BioInvent International AB presented the first clinical data from a Phase 1/2a trial of its second FcyRIIB-blocking antibody BI-1607. BioInvent pipeline currently includes five drug candidates progressing through six clinical trials. The Phase 1 data, presented in a poster at the San Antonio Breast Cancer Symposium, covered 18 patients treated at doses ranging from 75 mg up to 900 mg flat dose.

Treatment was well tolerated and no serious adverse events related to BI-1607 were observed. The best clinical response reported in the poster was stable disease (SD) in 4/11 evaluable patients, with disease control lasting up to 7 cycles (21 weeks). To date two additional SDs have been observed, adding to 6/11 evaluable patients.

Pharmacokinetic and pharmacodynamic data allowed identification of a wide dose range, where complete target engagement throughout a 3-week dose interval can be achieved, and this will provide the basis for further investigation in a Phase 2a trial, which planned to start 2024. BI-1607 is developed to enhance the efficacy and overcome resistance to existing cancer treatments such as trastuzumab. The reported trial is a first-in-human, open-label, multicenter, dose-escalation, consecutive-cohort study of BI-1607 in combination with trastuzumab in subjects with HER2+ advanced solid tumors.