Prana Therapies’ former shareholders are positioned to own 51.7% of Nasdaq-listed Bolt Biotherapeutics after the companies completed a stock-for-stock reverse merger on Oct. 23, provided a signed $120 million private placement closes and the preferred shares convert. The deal shifts Bolt’s focus from cancer drugs to Prana’s inflammation pipeline.
Before the PIPE, former Prana holders would own 88.2% of Bolt on a fully diluted, as-converted basis. After the financing, they would hold 51.7%, new investors 41.4% and legacy Bolt holders 6.9%. Bolt is the legal acquirer, but conversion of the preferred shares would make Prana’s former owners the majority; the conversion still requires a Bolt shareholder vote under Nasdaq rules.
Bolt agreed to sell convertible preferred shares and accompanying warrants for $120 million in upfront gross proceeds, with closing expected Oct. 26 subject to customary conditions. Warrant exercises could provide another $60 million, but that money is not committed. Bolt projects the upfront proceeds would extend its runway into 2028; at June 30, it had $18.1 million of cash and investments and had warned of substantial doubt about its ability to continue as a going concern.
The combined company will prioritize PRA-216, an experimental bispecific antibody intended to block IL-4Rα and TSLP, two signaling routes involved in inflammatory disease. Bolt said Phase 2 studies have begun in asthma, chronic obstructive pulmonary disease and atopic dermatitis, with another study planned in eosinophilic esophagitis. Prana designed the drug for subcutaneous maintenance dosing at home every eight to 12 weeks.
The clinical evidence remains preliminary. Prana’s disclosed Phase 1 study involved healthy volunteers and reported tolerability, changes in inflammatory biomarkers and extended drug exposure, rather than evidence that the treatment helps patients with the targeted diseases. Bolt expects data from the four Phase 2 studies between the second and fourth quarters of 2027.
The transaction also resets a company that had been conserving cash. Bolt’s June filing said it cut approximately half its workforce in a 2025 restructuring, while Fierce Biotech reported that an earlier cancer program was abandoned after off-target toxicity emerged. Bolt’s Oct. 23 filing says it does not expect to provide further updates on its BDC-4182 Phase 1 cancer study.