Corbus CRB-913 Phase 1b CANYON-1 Meets Primary Endpoint at All Three Doses: 5.0% Weight Loss at 60 mg vs 0.0% Placebo at 12 Weeks, No Plateau, No Suicidality; CRBP +12%
Corbus Pharmaceuticals (NASDAQ: CRBP) announced Monday September 14, 2026 positive topline results from the Phase 1b CANYON-1 trial evaluating CRB-913 (once-daily oral peripherally-restricted CB1 inverse agonist for obesity) in 254 obese non-diabetic U.S. adults across 15 sites (NCT07310901). Mean weight loss at 12 weeks: 5.0% at 60 mg (n=62), 3.3% at 40 mg (n=61), 2.8% at 20 mg (n=65) versus 0.0% on placebo (n=66) — all p<0.0001. No plateau was observed at any dose. Discontinuation rates ranged 3.1-13.1% across doses (comparable to 6.9-20.7% for oral GLP-1s in cross-trial comparison). At the 60 mg dose: nausea 22.6%, diarrhea 22.6%, constipation 4.8%, vomiting 1.6%. Psychiatric adverse events at 60 mg: depression 1.6%, anxiety 4.8%, irritability 9.7%, insomnia 0% — no serious psychiatric events or suicidality reported. CRB-913 was designed with approximately 15-fold lower brain penetration than monlunabant in preclinical models to preserve CB1-driven weight loss while limiting the psychiatric side effects that led to the 2008 withdrawal of Sanofi's Acomplia (rimonabant). CRBP shares closed up 12% on the day. Next steps: FDA clinical development plan engagement, Phase 2 monotherapy trial initiation in H1 2027, evaluation of a GLP-1 combination approach, and full data presentation at ObesityWeek 2026 (November 14-17, Washington DC).