subcutaneous (“PN-477sc”) routes of administration, as a development candidate for the treatment of obesity. We designed PN-477 to offer an optimal combination of total body weight loss, improved gastrointestinal tolerability and fat to lean mass ratio, with the dosing convenience of a once-daily oral agent and the added optionality of a once-weekly subcutaneous administration. A Phase 1 clinical study for PN-477sc has been initiated, and the initiation of a Phase 1 study for PN-477o is anticipated in the first half of 2027.

PN-458. In December 2025, we nominated development candidate PN-458, a potential best-in-class novel dual GLP-1 and GIP receptor agonist peptide, as a development candidate for the treatment of obesity. IND-enabling studies are ongoing, with the initiation of a Phase 1 study for the PN-458 oral formulation anticipated in the second half of 2027.

Oral Hepcidin Program

PN-8047. In December 2025, we nominated development candidate PN-8047, an orally administered small molecule hepcidin functional mimetic, which we believe may be complementary to the injectable rusfertide for offering the best treatment options for PV. IND-enabling studies for PN-8047 are ongoing, with the initiation of a Phase 1 study anticipated in the first quarter of 2027.

Other Programs

We also have pre-clinical stage drug discovery programs addressing biologically and commercially validated targets, including an oral IL-4R alpha antagonist for the treatment of atopic dermatitis and moderate-to-severe asthma, and amylinR-based oral and subcutaneous mono- and poly-agonists for the treatment of obesity.

Significant Cash Resources

We ended the second quarter of 2026 with cash, cash equivalents and marketable securities of approximately $849.5 million, as compared to cash, cash equivalents and marketable securities of approximately $646.0 million as of December 31, 2025. For the remainder of 2026 and beyond, we are eligible to receive significant milestone, royalty and other payments from our collaborations with JNJ and Takeda, as described below.

License and Collaboration Agreements

JNJ License and Collaboration Agreement

We and JNJ are parties to a license and collaboration agreement related to the development and commercialization of ICOTYDE. We entered into the agreement in July 2017, and amended it in May 2019, July 2021 and November 2024 (as amended, the “JNJ License and Collaboration Agreement”). Pursuant to the JNJ License and Collaboration Agreement, we were primarily responsible for the discovery, IND-enabling studies, and the initial Phase 1 study for ICOTYDE, and JNJ is primarily responsible for conducting all further development.

In March 2026, we earned a $50.0 million milestone payment upon FDA approval of ICOTYDE for the treatment of moderate-to-severe plaque psoriasis in adults and pediatric patients 12 years of age or older who weigh at least 40 kg and are candidates for systemic therapy or phototherapy. As of June 30, 2026, we have earned a total of $387.5 million in non-refundable upfront and milestone payments from JNJ under the agreement. We are eligible to

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receive up to $580.0 million in future development and sales milestone payments, including the following potential milestones:

Graphic

We will also receive upward tiered royalties on net worldwide ICOTYDE product sales at percentages ranging from 6% to 10%. Our weighted-average royalty rate on the first $4.0 billion in annual net sales is 7.25%, and the rate on net sales over $4.0 billion is 10%. The ultimate magnitude of our royalty stream, along with the achievement of development and commercial milestones, will depend upon ICOTYDE’s commercial launch success and market trajectory, which depends on the efforts of our collaboration partner, as well as the successful clinical development, regulatory approval, and commercialization of ICOTYDE in the additional indications currently being studied.

Takeda Collaboration Agreement

In January 2024, we entered into the Takeda Collaboration Agreement related to rusfertide (and specified second-generation injectable hepcidin mimetic compounds developed and commercialized under the agreement that are not currently in development). In December 2025, we and Takeda submitted an NDA to the FDA for rusfertide in PV, which is currently under priority review. We were primarily responsible for the clinical development of rusfertide through NDA filing and remain primarily responsible for the conduct of ongoing rusfertide long-term extension studies. Under the terms of the agreement, we received an upfront payment of $300.0 million in April 2024 and a $25.0 million milestone payment in September 2025 upon completion of the Phase 3 VERIFY clinical trial (NCT05210790) report.

Effective April 28, 2026, we exercised our right to opt-out of the U.S. profit and loss sharing arrangement (50% to us and 50% to Takeda) under the Takeda Collaboration Agreement. The opt-out election triggered a $200.0 million payment to us, which we received in the second quarter of 2026, and we also became eligible to receive an additional $200.0 million opt-out fee and a separate $75.0 million milestone, both of which are due upon FDA approval of rusfertide. Following the opt-out, Takeda has an exclusive worldwide license to develop and commercialize rusfertide, and we are eligible to receive tiered royalties ranging from 14% to 29% on annual worldwide net sales, with an approximate weighted-average royalty rate of 21% at $1.5 billion in annual net sales and a rate of 29% for incremental annual net sales over $1.5 billion. In addition, under the agreement, we are eligible to receive up to $775.0 million in sales milestones. Upcoming potential development milestones and potential sales milestones under the agreement include the following:

Graphic

The receipt of future royalties and commercial milestones is contingent upon the relevant products receiving FDA approval and achieving a successful commercial launch, which depends on the efforts of our collaboration partner.

