Massachusetts-based Caldera Therapeutics has agreed to merge with Synlogic, Inc. (OTC: SYBX) in an all-stock reverse merger that will see the combined company trade on Nasdaq under the ticker CALD. The transaction provides Caldera with a public listing and USD 278 million in concurrent PIPE financing to advance CLD-423, its TL1A × IL-23p19 bispecific antibody for inflammatory bowel disease (IBD). Like several venture-backed biotech companies this year, Caldera is using a reverse merger and sizeable PIPE financing to access the public markets, reflecting a broader shift toward capital-certain Nasdaq listings over traditional IPOs.
The PIPE is backed by investors including Bain Capital Life Sciences, TCGX, Atlas Venture, venBio Partners, Omega Funds, Blackstone Multi-Asset Investing, Wellington Management, and Janus Henderson Investors. Together with Synlogic's cash, the proceeds are expected to fund operations into 2029 and support Phase II development of CLD-423 in ulcerative colitis and Crohn's disease. The transaction is expected to close in early 2027, subject to stockholder approval and customary closing conditions. Caldera holds exclusive worldwide rights to CLD-423 under a license from China's Qyuns Therapeutics.
CLD-423 is a monovalent 1+1 format bispecific antibody designed to simultaneously inhibit TL1A and IL-23p19, two clinically validated pathways in IBD, within a single natural IgG structure. The molecule completed a Phase I healthy volunteer trial in Australia, demonstrating a serum half-life of more than 40 days, approximately 80% subcutaneous bioavailability, and low anti-drug antibody (ADA) incidence. Caldera believes the monovalent design may reduce the immunogenicity seen with bivalent anti-TL1A antibodies, supporting a potential maintenance dosing interval of every eight to 12 weeks. The USD 278 million financing will support Phase II development in ulcerative colitis and Crohn's disease.