NEW YORK – Veru on Tuesday announced it will evaluate its selective androgen receptor (AR)-targeting agonist enobosarm with Eli Lilly's CDK4/6 inhibitor abemaciclib (Verzenio) as a second-line treatment for metastatic breast cancer that is AR and estrogen receptor (ER) positive but HER2 negative.
Veru and Lilly will collaborate on the Phase III ENABLAR-2 clinical trial, which will involve patients with AR- and ER-positive tumors who previously received Pfizer's CDK4/6 inhibitor palbociclib (Ibrance) and an estrogen-blocking agent. Under the terms of the agreement, Veru will conduct the trial and Lilly will supply abemaciclib for study participants.
Approximately 186 patients will be randomized to receive either the enobosarm-abemaciclib combination or just an estrogen-blocking treatment. In the study, patients will be deemed AR positive if they have androgen receptor staining levels via immunohistochemistry testing of at least 40 percent in breast cancer tissue samples.
According to Veru, the combination of its selective AR-targeting agonist enobosarm and a CDK4/6 inhibitor demonstrated synergistic antitumor activity in breast cancer models previously treated with palbociclib and an estrogen-blocking agent.
The aim of the ENABLAR-2 trial, slated to start in the first quarter this year across 35 US-based sites, is to assess the safety and efficacy of the combination regimen compared to the control arm. Median radiographic progression-free survival will be the study's primary endpoint, and overall response rate will be one of the secondary endpoints.
Separately, in October, Miami-based Veru announced the launch of a registrational trial, ARTEST, evaluating enobosarm monotherapy in previously treated hormone receptor-positive, HER2-negative metastatic breast cancer patients.