A New Era in First-Line Metastatic TNBC: NCCN Guidelines Elevate Sacituzumab Govitecan to Category 1 Status

For over 2 decades, the landscape of first-line treatment for metastatic triple-negative breast cancer (mTNBC) remained stubbornly stagnant, characterized by limited options and poor patient outcomes. However, a series of landmark clinical trial results has recently culminated in a dramatic shift in the standard of care.^1,2

On February 27, 2026, the National Comprehensive Cancer Network (NCCN) updated its Clinical Practice Guidelines in Oncology, elevating sacituzumab govitecan (Trodelvy; Gilead Sciences, Inc) to a Category 1 preferred regimen for multiple frontline mTNBC indications.¹

This update represents the highest-level recommendation provided by the NCCN, signaling a fundamental change in how oncologists and multidisciplinary care teams approach this aggressive disease. The decision was driven by the success of 2 pivotal phase 3 trials—ASCENT-03 (NCT05382299) and ASCENT-04 (NCT05382286)—which demonstrated that sacituzumab govitecan could significantly outperform traditional chemotherapy in the first-line setting, regardless of a patient’s PD-L1 status.^1-3

The Evolution of the Guidelines

The NCCN’s move to designate Category 1 status was swift. In January 2026, the combination of sacituzumab govitecan and the PD-1 inhibitor pembrolizumab (Keytruda; Merck) was initially included as a Category 2A preferred option for patients with PD-L1–positive tumors. Following further review of the data, the NCCN upgraded this to Category 1 just 1 month later.¹

Simultaneously, sacituzumab govitecan monotherapy was established as a Category 1 preferred first-line treatment for patients with PD-L1–negative disease (combined positive score [CPS] < 10) who do not have germline BRCA1/2 mutations. This recognition validates the drug’s potential to serve as a “backbone” therapy in the treatment of mTNBC, a disease known for its high recurrence rates and limited survival, with a 5-year survival rate for metastatic patients sitting at 12%.¹

“This is a very exciting update,” said Jordan Hill, PharmD, BCOP, a clinical pharmacy specialist at West Virginia University Health, in an interview with Pharmacy Times. “It really dramatically shifts the treatment paradigm in the metastatic triple-negative space away from traditional chemotherapy to antibody-drug conjugates in the first-line setting.”

ASCENT-04: Redefining Care for PD-L1 Positive Patients

The recommendation for PD-L1–positive mTNBC (CPS > 10) is supported by the results of the ASCENT-04/KEYNOTE-D19 study. This global phase 3 trial randomly assigned 443 patients to receive either the combination of sacituzumab govitecan and pembrolizumab or the prior standard of care, pembrolizumab plus chemotherapy.³

The results, published in the New England Journal of Medicine, demonstrated that the combination reduced the risk of disease progression or death by 35%. Patients receiving the sacituzumab govitecan combination achieved a median progression-free survival (PFS) of 11.2 months, compared to 7.8 months for those on the chemotherapy-based regimen. Sara Tolaney, MD, MPH, chief of the Division of Breast Oncology at Dana-Farber Cancer Institute and principal investigator of ASCENT-04, described these findings as a “meaningful step forward” for a patient population that has long faced limited options.^3,4

“There was a very significant improvement in duration of response,” Hill said. “It is 5 to 7 months different in duration of response. Anecdotally, that is what you see in practice. The people who respond have very long responses.”

ASCENT-03: A Breakthrough for PD-L1–Negative Disease

For patients who are not candidates for immunotherapy, either because their tumors are PD-L1 negative or because they previously progressed on PD-1/PD-L1 inhibitors in a curative setting, the ASCENT-03 trial provided a new path forward. In this study, sacituzumab govitecan monotherapy was compared directly against physician’s choice of chemotherapy.²

ASCENT-03 met its primary end point with high statistical significance, showing a 38% reduced risk of disease progression or death for patients treated with the antibody-drug conjugate (ADC) compared to chemotherapy. The median PFS was 9.7 months for the sacituzumab govitecan arm vs 6.9 months for the chemotherapy arm. Notably, these benefits were consistent even among patients with a poorer prognosis, such as those whose cancer recurred less than a year after finishing curative treatment. Principal investigator Javier Cortés, MD, PhD, noted that this represents the first major treatment advance for this specific population in the 20 years since TNBC was first defined.^2,5

“Historically, this has not been a patient population with a lot of effective lines of therapy,” Hill said. “They are on their first-line treatment for over a year in those trials, and that is a dramatic shift from what we have seen previously.”

