Globenewswireยท2025-10-18 07:00Core Insights - Olema Pharmaceuticals announced updated data from the Phase 1b/2 study of palazestrant in combination with ribociclib for treating ER+/HER2- advanced or metastatic breast cancer, with findings to be presented at the ESMO Congress 2025 [1][2] Efficacy - The combination of palazestrant and ribociclib showed promising efficacy, with a median progression-free survival (PFS) of 15.5 months in the 120 mg palazestrant cohort across all patients [5][6] - In patients with prior CDK4/6 inhibitor treatment, median PFS was 9.2 months for those with ESR1 wild-type tumors and 13.8 months for those with ESR1 mutant tumors [5][6] Safety and Pharmacokinetics - The treatment demonstrated favorable tolerability, with no new safety signals or increased toxicity observed across the 72 patients treated [6] - The majority of treatment-emergent adverse events were grade 1 or 2, consistent with the expected safety profile of each drug [6] Ongoing Trials - Olema is conducting a second Phase 3 trial, OPERA-02, to evaluate palazestrant in combination with ribociclib in the frontline setting for advanced or metastatic breast cancer [2][5] Presentation Details - The findings will be presented in a poster session titled "Palazestrant (OP-1250) plus ribociclib in patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+, HER2-) advanced breast cancer" at the ESMO Congress 2025 [8]