Novartis and its breast cancer drug Kisqali won approval two years behind Pfizer’s Ibrance, and it’s lagging even farther behind in terms of sales. But the Swiss drugmaker now has new data it hopes can help close that yawning gap.
The new data, from a study called Monaleesa-3, shows Kisqali (ribociblib) didn’t just stall tumor development, but helps post-menopausal women live longer. When added to the hormone treatment fulvestrant, Kisqali cut the risk of death by 28% compared with fulvestrant alone.
The latest numbers echo results from a separate trial, Monaleesa-7, in pre-menopausal women, and the double overall survival win has Novartis executives talking up broader use of their drug. And to hear them tell it, they’re ready to match up their data against Pfizer’s blockbuster Ibrance.
When Kisqali was launched in March 2017, its progression-free survival numbers were “consistent across the studies” in the CDK4/6 class, said John Tsai, M.D., Novartis head of global drug development.
At that point, two years after Ibrance rolled onto the market, doctors were already accustomed to using the Pfizer drug and the argument for switching wasn’t resonating. Sales numbers show just how much Kisqali has been struggling to compete with the Pfizer juggernaut; Ibrance brought in $4.1 billion worldwide in 2018 while Kisqali delivered just $235 million.
But now that Kisqali has shown it can extend patients’ lives—and in two separate trials—the case has changed, Tsai argued during a briefing with reporters ahead of the data release. Doctors are taught to make decisions based on the evidence, and to Tsai, the evidence is now clearly in favor of Kisqali.
“Now with two studies, as a patient, I would want to have the best treatment,” he said. “Physicians are used to using Ibrance, and this is something we’ll have to break the habit of. We have to let them know they have to practice evidence-based medicine."
Kisquali and its CDK4/6 drug rivals treat HR-positive, HER2-negative breast cancer, and Monaleesa-3 enrolled women who had been treated with one previous round of therapy and those who were newly diagnosed. All of them had advanced or metastatic cancer. The trial was stopped early after an interim analysis.
At that point, the median survival for fulvestrant patients stood at 40 months, while the Kisqali combo group hadn’t yet found a median. Among previously untreated women, those treated with the Kisqali combo lived for a median 33.6 months without their cancer progressing, compared with 19.1 months for those treated with fulvestrant alone.
“This is a differentiator for us,” Tsai said. “We hope this will convince physicians to use ribociblib going forward.”