ArriVent BioPharma, Inc. (NASDAQ: AVBP), a clinical-stage company developing cancer therapies, announced on October 25, 2026 initial Phase 1 results for ARR-217, an antibody-drug conjugate (ADC) for gastrointestinal cancers. In an oral presentation at the European Society for Medical Oncology (ESMO) 2026 Congress, the company reported a 44.8% objective response rate at the 6 mg/kg dose in previously treated patients with colorectal cancer.

How ARR-217 Works

ARR-217, also known as MRG007, targets cadherin-17 (CDH17), a cell adhesion protein that colorectal cancer and several other gastrointestinal cancers frequently overexpress. Normal intestinal tissue and the pancreatic duct show limited expression of the protein, which the company says makes it an attractive ADC target. The drug carries an exatecan-based payload attached through a glycan linker.

ArriVent holds exclusive rights to develop and sell ARR-217 worldwide outside of Greater China under a collaboration with Lepu Biopharma. It is the first ADC from the company’s pipeline to reach clinical development.

Response Rates and Safety

As of an August 5, 2026 data cutoff, 123 heavily pretreated patients had received ARR-217 across six dose levels from 2 mg/kg to 8 mg/kg, including 113 with colorectal cancer. The study is running in the U.S. and China.

At 6 mg/kg every three weeks, 13 of 29 colorectal cancer patients responded, for the 44.8% rate. However, only seven of those responses were confirmed partial responses, while four were pending confirmation and two were unconfirmed. On a confirmed basis alone, the response rate at that dose was about 24%. The disease control rate at 6 mg/kg was 93.1%.

Across all doses of 4 mg/kg and higher, the response rate in colorectal cancer was 34.2%, or 25 of 73 patients, with 15 confirmed. In addition, the company reported that most responding patients remained on treatment at the cutoff.

On safety, 30.1% of all 123 patients experienced a Grade 3 or higher treatment-related adverse event, most commonly neutropenia and diarrhea. At 6 mg/kg, that rate was 20.4%. The study recorded no treatment-related deaths and no cases of interstitial lung disease.

Dose Optimization and Pipeline Context

ARR-217 has now advanced into a Phase 1b dose optimization study at 5 and 6 mg/kg, with data expected in 2027. “We believe the responses observed in this heavily pretreated patient population, together with a manageable safety profile, provided a strong foundation for advancing ARR-217,” said Bing Yao, Ph.D., Chief Executive Officer of ArriVent.

The ADC data follows a setback for firmonertinib, the company’s lead candidate. On October 6, ArriVent reported that its Phase 3 FURVENT trial in first-line lung cancer with EGFR exon 20 insertion mutations did not meet its primary endpoint of progression-free survival by independent review. The company is evaluating the full dataset to decide on the drug’s development path, while a separate Phase 3 study in EGFR PACC mutations continues.

Meanwhile, ArriVent reported cash and investments of $373.1 million as of June 30, 2026, which it expected at the time to fund operations into 2028. Its pipeline also includes ARR-002, a dual-targeting ADC for ovarian and endometrial cancers that has dosed its first patient.

Strategic Investment Summary

• ESMO Data: ArriVent BioPharma, Inc. (NASDAQ: AVBP) reported initial Phase 1 results for its CDH17-targeted ADC ARR-217 at ESMO 2026 on October 25, 2026.
• Headline Response: At 6 mg/kg, 13 of 29 colorectal cancer patients responded, a 44.8% rate that includes six responses still pending or unconfirmed.
• Disease Control: The disease control rate reached 93.1% at 6 mg/kg and 91.8% across doses of 4 mg/kg and higher.
• Safety: Grade 3 or higher treatment-related adverse events occurred in 20.4% of patients at 6 mg/kg, with no treatment-related deaths or interstitial lung disease.
• Next Data: Phase 1b dose optimization at 5 and 6 mg/kg is under way, with results expected in 2027.
• Lead Program: Firmonertinib missed its primary endpoint in the Phase 3 FURVENT trial, and ArriVent is reviewing the full dataset.

Find out more about the latest corporate developments and financial reports at the ArriVent investor portal.

The post ArriVent Reports Initial Phase 1 Data for ARR-217, Including a 44.8% Response Rate in Colorectal Cancer at One Dose appeared first on PRISM MarketView.

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