Cambridge, Massachusetts — Synlogic, Inc. and Caldera Therapeutics, Inc. have entered into a definitive all-stock merger agreement that will create a publicly traded biotechnology company focused on developing treatments for inflammatory bowel disease and other immune-mediated conditions.
The combined company will operate as Caldera Therapeutics, Inc. and plans to apply for listing on the Nasdaq Capital Market under the ticker symbol “CALD.”
Caldera has also secured commitments for an upsized $278 million private placement from a group of healthcare institutional investors and mutual funds. The financing, along with the combined company’s cash at closing, is expected to fund operations into 2029 and support Phase 2 trials of Caldera’s lead drug candidate, CLD-423, in ulcerative colitis and Crohn’s disease.
Participating investors include Bain Capital Life Sciences, TCGX, Atlas Venture, venBio Partners, Omega Funds, Blackstone Multi-Asset Investing, Wellington Management, Janus Henderson Investors, Vivo Capital and several other institutional investors.
“In just over a year, we’ve shown our team’s ability to open up a lead with compelling data from a molecule poised to deliver the next horizon of I&I therapy,” Caldera Chief Executive Officer Praveen Tipirneni, M.D., MBA, said. “These transactions provide the capital and public company platform to advance our vision as we move into Phase 2 development in IBD and continue exploring the potential of CLD-423 across additional immune-mediated diseases.”
CLD-423 is an investigational bispecific antibody designed to inhibit the TL1A and IL-23p19 pathways simultaneously. Caldera believes targeting both pathways in one molecule could provide greater effectiveness than therapies aimed at a single target.
The drug is being evaluated in a Phase 1 trial involving healthy volunteers in Australia. The study began in January 2026 and has completed dosing.
Caldera said data from the first four single ascending-dose cohorts showed that CLD-423 was generally well tolerated, with no dose-limiting toxicities. The drug demonstrated a serum half-life of more than 40 days within the anticipated therapeutic exposure range and approximately 80% bioavailability when administered subcutaneously.
The company said those findings could support maintenance dosing once every eight or 12 weeks in patients with inflammatory bowel disease. Caldera expects to report additional data from all five single-dose cohorts and multiple-dose cohorts later in 2026.
Caldera holds exclusive worldwide rights to develop and commercialize CLD-423 under a licensing agreement with Qyuns Therapeutics Co., Ltd.
“Following our evaluation of strategic alternatives, we believe this transaction represents the best path forward for our shareholders and an exciting opportunity to support the advancement of an innovative program with the potential to break through the current efficacy ceiling in inflammatory bowel disease,” Synlogic Principal Executive Officer and Principal Financial Officer Mary Beth Dooley said.
Under the merger agreement, existing Synlogic shareholders are expected to own approximately 2.3% of the combined company. Existing Caldera shareholders are expected to own about 62.8%, while investors in the private placement are expected to own approximately 34.9%.
Synlogic shareholders’ final ownership percentage may be adjusted based on the company’s estimated net cash before closing.
The boards of both companies have approved the transaction, which is expected to close by early 2027. Completion remains subject to shareholder approvals, the effectiveness of a registration statement filed with the U.S. Securities and Exchange Commission and other customary closing conditions.
Tipirneni will lead the combined company, and Caldera’s current board members will become directors of the merged organization.
