MBX Biosciences (NASDAQ: MBX) reports 2025 loss and cash runway into 2029

Rhea-AI Filing Summary

MBX Biosciences reported a larger full-year 2025 net loss of $86.97M, up from $61.92M in 2024, as it increased investment in its pipeline. Research and development spending rose to $79.16M, while general and administrative expenses grew to $18.90M as the company expanded its operations.

As of December 31, 2025, MBX held $373.71M in cash, cash equivalents and marketable securities, and subsequently raised an additional $85.4M through its ATM program, for pro forma cash and investments of $459.1M, which it expects will fund operations into 2029. The company is preparing a Phase 3 trial of once-weekly canvuparatide for hypoparathyroidism targeted to start in Q3 2026, advancing MBX 4291 in Phase 1 for obesity with 12-week data anticipated in Q4 2026, and running a Phase 2a trial of imapextide for post-bariatric hypoglycemia with results expected in Q2 2026.

Insights

Biotech equity analyst

MBX deepens R&D losses but secures cash runway into 2029.

MBX Biosciences is clearly in heavy investment mode. Full-year 2025 net loss widened to $86.97M as research and development spending reached $79.16M, reflecting parallel advancement of canvuparatide, MBX 4291, and imapextide programs.

On the balance sheet, year-end cash, cash equivalents and marketable securities of $373.71M, plus $85.4M raised via the ATM, bring pro forma cash and investments to $459.1M. Management states this should fund operations into 2029, which is notable runway for a clinical-stage company.

Key value drivers now hinge on execution against the disclosed milestones: initiating the Phase 3 canvuparatide trial in Q3 2026, reporting Phase 2 data in Q2 2026, generating MBX 4291 Phase 1 MAD data in Q4 2026, and delivering imapextide Phase 2a results in Q2 2026. Subsequent disclosures around these events will clarify how effectively this cash is converted into clinical progress.

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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): March 12, 2026

MBX Biosciences, Inc.

(Exact name of Registrant as Specified in Its Charter)

Delaware			001-42272	84-1882872
(State or Other Jurisdiction of Incorporation)			(Commission File Number)	(IRS Employer Identification No.)
11711 N. Meridian Street Suite 300
Carmel, Indiana				46032
(Address of Principal Executive Offices)				(Zip Code)

Registrant’s Telephone Number, Including Area Code: (317) 659-0200

Not Applicable

(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, $0.0001 par value per share		MBX		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 2.02 Results of Operations and Financial Condition.

On March 12, 2026, MBX Biosciences, Inc. (the "Company") announced its financial results for the year ended December 31, 2025. A copy of the press release is being furnished as Exhibit 99.1 to this Current Report on Form 8-K.

The information included under Item 2.02 of this Current Report on Form 8-K (including Exhibit 99.1 attached hereto), is intended to be furnished and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or otherwise subject to the liabilities of that section, and shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.	Description
99.1	Press Release Issued by MBX Biosciences, Inc. on March 12, 2026
104	Cover Page Interactive Data File (embedded within the Inline XBRL document)

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.

			MBX BIOSCIENCES, INC.
Date:	March 12, 2026	By:	/s/ P. Kent Hawryluk
			President and Chief Executive Officer (Principal Executive Officer)

EXHIBIT 99.1

MBX Biosciences Reports Fourth Quarter and Full-Year 2025 Financial Results and Recent Corporate Highlights

Phase 3 trial of once-weekly canvuparatide remains on track to initiate in Q3 2026 following recently completed, successful End-of-Phase 2 meeting with FDA

12-week MAD Phase 1 data from MBX 4291 for obesity anticipated in Q4 2026

Planned nomination of amycretin and GLP-1/GIP/glucagon receptor triple-agonist development candidates for obesity expected in Q2 and Q3 2026

$459.1 million in pro forma cash and investments as of December 31, 2025, including $85.4 million in net proceeds from top-tier institutional investors through ATM program; expected to support operations into 2029

CARMEL, Ind., March 12, 2026 (GLOBE NEWSWIRE) – MBX Biosciences, Inc. (Nasdaq: MBX), a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel precision peptide therapies for the treatment of endocrine and metabolic disorders, today reported financial results for the fourth quarter and full year ended December 31, 2025, and highlighted recent corporate progress.

“2025 was a year of continued growth and execution for MBX, highlighted by the clinical validation of our Precision Endocrine Peptide (PEP™) platform,” said Kent Hawryluk, President and Chief Executive Officer of MBX Biosciences. “Following a successful End-of-Phase 2 meeting with the FDA, we now have a clear path to initiate our Phase 3 trial of once-weekly canvuparatide. We are also advancing a growing obesity pipeline, built on our clinically validated PEPTM platform and designed for once-monthly dosing and improved tolerability. We look forward to a data-rich year ahead and to continuing our pursuit of bringing differentiated and best-in-class medicines to patients.”

