Verzenio (also known as abemaciclib) is a drug developed by Eli Lilly to treat HR-positive, HER2-negative patients with advanced or metastatic breast cancer who are not responding to treatment. It could be given in combination with fulvestrant (a type of endocrine therapy), or on its own for patients who had previously been treated with endocrine therapy and chemotherapy.
It works by inhibiting molecules called CDK4 and CDK6 that promote the growth of cancer cells. By blocking these molecules, Verzenio stops the cells from dividing, therefore slowing cancer growth. Similar drugs to this are palbociclib (Ibrance, Pfizer), and ribociclib (Kisqali, Novartis).
The FDA approval on September 28 was a result of 2 trials studying the safety and efficacy of Verzenio. In one trial, Verzenio was used in combination with fulvestrant and studied in 669 patients. The median progression-free survival was 16.4 months for patients receiving fulvestrant + Verzenio, versus 9.3 months for patients receiving fulvestrant + placebo. In the other trial, Verzenio was evaluated as a stand-alone treatment amongst 132 patients who had progressed after endocrine therapy and chemotherapy. In this study, 19.7% of treated patients experienced complete or partial shrinkage of their tumors that lasted for an average of 8.6 months.
The side effects of the drugs include diarrhoea, nausea, decreased appetite, low levels of white and red blood cells, blood clots, and elevated liver blood tests.
Study testing Verzenio in combination with fulvestrant (“MONARCH2” study): http://ascopubs.org/doi/full/10.1200/JCO.2017.73.7585
Study testing Verzenio as a single agent (“MONARCH1” study): http://clincancerres.aacrjournals.org/content/early/2017/05/20/1078-0432.CCR-17-0754