Arrivent Biopharma Inc. (AVBP.O): CDH17 Handily Beats ~30% ORR Bar in mCRC, Future Combo With Bev Positioned to Push ORR Higher

Citi views ARR-217's initial Phase 1 CRC data presented at ESMO as handily beating its ~30% ORR bar for competitive differentiation. At 6 mg/kg, ORR was 44.8% and confirmed ORR 37.9% in 29 efficacy-evaluable patients; all four pending PRs were subsequently confirmed, lifting confirmed responses to 11/29. Activity was consistent across RAS status, prior irinotecan exposure and treatment line, supporting broad development without biomarker selection. The 6 mg/kg dose showed the best efficacy-tolerability balance, with 20.4% grade >=3 TRAEs, 14.3% serious TRAEs, no discontinuations and no ILD, versus lower ORR and higher toxicity at 7 and 8 mg/kg. Citi believes the monotherapy profile supports a potential registrational strategy of ARR-217 plus bevacizumab versus Lonsurf plus bevacizumab, with the addition of bev potentially pushing ORR higher. Citi maintains a Buy/High Risk rating and a US$20 target price.