Pfizer, facing increasing pressure from Novartis, is touting a Phase III win for Ibrance as the first clinical evidence supporting the CDK4/6 inhibitor class’ use in patients with a specific type of breast cancer.
Pfizer’s Ibrance has shown efficacy in a new type of breast cancer, potentially expanding the patient population the blockbuster medicine can be used for. The Phase III clinical win comes at a pivotal time for Pfizer, as Novartis’ Kisqali was recently approved for another group of breast cancer patients.
Ibrance extended median progression-free survival (PFS) by more than 50% in patients with first-line HR+, HER2+ metastatic breast cancer when combined with anti-HER2 and endocrine therapy. The Phase III PATINA trial compared Ibrance to standard of care first-line maintenance therapy after chemotherapy. Median PFS was 44.3 months for the Ibrance group as compared to 29.1 months for those on the standard of care regimen.
Pfizer touted the results as the first time a CDK4/6 inhibitor has shown benefit in this group of patients, which represents about 10% of all breast cancers.
Ibrance was first approved in 2015 for treating postmenopausal woman with breast cancer. It has since racked up three more FDA nods for HR+, HER2- metastatic breast cancer; first-line HR+, HER2- metastatic breast cancer; and men with HR+, HER2- metastatic breast cancer.
Pfizer has had a clear headstart with its CDK4/6 inhibitor over Novartis, which followed with an initial approval for Kisqali in 2017 for HR+/HER2- metastatic breast cancer. A year later, the drug was approved for HR+/HER2- advanced breast cancer, and in September this year it got another nod in HR+/HER2- early breast cancer.
Ibrance brought in $4.75 billion worldwide for Pfizer in 2023, an increase of 7% over the prior year. Meanwhile, Novartis clocked $2.08 billion in net sales for Kisqali in the same year representing a 69% increase.
