Study summary

A two-target antibody-drug conjugate doubled the response rate over chemotherapy in heavily treated disease

Izalontamab brengitecan phase 3 · 386 people, phase 3 · Published October 2025, The Lancet

What was tested

Izalontamab brengitecan (iza-bren), an antibody-drug conjugate aimed at both EGFR and HER3, against chemotherapy, for recurrent or metastatic nasopharyngeal carcinoma after at least two earlier treatments.

What they found

• Tumors shrank in 54.6% vs 27.0% with chemotherapy.
• Survival data were not yet mature.
• Severe side effects, mainly low blood counts, were more common (80% vs 62%).

What it means

The first phase 3 win for an antibody-drug conjugate in this cancer; Bristol Myers Squibb is developing it outside China.