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Risks and Uncertainties

We describe the respective risks, uncertainties and assumptions that could affect our business, financial condition or results of operations in Part II, Item 1A. “Risk Factors” herein and in Part 1, Item 1A. “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2025.

Operations

We have incurred cumulative net losses from inception through June 30, 2026 of $304.0 million. Substantially all of our net losses have resulted from costs incurred in connection with our research and development programs and from general and administrative costs associated with our operations. We expect to continue to incur significant research and development expenses, and other expenses related to our ongoing operations, clinical development and pre-clinical discovery programs.

Critical Accounting Policies and Estimates

Our management’s discussion and analysis of our financial condition and results of operations is based on our unaudited condensed consolidated financial statements, which have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). The preparation of these unaudited condensed consolidated financial statements requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities at the date of the unaudited condensed consolidated financial statements, as well as the reported revenue generated and expenses incurred during the reporting periods. Our estimates are based on our historical experience and on various other factors that we believe are reasonable under the circumstances, and the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions.

There have been no material changes to our critical accounting policies during the three and six months ended June 30, 2026, as compared to those disclosed in “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Policies and Estimates” in our Annual Report for the year ended December 31, 2025 filed with the SEC on February 25, 2026.

Components of Our Results of Operations

License and Collaboration Revenue

Our license and collaboration revenue is derived from payments we receive from our collaboration partners under the JNJ License and Collaboration Agreement and the Takeda Collaboration Agreement. We expect our revenue to increase significantly in future periods due to the receipt of milestone payments, including payments related to NDA approvals and the exercise of our opt-out right under the Takeda Collaboration Agreement and royalties for sales of ICOTYDE for moderate-to-severe plaque psoriasis, and in other indications if approved. We also expect to receive royalties for rusfertide in PV if NDA approval is received and the product is successfully commercialized. See Note 3 to the condensed consolidated financial statements included elsewhere in this Quarterly Report for additional information.

Early in a product launch, prescription volume and recognized royalty revenue may not move in parallel. Commercial launches often include access-support initiatives, such as starter packs and bridge programs designed to help patients initiate therapy while reimbursement pathways are established. As a result, prescription activity can serve as a leading indicator of strong adoption, while associated royalty revenue may lag in the near term as prescriptions convert into reimbursed, recurring product sales.

Research and Development Expenses

Research and development expenses represent costs incurred to conduct research, such as the discovery and development of our product candidates. We recognize all research and development costs as they are incurred unless there is an alternative future use in other research and development projects or otherwise. Non-refundable advance

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payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when payment has been made. In instances where we enter into agreements with third parties to provide research and development services to us, costs are expensed as services are performed. Amounts due under such arrangements may be either fixed fee or fee for service and may include upfront payments, monthly payments, and payments upon the completion of milestones or the receipt of deliverables.

Research and development expenses consist primarily of the following:

expenses incurred under agreements with clinical trial sites that conduct research and development activities on our behalf;
employee-related expenses, which include salaries, benefits and stock-based compensation;
laboratory vendor expenses related to the preparation and conduct of pre-clinical studies and clinical trials;
costs related to production of clinical supplies and pre-clinical materials, including fees paid to contract manufacturers;
license fees and milestone payments under license and collaboration agreements; and
facilities and other allocated expenses, which include expenses for rent and maintenance of facilities, information technology, depreciation and amortization expense and administrative and other supplies.

We allocate direct and indirect costs incurred to product candidates when they enter clinical development. For product candidates in clinical development, direct costs consist primarily of clinical, pre-clinical, and drug discovery costs, costs of supplying drug substance and drug product for use in clinical and pre-clinical studies, including clinical manufacturing costs, contract research organization fees, and other contracted services pertaining to specific clinical and pre-clinical studies. Indirect costs allocated to our product candidates on a program-specific basis include research and development employee salaries, benefits, and stock-based compensation, and indirect overhead and other administrative support costs. Program-specific costs are unallocated when the related expenses are incurred for our early-stage research and drug discovery projects as our internal resources, employees and infrastructure are not tied to any one research or drug discovery project and are typically deployed across multiple projects. As such, we do not provide financial information regarding the costs incurred for early-stage pre-clinical and drug discovery programs on a program-specific basis prior to the clinical development stage.

The process of conducting research, identifying potential product candidates, conducting pre-clinical studies and clinical trials necessary to obtain regulatory approval and commencing pre-commercialization activities is costly and time intensive. We may never succeed in achieving marketing approval for our current or future product candidates regardless of our costs and efforts. The probability of success of our product candidates may be affected by numerous factors, including pre-clinical data, clinical data, competition, manufacturing capability, our cost of goods to be sold, our ability to receive, and the timing of, regulatory approvals, market conditions, and our ability to successfully commercialize our products if they are approved for marketing. As a result, we are unable to determine the duration and completion costs of our research and development projects or when and to what extent we will be able to generate revenue from the commercialization and sale of any of our current or future product candidates. Our research and development programs are subject to change from time to time as we evaluate our priorities and available resources.

