Bolt Biotherapeutics Buys Prana and Raises $120 Million

Bolt Biotherapeutics, a Nasdaq-listed company based in Redwood City, California, announced on October 23 that it has acquired Prana Therapies, a clinical-stage biotechnology company developing half-life-extended multispecific antibodies. At the same time, Bolt agreed to a private placement that brings $120 million in upfront gross proceeds.

Bolt will now focus on Prana's pipeline, which comes from its proprietary INSPIRE platform. The lead program, PRA-216, is a bispecific antibody aimed at IL-4Rα and TSLP. It is in Phase 2 development for asthma, chronic obstructive pulmonary disease and atopic dermatitis, and a Phase 2 study in eosinophilic esophagitis is planned. Patient data from all four trials are expected from the second quarter of 2027 through the fourth quarter of 2027.

How the deal is built

The acquisition is a stock-for-stock, sign-and-close reverse merger. Prana's equity was exchanged at a fixed ratio for 430,746 shares of Bolt common stock and 16,360.929 shares of Series D non-voting convertible preferred stock, which equals 16,791,675 common shares on an as-converted basis. Bolt's board approved the deal, as did Prana's board and stockholders. Neither closing needed a vote by Bolt stockholders.

The placement covers 13,995.311 Series D shares at $8,574.30 each, or $8.5743 per share as converted. Accompanying warrants could bring in up to $60 million more. Investors include Deep Track Capital, ADAR1 Capital, Andreessen Horowitz, LYFE Capital, Coastlands Capital, Eventide Asset Management and Casdin Capital, among others. The placement is expected to close on October 26, and Bolt says the money should fund operations into 2028.

The drug candidates

Prana presented Phase 1 results for PRA-216 in healthy volunteers as a late-breaking abstract at the 2026 European Respiratory Society meeting. The antibody was well tolerated and showed rapid, deep and durable activity across several markers of type 2 inflammation. Prana also points to bioavailability and exposure data that support at-home maintenance dosing every eight to 12 weeks.

A second program, an IL-31 bispecific antibody, is aimed first at atopic dermatitis, with first-in-human studies and data expected in the second half of 2027. Two undisclosed programs are expected to move toward IND-enabling development by the same period.

Sheila Gujrathi, Prana's co-founder and former chief executive, will join Bolt as chief strategy officer and a board member. Bolt chief executive Willie Quinn said the deal gives Bolt stockholders a chance to take part in a differentiated clinical-stage pipeline addressing large markets. Bolt will hold a conference call and webcast on October 26 at 8:30 a.m. ET.

Source: Bolt Biotherapeutics