NEW YORK – CytoDyn said on Friday that it received Institutional Review Board approval to begin its Phase II basket trial for its CCR5 antagonist leronlimab (PRO 140).
The Phase II trial will investigate the drug in 22 different solid tumors. The trial will enroll up to 30 patients who are CCR5 positive.
The single-arm study is examining the effects of a weekly dose of 350 mg leronlimab in combination with the standard-of-care chemotherapy drug. The primary endpoint of the study will be progression-free survival.
CCR5 is a cellular receptor that has been found to be implicated in HIV infections as well as tumor metastases. In several cancers, CCR5 expression has also been found to be an indicator of disease state. In pre-clinical trials, blocking CCR5 reduced tumor metastases in animal models of breast and prostate cancers.
In January, the company announced positive data from a Phase Ib/II trial of CCR5-positive, triple-negative metastatic breast cancer patients who test negative for estrogen receptors, progesterone receptors, and excess HER2 protein. Based on the preliminary findings, the company expressed interest in expanding the clinical trial to include patients with other solid tumors.
Peripheral blood samples from the first patient who received leronlimab for five months in the metastatic triple-negative breast cancer trial revealed no cancer cells or cancer-associated cells. The second patient who has been on leronlimab for almost three months in the metastatic breast cancer study continues to show stable lesions with possible sites of repairs in their tumors on recent CT scans. "These data are substantiating the relationship between CCR5 and immune cell infiltrates and response, which supports the current basket trial," Bruce Patterson, CEO of CytoDyn's diagnostic partner IncellDx, said in a statement.
In 2019, CytoDyn announced an exclusive worldwide licensing agreement with IncellDX to sell non-commercial grade quantities of PA-14 or PRO-140 for development and commercialization of immunoassays for measuring CCR5 levels on human cells. The partnership will likely lead to the creation of companion diagnostics for leronlimab.
To date, results from the metastatic triple-negative breast cancer and metastatic breast cancer patients continue to be positive. CytoDyn expects to wrap up enrollment for the basket trial in the next two months.