Starting cabozantinib at 60 mg/day, prior nephrectomy, favorable- or intermediate-risk disease, and body mass index of 25 kg/m2 or higher were all significantly associated with better OS.
“The CABOREAL study describes cabozantinib use in a real-life setting in the largest unselected population to date of patients with mRCC,” lead author, of the Gustave Roussy Cancer Center in Villejuif, France, and colleagues wrote.
The retrospective study enrolled 410 patients with mRCC who were treated with at least one dose of cabozantinib between September 2016 and February 2018. Clinical data were collected from medical records at 26 oncology centers in France.
The researchers evaluated the real-world use of cabozantinib, including duration of therapy, treatment discontinuations, and dose changes. OS and predictive factors of OS were assessed as well.
The median age of study participants was 63.0 years (range, 56.0-70.0 years). Roughly a third of patients (33.4%) received two prior lines of therapy (33.4%), and 41.2% received three or more lines of therapy before cabozantinib. Overall, 85.6% of patients had clear cell histology.
The median duration of cabozantinib treatment was 7.6 months (range, 3.2-15.7 months). The starting dose was 60 mg, 40 mg, and 20 mg in 70.9%, 26.7%, and 2.0% of patients, respectively.
The dose was decreased in 57.0% of patients, 58.7% required a dose modification, and 15.6% required a modified dose schedule. The median average daily dose was 40.0 mg (range, 13.9-60.0 mg).
Adverse events were the main reason for dose modification or treatment interruption. In all, 92.5% of patients had a modification because of an adverse event, and 85.0% had an interruption because of an adverse event.
Upon permanent discontinuation of cabozantinib, more than half of patients (54.4%) received subsequent therapy, including nivolumab (47.8%), axitinib (21.7%), and everolimus (19.0%).
The median OS was 14.4 months (95% confidence interval, 12.4-16.2 months), and the 1-year OS rate was 56.5% (95% CI, 51.5-61.2%).
Factors significantly associated with longer OS included cabozantinib initiation at 60 mg/day (P = .0486), prior nephrectomy (P = .0109), favorable or intermediate risk according to the International Metastatic RCC Database Consortium (P < .0001), and body mass index of 25 kg/m2 or higher (P = .0021).
“We report, for the first time, that the daily dose of 60 mg cabozantinib at initiation is an independent predictive factor of OS in a multivariate analysis,” the researchers wrote.
“It is interesting to see real-world studies like this to help to widen our understanding of how to utilize drugs like cabozantinib,” commented, of the University of Southampton (England).
“In general, we would expect a less favorable prognosis in patients with non-clear cell histology, likely in part part due to the underlying biology of the disease,” he added.
Dr. Albiges and colleagues acknowledged that the retrospective design and lack of a prospective safety evaluation were two key limitations of their study. However, the authors maintain that the reported cabozantinib use and exposure rates are indicative of the real-world setting.
This study was sponsored by Ipsen. Several authors disclosed financial relationships with Amgen, Astellas Pharma, AstraZeneca, Bristol-Myers Squibb, Exelixis, Ipsen, and numerous other companies. Dr. Crabb reported having no conflicts of interest related to this work.
SOURCE: Albiges L et al. Eur J Cancer. 2020 Nov 27. doi: 10.1016/j.ejca.2020.09.030.