Understanding the Mechanism: The Trop-2 ADC

The efficacy of sacituzumab govitecan lies in its design as a first-in-class Trop-2–directed ADC. Trop-2 is a cell surface antigen expressed in more than 90% of breast cancers. The drug consists of a humanized monoclonal antibody that targets Trop-2, connected via a proprietary hydrolyzable linker to SN-38, a potent topoisomerase I inhibitor. This design allows the drug to deliver a high payload of chemotherapy directly to the tumor cells and the surrounding tumor microenvironment through a “bystander effect,” maximizing local impact while potentially reducing systemic toxicity compared to free chemotherapy.^1,4,5

Critical Implications for Pharmacists

The elevation of sacituzumab govitecan to a Category 1 frontline therapy has significant implications for oncology pharmacists, who play a vital role in patient safety, education, and adverse effect management.

Pharmacists must be vigilant regarding the drug’s boxed warnings for severe neutropenia and diarrhea. Data from the trials showed that neutropenia occurred in 64% of patients, with grade 3 or 4 neutropenia reaching 49%.^2,3 Pharmacists are essential in ensuring that patients receive appropriate primary prophylaxis with granulocyte colony-stimulating factor, especially those at increased risk for febrile neutropenia.^1,4,5

Managing diarrhea is equally critical. Diarrhea occurred in 64% of patients, with 11% experiencing grade 3 or 4 severity.^2,3 Pharmacists must educate patients to initiate loperamide at the first sign of loose stools and monitor for dehydration.

“At our institution, we use primary prophylactic granulocyte colony-stimulating factor in almost all sacituzumab govitecan patients, which makes a big difference in neutropenia rates,” Hill said. “I do find these toxicities easier to prevent and manage than peripheral neuropathy.”

Another unique responsibility for pharmacists involves the UGT1A1 allele. Patients homozygous for the UGT1A1*28 allele are at a significantly increased risk for severe neutropenia and anemia.⁴ In studies, grade 3 or 4 neutropenia was 58% in homozygous patients compared to 43% in those with the wild-type allele.^2,3 Pharmacists should also screen for UGT1A1 inhibitors or inducers, as these can alter systemic exposure to the active payload, SN-38.

Because sacituzumab govitecan is highly emetogenic, pharmacists must ensure patients are premedicated with a 2- or 3-drug combination (eg, dexamethasone with a 5-HT3 or NK1 receptor agonist).⁴ Furthermore, they must monitor for hypersensitivity and infusion-related reactions, which occurred in 35% of patients within 24 hours of dosing.⁴

A Transformative Shift in Clinical Practice

The integration of sacituzumab govitecan into the first-line setting marks an historic shift in oncology. With approximately 50% of patients with mTNBC historically failing to receive any treatment beyond the first line, the introduction of more efficacious frontline options is a matter of urgent clinical need.

“I honestly find this change in practice to be pretty meaningful for patients,” Hill said. “I think that pharmacists have an integral role in ensuring that the necessary biomarker testing is not only occurring but also occurring as quickly as possible.”

The NCCN’s Category 1 recommendation not only validates the clinical trial data but also provides a framework for insurance coverage and clinical pathways, ensuring broader patient access to these therapies. As Gilead continues to seek formal FDA and European Medicines Agency approval for these specific frontline indications, the oncology community is already preparing for a future in which ADCs serve as the foundation of TNBC care.

REFERENCES

1. Trodelvy added as preferred regimen within first-line metastatic triple-negative breast cancer in NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines). News release. Gilead. Updated February 27, 2026. Accessed April 14, 2026. https://www.gilead.com/company/company-statements/2026/trodelvy-added-as-preferred-regimen-within-first-line-metastatic-triple-negative-breast-cancer-in-nccn-clinical-practice-guidelines-in-oncology-nccn-guidelines

2. Cortés J, Punie K, Barrios C, et al. Sacituzumab govitecan in untreated, advanced triple-negative breast cancer. N Engl J Med. 2025;393:1912-1925. doi:10.1056/NEJMoa2511734

3. Tolaney SM, de Azambuja E, Kalinsky K, et al. Sacituzumab govitecan plus pembrolizumab for advanced triple-negative breast cancer. N Engl J Med. 2026;394:354-366. doi:10.1056/NEJMoa2508959

4. New England Journal of Medicine publishes phase 3 ASCENT-04/KEYNOTE-D19 results supporting Trodelvy plus Keytruda as a potential new standard of care in first-line PD-L1+ metastatic triple-negative breast cancer. News release. Gilead. January 21, 2026. Accessed April 14, 2026. https://www.gilead.com/news/news-details/2026/new-england-journal-of-medicine-publishes-phase-3-ascent-04keynote-d19-results-supporting-trodelvy-plus-keytruda-as-a-potential-new-standard-of-care-in-first-line-pd-l1-metastatic-triple-neg

5. Trodelvy reduces risk of disease progression or death by 38% versus chemotherapy as first-line therapy in patients with metastatic triple-negative breast cancer in ASCENT-03 study. News release. Gilead. October 19, 2025. Accessed April 14, 2026. https://www.gilead.com/news/news-details/2025/trodelvy-reduces-risk-of-disease-progression-or-death-by-38-versus-chemotherapy-as-first-line-therapy-in-patients-with-metastatic-triple-negative-breast-cancer-in-ascent-03-study