FDA Approves Sacituzumab Govitecan-hziy for First-Line Metastatic Triple Negative Breast Cancer

The FDA has approved sacituzumab govitecan-hziy (Trodelvy; Gilead Sciences) for first-line use in metastatic triple-negative breast cancer (mTNBC), giving clinicians a new option for a cancer type that has gone more than 2 decades without a meaningful shift away from chemotherapy in the frontline setting.¹ The approval covers 2 patient populations and positions the Trop-2–directed antibody-drug conjugate (ADC) as a new backbone therapy regardless of PD-L1 status.

Announced June 24, 2026, the decision builds on the treatment’s footprint in later-line mTNBC and pretreated hormone receptor (HR)-positive, HER2-negative metastatic breast cancer, where it already carries category 1 National Comprehensive Cancer Network recommendations.² Because more than half of patients with mTNBC never reach a second line of therapy, a frontline option with a different mechanism than chemotherapy carries outsized clinical and coverage stakes.

What Did the FDA Approve and For Whom?

The approval splits along PD-L1 lines.¹ Patients whose tumors do not express PD-L1 and who are not candidates for PD-1 or PD-L1 inhibitor-based therapy are now eligible for sacituzumab govitecan-hziy as a single agent.

Patients with PD-L1–expressing tumors can receive the ADC with pembrolizumab (Keytruda; Merck & Co) or pembrolizumab and berahyaluronidase alfa-pmph (Keytruda Qlex; Merck & Co).³ Dosing is 10 mg/kg intravenously on days 1 and 8 of each 21–day cycle, continued until progression or unacceptable toxicity.¹

What Data Supported the Approval?

The single-agent indication rests on ASCENT-03 (NCT05382299), a phase 3 trial of 558 previously untreated patients not eligible for checkpoint inhibition. Median progression-free survival (PFS) reached 9.7 months with the ADC vs 6.9 months with chemotherapy, a 38% reduction in risk of progression or death (HR, 0.62; P < .0001). However, overall survival data remain immature.

The combination indication is built on ASCENT-04/KEYNOTE-D19 (NCT05382286), which enrolled 443 patients with PD-L1–expressing tumors. Adding the ADC to pembrolizumab cut the risk of progression or death by 35% vs pembrolizumab plus chemotherapy (HR, 0.65; P = .0009), with a median PFS of 11.2 vs 7.8 months. Gilead also reported a longer median duration of response across both trials.

The ASCENT-04 benefit held up long-term despite substantial crossover to second-line ADC therapy in the control arm.⁴ Sara M. Tolaney, MD, MPH, of Dana-Farber Cancer Institute, a principal investigator on the program, called the approval a practice-changing frontline option across PD-L1 status.²

“For people living with mTNBC, the first treatment choice can be pivotal, as many patients may not have the opportunity to receive subsequent therapies,” she said in a news release. “This approval is heartening news for patients and the clinical community, and I believe [it] offers a practice-changing first-line treatment option for all patients across PD-L1 status.”

Why Does Frontline Treatment Matter So Much in TNBC?

TNBC accounts for roughly 15% of breast cancer diagnoses and recurs faster than other subtypes, with 5-year survival for metastatic disease at 12%, vs 28% for other metastatic breast cancers. The disease also falls unevenly along racial lines.

Ricki Fairley, CEO of TOUCH, The Black Breast Cancer Alliance, said in Gilead's news release that TNBC disproportionately affects younger women and has lacked chemotherapy alternatives since the subtype was classified more than 20 years ago. In addition, Black women are about twice as likely to develop and die of TNBC, a gap tied to both biology and unequal access to genomic testing and targeted therapy.⁵

What Are the Safety Considerations?

Sacituzumab govitecan-hziy carries a boxed warning for severe or fatal neutropenia and diarrhea, plus warnings for hypersensitivity reactions, nausea/vomiting, and embryo-fetal toxicity.¹ Serious adverse reactions occurred in 26% of ASCENT-03 patients and 38% of ASCENT-04 patients, with fatal treatment-related events in roughly 3% of patients on each regimen.

What Does This Mean for Managed Care Stakeholders?

The frontline expansion puts payers and health systems in the position of evaluating an ADC-based regimen as a potential new standard of care, with implications for sequencing, prior authorization, and budget planning given the high-cost profile of sacituzumab govitecan-hziy. Real-world impact will hinge on how broadly health systems can operationalize PD-L1 testing and build the regimen into care pathways.

References

1. FDA approves sacituzumab govitecan-hziy as monotherapy and in combination with pembrolizumab for first-line treatment of triple-negative breast cancer. News release. FDA. June 24, 2026. Accessed June 25, 2026. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-sacituzumab-govitecan-hziy-monotherapy-and-combination-pembrolizumab-first-line
2. FDA approves Trodelvy for first-line treatment of metastatic triple-negative breast cancer. News release. Gilead June 24, 2026. Accessed June 25, 2026. https://www.gilead.com/news/news-details/2026/u-s--fda-approves-trodelvy-for-first-line-treatment-of-metastatic-triple-negative-breast-cancer
3. FDA approves KEYTRUDA (pembrolizumab) and KEYTRUDA QLEX (pembrolizumab and berahyaluronidase alfa-pmph), each with Trodelvy (sacituzumab govitecan-hziy) as first-line treatment of PD-L1+ (CPS $\ge$ 10) advanced triple-negative breast cancer (TNBC). News release. Merck. June 24, 2026. Accessed June 25, 2026.
4. Kalinsky K, Schmid P, de Azambuja E, et al. Progression-free survival after next line of treatment (PFS2) and subsequent therapies in the ASCENT-04 study of participants with previously untreated PD-L1+ metastatic triple-negative breast cancer treated with sacituzumab govitecan plus pembrolizumab vs chemotherapy plus pembrolizumab. Presented at: 2026 American Society of Clinical Oncology Annual Meeting; May 29–June 2, 2026; Chicago, IL. Abstract LBA1000.
5. McCrear S. Social disparities increase breast cancer mortality for Black women. AJMC^®. July 27, 2025. Accessed June 25, 2026. https://www.ajmc.com/view/social-disparities-increase-breast-cancer-mortality-for-black-women