General and Administrative Expenses

General and administrative expenses consist of personnel costs, allocated costs and other expenses for outside professional services, including legal, human resources, audit and accounting services. Personnel costs consist of salaries, benefits and stock-based compensation. Allocated costs consist of expenses for rent and maintenance of facilities, information technology, depreciation and amortization expense and administrative supplies. We expect to

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continue to incur expenses to support our continued operations as a public company, including expenses related to compliance with the rules and regulations of the SEC and those of the national securities exchange on which our securities are traded, insurance expenses, investor relations expenses, audit fees, professional services and general overhead and administrative costs.

Interest Income

Interest income consists of interest earned on our cash, cash equivalents and marketable securities, which is comprised of contractual interest, premium amortization and discount accretion.

Other (Expense) Income, Net

Other (expense) income, net consists primarily of amounts related to foreign exchange gains and losses, realized gains and losses on sale of marketable securities and related items.

Results of Operations

Comparison of the Three Months Ended June 30, 2026 and 2025

Three Months Ended

June 30, 

Dollar

%

  ​ ​ ​

2026

  ​ ​ ​

2025

  ​ ​ ​

Change

  ​ ​ ​

Change

(Dollars in thousands)

License and collaboration revenue

$

213,475

$

5,546

$

207,929

*

Operating expenses:

 

  ​

 

  ​

 

  ​

 

  ​

Research and development (1)

42,061

37,036

5,025

 

14

General and administrative (2)

 

12,648

 

10,551

 

2,097

 

20

Total operating expenses

 

54,709

 

47,587

 

7,122

 

15

Income (loss) from operations

 

158,766

 

(42,041)

 

200,807

 

(478)

Interest income

 

6,429

 

7,406

 

(977)

 

(13)

Other (expense) income, net

(81)

36

(117)

(325)

Income (loss) before income tax expense

165,114

(34,599)

199,713

*

Income tax expense

2,265

172

2,093

*

Net income (loss)

$

162,849

$

(34,771)

$

197,620

 

*

*Percentage not meaningful.

(1)Includes $7.5 million and $6.3 million of non-cash stock-based compensation expense for the three months ended June 30, 2026 and 2025, respectively.
(2)Includes $6.5 million and $4.6 million of non-cash stock-based compensation expense for the three months ended June 30, 2026 and 2025, respectively.

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License and Collaboration Revenue

License and collaboration revenue was comprised of the following for the periods presented:

Three Months Ended

June 30, 

Dollar

%

  ​ ​ ​

2026

  ​ ​ ​

2025

  ​ ​ ​

Change

  ​ ​ ​

Change

(Dollars in thousands)

License and collaboration revenue:

Takeda Collaboration Agreement and other

$

213,475

$

5,546

$

207,929

*

Total license and collaboration revenue

$

213,475

$

5,546

$

207,929

 

*

*Percentage not meaningful.

Our revenue is derived from licensing and collaboration agreements and is highly variable and dependent upon factors such as the timing of when regulatory and sales milestones are achieved, if at all, commercial launch efforts by our collaboration partners, and the accounting for any upfront payments associated with any existing or new agreements.

License and collaboration revenue for the three months ended June 30, 2026, was $213.5 million, which consisted of (i) $192.4 million related to the proportional recognition of the $200.0 million opt-out payment received from Takeda, and (ii) $21.1 million for ongoing development services, including post opt-out wind down services, rusfertide clinical supplies provided by us under the Takeda Collaboration Agreement and other revenues.

License and collaboration revenue for the three months ended June 30, 2025 was $5.5 million, which consisted of (i) $5.0 million for development services provided by us during the period under the Takeda Collaboration Agreement based on the cost-based input method and (ii) $0.5 million related to the proportional recognition of the $25.0 million milestone from Takeda deemed probable of being achieved due to the Phase 3 VERIFY trial meeting its primary endpoint.

As described above, we opted out of the U.S. profit and loss sharing arrangement under the Takeda Collaboration Agreement in April 2026 and are eligible to receive both an additional $200.0 million opt-out payment and an enhanced milestone payment of $75.0 million upon FDA approval of rusfertide, which is expected in August 2026. In addition, we may receive royalties and sales milestones from rusfertide, pending potential FDA approval and commercial launch.

Research and Development Expenses

Three Months Ended

June 30, 

Dollar

%

  ​ ​ ​

2026

2025

Change

Change

(Dollars in thousands)

Clinical and development expense — rusfertide

$

10,923

$

22,875

$

(11,952)

(52)

Clinical and development expense — PN-881

8,571

8,571

*

Clinical and development expense — other

40

38

2

5

Pre-clinical and drug discovery research expense

22,527

14,123

8,404

60

Total research and development expenses

$

42,061

$

37,036

$

5,025

14

*Percentage not meaningful.

