Purple Biotech Ltd. provided new results from exploratory analyses conducted as part of a Phase 1 dose escalation study that assessed the safety and tolerability of CM24 plus nivolumab (NCT04731467). The study enrolled 14 patients with advanced cancers including 11 patients with pancreatic adenocarcinoma (PDAC), two patients with colorectal adenocarcinoma (CRC) and one patient with papillary thyroid cancer. The analyses conducted in eight evaluable PDAC patients demonstrate clinically meaningful and durable reductions in serum myeloperoxidase, a biomarker for NETs, following treatment with CM24 plus nivolumab, immediately and 15 days after the first administration. In addition, analyses of tumor samples derived from the evaluable PDAC patients suggest that patient survival may be positively associated with higher levels of CEACAM1+ tumor-infiltrating lymphocytes in the TME. These results, along with additional data from this clinical study, are part of the Company’s effort aimed at identifying and evaluating the potential utility of a biomarker to optimize patient selection and treatment. Further study results on this topic will be presented at an upcoming medical conference.
NETs are web-like DNA structures and are covered with cancer-promoting proteins that are released by activated neutrophils and that have been shown to engulf tumors and promote immune evasion, tumor progression and metastases. When CEACAM1 is attached to NETs, it becomes a focal point of adhesion for cancer cells and, therefore, is suggested as a potential therapeutic target for preventing metastatic progression and immune evasion. In preclinical studies, CM24 has been shown to bind directly to NETs and to inhibit NET-induced cancer cell migration.
CM24, a first-in-class monoclonal antibody with the potential to treat multiple cancers, blocks CEACAM1, an immune checkpoint protein that supports tumor immune evasion and survival through multiple pathways. The Company is evaluating CM24 in patients with metastatic pancreatic cancer (PDAC) in combination with the PD-1 inhibitor nivolumab and chemotherapy in a randomized Phase 2 study. The primary endpoint of this Phase 2 study is to evaluate preliminary efficacy through overall survival in second-line PDAC.
“These encouraging biomarker results provide initial evidence of certain mechanistically relevant biomarkers and may enable us to implement a biomarker-driven strategy that could identify patients who will benefit from CM24,” said Gil Efron, Chief Executive Officer, Purple Biotech. “We look forward to further data that may establish these findings in our ongoing randomized Phase 2 clinical study evaluating CM24 in combination with nivolumab and chemotherapy for treatment of PDAC.”