Sensei Bio acquires Faeth Therapeutics

Sensei Biotherapeutics has acquired Faeth Therapeutics and simultaneously raised approximately $200 million through a private placement, positioning the combined entity to advance key oncology initiatives. This strategic maneuver aims to accelerate the development of Faeth’s lead asset, PIKTOR, an investigational all-oral combination therapy targeting the PI3K/AKT/mTOR pathway in solid tumors, with a focus on endometrial and breast cancer.

The acquisition brings PIKTOR’s promising pipeline under Sensei’s purview. This therapy has shown potential in early-stage trials, notably delivering a response rate of 47% in patients with prior multiple lines of therapy. Among these, patients with PI3K pathway mutations exhibited a 71% response rate, inclusive of complete responses and extended progression-free survival in specific cases. As part of the transaction, Faeth equityholders will receive a mix of Sensei common stock and Series B non-voting convertible preferred stock, equivalent to a total of 10,604,490 common shares on an as-converted basis.

Concurrent to the acquisition, Sensei has finalized a private placement agreement to issue Series B non-voting convertible preferred stock, generating around $200 million in gross proceeds. Notable investors in the round include B Group Capital, Balyasny Asset Management, and RA Capital Management. The capital infusion will primarily fund PIKTOR’s progression through critical clinical stages, particularly a Phase 2 trial in endometrial cancer and a Phase 1b trial targeting breast cancer, both anticipated to provide pivotal readouts by the end of 2026.

This move marks a significant consolidation in the biotech oncology sector. The combined resources and expertise aim to bolster Sensei’s competitive edge in targeted cancer therapies, a field dominated by the need for innovative, efficacious treatment options. The acquisition and funding reflect investor confidence and a calculated bet on the high-stakes oncology landscape, where successful development could lead to substantial market opportunities.

Regulatory and shareholder approvals are ongoing matters. Specifically, converting the Series B preferred stock into common stock requires Sensei stockholder consent. With Lucid Capital Markets and Sidley Austin LLP advising Sensei, and Cooley LLP representing Faeth, the companies are navigating complex integration and strategic planning. These procedural elements are poised to shape the operational dynamics of the newly configured entity in the coming months.