Roche reported that its oral selective estrogen receptor degrader (SERD), giredestrant, demonstrated efficacy in patients without ESR1 mutations—marking the first SERD to show benefit in that broad population. Complementary data indicate the pill delays tumor progression in closely watched breast-cancer studies presented at ESMO. If regulators accept the non‑mutant benefit as a reliable signal, giredestrant could differentiate from other estrogen‑degrading approaches and expand the addressable patient pool. Roche will pursue regulatory filings and further confirmatory trials while competitors monitor whether the data change prescribing practices and reimbursement for SERDs.