medwireNews: Cabozantinib significantly improves progression-free survival (PFS) in newly diagnosed patients with intermediate- or poor-risk metastatic renal cell carcinoma (RCC), shows a head-to-head comparison with the standard of care sunitinib.
Treatment with the multikinase inhibitor also improved the objective response rate (ORR) and overall survival (OS), although the latter findings are very preliminary, said Toni Choueiri (Dana-Farber Cancer Institute, Boston, Massachusetts, USA) at the ESMO 2016 Congress in Copenhagen, Denmark.
Nonetheless, he believes that “cabozantinib represents a potential first-line option in patients with advanced RCC.”
The CABOSUN trial recruited 157 untreated metastatic RCC patients considered intermediate- or poor-risk according to the International Metastatic RCC Database Consortium (IMDC) criteria. Furthermore, 13% of participants had an ECOG performance status of 2 and a third (36%) had bone metastases – that is, many patients had additional adverse prognostic factors beyond the IMDC category, said Choueiri.
At a median follow-up of 20.8 months, PFS was a median of 8.2 months for the 79 patients randomly assigned to receive cabozantinib 60 mg/day and 5.6 months for the 78 given sunitinib 50 mg/day on a 4 weeks-on, 2 weeks-off cycle. This equated to a significant 31% reduction in the risk of disease progression or death in favour of cabozantinib.
Forty-six percent of cabozantinib-treated participants achieved an objective response, compared with 18% of those given sunitinib.
And at this early timepoint, median OS was 30.3 and 21.8 months in the cabozantinib and sunitinib arms, respectively, but Choueiri and colleagues intend to present updated results in the next few months.
All-cause grade 3 or worse side effects occurred in 65% of patients in the cabozantinib group and in 68% of those in the sunitinib group.
There were “no surprises” with regard to the safety signals in the cabozantinib or sunitinib arms, said Choueiri, with the expected class effects of hypertension (28 vs 22%), diarrhoea (10 vs 11%), palmar–plantar erythrodysesthesia (8 vs 4%) and fatigue (6 vs 15%) the most common toxicities of grade 3 or higher.
More cabozantinib- than sunitinib-treated patients required dose reductions (58 vs 49%), but the rate of discontinuation owing to adverse events was comparable at 20% and 21%, respectively.
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