Fourth Quarter 2025 and Recent Corporate Highlights

Once-Weekly Canvuparatide for Hypoparathyroidism (HP)

•End-of-Phase 2 FDA meeting for once-weekly canvuparatide completed: FDA feedback supported advancement into a Phase 3 trial and trial design elements have now been selected, including the number of patients, primary endpoint and key secondary endpoints, as well as dose selection, titration schedule and duration of the study. Initiation of the Phase 3 program remains on track for Q3 2026.

•EU Orphan Drug Designation granted for canvuparatide: The European Medicines Agency granted orphan drug designation to canvuparatide for the treatment of chronic hypoparathyroidism, supporting its continued clinical development in Europe.

•MBX expects to present the complete 12-week dataset and one-year follow-up data from the Phase 2 AvailTM trial for once-weekly canvuparatide at a medical conference in Q2 2026.

MBX4291 and Early Pipeline Programs for Obesity

•MBX 4291 advancing through Phase 1: MBX 4291, a GLP-1/GIP co-agonist prodrug designed for potential once-monthly dosing, continues to advance through Phase 1, with 12-week multiple ascending dose data on track to be reported in Q4 2026.

•Obesity portfolio expansion planned in 2026: MBX expects to nominate two additional obesity development candidates enabled by its PEPTM platform, each designed for potential once-monthly dosing with improved tolerability, including an amycretin prodrug targeted for nomination in Q2 2026 and a GLP-1/GIP/glucagon receptor (GCGR) triple-agonist prodrug candidate targeted for nomination in Q3 2026.

Long-Acting Imapextide (MBX 1416) for Post-Bariatric Hypoglycemia (PBH)

•Phase 2a trial of imapextide (MBX 1416) ongoing: Results from the ongoing Phase 2a STEADITM trial of potential once-weekly imapextide for post-bariatric hypoglycemia are expected in Q2 2026.

Corporate

•Board Appointment: In January 2026, the Company announced the appointment of Laurie Stelzer to its Board of Directors as an independent director and Audit Committee Chair, adding strategic, commercial, and financial leadership to support the Company’s advancement toward late-stage development and long-term growth objectives.

•Leadership Addition: In March 2026, MBX announced the appointment of Karen Basbaum, MBA, as Chief Business Officer. Ms. Basbaum brings more than two decades of leadership in corporate strategy, business development, and strategic transactions across the biotechnology and pharmaceutical industries.

•Strengthened Balance Sheet: In February 2026, the Company raised $85.4 million in net proceeds through its At-the-Market (ATM) facility, with participation from new and existing institutional investors.

Anticipated Milestones

•Canvuparatide

•Q2 2026: Presentation of full Phase 2 AvailTM results at a medical conference, including data from the open-label extension

•Q3 2026: Initiation of Phase 3 trial in chronic hypoparathyroidism

•MBX 4291 and Early Obesity Pipeline

•Q2 2026: Nomination of amycretin prodrug candidate

•Q3 2026: Nomination of GLP-1/GIP/GCGR triple-agonist prodrug candidate

•Q4 2026: Results from 12-week multiple ascending dose portion of Phase 1 trial of MBX 4291

•Imapextide

•Q2 2026: Phase 2a STEADI™ trial results of imapextide for the treatment of post-bariatric hypoglycemia

Fourth Quarter and Full Year 2025 Financial Results

•Cash and Cash Equivalents and Marketable Securities: As of December 31, 2025, MBX Biosciences had cash, cash equivalents and marketable securities of $373.7 million. Subsequently, on February 4, 2026, the Company raised an additional $85.4 million in net proceeds through its ATM program, resulting in pro forma cash and investments of $459.1 million as of December 31, 2025. Based on its current operating plan, the Company expects the combined cash, cash equivalents and marketable securities balance to fund operations into 2029.

•R&D Expenses: Research and development expenses for the three months and full year ended December 31, 2025, were $19.8 million and $79.2 million, respectively, compared to $15.2 million and $57.4 million for the same periods in 2024. The increases of $4.6 million and $21.8 million respectively were driven by costs associated with the ongoing MBX 4291 Phase 1 clinical trial, the canvuparatide Phase 2 AvailTM clinical trial and preparation activities for a Phase 3 clinical trial in canvuparatide.

