ELECTRA: elacestrant + abemaciclib for previously treated HR+/HER2- advanced breast cancer

During ESMO 2024, Dr Eva Ciruelos, medical oncologist at the Hospital Universitario 12 de Octubre in Madrid presented the results of the phase Ib part of the ELECTRA trial. This study evaluates the combination of elacestrant and abemaciclib in patients with previously treated, HR+/HER2- advanced breast cancer. 

In total, 27 patients were treated with this combination in three different dose cohorts. Patients had to be pretreated in the metastatic setting with at least one line of endocrine therapy, no more than 2 lines of chemotherapy and no more than 2 CDK4/6 inhibitors (not including abemaciclib). Overall, the treatment was well-tolerated without a marked increase in the incidence of diarrhea and neutropenia compared to abemaciclib alone. Elacestrant in combination with abemaciclib demonstrated favorable efficacy in this study, regardless of the metastasis site. The overall response rate across the three cohorts was reported at 26%, with a clinical benefit rate of 57% at week 24.

The phase 2 portion of ELECTRA is currently ongoing at a dose of 345 mg qd for elacestrant and 150 mg bid for abemaciclib. In contrast to the phase Ib part presented at ESMO2024, part 2 of the trial will specifically evaluate the combination of elacestrant and abemaciclib in patients with brain metastases.