Roche presented detailed ESMO data showing its oral selective estrogen receptor degrader, giredestrant, meaningfully delayed tumor progression in previously treated ER-positive, HER2-negative breast cancer populations. Results include substantial progression-free survival gains in both the intention-to-treat and ESR1-mutant subgroups presented at the congress and in companion abstracts. The Swiss pharma framed giredestrant as first-in-class for non-mutant patients in a head-to-head context versus standard endocrine therapies, positioning the compound against injectable SERDs and other hormonal agents. Trial readouts have prompted Roche to advance regulatory planning and include the agent in combination regimens, underscoring competitive stakes in the endocrine therapy market.