Phathom (PHAT) fully enrolls Phase 2 VOQUEZNA EoE trial, data in Q4 2026

Rhea-AI Filing Summary

Phathom Pharmaceuticals filed an update on its drug development program, confirming it has completed enrollment in its Phase 2 pHalcon-EoE-201 trial of VOQUEZNA (vonoprazan) tablets for adults with eosinophilic esophagitis (EoE). The study has enrolled 95 patients across 41 U.S. sites, with topline results expected in the fourth quarter of 2026.

The randomized, double-blind, placebo-controlled study gives patients VOQUEZNA 20 mg or placebo once daily for 12 weeks, followed by an optional 12-week extension phase where all receive VOQUEZNA. If results are positive, Phathom plans to discuss future development in EoE with the FDA, including a potential pediatric program that could support an extension of VOQUEZNA’s regulatory exclusivity.

Insights

Biopharma pipeline analyst

Phathom advances its EoE program by fully enrolling a Phase 2 trial, with key data expected in late 2026.

Phathom has completed enrollment of 95 adults with eosinophilic esophagitis in its randomized, double-blind, placebo-controlled Phase 2 pHalcon-EoE-201 study of VOQUEZNA. This moves the EoE program from setup into the data-generation phase, a standard but important step in clinical development.

Topline results are anticipated in the fourth quarter of 2026. The company states that, if results are positive, it expects to discuss potential future development plans in EoE with the FDA, including pediatric evaluation that could potentially support additional regulatory exclusivity. Actual impact will depend on the eventual efficacy, safety, and regulatory feedback once data are available.

8-K Event Classification

Item 8.01 — Other Events

1 item

Item 8.01 Other Events Other

Voluntary disclosure of events the company deems important to shareholders but not covered by other items.

Key Figures

Patients enrolled: 95 patients Study sites: 41 U.S. sites Dose: 20 mg once daily +3 more

6 metrics

Patients enrolled 95 patients Phase 2 pHalcon-EoE-201 VOQUEZNA EoE trial

Study sites 41 U.S. sites Locations for Phase 2 EoE study enrollment

Dose 20 mg once daily VOQUEZNA regimen in Parts 1 and 2

Treatment duration Part 1 12 weeks Initial randomized VOQUEZNA vs placebo period

Extension duration Part 2 12 weeks All participants receive VOQUEZNA 20 mg

Topline results timing Q4 2026 Anticipated timing for Phase 2 EoE data

Key Terms

eosinophilic esophagitis, Phase 2, double-blind, placebo-controlled, +1 more

5 terms

eosinophilic esophagitis medical

"investigational treatment for eosinophilic esophagitis (“EoE”) in adults"

A chronic allergic condition in which a type of white blood cell builds up in the tube that carries food from the mouth to the stomach, causing inflammation, difficulty swallowing and chest or throat pain; think of it as sticky residue narrowing a pipe. It matters to investors because prevalence, diagnostic rates and treatment options drive demand for drugs, tests and procedures, and clinical or regulatory news can quickly change revenue and valuation for healthcare companies working on therapies or diagnostics.

Phase 2 medical

"Phase 2 pHalcon-EoE-201 clinical trial evaluating VOQUEZNA"

Phase 2 is the mid-stage clinical trial where a new drug or treatment is tested in a larger group of patients to see if it works and to keep checking safety after initial human testing. Think of it as a field test that proves whether a product actually delivers its promised benefit. Investors watch Phase 2 closely because its results strongly influence a medicine’s chances of reaching the market, the size of its potential sales, and the company’s valuation.

double-blind medical

"a two-part, randomized, double-blind, placebo-controlled Phase 2 study"

A double-blind process means that neither the people conducting an activity nor the people involved know certain key details, such as who is receiving a treatment or a placebo. This approach helps prevent bias from influencing the results, making the outcome more trustworthy. For investors, it ensures that decisions or judgments are based on unbiased information rather than preconceived opinions or expectations.

placebo-controlled medical

"a two-part, randomized, double-blind, placebo-controlled Phase 2 study"

"Placebo-controlled" describes a testing method where one group receives the actual treatment or intervention, while another group receives a harmless, inactive version called a placebo. This approach helps determine whether the real treatment has genuine effects beyond psychological expectations. For investors, understanding this ensures confidence that reported benefits are real and not influenced by bias or false perceptions.

regulatory exclusivity regulatory

"could potentially support an extension of regulatory exclusivity"

A period during which regulators prevent competitors from relying on a drug or device maker’s safety and effectiveness data to win approval for their own rival product, creating a temporary market shield beyond or instead of a patent. For investors, this delay in direct competition can extend a product’s revenue runway and improve predictable cash flow, like giving a seller exclusive access to a popular storefront for a set time before others can move in.

FAQ

What did Phathom Pharmaceuticals (PHAT) announce in this 8-K?

Phathom announced completion of enrollment in its Phase 2 pHalcon-EoE-201 trial of VOQUEZNA for eosinophilic esophagitis in adults. The company now moves toward data readout, with topline results expected in the fourth quarter of 2026, subject to standard study execution and analysis.

How many patients are enrolled in Phathom’s Phase 2 EoE trial?

The Phase 2 pHalcon-EoE-201 study has enrolled 95 adult patients with eosinophilic esophagitis. Participants were recruited across 41 U.S. sites and randomized to receive VOQUEZNA 20 mg or placebo once daily for 12 weeks, with an optional 12-week VOQUEZNA extension phase.

