Future Directions of Lasofoxifene Research in Breast Cancer

Matthew P. Goetz, MD, consultant, Division of Medical Oncology, Department of Oncology, Mayo Clinic, discusses the next steps for evaluating treatment with lasofoxifene.

According to Goetz, researchers must continue to evaluate lasofoxifence in combination with CDK4/6 inhibitors. He highlights that some of this kind of research was already done in the ELAINE-2 trial (NCT04432454).

ELAINE-2 was an open-label, multicenter, single-arm study which assessed the safety and tolerability of lasofoxifene and abemaciclib (Verzenio) for the treatment of pre- and postmenopausal women with locally advanced or metastatic estrogen receptor-positive/HER2- breast cancer. Those enrolled in the study were patients who had disease progression on first- and/or second-line hormonal treatment for metastatic disease, and those who had an ESR1 mutation.

Goetz bdlieves that more studies of lasofoxifence with CDK4/6 inhibitors and other targeted therspieswill continue to further the development of the agent for patients with breast cancer.

Transcription:

0:08 | A very important next step is to look at the efficacy of lasofoxifene in combination with CDK4/6 inhibitors. In fact, we already have those data from the ELAINE-2 trial that was presented at the [American Society of Clinical Oncology meeting] in 2022. The ELAINE-2 trial is a single arm study evaluating the combination of abemaciclib plus lasofoxifene in women who had progressed on a CDK4/6 inhibitor. Many of them had progressed on chemotherapy and again, had evidence of an ESR1 mutation. In that trial, the overall response rate was 50% with a median progression-free survival that approached 14 months.

1:02 | What we believe is that effective targeting of patients who have these ESR1 mutations will include both a drug that effectively targets ESR1 as well as a drug, such as the CDK4/6 inhibitor, targeting these alternative pathways. I think that's where we're going to see the further development of lasofoxifene in combination with other targeted therapies.