LONDON and NEW HAVEN, Conn., Dec. 11, 2025 — Biohaven reported Phase 1 data showing that BHV-1510, a next-generation Trop2-directed antibody drug conjugate (ADC) combined with Regeneron’s anti-PD-1 cemiplimab, demonstrated encouraging clinical activity and a manageable safety profile in patients with advanced solid tumors.
At the BHV-1510 dose of 2.5 mg/kg every three weeks (Q3W) plus cemiplimab, the confirmed objective response rate (ORR) was 72.7%. Tumor-specific confirmed responses at that dose included 3 of 5 (60%) in non–small cell lung cancer (NSCLC), 4 of 4 (100%) in endometrial cancer — including a complete response — and 1 of 2 (50%) in urothelial cancer. Across all dose levels, among 23 efficacy-evaluable participants as of the October 10, 2025 cutoff, the confirmed ORR was 52.2%, with responses in 6 of 14 (42.9%) NSCLC patients, 4 of 6 (66.7%) endometrial cancer patients and 1 of 2 (50%) urothelial cancer patients. A confirmed response was also observed in a participant with triple-negative breast cancer. Median time to response was 11.1 weeks, and 18 participants remained on study treatment at six months or longer.
The study population was heavily pretreated, with a median of two prior lines of therapy for advanced or metastatic disease; 87.1% had prior exposure to PD-(L)1 agents and 51.6% received a PD-(L)1 agent as their most recent therapy. The maximum tolerated dose was not reached. One dose-limiting toxicity of Grade 3 stomatitis occurred at 2.75 mg/kg Q3W. As of the cutoff date, 31 participants had received the combination, with BHV-1510 doses ranging from 2–2.75 mg/kg Q3W and 1.25–1.5 mg/kg given on days 1 and 8 of a 21-day cycle (D1D8Q3W); cemiplimab was administered at 350 mg Q3W.
BHV-1510 was generally well tolerated and showed a safety profile differentiated from other Trop2-directed ADCs. Neutrophil count decreases occurred in 12.9% of participants (6.5% Grade ≥3). Treatment-emergent diarrhea was reported in 6.5% (no Grade ≥3 events), and alopecia in 9.7%. Oral mucositis/stomatitis, a known class effect, was the most frequent toxicity: Q3W dosing saw stomatitis in 59.1% of participants (22.7% Grade ≥3), and D1D8Q3W dosing in 33.3% (11.1% Grade ≥3). There were no cases of interstitial lung disease and no participants discontinued treatment because of adverse events. Four participants experienced treatment-emergent serious adverse events, none attributed to study treatment. Pharmacokinetic data indicated low levels of unconjugated payload and a payload-to-ADC molar ratio below 1%, suggesting high ADC stability in circulation.
Biohaven said the data support further evaluation of BHV-1510, particularly in combination with checkpoint inhibitors, and noted the potential to move the agent into earlier lines of therapy pending additional study.
Data were presented at the 2025 European Society for Medical Oncology Immuno-Oncology Congress (ESMO IO Congress). Poster 252P, “Phase 1 clinical trial of BHV-1510, a next generation Trop2 ADC, in combination with the PD-1 monoclonal antibody cemiplimab in patients with advanced solid tumors,” was scheduled for Wednesday, December 10, 2025, 5:15–6:30 pm GMT. The poster will be available on Biohaven’s website after the conference.
Biohaven is a biopharmaceutical company developing treatments in immunology, neuroscience and oncology, advancing programs across multiple proprietary platforms. For more information, visit www.biohaven.com.
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