Research and development expenses increased $5.0 million, or 14%, from $37.0 million for the three months ended June 30, 2025 to $42.1 million for the three months ended June 30, 2026. The increase was primarily due to an increase of $8.6 million in costs related to our Phase 1 study for development candidate PN-881 initiated in the third quarter of 2025 and an $8.4 million increase in pre-clinical and drug discovery research program expense, partially offset by a decrease of $12.0 million in rusfertide expenses primarily related to the completion of our Phase 3 VERIFY trial during the first quarter of 2025.

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We had 108 and 100 full-time equivalent research and development headcount as of June 30, 2026 and 2025, respectively. Research and development personnel-related expenses for the three months ended June 30, 2026 increased by $1.9 million as compared to the three months ended June 30, 2025, primarily driven by increases in wages, benefits and stock-based compensation.

We expect research and development expenses to increase significantly in the second half of 2026 compared to the first half of 2026. The increase is expected to be driven primarily by the advancement of PN-881 into a comprehensive Phase 2b psoriasis program, planned investments in clinical manufacturing and related activities, including at-risk expenditures to ensure readiness for other programs as they advance to clinical development (PN-477sc, PN-458, PN-8047), additional pre-clinical discovery programs, and increases in headcount and stock-based compensation expense. The timing and magnitude of these expenses will vary depending on the progress of our programs, including the initiation and pace of clinical trials and related development activities.

General and Administrative Expenses

General and administrative expenses increased $2.1 million, or 20%, from $10.6 million for the three months ended June 30, 2025 to $12.6 million for the three months ended June 30, 2026. The increase was primarily due to an increase in personnel-related expenses driven by increases in wages, benefits and stock-based compensation.

We had 33 and 30 full-time equivalent general and administrative headcount as of June 30, 2026 and 2025, respectively.

Interest Income

Interest income decreased by $1.0 million, or 13%, from $7.4 million for the three months ended June 30, 2025 to $6.4 million for the three months ended June 30, 2026 primarily due to lower yields and lower average investment balance as compared to the prior period.

Income Tax Expense

Income tax expense was $2.3 million and $0.2 million for the three months ended June 30, 2026 and 2025, respectively. The increase in income tax expense for the three months ended June 30, 2026 was primarily due to pretax income recorded as compared to a pretax loss for the prior year period. The effective tax rate was 1.4% and 0% for the three months ended June 30, 2026 and 2025, respectively.

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Comparison of the Six Months Ended June 30, 2026 and 2025

Six Months Ended

June 30, 

Dollar

%

  ​ ​ ​

2026

  ​ ​ ​

2025

  ​ ​ ​

Change

  ​ ​ ​

Change

(Dollars in thousands)

License and collaboration revenue

$

269,843

$

33,867

$

235,976

*

Operating expenses:

 

  ​

 

  ​

 

  ​

 

  ​

Research and development (1)

88,800

72,929

15,871

 

22

General and administrative (2)

 

25,925

 

22,289

 

3,636

 

16

Total operating expenses

 

114,725

 

95,218

 

19,507

 

20

Income (loss) from operations

 

155,118

 

(61,351)

 

216,469

 

(353)

Interest income

 

12,305

14,979

 

(2,674)

 

(18)

Other (expense) income, net

(28)

118

(146)

(124)

Income (loss) before income tax expense

167,395

(46,254)

213,649

(462)

Income tax expense

763

172

591

344

Net income (loss)

$

166,632

$

(46,426)

$

213,058

 

(459)

*Percentage not meaningful.

(1)Includes $15.3 million and $14.3 million of non-cash stock-based compensation expense for the six months ended June 30, 2026 and 2025, respectively.
(2)Includes $13.2 million and $10.4 million of non-cash stock-based compensation expense for the six months ended June 30, 2026 and 2025, respectively.

License and Collaboration Revenue

License and collaboration revenue was comprised of the following for the periods presented:

Six Months Ended

June 30, 

Dollar

%

  ​ ​ ​

2026

  ​ ​ ​

2025

  ​ ​ ​

Change

  ​ ​ ​

Change

(Dollars in thousands)

License and collaboration revenue:

Takeda Collaboration Agreement and other

$

219,843

$

33,867

$

185,976

*

JNJ License and Collaboration Agreement milestone

 

50,000

 

 

50,000

 

*

Total license and collaboration revenue

$

269,843

$

33,867

$

235,976

 

*

*Percentage not meaningful.

Our revenue is derived from licensing and collaboration agreements and is highly variable and dependent upon factors such as the timing of when regulatory and sales milestones are achieved, if at all, commercial launch efforts by our collaboration partners, and the accounting for any upfront payments associated with any existing or new agreements.

