The MBX Biosciences, Inc. (Nasdaq: MBX) SEC filings page on Stock Titan provides access to the company’s regulatory disclosures as filed with the U.S. Securities and Exchange Commission. As a clinical-stage biopharmaceutical company and emerging growth company, MBX uses filings such as Forms S-1, 10-K, 10-Q, and 8-K to describe its Precision Endocrine Peptide™ (PEP™) platform, clinical programs, risk factors, and capital-raising activities.
In its S-1 registration statement, MBX outlines its focus on novel precision peptide therapies for endocrine and metabolic disorders and details key product candidates, including canvuparatide (MBX 2109) for chronic hypoparathyroidism, imapextide (MBX 1416) for post-bariatric hypoglycemia, and MBX 4291 for obesity. Subsequent 8-K filings report material events such as topline results from the Phase 2 Avail™ trial of canvuparatide, initiation of the Phase 1 trial of MBX 4291, public equity offerings, and changes in board and committee roles.
Through this page, users can review MBX’s periodic financial reports, which discuss research and development spending, cash and marketable securities, and expectations about funding operations, as well as prospectus materials that describe intended uses of offering proceeds. Form 8-K filings also summarize key clinical data, trial designs, and future development plans for the company’s programs.
Stock Titan enhances these filings with AI-powered summaries that highlight the main points of lengthy documents, helping readers quickly understand topics such as clinical results, financing terms, and governance updates. Real-time updates from EDGAR, along with structured access to material event reports and registration statements, make this page a central resource for analyzing MBX’s regulatory and financial disclosures.
MBX Biosciences is advancing a pipeline of long‑acting peptide prodrugs built on its proprietary PEP platform, focused on hypoparathyroidism (HP), post‑bariatric hypoglycemia (PBH) and obesity. Its lead candidate, canvuparatide (MBX 2109), is intended as a once‑weekly PTH replacement; a Phase 2 trial enrolled 64 patients, completed enrollment in March 2025 and reported topline data in September 2025. At 12 weeks the primary composite endpoint was met in 63% of treated patients versus 31% for placebo (p=0.042). In an open‑label extension, 79% of evaluable patients were responders at six months. Pharmacokinetics support once‑weekly dosing and canvuparatide was generally well tolerated with no drug‑related serious adverse events. Imapextide (MBX 1416) showed a median half‑life of 90 hours in Phase 1, is expected to begin Phase 2a in Q3 2025 after an End‑of‑Phase 1 FDA meeting. MBX 4291 (obesity) received IND clearance in July 2025 and initiated Phase 1 in September 2025 with topline results anticipated in 2027. The prospectus discloses financing assumptions (an illustrative 10,000,000 share offering at $10.00) and an estimated need of approximately $248.0 million to advance the three clinical programs through stated milestones.
MBX Biosciences is advancing a pipeline of long‑acting peptide prodrugs built on its proprietary PEP platform, focused on hypoparathyroidism (HP), post‑bariatric hypoglycemia (PBH) and obesity. Its lead candidate, canvuparatide (MBX 2109), is intended as a once‑weekly PTH replacement; a Phase 2 trial enrolled 64 patients, completed enrollment in March 2025 and reported topline data in September 2025. At 12 weeks the primary composite endpoint was met in 63% of treated patients versus 31% for placebo (p=0.042). In an open‑label extension, 79% of evaluable patients were responders at six months. Pharmacokinetics support once‑weekly dosing and canvuparatide was generally well tolerated with no drug‑related serious adverse events. Imapextide (MBX 1416) showed a median half‑life of 90 hours in Phase 1, is expected to begin Phase 2a in Q3 2025 after an End‑of‑Phase 1 FDA meeting. MBX 4291 (obesity) received IND clearance in July 2025 and initiated Phase 1 in September 2025 with topline results anticipated in 2027. The prospectus discloses financing assumptions (an illustrative 10,000,000 share offering at $10.00) and an estimated need of approximately $248.0 million to advance the three clinical programs through stated milestones.
