BioInvent International AB announced the U.S. Food and Drug Administration has approved its Investigational New Drug application for its FcyRIIB-blocking antibody BI-1607. BI-1607 is intended to enhance efficacy and overcome resistance to existing cancer treatments such as trastuzumab. The IND approval allows for a Phase 1/2a trial with BI-1607, in combination with trastuzumab in HER2+ solid tumors, to be extended to U.S. centers.

The study is currently in the dose-escalation phase, with the selected dose of BI-1607 to be studied in the subsequent Phase 2a part of the trial along with trastuzumab in advanced breast, metastatic gastric and gastroesophageal junction HER2+ cancers. The Phase 1 part of the study is expected to recruit between 12 and 26 subjects. The Phase 2a part aims to recruit 30 patients in two cohorts of 15 subjects each.

The study will be carried out at 7-12 sites in Spain, the UK, Germany, and in the U.S. HER2 is a driver of tumor formation and growth and is overexpressed in approximately 20% of breast cancers, the most common cancer worldwide in women, and in gastric and gastroesophageal junction adenocarcinoma. Like BI-1206, BioInvent's lead FcyRIIB antibody, BI-1607 is intended to enhance the efficacy and overcome resistance to existing cancer treatments such as trastuzumab. Trastuzumab alone or in combination with chemotherapy significantly improves overall survival of HER2+ breast cancer patients but many patients remain uncured and develop resistance to trastuzumab resulting in relapse or progression of the disease.

BI-1607 differs from BI-1206 in that BI-1607 has been engineered for reduced Fc-binding to FcyRs. This alteration generates a major differentiating factor between the two antibodies, and specifically with respect to the best combination partners.