Dr. Cristofanilli on Data With Lasofoxifene in ESR1-Mutant Breast Cancer

Massimo Cristofanilli, MD, professor of medicine, Hematology Oncology Division, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, discusses data with lasofoxifene in women with ESR1-mutant breast cancer.

If a drug is to move forward in development, it has to demonstrate safety and efficacy, says Cristofanilli. As an oral agent, gastrointestinal adverse events may occur with lasofoxifene, but should be easily manageable, he adds. Lasofoxifene has shown encouraging preclinical efficacy. At the 2019 ASCO Annual Meeting, preclinical data showed that the nonsteroidal selective estrogen receptor modulator was able to slow the time to metastasis compared with fulvestrant (Faslodex) in xenograph models.

Currently, lasofoxifene is being evaluated in the randomized phase II ELAINE trial. Postmenopausal patients with locally advanced or metastatic estrogen receptor-positive, HER2-negative breast cancer who harbor an acquired ESR1 mutation and have progressed on the combination of an aromatase inhibitor and a CDK4/6 inhibitor are eligible for enrollment. Notably, patients must have also received 1 prior chemotherapy regimen in the neoadjuvant or adjuvant setting.