How safe and effective is targeted therapy abemaciclib for patients with relapsed or refractory mantle cell lymphoma?

This study examined the safety and effectiveness of targeted therapy abemaciclib (Verzenio) for patients with relapsed or refractory mantle cell lymphoma (MCL). The results showed that abemaciclib had promising effectiveness and was relatively safe in these patients.

MCL is an aggressive type of lymphoma. During initial treatment, some patients with MCL do not respond (refractory), while cancer returns in other patients after treatment (relapse). There are limited options for patients with relapsed or refractory MCL.

A characteristic of MCL cells is that they overproduce a protein called cyclin D1. Cyclin D1 encourages MCL cell growth. Abemaciclib is a medication that blocks cyclin D1 and stops cell growth. Early studies suggest that abemaciclib could be effective for patients with relapsed or refractory MCL. Further confirmation is needed.

28 patients with relapsed or refractory MCL were included in this study. All patients received abemaciclib. Overproduction of cyclin D1 was confirmed in 71.4% of patients. Patients were followed for an average of 13.8 months.

Abemaciclib treatment stopped cancer growth in 71.4% of patients. 7.1% of patients had no detectable cancer after treatment. 28.6% of patients had a significant reduction in the amount of cancer detected after treatment. The effects of treatment lasted for an average of 12.39 months. Patients survived for 16.03 months on average. Patients survived without cancer worsening for 8.18 months on average. 

67.8% of patients had received 3 or fewer types of treatments before abemaciclib. Abemaciclib was more effective in patients who received 3 or fewer types of treatments previously than patients who received more than 3 types. Cancer was controlled in 84.2% of patients who received 3 or fewer types of treatments and 44.4% of patients who received more than 3.

The most common side effects were diarrhea (75% of patients), low platelets (50%), and fatigue (42.9%).

The authors concluded that abemaciclib is relatively safe and effective for patients with relapsed or refractory MCL.  

The manufacturer of abemaciclib, Eli Lilly, funded this study. This was a small phase II trial. No comparison treatment was used in this trial so it is difficult to compare it to competitor treatments. This study would benefit from including a larger group of patients.