When are topline results from Phathom’s EoE study expected?

Phathom anticipates topline results from the Phase 2 pHalcon-EoE-201 trial in the fourth quarter of 2026. This readout will inform whether VOQUEZNA shows a favorable profile in eosinophilic esophagitis and guide discussions with the FDA about potential future development in this indication.

What is the design of Phathom’s pHalcon-EoE-201 Phase 2 study?

The pHalcon-EoE-201 study is a two-part, randomized, double-blind, placebo-controlled Phase 2 trial. In Part 1, 95 adults receive VOQUEZNA 20 mg or placebo once daily for 12 weeks. Those who complete Part 1 may enter Part 2, a 12-week extension with VOQUEZNA 20 mg for all participants.

How could this EoE study affect VOQUEZNA’s regulatory exclusivity?

Phathom states that if the Phase 2 EoE trial generates positive results, it expects to discuss a pediatric evaluation program with the FDA. A pediatric program in eosinophilic esophagitis could potentially support an extension of VOQUEZNA’s regulatory exclusivity, depending on future study outcomes and regulatory decisions.

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

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Understanding 8-K Material Events →

Available on EDGAR 06/23/2026 - 08:00 AM Accepted by SEC EDGAR 06/23/2026 - 08:00 AM Learn about SEC filing dates

false 0001783183 0001783183 2026-06-23 2026-06-23

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of report (Date of earliest event reported): June 23, 2026

PHATHOM PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

Delaware		001-39094		82-4151574
(State or other jurisdiction of incorporation or organization)		(Commission File Number)		(I.R.S. Employer Identification No.)

100 Campus Drive, Suite 102

Florham Park, New Jersey 07932

(Address of principal executive offices) (Zip Code)

(877) 742-8466

(Registrant’s telephone number, include area code)

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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 $0.0001 per share		PHAT		The Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

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. ☐

Item 8.01 Other Events.

On June 23, 2026, Phathom Pharmaceuticals, Inc. (“Phathom” or the “Company”) announced it has completed enrollment in its Phase 2 pHalcon-EoE-201 clinical trial evaluating VOQUEZNA^® (vonoprazan) tablets as an investigational treatment for eosinophilic esophagitis (“EoE”) in adults. The study has enrolled 95 patients at 41 U.S. sites. Topline results are anticipated in the fourth quarter 2026.

The pHalcon-EoE-201 study is a two-part, randomized, double-blind, placebo-controlled Phase 2 study. In Part 1, 95 adults with endoscopically confirmed EoE and dysphagia have been randomized evenly to receive VOQUEZNA 20 mg or placebo once daily for 12 weeks. Patients who complete Part 1 are eligible to enter Part 2, a 12-week extension phase in which all participants receive VOQUEZNA 20 mg once daily. If the Phase 2 pHalcon-EoE-201 study generates positive results, Phathom expects to discuss with FDA potential future development plans in EoE, including pediatric evaluation that could potentially support an extension of regulatory exclusivity.

Forward Looking Statements

This report contains forward-looking statements, including statements regarding: Phathom’s plans, expectations, and goals for development of VOQUEZNA in eosinophilic esophagitis (“EoE”); the potential timeline for reporting top-line results from the pHalcon-EoE-201 study (the “Study”); the potential for the Study to generate positive results and to inform Phathom’s future development strategy in EoE; the potential for the Study to support future discussions with the FDA on a pediatric program and the potential for such a pediatric program to extend regulatory exclusivity; the unmet need for additional options in the treatment of EoE and the potential of vonoprazan as a future treatment option; Phathom’s business strategies, goals, mission and vision; and Phathom’s expectations, forecasts and predictions as to future performance, results and likelihood of success. In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “contemplates,” “believes,” “estimates,” “predicts,” “potential”, “guidance”, or “continue” or the negative of these terms or other similar expressions. These statements involve known and unknown risks, uncertainties and other important factors that may cause Phathom’s actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including the risk that: Phathom may encounter issues with conduct of the Study or analysis of results that delay Phathom’s timeline for reporting results; Phathom may receive negative or mixed results from the Study that are not sufficient to advance the program; even if the results of the Study are positive, Phathom may decide not to advance the EoE program or Phathom may not agree with the FDA on a pediatric program or may decide not to conduct a pediatric program in EoE; if Phathom decides to conduct a pediatric program in EoE, the studies it conducts may not meet the requirements or timeline for receiving an extension of Phathom’s regulatory exclusivity for VOQUEZNA; the data from the Study or any future studies Phathom may conduct in EoE may not support the potential for VOQUEZNA as a treatment option in this indication; the success of the EoE program may be impacted by potential safety or tolerability issues, competition from other therapies or treatment approaches, or technical issues; even if the Study and future studies are successful, regulatory authorities may not approve VOQUEZNA for EoE; future cash needs may cause Phathom to change its plans; and any of the foregoing or other factors may negatively impact Phathom’s ability to achieve its plans, goals, mission, vision and potential. For additional discussion of these and other risks, see the risk disclosure in Phathom’s filings with the Securities and Exchange Commission (“SEC”), including Phathom’s Annual Report on Form 10-K and any subsequent filings with the SEC. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and Phathom undertakes no obligation to revise or update this report to reflect events or circumstances after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

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 hereunto duly authorized.

				PHATHOM PHARMACEUTICALS, INC.
Date: June 23, 2026				By:		/s/ Anne Marie Cook
						Anne Marie Cook
						Chief Legal Officer

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