January 21, 2026--FOSTER CITY, Calif.--(BUSINESS WIRE)-- Gilead Sciences, Inc. (Nasdaq: GILD) today announced The New England Journal of Medicine (NEJM) published the full results from the positive Phase 3 ASCENT-04/KEYNOTE-D19 study evaluating the combination of Trodelvy® (sacituzumab govitecan-hziy) plus Keytruda® (pembrolizumab) in first-line PD-L1+ (CPS ≥10) metastatic triple-negative breast cancer (TNBC). ASCENT-04 successfully met its primary endpoint of progression-free survival (PFS) with a 35% (HR: 0.65; p<0.001) reduced risk of disease progression or death for Trodelvy plus Keytruda (n=221) versus standard of care Keytruda plus chemotherapy (n=222). Median PFS with Trodelvy plus Keytruda was 11.2 months versus 7.8 months when Keytruda was given in combination with chemotherapy.
“Metastatic TNBC patients often show rapid progression and poor outcomes after current first-line therapies, illustrating the urgent need for new and more efficacious treatment options,” said Dietmar Berger, MD, PhD, Chief Medical Officer, Gilead Sciences. “These results represent important progress toward our goal of delivering Trodelvy to patients in earlier lines of breast cancer treatment, with potential to become a backbone therapy for all frontline metastatic TNBC patients in need of innovative therapeutics.”
“Patients with PD-L1+ metastatic triple-negative breast cancer continue to face limited options in the first-line setting,” said Sara Tolaney, MD, MPH, Chief of the Division of Breast Oncology at Dana-Farber Cancer Institute and Principal Investigator of the ASCENT-04 study. “As such, these very promising data with the novel combination of sacituzumab govitecan and pembrolizumab in frontline metastatic TNBC represent a meaningful step forward in establishing a potential new standard of care for this challenging disease.”
The NEJM publication of the ASCENT-04 results follow a data presentation at the 2025 ASCO Annual Congress, as well a simultaneous presentation at the 2025 European Society for Medical Oncology Congress and publication in NEJM of primary results from the ASCENT-03 trial of Trodelvy monotherapy in patients with first-line metastatic TNBC who are not candidates for PD-1/PD-L1 inhibitors. Gilead has submitted supplemental applications for both indications to the U.S. Food and Drug Administration and European Medicines Agency.
The safety profile of Trodelvy plus Keytruda in ASCENT-04 was consistent with the known safety profile of each agent. No new safety signals were identified with the combination, and the combination did not exacerbate the safety profile of either therapy. The most frequent (≥10% of patients) grade ≥3 treatment-emergent adverse events with Trodelvy plus Keytruda were neutropenia (43%) and diarrhea (10%), and with Keytruda plus chemotherapy were neutropenia (45%), anemia (16%) and thrombocytopenia (14%). Fewer patients discontinued treatment due to adverse events on the Trodelvy plus Keytruda arm than with Keytruda plus chemotherapy (12% vs. 31%).
Healthcare professionals have well-established experience with Trodelvy, with more than 60,000 breast cancer patients treated across 50+ countries over the past five years. It remains the only Trop-2-directed antibody-drug conjugate (ADC) to demonstrate meaningful survival benefits in both 2L+ metastatic TNBC and pre-treated HR+/HER2- metastatic breast cancer. With ASCENT, TROPiCS-02, ASCENT-03 and ASCENT-04, Trodelvy is also the only ADC with four positive Phase 3 trials in HER2- mBC (IHC 0, IHC 1+, or IHC 2+/ISH–).
The use of Trodelvy plus Keytruda in patients with first-line PD-L1+ metastatic TNBC and Trodelvy as monotherapy in patients with first-line metastatic TNBC who are not candidates for PD-1/PD-L1 inhibitors are investigational, and the safety and efficacy of these uses have not been established.
KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC., a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.
About Triple-Negative Breast Cancer with PD-L1+ Tumors
TNBC is the most aggressive type of breast cancer and has historically been difficult to treat, accounting for approximately 15% of all breast cancers. TNBC disproportionally impacts younger, premenopausal, and Black and Hispanic women. TNBC cells do not have estrogen and progesterone receptors and have limited HER2 expression. Due to the nature of TNBC, treatment options are extremely limited compared with other breast cancer types. TNBC has a higher chance of recurrence and metastases than other breast cancer types. The average time to metastatic recurrence for TNBC is approximately 2.6 years compared with 5 years for other breast cancers, and the relative five-year survival rate is much lower. Among women with metastatic TNBC, the five-year survival rate is 12%, compared with 28% for those with other types of mBC.
