Breast cancer remains the leading cause of cancer-related deaths among women globally, with ER-positive breast cancer constituting about 70% of cases.

Other companies like Eli Lilly have also reported success with oral SERDs, such as imlunestrant, which reduced the risk of disease progression or death, though benefits were limited to certain patient groups.

Giredestrant is currently in five other Phase III trials targeting breast cancer, with an estimated sales potential of $675 million by 2031 if approved.

Results will be submitted to regulatory authorities and shared at upcoming medical meetings, with the goal of making this treatment available to patients soon.

Roche announced positive results from the Phase III evERA study, showing that the combination of giredestrant and everolimus significantly improved progression-free survival (PFS) in patients with ER-positive, HER2-negative advanced breast cancer who had previously received CDK4/6 inhibitors and endocrine therapy.

Giredestrant, an investigational oral selective estrogen receptor degrader (SERD), is designed to block estrogen binding and promote receptor degradation, with ongoing studies exploring its efficacy across multiple treatment settings.

This positive data marks a potential comeback for oral SERDs, especially after setbacks with other drugs in the class, such as Sanofi’s amcenestrant and Roche’s earlier failure with giredestrant.

As an all-oral treatment, this combination could reduce the impact on patients' quality of life by avoiding injections and hospital visits.

The combination therapy was well tolerated, with adverse events consistent with the known safety profiles of the individual drugs and no new safety signals reported.

The evERA study met its primary endpoints, demonstrating that the all-oral regimen was both effective and safe, offering a potentially less burdensome treatment option.

While overall survival data are still immature, early indications suggest a positive trend, and further follow-up is planned to obtain more definitive results.

The study specifically focused on ESR1-mutated patients, raising questions about its efficacy in ESR1-wild-type patients, which could expand its market potential.

Additional data from Roche’s larger trials, persevERA and lidERA, are expected in 2026, providing further insights into giredestrant’s role in breast cancer treatment.