PharmAbcine Inc. announced the completion of last patient last visit in its Phase Ib combination trial for mTNBC (metastatic Triple-Negative Breast Cancer) patients in Australia. The clinical study, which had the first patient dosed in December 2018, evaluated the safety and clinical efficacy of olinvacimab, the Company's anti-VEGFR2 (Vascular Endothelial Growth Factor Receptors) antibody candidate, in combination with  MSD's (Merck & Co. Inc., Kenilworth, NJ., USA) anti-PD-1 therapy, KEYTRUDA® (pembrolizumab).

A total of 11 patients were recruited and divided into two cohorts. The low-dose cohort (five patients) received a 12mg/kg weekly dose of olinvacimab, and the high-dose cohort (six patients) received a 16mg/kg weekly dose of olinvacimab. All patients equally received a 200mg flat dose of pembrolizumab every three weeks.  In December 2020, PharmAbcine presented the highly encouraging interim data of the study at SABCS (San Antonio Breast Cancer Symposium).

In the high-dose olinvacimab cohort, an ORR (Overall Response Rate) of 50% was reported in three of six patients, and a DCR (Disease Control Rate) of 67% was reported in four out of six patients. Notably, one patient in the high-dose cohort showed CR (Complete Response) in the target lesion but was labeled as PR (Partial Response) due to a tumor remaining in a non-target lesion. The last patient, who just completed 35 cycles of olinvacimab and pembrolizumab combo treatment, will receive olinvacimab in monotherapy as compassionate use starting from early March 2022.

In addition, another patient, who showed CR in the target lesion, has already been receiving olinvacimab as compassionate use since August 2021 and is in stable condition.