Core Insights - Olema Pharmaceuticals announced updated data from the Phase 1b/2 study of palazestrant in combination with ribociclib for 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 [6][7] - 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 [6][7] - The 90 mg palazestrant cohort did not reach median PFS, while the 120 mg cohort had a median follow-up of over 19 months, indicating mature data [7] Safety and Pharmacokinetics - The combination therapy was well tolerated, with no new safety signals or increased toxicity observed across 72 patients treated with either 90 mg or 120 mg of palazestrant combined with 600 mg of ribociclib daily [6][7] - The majority of treatment-emergent adverse events were grade 1 or 2, consistent with the expected safety profiles of the individual drugs [7] Ongoing Trials - Olema is conducting a Phase 3 trial, OPERA-02, to further evaluate palazestrant in combination with ribociclib in the frontline setting for advanced or metastatic breast cancer [2][6] Company Overview - Olema Oncology is focused on transforming breast cancer treatment through novel therapies, with palazestrant being a key candidate in their pipeline [10][11] - Palazestrant is a dual-action drug, functioning as both a complete estrogen receptor antagonist and a selective estrogen receptor degrader, currently in pivotal Phase 3 trials [11]