CAMBRIDGE, Mass., July 29, 2026
Synlogic, Inc. and Caldera Therapeutics, Inc. have entered into a definitive all-stock merger agreement that will create a combined biotechnology company focused on advancing CLD-423, a potential first-in-class TL1A x IL-23p19 bispecific antibody for the treatment of inflammatory bowel disease (IBD) and other immune-mediated disorders. Alongside the merger, Caldera has secured an upsized $278 million private placement from a syndicate of leading healthcare institutional investors and mutual funds, providing sufficient capital to fund operations through planned Phase 2 clinical trials in ulcerative colitis and Crohn’s disease, with an anticipated cash runway extending into 2029. Upon completion of the transaction, the merged company will operate under the Caldera Therapeutics name and intends to list on the Nasdaq Capital Market under the ticker “CALD.” The transaction strengthens Caldera’s financial position while providing the public company platform needed to accelerate the development of innovative immunology therapies targeting major unmet medical needs.
Merger Creates a Well-Funded Immunology Biotech Leader
The proposed merger combines Synlogic’s public company platform with Caldera Therapeutics’ clinical-stage immunology pipeline, creating a biotechnology company positioned to advance innovative treatments for inflammatory diseases. The concurrent $278 million private financing, backed by prominent healthcare investors, will support the continued clinical development of CLD-423 while strengthening the company’s balance sheet through projected operations into 2029. The financing is expected to close simultaneously with the merger, subject to customary closing conditions, including shareholder approvals and regulatory requirements. Following completion, existing Caldera shareholders are expected to own approximately 62.8% of the combined company, while investors participating in the private placement will hold approximately 34.9%, with current Synlogic shareholders owning the remaining equity. The combined organization will continue under Caldera’s leadership team, providing continuity as the company advances its next-generation immunology programs.
CLD-423 Targets Two Key Inflammatory Pathways
The combined company’s lead investigational therapy, CLD-423, is a bispecific antibody designed to simultaneously inhibit the clinically validated TL1A and IL-23p19 pathways, two important drivers of inflammatory bowel disease and other immune-mediated disorders. By combining both mechanisms into a single molecule, the therapy has the potential to deliver greater clinical efficacy than existing single-target biologic treatments. CLD-423 is currently undergoing a Phase 1 clinical trial in healthy volunteers in Australia, where early data have demonstrated encouraging safety, favorable pharmacokinetics, prolonged half-life exceeding 40 days, strong target engagement, and low immunogenicity. These findings support the potential for convenient subcutaneous maintenance dosing every eight to twelve weeks, an attribute that could significantly improve treatment convenience for patients with chronic inflammatory diseases. Caldera plans to initiate Phase 2 clinical studies in ulcerative colitis and Crohn’s disease while evaluating future expansion into additional immune-mediated indications.
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Strategic Transaction Accelerates Clinical Development
The merger represents an important strategic milestone for both companies, combining financial strength with an advanced clinical pipeline focused on one of the fastest-growing therapeutic areas in biotechnology. By leveraging significant new capital, the combined company aims to accelerate the development of CLD-423 while expanding research into additional inflammatory diseases where dual inhibition of TL1A and IL-23p19 may provide therapeutic benefit. The proposed transaction, expected to close in early 2027, reflects continued investor confidence in next-generation bispecific antibody therapies and reinforces growing industry interest in precision biologics targeting complex immune-mediated diseases. If successfully developed, CLD-423 could represent a differentiated treatment option capable of addressing important limitations associated with current standards of care for patients living with chronic inflammatory bowel diseases.
Source: Synlogic, Caldera Therapeutics press release
