Combination Regimen Under Study in Metastatic Urothelial Carcinoma
Posted: Friday, October 30, 2020
For patients with metastatic urothelial carcinoma and other genitourinary tumors, combining the tyrosine kinase inhibitor cabozantinib and the checkpoint inhibitor nivolumab with or without another checkpoint inhibitor ipilimumab may yield clinical activity, according to a phase I study published in the Journal of Clinical Oncology. The early study findings have led to additional expansion cohorts within this study, reported Amir Mortazavi, MD, of The Ohio State University and The Comprehensive Cancer Center, Columbus, and colleagues.
A total of 54 patients were recruited for the study. Patient inclusion criteria included a genitourinary malignancy with new or progressive lesions. All patients received escalating doses of either cabozantinib plus nivolumab or this doublet plus ipilimumab, according to the rolling six, phase I trial design protocol.
The investigators established the recommended phase II dose for the doublet regimen as 40 mg/d of cabozantinib plus 3 mg/kg of nivolumab. The triplet was the same doses plus 1 mg/kg of ipilimumab. Based on these dosages, the objective response rate was 38.5% for patients with metastatic urothelial cancer and 30.6% for all patients. In addition, there was a 21-month median duration of response for all patients. Moreover, the progression-free survival for patients with metastatic urothelial carcinoma was 12.8 months and 5.1 months for all patients.
Furthermore, most patients experienced treatment-related adverse effects (75% with cabozantinib plus nivolumab and 87% with cabozantinib, nivolumab, plus ipilimumab. These events included hypertension (21% vs. 10%), fatigue (17% vs. 10%), diarrhea (4% vs. 7%), hepatitis (0% vs. 13%), and colitis (0% vs. 7%), respectively.
“The broad applicability of both combinations makes them attractive treatment options for many solid tumors in which tyrosine kinase inhibitors and immune checkpoint inhibitors have already demonstrated activity,” the investigators noted.
Disclosure: For full disclosures of the study authors, visit ascopubs.org.