CHICAGO—Even before it launched, Novartis’ Kisqali was living in the shadow of classmate Ibrance, and it has been ever since. But with its latest data set, Kisqali now has an advantage the Pfizer blockbuster can’t boast.
In a phase 3 trial of premenopausal women with HR-positive, HER-2 negative breast cancer and no prior endocrine therapy, the combination of Kisqali, the hormone suppressant gosrelin, and either tamoxifen or an aromatase inhibitor cut the risk of death by 29% compared with endocrine therapy alone. At the 42-month mark, 70.2% of Kisqali patients were still alive, compared with 46% of those in the placebo group.
The study, which rolled out at the American Society of Clinical Oncology annual meeting, marks the first time a member of Kisqali’s CDK 4/6 class of cancer-fighters—a group that also includes Ibrance and Eli Lilly challenger Verzenio—has demonstrated an overall survival benefit when combined with endocrine therapy, said Sara Hurvitz, M.D., director of the breast cancer clinical trials program at UCLA.
The results are “pretty impactful and important because … we’re looking at a group of women who are younger and may have more aggressive disease biology. We’ve demonstrated that adding this therapy significantly prolongs how long they live,” she said.
The survival results follow previously reported data that showed adding Kisqali to endocrine therapy kept cancer at bay for 23.8 months compared with just 13 months for endocrine therapy and placebo. But while Hurwitz said she was “cautiously optimistic” Kisqali would prove to extend lives in the population, a substantial progression-free survival showing doesn’t always dovetail into an overall survival benefit.
“You can never assume that,” she said.
Now that Kisqali has come through, though, it has a new distinction among its peers, and it’s one Hurwitz said “may impact clinicians to move over to utilizing” the drug “preferentially.”
Novartis certainly hopes so. Kisqali has struggled to live up to sales expectations, pulling in just $235 million in 2018.