MBX Biosciences is advancing a pipeline of long‑acting peptide prodrugs built on its proprietary PEP platform, focused on hypoparathyroidism (HP), post‑bariatric hypoglycemia (PBH) and obesity. Its lead candidate, canvuparatide (MBX 2109), is intended as a once‑weekly PTH replacement; a Phase 2 trial enrolled 64 patients, completed enrollment in March 2025 and reported topline data in September 2025. At 12 weeks the primary composite endpoint was met in 63% of treated patients versus 31% for placebo (p=0.042). In an open‑label extension, 79% of evaluable patients were responders at six months. Pharmacokinetics support once‑weekly dosing and canvuparatide was generally well tolerated with no drug‑related serious adverse events. Imapextide (MBX 1416) showed a median half‑life of 90 hours in Phase 1, is expected to begin Phase 2a in Q3 2025 after an End‑of‑Phase 1 FDA meeting. MBX 4291 (obesity) received IND clearance in July 2025 and initiated Phase 1 in September 2025 with topline results anticipated in 2027. The prospectus discloses financing assumptions (an illustrative 10,000,000 share offering at $10.00) and an estimated need of approximately $248.0 million to advance the three clinical programs through stated milestones.
MBX Biosciences is advancing a pipeline of long‑acting peptide prodrugs built on its proprietary PEP platform, focused on hypoparathyroidism (HP), post‑bariatric hypoglycemia (PBH) and obesity. Its lead candidate, canvuparatide (MBX 2109), is intended as a once‑weekly PTH replacement; a Phase 2 trial enrolled 64 patients, completed enrollment in March 2025 and reported topline data in September 2025. At 12 weeks the primary composite endpoint was met in 63% of treated patients versus 31% for placebo (p=0.042). In an open‑label extension, 79% of evaluable patients were responders at six months. Pharmacokinetics support once‑weekly dosing and canvuparatide was generally well tolerated with no drug‑related serious adverse events. Imapextide (MBX 1416) showed a median half‑life of 90 hours in Phase 1, is expected to begin Phase 2a in Q3 2025 after an End‑of‑Phase 1 FDA meeting. MBX 4291 (obesity) received IND clearance in July 2025 and initiated Phase 1 in September 2025 with topline results anticipated in 2027. The prospectus discloses financing assumptions (an illustrative 10,000,000 share offering at $10.00) and an estimated need of approximately $248.0 million to advance the three clinical programs through stated milestones.
MBX Biosciences reported positive topline results from its Phase 2 Avail™ trial of once-weekly canvuparatide in adults with chronic hypoparathyroidism. At 12 weeks, 63% of canvuparatide-treated patients (30/48) met the primary composite endpoint, compared with 31% on placebo (5/16) with a p-value of 0.042. In the six‑month open-label extension, 79% of treated patients (44/56 evaluable) were responders, and 94% of the original 64 patients chose to enter this extension.
Treatment was generally well tolerated, with no serious adverse events or deaths related to canvuparatide and no discontinuations attributed to the drug. Bone turnover markers increased versus placebo, and in patients whose elevated urine calcium normalized by Week 12, mean urine calcium fell 48% on canvuparatide versus 33% on placebo. The company plans to start a Phase 3 study of once-weekly canvuparatide in 2026.
MBX Biosciences reported positive topline results from its Phase 2 Avail™ trial of once-weekly canvuparatide in adults with chronic hypoparathyroidism. At 12 weeks, 63% of canvuparatide-treated patients (30/48) met the primary composite endpoint, compared with 31% on placebo (5/16) with a p-value of 0.042. In the six‑month open-label extension, 79% of treated patients (44/56 evaluable) were responders, and 94% of the original 64 patients chose to enter this extension.
Treatment was generally well tolerated, with no serious adverse events or deaths related to canvuparatide and no discontinuations attributed to the drug. Bone turnover markers increased versus placebo, and in patients whose elevated urine calcium normalized by Week 12, mean urine calcium fell 48% on canvuparatide versus 33% on placebo. The company plans to start a Phase 3 study of once-weekly canvuparatide in 2026.
MBX Biosciences reported positive topline results from its Phase 2 Avail™ trial of once-weekly canvuparatide in adults with chronic hypoparathyroidism. At 12 weeks, 63% of canvuparatide-treated patients (30/48) met the primary composite endpoint, compared with 31% on placebo (5/16) with a p-value of 0.042. In the six‑month open-label extension, 79% of treated patients (44/56 evaluable) were responders, and 94% of the original 64 patients chose to enter this extension.
Treatment was generally well tolerated, with no serious adverse events or deaths related to canvuparatide and no discontinuations attributed to the drug. Bone turnover markers increased versus placebo, and in patients whose elevated urine calcium normalized by Week 12, mean urine calcium fell 48% on canvuparatide versus 33% on placebo. The company plans to start a Phase 3 study of once-weekly canvuparatide in 2026.
