Bolt Biotherapeutics, Inc. has agreed to acquire Prana Therapies, Inc., a clinical-stage biotechnology company, in a transaction that pairs the acquisition with a concurrent private placement financing of $120 million. The move positions Bolt to advance Prana's pipeline of next-generation, half-life-extended multispecific antibodies, raising the question of how the combined entity will integrate these assets into its broader inflammatory disease strategy.
The acquisition is structured as a stock-for-stock transaction via a sign-and-close reverse merger. Under the agreement, Prana equity holders will receive a fixed exchange of Bolt common shares and Series D non-voting convertible preferred stock. On an as-converted basis, the preferred stock represents 16,791,675 shares of Bolt common stock, without giving effect to beneficial ownership limitations. Concurrently, Bolt entered into a securities purchase agreement to raise $120 million in upfront gross proceeds from a syndicate of healthcare institutional investors. This initial financing includes the potential to receive an additional $60 million upon the exercise of accompanying warrants.
The lead asset in the combined portfolio is PRA-216, a fully human bispecific antibody targeting IL-4Rα and TSLP. Currently in Phase 2 development for asthma, chronic obstructive pulmonary disease, and atopic dermatitis, PRA-216 is the first clinical program generated from Prana's INSPIRE platform. A Phase 2 study for eosinophilic esophagitis is also planned. Data from the Phase 1 healthy volunteer study, presented at the 2026 European Respiratory Society, indicated that PRA-216 was well tolerated and demonstrated durable pharmacodynamic activity across multiple Type 2 inflammatory biomarkers. The company expects patient data from all four Phase 2 trials to begin arriving in the second quarter of 2027 and continue through the fourth quarter of that year.
Bolt CEO Willie Quinn stated that the acquisition provides an opportunity for stockholders to participate in a differentiated pipeline addressing large markets in inflammatory disease. He cited the clinical profile of PRA-216 and the broader potential of the INSPIRE platform as key drivers for the deal. Sheila Gujrathi, M.D., Prana's co-founder and former chief executive officer, will join Bolt's executive team as Chief Strategy Officer and its Board of Directors. She noted that the financing provides resources to advance PRA-216 through multiple Phase 2 readouts in 2027 while expanding the INSPIRE pipeline.
The private placement involves the purchase of Series D non-voting convertible preferred stock by investors including Deep Track Capital, ADAR1 Capital, Andreessen Horowitz, LYFE Capital, Coastlands Capital, Eventide Asset Management, Casdin Capital, Curie.Bio, SilverArc Capital, Soleus Capital, and Deviation Capital. The preferred shares are priced at $8.5743 per share on an as-converted basis. Subject to stockholder approval under Nasdaq listing rules, each share of Series D preferred stock will automatically convert into 1,000 shares of Bolt common stock. The private placement is expected to close on October 26, 2026, with proceeds expected to fund operations into 2028.