The U.S. Food and Drug Administration (FDA) has approved Eli Lilly and Company’s Verzenio (abemaciclib) for the treatment of HR-positive, HER2-negative type of advanced or metastatic breast cancer if a patient relapses after endocrine therapy.
The FDA decision was delivered months ahead of its planned action date — the first quarter of 2018 — on the company’s new drug application (NDA), which the agency handled under Priority Review. The speedy review might have been linked to the fact that the FDA had earlier granted Verzenio a breakthrough therapy designation.
Verzenio’s approval in indicated to be used in combination with the endocrine therapy Faslodex (fulvestrant). But the approval also stated that patients can receive Verzenio as the sole treatment if they have failed endocrine therapy and chemotherapy given once the cancer metastasized.
This set the therapy apart from other drugs acting in a similar manner.
“Verzenio provides a new targeted treatment option for certain patients with breast cancer who are not responding to treatment, and unlike other drugs in the class, it can be given as a stand-alone treatment to patients who were previously treated with endocrine therapy and chemotherapy,” Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence, said in a press release.
The other drugs referred to by Pazdur — who is also the acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research — are Pfizer’s Ibrance (palbociclib) and Novartis’ Kisqali (ribociclib).
All three drugs prevent cancer cells from multiplying by blocking two factors called CDK4 and CDK6.
Eli Lilly provided the FDA with data from two clinical trials to consider. The Phase 3 MONARCH 2 clinical trial (NCT02107703) included 669 patients with HR-positive, HER2-negative breast cancer who were randomly assigned treatment with the Verzenio-Faslodex combo or a placebo-Faslodex combination.
These patients had not received chemotherapy, and a maximum of one round of endocrine treatment after their cancer metastasized. Those receiving active treatment had a median progression-free survival of 16.4 months, compared to 9.3 months for patients taking a placebo with Faslodex.
Data on Verzenio’s suitability as a stand-alone therapy came from the Phase 2 MONARCH 1 trial (NCT02102490), which included 132 patients that had progressed after receiving endocrine therapy and chemotherapy for their metastatic cancer.
Researchers reported that 19.7 percent of Verzenio-treated patients had their tumors shrink or disappear after the treatment. The responses were upheld for a median 8.6 months.
Verzenio, like all cancer therapies, may cause severe side effects. The studies demonstrated that Verzenio can cause severe diarrhea, a depletion of certain immune cells, abnormal liver blood tests, and blood clots. Moreover, it may be toxic to developing fetuses.
Other common side effects include nausea, depletion of various types of blood cells, infections, and vomiting.