•G&A Expenses: General and administrative expenses for the three months and full year ended December 31, 2025, were $6.0 million and $18.9 million, respectively, compared to $3.4 million and $10.8 million for the same periods in 2024. The increases of $2.6 million and $8.1 million, respectively, were driven by increased personnel-related costs as the Company expanded its infrastructure to support its growth in operations and higher professional fees to support operations as a public company.

•Net Loss: Net loss for the three months ended December 31, 2025, was $22.1 million compared to a net loss of $15.6 million for the same period in 2024. Net loss for the full year ended December 31, 2025 was $87.0 million compared to a net loss of $61.9 million for the same period in 2024.

About MBX Biosciences

MBX Biosciences is a biopharmaceutical company focused on the discovery, development and commercialization of novel precision peptide therapies based on its proprietary PEP™ platform, for the treatment of endocrine and metabolic disorders. The Company is advancing a pipeline of novel candidates for endocrine and metabolic disorders with clinically validated targets, established endpoints for regulatory approval, significant unmet medical needs and large potential market opportunities. The Company’s pipeline includes canvuparatide (MBX 2109) for the treatment of chronic hypoparathyroidism (HP) preparing for Phase 3 development; an obesity portfolio that includes MBX 4291 in Phase 1 development, as well as multiple discovery and pre-clinical obesity candidates; and imapextide (MBX 1416) for the treatment of post-bariatric hypoglycemia (PBH) in Phase 2 development. The Company is based in Carmel, Indiana. To learn more, please visit the Company website at www.mbxbio.com and follow it on LinkedIn.

About MBX’s Proprietary Precision Endocrine Peptide (PEP™) Platform

MBX was founded by global leaders with a transformative approach to peptide drug design and development. Leveraging this expertise, the Company designed its proprietary Precision

Endocrine Peptide™ (PEP™) platform to overcome the key limitations of unmodified and modified peptide therapies and to improve clinical outcomes and simplify disease management for patients. PEPs are selectively engineered to have optimized pharmaceutical properties, including extended time-action profiles and consistent drug concentrations with low peak-to-trough concentration ratios, consistent exposure to target tissues, and less frequent dosing.

Forward-Looking Statements

This press release contains “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, each as amended. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “would” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These forward-looking statements include, but are not limited to, express or implied statements regarding: MBX Biosciences’ expectations regarding the further advancement of its pipeline of programs in endocrine and metabolic disorders, including timing of initiation of a Phase 3 trial for canvuparatide in Q3 2026 and clinical data presentation in Q2 2026; statements regarding MBX Biosciences’ delivery of differentiated endocrine and metabolic compounds allow patient freedom; MBX Biosicences’ pro forma cash and investments as a result of sales under the ATM program; the contributions of its board of directors; the potential for canvuparatide to be a once-weekly PTH replacement therapy; the expected timing of the Phase 1 readout for MBX 4291 and candidate nominations; the potential for MBX Biosciences to develop therapies for obesity dosed once monthly; the expected timing for the Phase 2a STEADI™ trial results; the ability of MBX 1416 to be a treatment of PBH; and expectations regarding MBX Biosciences’ uses of capital, expenses and financial results, including the anticipated cash runway timing.

Forward-looking statements are based on management’s current expectations and are subject to risks and uncertainties that could negatively affect MBX Biosciences’ business, operating results, financial condition and stock value. Factors that could cause actual results to differ materially from those currently anticipated include: risks relating to the Company’s research and development activities; MBX Biosciences’ ability to execute on its strategy including obtaining the requisite regulatory approvals on the expected timeline, if at all; uncertainties relating to preclinical and clinical development activities; the Company’s dependence on third parties to conduct clinical trials, manufacture its product candidates and develop and commercialize its product candidates, if approved; MBX Biosciences’ ability to attract, integrate and retain key personnel; risks related to the Company’s financial condition and need for substantial additional funds in order to complete development activities and commercialize a product candidate, if approved; risks related to regulatory developments and approval processes of the U.S. Food and Drug Administration and comparable foreign regulatory authorities; risks related to establishing and maintaining MBX Biosciences’ intellectual property protections; risks related to the competitive landscape for MBX Biosciences’ product candidates; and final audit adjustments and other developments that may arise that would cause MBX Biosciences’ expectations with respect to the estimate of cash, cash equivalents and marketable securities as of December 31, 2025 to differ, perhaps materially, from the financial results that will be reflected in MBX Biosciences’ audited consolidated financial statements for the fiscal year ended December 31, 2025; as well as other risks described in “Risk Factors,” in MBX Biosciences’ Quarterly Report on Form 10-Q for the three months ended September 30, 2025, Annual Report on Form 10-K for the year ended December 31, 2025, as well as subsequent filings filed with the Securities and Exchange Commission (SEC). MBX Biosciences expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements

contained herein to reflect any change in its expectations or any changes in events, conditions or circumstances on which any such statement is based, except as required by law, and claims the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995.

