BioXcel BXCL701 Combo Therapy Shows Encouraging Response Rates In Prostate Cancer

BioXcel Therapeutics Inc BTAI announced results from its ongoing Phase 2 trial of BXCL701 in metastatic castration-resistant prostate cancer (mCRPC) patients with either adenocarcinoma or small cell neuroendocrine carcinoma (SCNC) phenotype. 

• Results will be highlighted in two poster presentations at the 2022 ASCO Genitourinary Cancers Symposium.
• The trial is evaluating the combination of BXCL701 with Merck & Co Inc's MRK Keytruda (pembrolizumab).
• SCNC Findings: In the evaluable patient cohort (n = 15), 5 (33%) patients achieved a composite response at the planned interim analysis.
• In patients with measurable disease (n = 12), partial response was observed in 4 (33%) patients (3 confirmed responses), and the disease control rate was 58% (7 patients).
• Also See: FDA Pushes Review Of BioXcel's Candidate For Agitation Associated With Neuropsychiatric Disorders.
• Key Adenocarcinoma Findings: In the evaluable patient cohort (n = 29), 6 (21%) patients achieved a composite response.
• In patients with measurable disease (n = 18), partial response was observed in 4 (22%) patients (3 confirmed responses), and the disease control rate was 83% (15 patients); all responders experienced a decrease in tumor size from baseline.
• In the 29 patients who had at least 1 post-baseline prostate-specific antigen (PSA) measurement, the PSA50 was 17%, including five patients who showed a -100% to -57% PSA decrease.
• From historical data, single-agent pembrolizumab showed an objective response rate of 3% to 5%, a disease control rate of 12%, and a PSA50 response of 6%.1
• Price Action: BTAI shares closed at $17.59 on Monday.