License and collaboration revenue for the six months ended June 30, 2026 was $269.8 million, which consisted of (i) $192.4 million related to the proportional recognition of the $200.0 million opt-out payment received under the Takeda Collaboration Agreement, (ii) $27.4 million for ongoing development services, including post opt-out wind down services, rusfertide clinical supplies provided by us under the Takeda Collaboration Agreement and other revenues, and (iii) a $50.0 million milestone payment related to the JNJ License and Collaboration Agreement, which was earned upon FDA approval of ICOTYDE for the treatment of moderate-to-severe plaque psoriasis.

License and collaboration revenue for the six months ended June 30, 2025 was $33.9 million, which consisted of (i) $23.4 million related to the proportional recognition of the $25.0 million milestone from Takeda deemed probable of being achieved due to the Phase 3 VERIFY trial meeting its primary endpoint and (ii) $10.5 million for development

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services provided by us during the period under the Takeda Collaboration Agreement based on the cost-based input method.

Research and Development Expenses

Six Months Ended

June 30, 

Dollar

%

  ​ ​ ​

2026

2025

Change

Change

(Dollars in thousands)

Clinical and development expense — rusfertide

$

28,372

$

44,275

$

(15,903)

(36)

Clinical and development expense — PN-881

17,454

17,454

*

Clinical and development expense — other

91

154

(63)

(41)

Pre-clinical and drug discovery research expense

42,883

28,500

14,383

50

Total research and development expenses

$

88,800

$

72,929

$

15,871

22

*Percentage not meaningful.

Research and development expenses increased $15.9 million, or 22%, from $72.9 million for the six months ended June 30, 2025 to $88.8 million for the six months ended June 30, 2026. The increase was primarily due to an increase of $17.4 million in costs related to our Phase 1 study for development candidate PN-881 initiated in the third quarter of 2025 and a $14.4 million increase in pre-clinical and drug discovery research program expense, partially offset by a decrease of $15.9 million in rusfertide expenses primarily related to the completion of our Phase 3 VERIFY trial during the first quarter of 2025.

We had 108 and 100 full-time equivalent research and development headcount as of June 30, 2026 and 2025, respectively. Research and development personnel-related expenses for the six months ended June 30, 2026 increased by $2.9 million as compared to the six months ended June 30, 2025, primarily driven by increases in wages, benefits and stock-based compensation.

We expect research and development expenses to increase significantly in the second half of 2026 compared to the first half of 2026. The increase is expected to be driven primarily by the advancement of PN-881 into a comprehensive Phase 2b psoriasis program, planned investments in clinical manufacturing and related activities, including at-risk expenditures to ensure readiness for other programs as they advance to clinical development (PN-477sc, PN-458, PN-8047), additional pre-clinical discovery programs, and increases in headcount and stock-based compensation expense. The timing and magnitude of these expenses will vary depending on the progress of our programs, including the initiation and pace of clinical trials and related development activities.

General and Administrative Expenses

General and administrative expenses increased $3.6 million, or 16%, from $22.3 million for the six months ended June 30, 2025 to $25.9 million for the six months ended June 30, 2026. The increase was primarily due to an increase in personnel-related expenses, primarily driven by increases in wages, benefits and stock-based compensation.

We had 33 and 30 full-time equivalent general and administrative headcount as of June 30, 2026 and 2025, respectively.

Interest Income

Interest income decreased by $2.7 million, or 18%, from $15.0 million for the six months ended June 30, 2025 to $12.3 million for the six months ended June 30, 2026 primarily due to lower yields and lower average investment balance as compared to the prior period.

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Income Tax Expense

Income tax expense was $0.8 million and $0.2 million for the six months ended June 30, 2026 and 2025, respectively. The increase in income tax expense for the six months ended June 30, 2026 was primarily due to pretax income recorded as compared to a pretax loss for the prior year period. The effective tax rate was 0.5% and 0% for the six months ended June 30, 2026 and 2025, respectively.

Liquidity and Capital Resources

Sources of Liquidity

We had $849.5 million and $646.0 million in cash, cash equivalents and marketable securities as of June 30, 2026 and December 31, 2025, respectively. Historically, we have funded our operations primarily from receipt of payments under collaboration agreements, as discussed in “Collaboration Agreements” above, and net proceeds from the sale of shares of our common stock.

Capital Requirements

As of June 30, 2026, we had $849.5 million in cash, cash equivalents and marketable securities and an accumulated deficit of $304.0 million. Our capital expenditures were $0.4 million and $1.6 million for the six months ended June 30, 2026 and the year ended December 31, 2025, respectively. Our primary uses of cash are to fund our operating expenses, including our research and development expenditures and general and administrative costs. We expect that our existing cash, cash equivalents and marketable securities will be sufficient to fund our operations for at least the next twelve months from the date of this Quarterly Report based on current operating plans and financial forecasts.

We do not currently anticipate a need for additional funding in the near term. However, we may require additional funding in the future to advance our discovery pipeline and to develop, acquire, or in-license other potential product candidates. Our future funding requirements will depend on many factors, including those described in Part II, Item 1A, “Risk Factors” herein and in Part 1, Item 1A, “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2025. Such additional funding may come from various sources, including raising additional capital, seeking access to debt, and seeking additional collaborative or other arrangements with partners, but such funding may not be available on terms acceptable to us, if at all.