MBX Biosciences reported positive topline results from its Phase 2 Avail™ trial of once-weekly canvuparatide in adults with chronic hypoparathyroidism. At 12 weeks, 63% of canvuparatide-treated patients (30/48) met the primary composite endpoint, compared with 31% on placebo (5/16) with a p-value of 0.042. In the six‑month open-label extension, 79% of treated patients (44/56 evaluable) were responders, and 94% of the original 64 patients chose to enter this extension.
Treatment was generally well tolerated, with no serious adverse events or deaths related to canvuparatide and no discontinuations attributed to the drug. Bone turnover markers increased versus placebo, and in patients whose elevated urine calcium normalized by Week 12, mean urine calcium fell 48% on canvuparatide versus 33% on placebo. The company plans to start a Phase 3 study of once-weekly canvuparatide in 2026.
MBX Biosciences, Inc. filed a current report describing progress in its obesity program. On September 4, 2025, the company dosed the first participant in a Phase 1 clinical trial of MBX 4291, a long-acting GLP-1/GIP receptor co-agonist prodrug being developed for the treatment of obesity.
The Phase 1 study is a randomized, double-blind, placebo-controlled, first-in-human trial in adults with obesity. It includes a single ascending dose part with five cohorts of eight participants and a four-week multiple ascending dose part with three cohorts of eight participants, all using a 3:1 randomization of MBX 4291 to placebo. After these parts, the company plans additional multiple-dose cohorts over 12 weeks in up to two groups of 30 participants each, using a 2:1 randomization.
Participants are followed for several weeks after dosing to evaluate safety, tolerability, pharmacokinetics, and pharmacodynamics. MBX Biosciences anticipates topline Phase 1 results in 2027 and highlights that these plans and timelines are forward-looking and subject to clinical, regulatory, and funding risks.
Frazier Life Sciences-related funds report holdings in MBX Biosciences following IPO conversions and purchases. Frazier Life Sciences X, L.P. holds 4,552,774 shares (13.6% of 33,593,866 outstanding), Frazier Life Sciences Public Fund, L.P. holds 1,103,920 shares (3.3%), Frazier Life Sciences Public Overage Fund, L.P. holds 325,653 shares (1.0%), and FLS XI holds 3,000 shares. These positions arose from pre-IPO preferred-stock purchases that converted at a 12.0221-to-1 ratio plus additional IPO purchases at $16.00 per share. The filers state purchases were funded from each fund's working capital and correct prior attributions of beneficial ownership for certain investment committee members.
Deep Track Capital, Deep Track Biotechnology Master Fund and David Kroin report shared beneficial ownership of 2,188,592 common shares of MBX Biosciences, representing 6.55% of the outstanding common stock. The filing shows the reporting persons hold shared voting and shared dispositive power over these shares, and the percent is calculated using 33,424,371 shares outstanding per the issuer's disclosure. The statement is a joint filing under Schedule 13G, identifying the reporting persons and their filing classifications (Deep Track Capital: IA, OO; Deep Track Biotechnology Master Fund: CO; David Kroin: HC, IN), and certifies the holdings were not acquired to change or influence control.
Wellington Management affiliates report beneficial ownership of 2,266,628 shares of MBX Biosciences common stock, shown on the cover pages as 6.8% of the class and noted elsewhere as 6.78%. Four Wellington entities are listed as reporting persons and the schedules show no sole voting or dispositive power, with voting and disposition attributed on a shared basis.
The filing includes an Item 10 certification that the securities are held in the ordinary course of business and were not acquired to change or influence control. The statement indicates these positions are held of record by clients of Wellington investment advisers and names two funds with specified interests.
MBX Biosciences 10-Q (Q2 2025) — MBX reported cash, cash equivalents and marketable securities of $224.9 million and an accumulated deficit of $180.8 million as of June 30, 2025. Net loss was $43.3 million for the six months ended June 30, 2025; R&D expense was $40.13 million for the same period.
Development updates: enrollment for the Phase 2 canvuparatide trial is complete with topline data expected in Q3 2025; imapextide reported positive Phase 1 SAD/MAD results and a Phase 2a is anticipated to start in Q3 2025; MBX 4291 IND was submitted June 16, 2025 and cleared in July 2025 to proceed to Phase 1 in Q3 2025. Management expects liquidity to fund operations into mid-2027.