Phase 3 study results show that giredestrant significantly improved survival without tumor progression in ER-positive advanced breast cancer, according to a news release from Roche. The breast cancer study is a randomized, open-label, multicenter trial. ESR1 mutations, which can make breast cancer resistant to hormone therapy, occur in up to 40% of people with ER-positive breast cancer after CDK4/6 inhibitor treatment. Breast cancer is the most common cancer in women, with 2.3 million diagnosed and 670,000 dying from the disease each year. Reference“Positive phase III results show Roche’s giredestrant significantly improved progression-free survival in ER-positive advanced breast cancer.” Roche.