The combination of elacestrant (Orserdu) and abemaciclib (Verzenio) provided clinical benefit with acceptable safety in patients with estrogen receptor (ER)–positive/HER2-negative advance or metastatic breast cancer with prior exposure to endocrine therapy and CDK4/6 inhibitors, irrespective of ESR1 mutational status, according to data from a pooled analysis of the phase 1b portion of the ELECTRA (NCT05386108) and arm C of the phase 2 ELEVATE (NCT05563220) studies. The pooled data of cohort 3 from ELECTRA and arm C of ELEVATE, which were presented during the 2024 San Antonio Breast Cancer Symposium, showed that when elacestrant was given at a daily dose of 345 mg plus abemaciclib at 150 mg twice daily (n = 38), the regimen induced an objective response rate (ORR) of 18%, which included a complete response (CR) rate of 5% and a partial response (PR) rate of 13%; the stable disease (SD) rate was 66% and 16% of patients experienced disease progression. The clinical benefit rate (CBR) was 84%.
Unfortunately, though promising, only a phase 1 B study had been completed. So far, this si an E/I treatment and larger studies are awaited.
Rugo HS, Tolaney SM, Chan N, et al. Elacestrant plus abemaciclib (abema) combination in patients (pts) with estrogen receptor-positive (ER+), HER2-negative (HER2-) advanced or metastatic breast cancer (mBC). Presented at: 2024 San Antonio Breast Cancer Symposium; December 10-13, 2024; San Antonio, TX. Poster PS7-07.
Ibrahim NK, Hamilton EP, Kim S-B, et al. Elacestrant in combination with abemaciclib in patients (pts) with brain metastasis from estrogen receptor-positive (ER+), HER2-negative (HER2-) breast cancer: Preliminary data from ELECTRA, an open-label, multicenter, phase 1b/2 study. J Clin Oncol. 2024;42(suppl 16):1064. doi:10.1200/JCO.2024.42.16_suppl.1064