US oncology company Oncternal Therapeutics said that the first patient enrolled in a phase 1b trial of its investigational breast cancer drug cirmtuzumab in combination with paclitaxel, a standard-of-care chemotherapy drug, has been dosed.
The phase 1b trial is evaluating the anti-ROR1 monoclonal antibody cirmtuzumab combination with paclitaxel, in breast cancer patients who are negative to HER2/neu and whose cancer is metastatic or locally advanced and is also unresectable.
The phase 1b cirmtuzumab clinical trial, which will feature up to 15 patients, is being carried out in collaboration with researchers at the University of California San Diego (UC San Diego) School of Medicine.
During a 6-month period, the participating patients will be subjected to an intravenous infusion of the investigational breast cancer drug cirmtuzumab once every 14 days for two doses and then once every 28 days, and paclitaxel weekly once for up to six 28-day cycles.
The main objectives of the cirmtuzumab phase 1b trial are safety, tolerability, time to progression, objective response rate and ROR1 expression and activity measures.
Commenting on the phase 1b trial of the investigational breast cancer drug cirmtuzumab combination with paclitaxel, James Breitmeyer – Oncternal’s President and CEO, said: “Expression of ROR1 on primary breast cancers has been shown to be associated with a higher risk of relapse over time, and is correlated with markers of EMT (epithelial-mesenchymal transition). Treatment of breast cancer cells in the laboratory with cirmtuzumab, which binds with high affinity to cell-surface ROR1, inhibits tumor growth and metastasis.
“In further preclinical studies, our collaborators showed that no tumors formed when cells harvested from breast cancer tumors treated with cirmtuzumab and paclitaxel were implanted into new animals. These data validate the rationale for combining cirmtuzumab with paclitaxel, and Oncternal is excited to support the combination trial at UC San Diego.”
Currently, the investigational breast cancer drug Cirmtuzumab is also being assessed as a potential therapy for chronic lymphocytic leukemia and mantle cell lymphoma. In May 2018, Oncternal Therapeutics initiated a phase 1b/2 trial of cirmtuzumab in combination with ibrutinib in the B-cell malignancies.