Despite progress in treatment, first-line metastatic TNBC has seen limited new approvals in recent years for tumors that express PD-L1+, and additional options are urgently needed. Despite recent advances, over 50% of patients do not receive treatment beyond first-line, reinforcing the urgent need for new options to help improve patient outcomes. Breast cancers expressing PD-L1 are overall more aggressive and associated with reduced survival time.
About the ASCENT-04/KEYNOTE-D19 Study
In 2021, Gilead entered a collaboration with Merck & Co. to investigate Trodelvy in combination with Keytruda in the Phase 3 trial, ASCENT-04/KEYNOTE-D19. The ASCENT-04/KEYNOTE-D19 study is a global, open-label, randomized Phase 3 trial evaluating the efficacy and safety of Trodelvy in combination with Keytruda compared with treatment of chemotherapy plus Keytruda in patients with previously untreated, inoperable locally advanced or metastatic triple-negative breast cancer (TNBC) whose tumors express PD-L1. The study enrolled 443 patients across multiple study sites.
Patients were randomized in a 1:1 ratio to receive either Trodelvy (10 mg/kg intravenously on Days 1 and 8 of a 21-day cycle) plus Keytruda (200 mg intravenously on Day 1 of a 21-day cycle) or chemotherapy plus Keytruda. The chemotherapy regimen included gemcitabine plus carboplatin, paclitaxel, or nab-paclitaxel. Treatment continued until blinded independent central review (BICR)-verified disease progression or unacceptable toxicity. Patients randomized to chemotherapy were allowed to cross over and receive Trodelvy upon disease progression as part of the study.
The primary endpoint of the study is progression-free survival (PFS) as determined by BICR using RECIST v1.1. Secondary endpoints include overall survival (OS), objective response rate (ORR), duration of response (DOR), time to onset of response (TTR), patient-reported outcomes (PROs) and safety.
More information about ASCENT-04/KEYNOTE-D19 is available at ClinicalTrials.gov: NCT05382286.
About Trodelvy
Trodelvy (sacituzumab govitecan-hziy) is a first-in-class Trop-2-directed antibody-drug conjugate. Trop-2 is a cell surface antigen highly expressed in multiple tumor types, including in more than 90% of breast and lung cancers. Trodelvy is intentionally designed with a proprietary hydrolyzable linker attached to SN-38, a topoisomerase I inhibitor payload. This unique combination delivers potent activity to both Trop-2 expressing cells and the tumor microenvironment through a bystander effect.
Trodelvy is currently approved in more than 50 countries for second-line or later metastatic triple-negative breast cancer (TNBC) and in more than 40 countries for certain patients with pre-treated HR+/HER2- metastatic breast cancer (mBC).
Trodelvy is currently being evaluated in multiple ongoing Phase 3 trials across a range of tumor types with high Trop-2 expression. These studies with Trodelvy, both in monotherapy and in combination with pembrolizumab, involve earlier lines of treatment for TNBC and HR+/HER2- breast cancer—including in curative settings—as well as in lung and gynecologic cancers, where previous proof-of-concept studies have demonstrated clinical activity.
About Gilead and Kite Oncology
Gilead and Kite Oncology are working to transform how cancer is treated. We are innovating with next-generation therapies, combinations and technologies to deliver improved outcomes for people with cancer. We are purposefully building our oncology portfolio and pipeline to address the greatest gaps in care. From antibody-drug conjugate technologies and small molecules to cell therapy-based approaches, we are creating new possibilities for people with cancer.
About Gilead Sciences
Gilead Sciences, Inc. is a biopharmaceutical company that has pursued and achieved breakthroughs in medicine for more than three decades, with the goal of creating a healthier world for all people. The company is committed to advancing innovative medicines to prevent and treat life-threatening diseases, including HIV, viral hepatitis, COVID-19, cancer and inflammation. In 2025, Gilead announced a planned $32 billion investment to further strengthen its U.S. footprint to power the next era of discovery, job creation and public health preparedness – while continuing to invest globally to ensure patients everywhere benefit from its scientific innovation. Gilead operates in more than 35 countries worldwide, with headquarters in Foster City, Calif.