Cash Flows

The following table summarizes our cash flows for the periods indicated:

Six Months Ended

June 30, 

  ​ ​ ​

2026

  ​ ​ ​

2025

Condensed Consolidated Statements of Cash Flows Data:

(Dollars in thousands)

Cash provided by operating activities

$

170,109

$

96,583

Cash provided by (used in) investing activities

$

88,462

$

(39,592)

Cash provided by financing activities

$

33,117

$

14,368

Stock-based compensation

$

28,556

$

24,714

Change in deferred revenue

$

109

$

(10,504)

Cash Provided by Operating Activities

Cash provided by operating activities for the six months ended June 30, 2026 was $170.1 million and consisted primarily of net income of $166.6 million and certain non-cash items, including $28.6 million of stock-based compensation expense, partially offset by a net change of $24.7 million in net operating assets and liabilities. The $73.5 million increase in cash provided by operating activities during the six months ended June 30, 2026, as compared

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to the six months ended June 30, 2025, was primarily due to a $200.0 million payment received upon the exercise of our opt-out right under the Takeda Collaboration Agreement in April 2026 and a $50.0 million milestone payment received under the JNJ License and Collaboration Agreement, partially offset by a $178.3 million change in receivable from collaboration partner during the six months ended June 30, 2026.

Cash Provided by (Used in) Investing Activities

Cash provided by investing activities for the six months ended June 30, 2026 was $88.5 million and consisted primarily of proceeds from maturities and sales of marketable securities of $292.5 million, partially offset by purchases of marketable securities of $203.6 million and purchases of property and equipment of $0.4 million. The $128.1 million increase in cash provided by investing activities for the six months ended June 30, 2026, as compared to the six months ended June 30, 2025, was primarily related to the investment of payments received from collaboration partners in 2026. Purchases of property and equipment were primarily related to laboratory equipment and furniture and fixtures.

Cash Provided by Financing Activities

Cash provided by financing activities for the six months ended June 30, 2026 was $33.1 million and consisted of net cash proceeds from the issuance of common stock upon exercises of stock options and purchases of stock under our employee stock purchase plan (“ESPP”). The $18.7 million increase in cash provided by financing activities for the six months ended June 30, 2026, as compared to the six months ended June 30, 2025, was primarily due to an $18.3 million increase in proceeds from the issuance of common stock upon exercise of options and purchases of common stock under the ESPP.

Contractual Obligations and Other Commitments

During the six months ended June 30, 2026, there were no material changes to our material cash requirements, including commitments for capital expenditures, described under Management’s Discussion and Analysis of Financial Condition and Results of Operations in our Annual Report on Form 10-K for the year ended December 31, 2025 filed with the SEC on February 25, 2026.

ITEM 3.QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

We are exposed to market risks in the ordinary course of our business. These risks primarily include interest rate sensitivities related to our interest-earning investments and inflation risk affecting labor costs and clinical trial costs.

Interest Rate Fluctuation Risk

We had $849.5 million and $646.0 million in cash, cash equivalents and marketable securities at June 30, 2026 and December 31, 2025, respectively. Our cash and cash equivalents consist of cash, money market funds, certificates of deposit and commercial paper. Marketable securities consist of government and agency bonds, commercial paper and corporate bonds. A portion of our investments may be subject to interest rate risk and could decline in value if market interest rates increase. Based on our interest rate sensitivity analysis, an immediate 100 basis point increase in interest rates would increase our annual interest income by approximately $5.4 million, while an immediate 100 basis point decrease in interest rates would decrease our annual interest income by approximately $5.4 million.

Approximately $2.5 million and $2.8 million of our cash balance was located in Australia at June 30, 2026 and December 31, 2025, respectively. Our expenses, except those related to our Australian operations, are generally denominated in U.S. dollars. For our operations in Australia, the majority of our expenses are denominated in Australian dollars. To date, we have not had a formal hedging program with respect to foreign currency, but we may do so in the future if our exposure to foreign currency becomes more significant. A 10% increase or decrease in current exchange rates would not have a material effect on the results of our operations.

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Inflation Fluctuation Risk

Inflation generally affects us by increasing our costs, such as the cost of labor and research and development contract costs. We do not believe inflation has had a material adverse effect on the results of our operations during the six months ended June 30, 2026.

ITEM 4.CONTROLS AND PROCEDURES

Evaluation of Disclosure Controls and Procedures

Management, under the supervision and with the participation of our Chief Executive Officer (Principal Executive Officer) and Chief Financial Officer (Principal Financial Officer), has evaluated the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act) as of the end of the period covered by this report. Based on the evaluation of our disclosure controls and procedures, our Chief Executive Officer and Chief Financial Officer have concluded that, as of the end of the period covered by this report, our disclosure controls and procedures were effective at the reasonable assurance level.

