Phase Ib/II study of lacnotuzumab (MCS110) combined with spartalizumab (PDR001) in patients (pts) with advanced tumors.

3014Background: Tumor-associated macrophages mediate intrinsic/acquired resistance to programmed death-1 (PD-1) inhibitors; these cells can be reduced by inhibiting the colony-stimulating factor-1 (CSF-1)/receptor pathway. Targeting CSF-1 with lacnotuzumab (MCS110), a high-affinity, humanized mAb, combined with spartalizumab (PDR001), a humanized anti-PD-1 mAb, is hypothesized to result in synergistic antitumor activity. Methods: This Phase Ib/II study (NCT02807844) assesses lacnotuzumab with spartalizumab in pts with advanced melanoma, endometrial, pancreatic (PC), or triple-negative breast cancer. During dose escalation, pts received lacnotuzumab at 1 or 3 mg/kg with 100 mg spartalizumab, or 3, 5, 7.5, or 10 mg/kg lacnotuzumab with 300 mg spartalizumab, every 3 weeks. For the Phase Ib part, primary endpoints are safety, tolerability, and recommended Phase II dose; secondary endpoints include antitumor activity and PK. Tumor biopsies are collected before and during treatment. Results: At data cut-off 24 ...