Phase 1 Results Overview
ArriVent BioPharma (NASDAQ: AVBP) announced initial Phase 1 results for its antibody‑drug conjugate ARR‑217, developed in collaboration with Lepu Biopharma Co., Ltd., targeting gastrointestinal malignancies. The multicenter, open‑label study evaluated safety, tolerability, efficacy and pharmacokinetics in patients with unresectable, locally advanced or metastatic solid tumours. As of the data cutoff on 5 August 2026, a total of 123 patients with gastrointestinal cancers were treated across six dose levels ranging from 2 mg/kg to 8 mg/kg, of which 113 patients had colorectal cancer.
Efficacy Findings
At the 6 mg/kg dose administered every three weeks, the trial reported an objective response rate (ORR) of 44.8 % among pre‑treated colorectal cancer patients, comprising seven confirmed partial responses, four partial responses pending confirmation and two unconfirmed partial responses. The disease‑control rate (DCR) at this dose was 93.1 %. Across all dose levels of 4 mg/kg and higher, the ORR in colorectal cancer patients was 34.2 % with a DCR of 91.8 %.
Safety Profile
The most frequently observed treatment‑related adverse events were Grade 1 or Grade 2. Across all dose levels, 30.1 % of patients experienced Grade 3 or higher treatment‑related adverse events, the most common being neutropenia (12.2 %) and diarrhea (8.9 %). Specifically at the 6 mg/kg dose, Grade 3 or higher events occurred in 20.4 % of patients. No Grade 5 treatment‑related adverse events or cases of interstitial lung disease were reported.
Development Path Forward
Based on the Phase 1 data, ARR‑217 has progressed to a Phase 1b dose‑optimization study evaluating the 5 mg/kg and 6 mg/kg dose levels, with additional data anticipated in 2027. Under the collaboration agreement, ArriVent retains exclusive worldwide rights to develop and commercialise ARR‑217 outside Greater China.