Dr. Damodaran on the ELAINE-2 Trial of Lasofoxifene/Abemaciclib in ESR1-Mutated, ER+/HER2- Breast Cancer

Senthil Damodaran, MD, PhD, assistant professor, Department of Breast Medical Oncology, Division of Cancer Medicine, the University of Texas MD Anderson Cancer Center, discusses the phase 2 ELAINE-2 trial (NCT04432454).

In the trial, investigators evaluated the safety and efficacy of lasofoxifene in combination with abemaciclib (Verzenio) in patients with locally advanced or metastatic ESR1-mutated, estrogen receptor (ER)–positive/HER2-negative metastatic breast cancer.

Efficacy data presented at the 2022 ASCO Annual Meeting showed that the censored median progression-free survival (PFS) achieved with the regimen was 13 months (95% CI, 32.0 weeks–not estimable). Of the 29 patients who were enrolled to the trial, 12 remained on treatment at the time of the presentation, Damodaran says.

Moreover, the objective response rate (ORR) achieved with the doublet was 50% (95% CI, 29.0%-71.0%). Damodaran explains that this percentage is notable, since 96.6% of enrolled patients previously received a CDK4/6 inhibitor, 79.3% received prior fulvestrant (Faslodex), and 48.3% received prior chemotherapy in the metastatic setting.

Given the prior treatment received by patients who participated in ELAINE-2, the PFS and ORR benefits provided with the combination of lasofoxifene plus abemaciclib are promising for this patient population, Damodaran concludes.