Arvinas, Pfizer: Positive topline from phase 3 VERITAC-2 trial

Arvinas, Pfizer: Positive topline from phase 3 VERITAC-2 trial

The pharmaceutical industry witnessed a significant milestone with the recent announcement of positive topline results from the Phase 3 VERITAC-2 clinical trial by Arvinas, Inc. (Nasdaq: ARVN) and Pfizer Inc. (NYSE: PFE) [1]. This trial evaluated vepdegestrant, an oral PROteolysis TArgeting Chimera (PROTAC) ER degrader, in adults with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-) advanced or metastatic breast cancer whose disease progressed following prior treatment with cyclin-dependent kinase (CDK) 4/6 inhibitors and endocrine therapy.

The trial, which is the first of its kind to report Phase 3 data for a PROTAC degrader, achieved its primary endpoint in the estrogen receptor 1-mutant (ESR1m) population. This population represents a significant patient subset, as mutations in the ESR1 gene are known to contribute to treatment resistance and poor prognosis in ER+ breast cancer [2]. The results demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (PFS) compared to fulvestrant, exceeding the pre-specified target hazard ratio of 0.60 [1].

Although the trial did not reach statistical significance in improvement in PFS in the intent-to-treat (ITT) population, these findings are still noteworthy. The results for the ESR1m population are particularly encouraging, as this patient subset is known to have limited treatment options. Furthermore, the overall survival data were not mature at the time of analysis, with less than a quarter of the required number of events having occurred. The trial will continue to assess overall survival as a key secondary endpoint.

Vepdegestrant was generally well tolerated, and its safety profile was consistent with what has been observed in previous studies [1]. These results are a testament to the potential of PROTAC degraders as a novel therapeutic approach for treating various diseases, including cancer.

The success of this collaboration between Arvinas and Pfizer represents a significant achievement in the field of oncology. These data will be shared with health authorities and at a medical conference in 2025. With the potential to provide clinically meaningful outcomes for thousands of patients with metastatic breast cancer whose tumors harbor ESR1 mutations, vepdegestrant has the potential to become a valuable addition to the oncology treatment landscape.

References:
[1] Arvinas, Inc. and Pfizer, Inc. (2025, March 11). Arvinas and Pfizer Announce Positive Topline Results from Phase 3 VERITAC-2 Clinical Trial. Retrieved from https://www.globenewswire.com/news-release/2025/03/11/3040386/0/en/Arvinas-and-Pfizer-Announce-Positive-Topline-Results-from-Phase-3-VERITAC-2-Clinical-Trial.html
[2] American Cancer Society. (2021). Estrogen Receptor-Positive (ER+) Breast Cancer. Retrieved from https://www.cancer.org/cancer/breast-cancer/understanding-breast-cancer/estrogen-receptor-positive-breast-cancer.html