By Fineline Cube 
Roche (SWX: ROG, OTCMKTS: RHHBY) announced that its Phase III evERA trial has met both co‑primary endpoints, demonstrating a statistically significant and clinically meaningful improvement in progression‑free survival (PFS) for patients with estrogen‑receptor‑positive, HER2‑negative breast cancer who had progressed on a CDK 4/6 inhibitor and endocrine therapy.
Study Highlights
- Population – 1,011 patients with locally advanced or metastatic, ER‑positive/HER2‑negative disease; 75 % were ESR1‑mutated.
- Intervention – Oral giredestrant (next‑generation SERD) + everolimus vs. standard‑of‑care endocrine therapy + everolimus.
- Primary Endpoints –
- Intention‑to‑treat PFS – Median PFS 13.2 months vs. 8.5 months (HR 0.66; p < 0.001).
- ESR1‑mutated PFS – Median PFS 12.7 months vs. 7.9 months (HR 0.68; p < 0.001).
- Overall Survival – Mature data pending; interim analysis shows a favorable trend.
Mechanism of Action
giredestrant is an oral, full‑antagonist selective estrogen receptor degrader (SERD). By blocking estrogen binding, it triggers rapid ER degradation and halts proliferation of ER‑dependent cancer cells—offering a novel therapeutic approach after CDK 4/6 inhibitor resistance.
Market Implications
- Therapeutic Gap – The study addresses the unmet need for effective options after CDK 4/6 inhibitor failure.
- Roche’s Pipeline – These positive results bolster Roche’s portfolio of targeted breast‑cancer therapies and may accelerate regulatory submissions in the U.S. and EU.
- Competitive Landscape – giredestrant’s oral formulation and potent ER‑degradation profile position Roche ahead of other SERDs that require injection.-Fineline Info & Tech