Limitations on Effectiveness of Controls and Procedures and Internal Control over Financial Reporting

In designing and evaluating the disclosure controls and procedures and internal control over financial reporting, management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives. In addition, the design of disclosure controls and procedures and internal control over financial reporting must reflect the fact that there are resource constraints, and that management is required to apply judgment in evaluating the benefits of possible controls and procedures relative to their costs.

Changes in Internal Control over Financial Reporting

There have been no changes in our internal control over financial reporting that occurred during the most recent fiscal quarter that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

PART II – OTHER INFORMATION

ITEM 1.LEGAL PROCEEDINGS

From time to time, we may become subject to litigation and claims arising in the ordinary course of business. We are not currently a party to any material legal proceedings, and we are not aware of any pending or threatened legal proceeding against us that we believe could have a material adverse effect on our business, operating results, financial condition or cash flows.

ITEM 1A.RISK FACTORS

Our business, results of operations and financial condition are subject to various risks. These risks are described elsewhere in this Quarterly Report on Form 10-Q and in our other filings with the SEC, including our Annual Report on Form 10-K for the year ended December 31, 2025. Except as disclosed below, there have been no material changes from the risk factors identified in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025.

We are dependent on Takeda for the commercialization of rusfertide. Failure by Takeda to commercialize rusfertide could result in a material adverse effect on our business and operating results.

Pursuant to the terms of the Takeda Collaboration Agreement, following our exercise of our right to opt out of the U.S. profit and loss sharing arrangement in April 2026, Takeda has an exclusive worldwide license to develop and commercialize rusfertide, and we are eligible to receive tiered royalties ranging from 14% to 29% on annual worldwide

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net sales, with an approximate weighted-average royalty rate of 21% at $1.5 billion in annual net sales and a rate of 29% for incremental annual net sales over $1.5 billion. In addition, under the agreement, we are eligible to receive up to $775.0 million in sales milestone payments.

A substantial portion of our total revenue may be based on royalties and milestones received from Takeda. The commercial success of rusfertide, if approved, including our potential royalties, depends on, among other things, the efforts and allocation of resources of Takeda, which we do not control. Our partnership with Takeda may not be successful, and we may not realize the expected benefits from such partnership, due to a number of important factors, including but not limited to the following:

Takeda may change the focus of its commercialization efforts or pursue higher priority programs;
Takeda may fail to manufacture or supply sufficient drug product of rusfertide in compliance with applicable laws and regulations, which could result in program delays or lost revenue; and
We may disagree with Takeda regarding the development or commercialization of rusfertide, or other matters under the Takeda Collaboration Agreement, or Takeda could breach or terminate the Takeda Collaboration Agreement.

Unstable market and macroeconomic conditions, including geopolitical instability and tariffs or trade policy, may have serious adverse consequences on our business, financial condition and stock price.

As has been widely reported, we are currently operating in a period of macroeconomic uncertainty and capital markets disruption, which has been significantly impacted by domestic and global monetary and fiscal policy, trade regulations, including changes in trade policies, tariffs or other trade restrictions or the threat of such actions, geopolitical instability, including ongoing military conflicts in the Middle East and between Russia and Ukraine, rising tensions between China and Taiwan, and high interest rates. In particular, the conflicts in the Middle East and Ukraine have exacerbated market disruptions, including significant volatility in commodity prices, as well as supply chain interruptions, and have contributed to inflation globally. The U.S. Federal Reserve and other central banks may be unable to contain inflation through more restrictive monetary policy and inflation may increase or continue for a prolonged period of time. Inflationary factors, such as increases in the cost of clinical supplies, interest rates, overhead costs and transportation costs may adversely affect our operating results. In addition, in September 2025, the United States announced the imposition of up to 100% tariffs on imported branded or patented pharmaceuticals, subject to certain exceptions. In early April 2026, the current administration issued a proclamation under Section 232 of the Trade Expansion Act of 1962 determining that imports of certain pharmaceutical products, including patented pharmaceuticals, associated active pharmaceutical ingredients and related materials could threaten U.S. national security and authorized the imposition of tariffs of up to 100% on covered imports, effective July 31, 2026. Imports of certain listed products from specific partner countries, including South Korea and the European Union, may be subject to reduced tariff rates. Certain tariff exemptions or zero-rate treatment may be available for products where all approved indications are designated as orphan, subject to applicable determinations, conditions and implementation guidance. There remains substantial uncertainty as to whether such tariffs would apply to the importation of active pharmaceutical ingredients or bulk drug products that are intended for use in clinical trials and, more generally, about the duration of existing tariffs, tariff levels, implementation of announced tariffs, litigation challenging tariffs and whether additional tariffs or retaliatory actions may be imposed, modified or suspended. Although we do not believe that the macroeconomic factors discussed above have had a material impact on our financial position or results of operations to date, our financial position or results of operations may be adversely affected in the future due to these factors, and such factors may lead to increases in the cost of manufacturing our product candidates and delays in initiating trials. In addition, global credit and financial markets have experienced extreme volatility and disruption in the past several years and the foregoing factors have led to and may continue to cause diminished liquidity and credit availability, declines in consumer confidence, declines in economic growth, uncertainty about economic stability and continued inflation.