MBX Biosciences uses and intends to continue to use its Investor Relations website as a means of disclosing material nonpublic information and for complying with its disclosure obligations under Regulation FD. Accordingly, investors should monitor the Company's Investor Relations website, in addition to following the Company's press releases, SEC filings, public conference calls, presentations, and webcasts.

Media Contact:

George Shea

We. Communications

gshea@wecommunications.com

Investor Contact:

Jim DeNike

MBX Biosciences

jdenike@mbxbio.com

MBX BIOSCIENCES, INC.

SELECTED FINANCIAL INFORMATION

		(Unaudited)
Statements of Operations Data:		Three months ended December 31,								Year ended December 31,
(in thousands, except per share and per share data)		2025				2024				2025				2024
Operating expenses
Research and development		$	19,759			$	15,223			$	79,159			$	57,415
General and administrative			6,036				3,387				18,896				10,779
Total operating expenses			25,795				18,610				98,055				68,194
Loss from operations			(25,795	)			(18,610	)			(98,055	)			(68,194	)
Interest and other income, net			3,733				3,024				11,084				6,272
Net loss		$	(22,062	)		$	(15,586	)		$	(86,971	)		$	(61,922	)
Net loss per common share, basic and diluted		$	(0.49	)		$	(0.47	)		$	(2.38	)		$	(5.82	)
Weighted average number of common shares    outstanding used in computation of net loss    per common share, basic and diluted			44,866,468				33,392,615				36,506,092				10,642,954

		(Unaudited)
Balance Sheet Selected Financial Data:		December 31,				December 31,
(in thousands)		2025				2024
Cash, cash equivalents and marketable securities		$	373,705			$	262,149
Working capital(1)			366,044				256,235
Total assets			385,144				268,535
Total liabilities			15,921				11,093
Accumulated deficit			(224,476	)			(137,505	)
Total stockholders’ equity			369,223				257,442

(1) Working capital is defined as total current assets less total current liabilities. See our financial statements and the related notes thereto included in our Annual Report on Form 10-K for the Years Ending December 31, 2025 and December 31, 2024 for further details regarding our current assets and current liabilities.

FAQ

How did MBX (MBX) perform financially in full-year 2025?

MBX reported a full-year 2025 net loss of $86.97M, compared with $61.92M in 2024. The wider loss reflects higher research and development spending of $79.16M and increased general and administrative expenses of $18.90M as the company expanded operations.

What is MBX (MBX) cash position and runway after its ATM raise?

As of December 31, 2025, MBX held $373.71M in cash, cash equivalents and marketable securities. It subsequently raised $85.4M in net proceeds via its ATM program, bringing pro forma cash and investments to $459.1M, which it expects will fund operations into 2029.

What are the key clinical milestones for MBX (MBX) canvuparatide program?

MBX plans to present full Phase 2 and one-year follow-up data for once-weekly canvuparatide in Q2 2026. Following a successful End-of-Phase 2 FDA meeting, the company expects to initiate a Phase 3 trial in chronic hypoparathyroidism in Q3 2026, using FDA-supported design elements.

What progress is MBX (MBX) making in its obesity pipeline including MBX 4291?

MBX 4291, a GLP-1/GIP co-agonist prodrug, is in Phase 1 with 12-week multiple ascending dose data expected in Q4 2026. The company also plans to nominate an amycretin prodrug candidate in Q2 2026 and a GLP-1/GIP/GCGR triple-agonist prodrug candidate in Q3 2026.

What is the status of MBX (MBX) imapextide program for post-bariatric hypoglycemia?

Imapextide (MBX 1416) is being evaluated in an ongoing Phase 2a STEADI™ trial for post-bariatric hypoglycemia. MBX expects to report results from this trial in Q2 2026. The candidate is designed as a potential once-weekly therapy for this endocrine complication.

How did MBX (MBX) operating expenses change in 2025 versus 2024?

Total operating expenses rose to $98.06M in 2025 from $68.19M in 2024. Research and development grew to $79.16M and general and administrative expenses increased to $18.90M, driven by clinical trial activity and infrastructure build-out for public-company operations.

Filing Exhibits & Attachments

2 documents

Press Releases

• EX-99.1 EX-99.1 144.4 KB

Other Documents

• EX-101 XBRL TAXONOMY EXTENSION SCHEMA WITH EMBEDDED LINKBASES DOCUMENT 26.3 KB