Following platinum-based chemotherapy, cabozantinib did not demonstrate a significant benefit vs placebo as switch maintenance therapy for patients with metastatic urothelial carcinoma, according to findings from the ATLANTIS trial presented at the 2022 ASCO Annual Meeting.

“Platinum-based chemotherapy is an active first-line therapy in [metastatic urothelial carcinoma], but duration of response is usually short,” explained Robert J. Jones, MD, University of Glasgow, United Kingdom, and colleagues.

The phase 2 ATLANTIS trial aimed to evaluate the effect of switch maintenance therapy with cabozantinib on outcomes among patients with metastatic urothelial carcinoma who derived clinical benefit from platinum-based chemotherapy.

ATLANTIS is testing multiple maintenance therapies for patients with metastatic urothelial carcinoma who had completed 4 to 8 cycles of chemotherapy and showed no disease progression. Some patients were randomized to alternative comparisons based on predictive biomarkers, the rest were randomized to receive either cabozantinib at 40mg once daily or placebo within 10 weeks of chemotherapy completion and lasting until progression.

The primary trial end point was progression free survival (PFS). Secondary end points included overall survival (OS), response rate, maximum percentage decrease in measurable disease, safety, and tolerability.

A total of 30 patients received cabozantinib and 31 received placebo across 25 sites between February 2017 and March 2021. There were 25 (83.3%) and 26 (83.9%) PFS events in the cabozantinib and placebo arms, respectively. The median PFS with cabozantinib was 13.7 weeks and 15.8 weeks with placebo. There was no difference in OS between the 2 arms.

In the safety population, which consisted of 61 patients, there were mostly low-grade treatment–related adverse events (AEs). The most common AEs were fatigue, hypertension, nausea, and diarrhea, and they were more common with cabozantinib.

“Though tolerable, cabozantinib did not show a significant benefit compared to placebo when used in the switch maintenance setting following platinum-based chemotherapy,” Dr Jones and colleagues concluded.

Source:

Jones RJ, Hussain SA, Birtle AJ, et al. A randomised, double blind, phase II clinical trial of maintenance cabozantinib following chemotherapy for metastatic urothelial carcinoma (mUC): Final analysis of the ATLANTIS cabozantinib comparison. Presented at: American Society of Clinical Oncology; June 3-7, 2022. Chicago, IL, and virtual. Abstract LBA4505.