Head-to-head evidence
Elacestrant vs Palazestrant
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
Elacestrant
Marketed by Stemline Therapeutics, Inc.
NCT03778931 · Phase 3 · completed
This was a large randomized trial comparing elacestrant with active standard-of-care treatment, but it was open-label rather than double-blind. The primary progression-free survival endpoints, assessed by blinded imaging review, were statistically significantly better with elacestrant in both ESR1-mutant and all participants, but the lack of participant and investigator blinding limits the strength of the evidence.
Next expected readout: November 2026 · NCT06691035 (registry estimate)
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)
The full competitive landscape for each asset (every same-race competitor with aligned evidence, sortable) is on the asset pages: Elacestrant's landscape · Palazestrant's landscape