Head-to-head evidence
Palazestrant vs tamoxifen
Same mechanism, same race: design-graded trial evidence for both assets, with the grading rationale shown. Grades describe the quality of the evidence, never the merits of either security.
HR+/HER2- Metastatic Breast Cancer
Shared mechanism: Estrogen receptor · full HR+/HER2- Metastatic Breast Cancer pipeline
Palazestrant
Developed by Olema Pharmaceuticals, Inc.
NCT04505826 · Phase 1/2 · completed
The study was nonrandomized, unblinded, and single-arm, with participants receiving OP-1250 at sequential dose levels and no placebo or active comparator. Its results were descriptive rather than a formal comparative test: dose-limiting toxicities were 0/42 during dose escalation, while confirmed partial responses included 4/62 participants at 120 mg once daily; therefore, the primary outcomes were not formally met or missed against a control.
Next expected readout: October 2026 · NCT06016738 (registry estimate)
tamoxifen
Marketed by Mayne Pharma
NCT00066690 · Phase 3 · completed
The trial was large and randomized, with tamoxifen as an active comparator, but it was open-label rather than blinded. Its hard primary endpoint, five-year disease-free survival, produced mixed results: exemestane plus ovarian suppression was superior to tamoxifen alone, whereas tamoxifen plus ovarian suppression was not statistically significant compared with tamoxifen alone.
Next expected readout: October 2026 · NCT03707340 (registry estimate)
The full competitive landscape for each asset (every same-race competitor with aligned evidence, sortable) is on the asset pages: Palazestrant's landscape · tamoxifen's landscape