Kisqali, a major targeted therapy for breast cancer from Novartis, has until now only been indicated for patients with metastatic disease. But on Tuesday, the Food and Drug Administration approved Kisqali in combination with hormone therapy for patients with certain early-stage breast cancers, significantly expanding the number of patients who can access these types of drugs.
“It includes all of Phase 3 and 70% of Phase 2. That’s twice the size of what other CDK4/6 inhibitors are approved for,” said Victor Bulto, president of Novartis’ US unit.
Kisqali, also called ribociclib, specifically targets proteins called CDK4 and 6, which can cause cancer cells to grow and divide uncontrollably when they are overactive. CDK4/6 inhibitors have been an important part of the treatment of advanced hormone receptor-positive, HER2-negative breast cancer, the most common form of breast cancer, for several years. Last year, the FDA approved Eli Lilly’s CDK4/6 inhibitor, abemaciclib or Verzenio, for use in stage 2 and 3 HR-positive, HER2-negative breast cancer, but not for breast cancer that had not yet spread to nearby lymph nodes.
This new approval for Kisqali takes an additional step and now offers CDK4/6 inhibitors for the first time to patients who do not have positive lymph nodes. “It is not known which of these therapies is best,” said Harold Burstein, a breast cancer oncologist and researcher at the Dana-Farber Cancer Institute who did not work on the drugs. The approval allows patients who may not be considered candidates for Verzenio to receive a CDK4/6 inhibitor, Burstein said, adding that this option was expanded to a “slightly larger group of patients.”
These patients may receive Kisqali with endocrine therapy for three years after surgery to help reduce the risk of recurrence. According to data from Novartis’ Phase 3 NATALEE trial, which was presented this week at the European Society of Medical Oncology meeting in Barcelona, Kisqali may reduce the risk of recurrence by 28.5% compared to endocrine therapy alone. That was an analysis done on patients one year after they completed treatment.
“We treat them to hopefully prevent recurrence during their lifetime. Doctors wanted to see if the effect persisted and deepened even when patients stopped treatment,” said Bulto of Novartis. “It means they’re off active treatment for a year, and we’re still seeing a benefit and a deepening benefit.”
Kisqali has some side effects. The most common were low white blood cell counts and joint pain, and the drug is intended to be taken for 3 years after surgery. Verzenio, on the other hand, is taken for 2 years but can cause diarrhea. That underlines the importance of early detection, says Dana-Farber’s Burstein, because breast cancer at even earlier stages can often be treated effectively without the need for CDK4/6 inhibitors or even chemotherapy.