FDA Approves Vepdegestrant for ESR1-Mutated, ER-Positive, HER2-Negative Advanced Breast Cancer

On May 1, 2026, the FDA approved vepdegestrant (Veppanu; Arvinas Operations Inc) for adults with estrogen receptor (ER)–positive, human epidermal growth factor receptor 2 (HER2)–negative, ESR1-mutated advanced or metastatic breast cancer whose disease has progressed following at least 1 prior line of endocrine therapy.¹ The agent is the first heterobifunctional protein degrader, commonly referred to as a PROTAC (proteolysis-targeting chimera), to receive FDA approval in breast cancer.²

The approval is restricted to patients with confirmed ESR1 mutations, which are associated with resistance to standard endocrine agents. Concurrent with the drug approval, the FDA authorized Guardant360 CDx as a companion diagnostic to identify eligible patients via testing.

Trial Design and Efficacy

Approval was supported by data from VERITAC-2 (NCT05654623), a randomized, open-label, active-controlled, multicenter phase 3 trial enrolling 624 adults with ER-positive, HER2-negative advanced or metastatic breast cancer, of whom 270 harbored ESR1-mutated tumors. Enrollment required prior progression on 1 to 2 lines of endocrine therapy, including at least 1 CDK4/6 inhibitor–based regimen. Patients were randomized 1:1 to receive oral vepdegestrant once daily or intramuscular fulvestrant per standard dosing, with stratification by ESR1 mutation status and presence of visceral metastases.

The coprimary endpoint was progression-free survival (PFS) by blinded independent central review in both the ESR1-mutant population and the overall intent-to-treat population. In the biomarker-defined ESR1-mutant cohort, vepdegestrant demonstrated a statistically significant and clinically meaningful improvement in PFS, with a median of 5.0 months (95% CI, 3.7-7.4) vs 2.1 months (95% CI, 1.9-3.5) in the fulvestrant arm (HR, 0.57; 95% CI, 0.42-0.77; P = .0001). Objective response rate (ORR) also favored vepdegestrant at 19% (95% CI, 12%-27%) compared with 4% (95% CI, 1.6%-1.0%) for fulvestrant. Overall survival data remain immature, with only 16% of events recorded at the time of the PFS analysis.

Vepdegestrant's approval carries broader significance beyond its indication, as it marks the first time the FDA has approved any PROTAC therapy, which is a novel drug class that works by harnessing the body's natural protein disposal system to selectively tag and eliminate disease-causing proteins, rather than simply inhibiting them.² This mechanistic distinction may be particularly relevant in ESR1-mutated disease, where the ESR1 mutation drives endocrine resistance by altering the estrogen receptor in ways that reduce the effectiveness of traditional inhibitors. By degrading the receptor entirely rather than blocking it, vepdegestrant targets a key biological driver of resistance to existing endocrine therapies. Developed through a collaboration between Arvinas and Pfizer with roots in pioneering research at Yale University, the approval may also signal growing regulatory and clinical confidence in protein degradation.

Randy Teel, PhD, president and CEO at Arvinas said, in a statement, “This milestone demonstrates that targeted protein degradation can translate into meaningful clinical impact. It also strengthens our confidence in the breadth and versatility of our exciting clinical pipeline across oncology, neurodegenerative, and neuromuscular diseases.”²

Safety and Dosing

The recommended dose is 200 mg orally once daily with food, continued until disease progression or unacceptable toxicity. Key warnings in the prescribing information include QTc interval prolongation and embryo-fetal toxicity, both of which warrant appropriate monitoring and patient counseling.¹ The safety profile was consistent with prior studies, with adverse events largely low-grade in nature.²

Clinical and Policy Implications

For payers, health systems, and managed care stakeholders, this approval introduces a new oral option in a setting where treatment choices after CDK4/6 inhibitor progression remain limited. The companion diagnostic requirement will direct attention to the role of liquid biopsy–based biomarker testing in formulary and utilization management decisions. The FDA approved this application 1 month ahead of the agency's goal date, reflecting the use of the Assessment Aid to expedite review. Vepdegestrant’s entry into the market may prompt reassessment of current sequencing strategies in the ESR1-mutant population.

References

1. FDA approves vepdegestrant for ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer. FDA. May 1, 2026. Accessed May 4, 2026. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-vepdegestrant-er-positive-her2-negative-esr1-mutated-advanced-or-metastatic-breast
2. Arvinas announces FDA approval of VEPPANU (vepdegestrant) for the treatment of ESR1m, ER+/HER2- advanced breast cancer. News release. Arvinas Inc. May 1, 2026. Accessed May 4, 2026. https://ir.arvinas.com/news-releases/news-release-details/arvinas-announces-fda-approval-veppanu-vepdegestrant-treatment