ArriVent BioPharma Reports Initial Phase 1 Data for ADC ARR-217 at ESMO 2026

ArriVent BioPharma, Inc. (Nasdaq: AVBP) announced on October 25, 2026, the presentation of initial Phase 1 data for ARR-217 (MRG007), a cadherin-17 (CDH17)-targeted antibody-drug conjugate (ADC), at the 2026 European Society for Medical Oncology (ESMO) Congress. The multicenter, open-label study, conducted in the United States and China, is evaluating the safety, tolerability, efficacy, and pharmacokinetics of ARR-217 in patients with unresectable, locally advanced, or metastatic solid tumors, with an initial focus on colorectal, pancreatic, and other gastrointestinal cancers.

As of the August 5, 2026, data cutoff, 123 patients with heavily pretreated gastrointestinal malignancies were treated across six dose levels ranging from 2 mg/kg to 8 mg/kg, including 113 patients with colorectal cancer. The company reported strong anti-tumor activity across multiple dose levels. At the 6 mg/kg dose administered every three weeks (Q3W), an objective response rate (ORR) of 44.8 percent (13 out of 29 patients) was observed in pre-treated colorectal cancer patients. This included 7 confirmed partial responses, 4 partial responses pending confirmation, and 2 unconfirmed partial responses. A disease control rate (DCR) of 93.1 percent (27 out of 29 patients) was also recorded at this dose level.

ARR-217 was developed in partnership with Lepu Biopharma Co., Ltd., which granted ArriVent exclusive rights to develop and commercialize the drug worldwide outside of Greater China. The ADC utilizes a glycan-linked, exatecan-based payload. The company stated that the safety profile was generally manageable, with the most common treatment-related adverse events being Grade 1 or 2. Across all doses, 30.1 percent of patients (37 out of 123) experienced Grade 3 or higher treatment-related adverse events, including neutropenia (12.2 percent) and diarrhea (8.9 percent). No grade 5 treatment-related adverse events or interstitial lung disease (ILD) were observed. ArriVent plans to host a virtual webinar on Monday, October 26, 2026, at 8:00 am ET to discuss the data.