Bolt Biotherapeutics is acquiring Prana Therapies in a stock-for-stock reverse merger aimed at advancing Prana’s pipeline of antibodies targeting inflammatory conditions.
The deal is accompanied by a $120 million private placement in Bolt, with the potential for an additional $60 million through the exercise of warrants.
The syndicate of investors includes Deep Track Capital, ADAR1 Capital, Andreessen Horowitz (a16z), LYFE Capital, Eventide Asset Management, Casdin Capital and Soleus Capital, among others. The financing is expected to extend Bolt's cash runway into 2028, according to the company's Oct. 23 release.
Prana’s proprietary INSPIRE platform is part of the deal and has already produced its lead bispecific antibody, PRA-216, with plans to generate more multispecific antibodies designed for subcutaneous delivery.
PRA-216 is a bispecific antibody that blocks interleukin-4 receptor alpha (IL-4Rα) and thymic stromal lymphopoietin (TSLP). TSLP is an epithelial alarmin, or a cytokine that acts as an early warning signal in the inflammatory cascade, while IL-4Rα mediates signaling by IL-4 and IL-13, two key drivers of type 2 inflammation seen in conditions such as asthma and atopic dermatitis.
The asset is currently in phase 2 development for asthma, chronic obstructive pulmonary disease and atopic dermatitis. Prana is also planning a phase 2 study of PRA-216 in eosinophilic esophagitis, a chronic inflammatory condition of the esophagus. Patient data from all four trials are expected between the second and fourth quarters of 2027, according to the company.
“This transaction and financing provide the resources to advance PRA-216 through multiple Phase 2 readouts in 2027 while continuing to expand our INSPIRE pipeline," Sheila Gujrathi, M.D., former CEO of Prana and newly appointed chief strategy officer, said in the release. "We are grateful for the support of our new and existing investors as we enter this next stage of development.”
Bolt Biotherapeutics launched in 2015 with a focus on cancer and raked in $230 million from its upsized IPO in 2021. The Redwood City, California-based company hit a roadblock in 2022 when off-target toxicity led to the axing of an immune-stimulating antibody candidate. Since then, it has undergone multiple workforce reductions over a two-year span.
The biotech also has ongoing collaborations with Genmab and Toray focused on cancer immune-stimulating antibody conjugates.