BXCL701 (talabostat)is an investigational, oral small molecule inhibitor of dipeptidyl peptidases (DPP)—primarily DPP 8/9 and DPP 4—which triggers inflammasome to alert and prime immune cells, leading to induction of IL-18 and IL-1ß, bridging innate & adaptive immunity. BXCL701 is currently being developed for the treatment of aggressive forms of prostate cancer and advanced solid ”hot” tumors that are refractory or treatment naïve to checkpoint inhibitors.

BXCL701 currently has two ongoing combination therapy clinical trials. The Company is conducting a Phase 1b/2 trial of BXCL701 in combination with KEYTRUDA^® (pembrolizumab) for metastatic castration-resistant prostate cancer (mCRPC), in patients with adenocarcinoma and in patients with the aggressive variant small-cell neuroendocrine carcinoma.. The trial will now continue to full enrollment and more complete efficacy data are expected to be presented at a scientific conference early next year.

The MD Anderson-led Phase 2 open-label basket trial was designed to evaluate the response rate of orallyadministered BXCL701, combined with KEYTRUDA, in two arms. Arm A is enrolling checkpoint naïve patients where checkpoint therapy is indicated (also referred to as “hot tumors”); and Arm B is enrolling patients who have progressed following checkpoint therapy alone. The Stage 1 efficacy bar was met for the checkpoint naïve patients, allowing Arm A of the trial to advance to completion. The Company plans to report an efficacy update from the trial in mid-2022.