NEW YORK – Oncotelic Therapeutics on Wednesday received clearance from the US Food and Drug Administration to begin a Phase II clinical trial of its TGF-β inhibitor, OT-101, plus Merck's Keytruda (pembrolizumab) in patients with metastatic plural mesothelioma.
The investigator-initiated study will enroll up to 63 patients with malignant pleural mesothelioma who did not achieve or maintain response to checkpoint inhibition. The multicenter trial will be led by Melina Marmarelis, medical director of the University of Pennsylvania Pleural and Mesothelioma Center.
The researchers will determine the recommended Phase II dose and evaluate the response rate as the primary objective. They will also explore biomarkers of response to the treatment. For example, they will consider whether the OT-101 and Keytruda combination increases T-cell infiltration and clonality in some tumors and whether that correlates with a reduced TGF-β response signature. Researchers will also explore whether a pretreatment TGF-β response signature can predict which patients have a better response rate, duration of response, and survival to the treatment regimen.
"This study encompasses a broad clinical strategy, which includes a robust and rigorous assessment of changes within the tumor microenvironment of various indications relative to pre- and post-therapy including the measurement of nearly 800 genes, spatial distribution of immune effector cells, expression of cytokines, phenotypic and functional changes, immunohistochemistry and deep sequencing in the hopes of better understanding the etiology and progression of malignancies and ultimately clinical benefit," Anthony Maida, chief clinical officer of translational medicine at Oncotelic, said in a statement.
Oncotelic, based in Agoura Hills, California, is also studying OT-101 in a Phase Ib trial in combination with IL-2 (aldesleukin) in patients with advanced or metastatic solid tumors, including pancreatic cancer and melanoma, and in a Phase II trial in COVID-19 patients.