There can be no assurance that further deterioration in credit and financial markets and confidence in economic conditions will not occur. A future recession or market correction or other significant geopolitical events could materially affect our business and the value of our common stock. Our general business strategy may be adversely

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affected by any such economic downturn, volatile business environment or continued unpredictable and unstable market conditions. If the current equity and credit markets deteriorate, or do not improve, it may make any necessary debt or equity financing more difficult, more costly, and more dilutive. Failure to secure any necessary financing in a timely manner and on favorable terms could have a material adverse effect on our growth strategy, financial performance and stock price and could require us to delay or abandon clinical development plans. In addition, there is a risk that one or more of our current service providers, manufacturers and other partners may not survive these difficult economic times, which could directly affect our ability to attain our operating goals.

ITEM 2.UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS

Recent Sales of Unregistered Securities

None.

Repurchases of Shares or of Company Equity Securities

None.

ITEM 3.DEFAULTS UPON SENIOR SECURITIES

None.

ITEM 4.MINE SAFETY DISCLOSURES

Not applicable.

ITEM 5.OTHER INFORMATION

(c) Trading Plans

On June 30, 2026, Asif Ali, our Chief Financial Officer, adopted a trading plan intended to satisfy Rule 10b5-1(c) to sell up to (i) 73,214 shares of the Company’s common stock, (ii) 50% of the net shares issued to Mr. Ali after withholding taxes upon the vesting of restricted stock unit awards representing 21,346 shares of the Company’s common stock, and (iii) 50% of the net shares issued to Mr. Ali after withholding taxes upon the vesting of performance stock unit awards representing 12,800 shares of the Company’s common stock (assuming that such shares underlying performance stock units vest at target amounts) through September 30, 2027, or such earlier date when all transactions under the trading plan are completed, subject to certain conditions.

Except as discussed above, during the fiscal quarter ended June 30, 2026, no director or Section 16 officer adopted or terminated any Rule 10b5-1 trading arrangement or a non-Rule 10b5-1 trading arrangement (in each case as defined in Item 408(a) of Regulation S-K).

ITEM 6.EXHIBITS

EXHIBIT INDEX

Exhibit

Incorporation By Reference

Number

  ​ ​ ​

Exhibit Description

  ​ ​ ​

Form

  ​ ​ ​

SEC File No.

  ​ ​ ​

Exhibit

  ​ ​ ​

Filing Date

3.1

Amended and Restated Certificate of Incorporation

8-K

001-37852

3.1

8/16/2016

3.2

Certificate of Amendment to the Amended and Restated Certificate of Incorporation

8-K

001-37852

3.1

6/26/2024

3.3

Amended and Restated Bylaws

S-1/A

333-212476

3.2b

8/1/2016

10.1

Protagonist Therapeutics, Inc. 2026 Equity Incentive Plan

8-K

001-37852

10.1

6/18/2026

31.1+

Certification of Chief Executive Officer required by Rule 13a-14(a) or Rule 15d-14(a) of the Securities

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Exchange Act of 1934, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

31.2+

Certification of Chief Financial Officer required by Rule 13a-14(a) or Rule 15d-14(a) of the Securities Exchange Act of 1934, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

32.1+*

Certification of Chief Executive Officer and Chief Financial Officer, as required by Rule 13a-14(b) or Rule 15d-14(b) and Section 1350 of Chapter 63 of Title 18 of the United States Code (18 U.S.C. §1350), as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

101.INS+

Inline XBRL Instance Document - the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL Document.

101.SCH+

Inline XBRL Taxonomy Extension Schema Document

101.CAL+

Inline XBRL Taxonomy Extension Calculation Linkbase Document

101.DEF+

Inline XBRL Taxonomy Extension Definition Linkbase Document

101.LAB+

Inline XBRL Taxonomy Extension Labels Linkbase Document

101.PRE+

Inline XBRL Taxonomy Extension Presentation Linkbase Document

104

Cover Page Interactive Data File - The cover page interactive data file does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document

+     Filed herewith.

*     This certification attached as Exhibit 32.1 that accompanies this Quarterly Report on Form 10-Q is not deemed filed with the Securities and Exchange Commission and is not to be incorporated by reference into any filing of Protagonist Therapeutics, Inc. under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, whether made before or after the date of the Form 10-Q, irrespective of any general incorporation language contained in such filing.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

PROTAGONIST THERAPEUTICS, INC.

Date:  August 5, 2026

By:

/s/ Dinesh V. Patel, Ph.D.

Dinesh V. Patel, Ph.D.

President, Chief Executive Officer and Director

(Principal Executive Officer)

Date:  August 5, 2026

By:

/s/ Asif Ali

Asif Ali

Executive Vice President, Chief Financial Officer

(Principal Financial and Accounting Officer)

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