The FDA just gave Gilead Sciences Inc. (Gilead (GILD)) a nice Wednesday surprise: an expanded approval for its antibody-drug conjugate Trodelvy (sacituzumab govitecan-hziy) in metastatic triple-negative breast cancer (mTNBC). This isn't just a tweak to the label—it's a significant expansion into first-line treatment, opening up the drug to a much larger pool of patients.
Under the new label, Trodelvy can now be used as a standalone therapy for first-line mTNBC patients who aren't eligible for PD-(L)1 inhibitor-based therapy. And for patients whose tumors express PD-L1 with a combined positive score of at least 10, Trodelvy can be combined with Merck & Co. Inc.'s (Merck (MRK)) Keytruda (pembrolizumab) or Keytruda Qlex.
The approval is backed by data from two Phase 3 studies: ASCENT-03 and ASCENT-04/KEYNOTE-D19. In ASCENT-03, Trodelvy monotherapy cut the risk of disease progression or death by 38% compared to chemotherapy in patients not eligible for PD-L1-directed treatment. In ASCENT-04, the Trodelvy-Keytruda combo reduced that risk by 35% versus Keytruda plus chemotherapy in PD-L1-positive patients.
And the responses lasted longer. In ASCENT-03, the median duration of response was 12.2 months with Trodelvy alone versus 7.2 months with chemo. In ASCENT-04, patients on the combo hit 16.5 months, compared to 9.2 months for Keytruda plus chemo.
The National Comprehensive Cancer Network (NCCN) has already updated its guidelines, giving Trodelvy—with or without Keytruda—a category 1 preferred first-line treatment recommendation for mTNBC, regardless of PD-L1 status. Trodelvy also holds category 1 recommendations in second-line mTNBC and in previously treated HR-positive/HER2-negative metastatic breast cancer.
Gilead says more than 75,000 breast cancer patients across over 60 countries have received Trodelvy over the past six years. The company also notes that Trodelvy remains the only Trop-2-directed antibody-drug conjugate to show overall survival benefits in both later-line metastatic TNBC and pre-treated HR-positive/HER2-negative metastatic breast cancer.
As of Thursday, Gilead shares were up 0.51% at $125.80. Not a huge move, but the market seems to appreciate the expanded runway for a key drug.
