Summit’s Ivonescimab Outperforms Tislelizumab in Trial

Share

Summit Therapeutics is reporting that its investigational bispecific antibody ivonescimab, when combined with chemotherapy, significantly reduced the risk of disease progression or death by 40% compared with tislelizumab (BeiGene’s Tevimbra) plus chemotherapy in the Phase 3 HARMONi-6 trial for first-line treatment of patients with advanced squamous non-small cell lung cancer.

The data, generated by Summit’s partner Akeso and presented at the European Society for Medical Oncology Congress 2025 in Berlin, mark the first known instance in which a PD-(L)1/VEGF bispecific antibody regimen has demonstrated a clinically meaningful advantage over an anti–PD-1 plus chemotherapy combination in a head-to-head Phase 3 setting, according to the company. It says patients treated with ivonescimab plus chemotherapy achieved a median progression-free survival (PFS) of 11.1 months, compared to 6.9 months for those receiving tislelizumab plus chemotherapy. The overall response rate was 75.9% versus 66.5%.

Safety was comparable between arms, with similar rates of serious treatment-related adverse events and discontinuation, Summit says, adding that Grade 3 or higher VEGF-related side effects, including hypertension and proteinuria, occurred slightly more often in the ivonescimab arm but were largely manageable.

Read more