Biopharmaceutical company Gilead Sciences Inc (Nasdaq:GILD) on Monday reported positive topline results from the Phase 3 ASCENT-04/KEYNOTE-D19 trial evaluating Trodelvy (sacituzumab govitecan-hziy) in combination with Keytruda (pembrolizumab) in previously untreated patients with PD-L1 positive metastatic triple-negative breast cancer.

Keytruda is owned by US pharmaceutical company Merck & Co Inc (NYSE:MRK), known as MSD outside the US and Canada.

The combination demonstrated a statistically significant and clinically meaningful improvement in progression-free survival compared to the current standard of care, Keytruda plus chemotherapy.

This marks the first pivotal Phase 3 trial to show superiority of a Trop-2-directed antibody-drug conjugate combined with immunotherapy in this setting.

An early trend toward overall survival improvement was also observed, although the data remain immature.

The safety profile of the Trodelvy-Keytruda combination was consistent with known profiles of each therapy, and no new safety signals emerged.

Trodelvy is the only approved Trop-2-directed antibody-drug conjugate with demonstrated survival benefits in multiple metastatic breast cancer indications.

The ASCENT-04 results support the potential of Trodelvy plus Keytruda as a new first-line treatment option for patients with PD-L1 positive locally advanced or metastatic triple-negative breast cancer.