MBX Biosciences follows Bicara Therapeutics and Zenas Biopharma, which also announced last week their respective plans to go public in a potential boost to the recent slump in the IPO market.
Indiana-based MBX Biosciences on Friday filed with the SEC for an initial public offering, joining two other clinical-stage biotechs that have reinvigorated the industry’s slumping IPO market in recent months.
MBX has not yet specified how much it expects to raise, only indicating the usual $100-million placeholder in its SEC filing, a value that typically changes. Like most IPOs, MBX is also giving underwriters a 30-day window to purchase additional shares of its common stock, minus discounts and commissions.
The biotech, which will trade under the Nasdaq ticker symbol MBX, has not yet revealed its target closing date for the IPO.
The precision peptide therapeutics developer will use the IPO proceeds to push its lead program MBX 2109 through Phase II development and into Phase III studies. MBX 2109 is a peptide prodrug of the parathyroid hormone being trialed for the rare disease chronic hypoparathyroidism. Designed to be administered once-weekly, the treatment works by acting as a continuous, infusion-like exposure to parathyroid hormone, targeting the underlying pathology of the disease.
MBX 2109 is currently in a Phase II study, with topline data expected in the third quarter of 2025.
MBX will also earmark some of the IPO proceeds to support its investigational GLP-1 receptor antagonist MBX 1416, taking it through Phase I and into Phase II for post-bariatric hypoglycemia, as well as its preclinical candidate MBX 4291, which the biotech is developing for obesity. MBX 4291 is currently undergoing studies to enable an investigational new drug submission, with an estimated filing date in the second quarter of 2025.
The remainder of MBX’s IPO proceeds will help fund its other R&D activities and general corporate functions, according to the SEC filing. MBX could also use the money for business deals, including the in-licensing in, acquisition of or investment into complementary products, platforms or companies.
In addition to the funds raised from the IPO, MBX also has the $63.5 million it raised in a Series C financing round, which closed earlier this month. The raise will help sustain the biotech into 2026 and past key data milestones for its pipeline.
With Friday’s IPO announcement, MBX follows in the footsteps of two other clinical-stage companies that are looking to go public.
On Thursday, cancer-focused Bicara Therapeutics announced its Nasdaq bid, seeking to advance its investigational bifunctional antibody ficerafusp alfa through a pivotal Phase II/III study for head and neck squamous cell carcinoma. Ficerafusp alfa targets EGFR and TGF-β—both validated in cancer—and with its IPO proceeds, Bicara hopes to be able to file a Biologics License Application for the candidate.
Immunology specialist Zenas Biopharma on Thursday also filed its IPO plan with the SEC, looking to drum up support for lead asset obexelimab, which is also a bifunctional antibody. By targeting both CD19 and the Fcγ receptor IIb, Zenas is positioning obexelimab as a broad program for several autoimmune conditions, such as multiple sclerosis and systemic lupus erythematosus.
