Roche Unveils Promising Results for Giredestrant in Breast Cancer

Roche has announced significant findings regarding its oral selective estrogen receptor degrader (SERD) giredestrant, which may enhance treatment options for patients with early-stage breast cancer. The results from the lidERA trial, presented at the San Antonio Breast Cancer Symposium (SABCS), indicate that giredestrant demonstrated a 30% reduction in invasive disease-free survival (iDFS) compared to standard endocrine therapy in patients with hormone receptor-positive (HR-positive), human epidermal growth factor receptor 2-negative (HER2-negative) early breast cancer.

In this phase 3 trial, Roche highlighted that giredestrant is the only oral SERD to achieve such outcomes in an adjuvant setting, marking what the company describes as “the first significant endocrine therapy advance in over 20 years” for this patient group. Additionally, there was a trend towards improved overall survival (OS), with 92.4% of patients on giredestrant surviving at three years, compared to 89.6% in the endocrine therapy cohort. However, this OS data has not yet reached statistical significance and is considered immature.

HR-positive breast cancer represents approximately 70% of all breast cancer cases. Notably, up to a third of patients experience a recurrence following adjuvant endocrine therapy, underscoring the need for more effective treatment options. The promising results from the lidERA trial could allow Roche to position giredestrant in earlier treatment stages than its competitors.

Competitive Landscape of Oral SERDs

Currently, two other oral SERDs are available on the market: Menarini/Stemline’s Orserdu (elacestrant) and Eli Lilly’s Inluriyo (imlunestrant). Both are approved as second-line treatments for advanced HR+/HER2- breast cancer with ESR1 mutations and are undergoing late-stage testing for adjuvant use.

It’s worth noting that the lidERA trial commenced prior to the approval of two CDK4/6 inhibitors—Eli Lilly’s Verzenio (abemaciclib) and Novartis’ Kisqali (ribociclib)—which have shown efficacy in the adjuvant setting for HR+/HER2- breast cancer. Verzenio, a blockbuster with annual sales exceeding $5 billion, has been shown to improve overall survival by a statistically significant 15.8% when combined with endocrine therapy, based on findings from the monarchE trial. In contrast, Kisqali, which generated $3 billion in sales last year, did not show significant OS improvement in the NATALEE trial but has gained traction due to its approval for both node-positive and node-negative patients.

Future Considerations for Giredestrant

If giredestrant gains regulatory approval, its position in the adjuvant treatment landscape will likely hinge on various factors, including its safety profile, as the three oral SERDs exhibit different side effects. Further, the classification of patients as high, intermediate, or low risk for recurrence will play a critical role in treatment decisions, as discussed during the SABCS presentations.

As Roche continues to explore the potential of giredestrant, the company aims to address a significant unmet need in the treatment of early-stage breast cancer, providing hope for improved outcomes in this prevalent disease.