Olema Oncology’s OP-3136 Shrinks Tumors in 68% of Patients with Good Tolerability
OP-3136 induced tumor shrinkage in 13 of 19 evaluable patients (68%) across ER+/HER2- breast, metastatic prostate and non-small cell lung cancers in early Phase 1 data. The oral KAT6 inhibitor showed no dose-limiting toxicities up to 45 mg daily, with mild to moderate side effects and predictable dose-related exposure.
1. Early Phase 1 Results
In the Phase 1 dose-escalation and expansion study, OP-3136 triggered tumor shrinkage in 13 of 19 evaluable patients, representing 68% response rate. Shrinkage occurred across ER+/HER2- breast cancer, metastatic prostate cancer and non-small cell lung cancer cohorts.
2. Safety and Tolerability Profile
OP-3136 exhibited a clean safety profile with no dose-limiting toxicities or treatment-related discontinuations up to the highest dose of 45 mg daily. Reported adverse events were mostly mild to moderate, including taste changes, anemia and neutropenia.
3. Study Design and Patient Population
The trial enrolled 32 heavily pretreated patients in 28-day cycles, with doses ranging from 2 mg to 45 mg once daily. Patients had stopped responding to standard therapies, and 62 weeks represented the longest treatment duration observed.
4. Next Steps and Data Presentation
Pharmacokinetic analysis showed dose-related exposure meeting efficacy targets at ≥6 mg. Full Phase 1 data will be presented on May 30 at the ASCO Annual Meeting, guiding further development and combination studies with palazestrant in metastatic breast cancer.