Pfizer (Pfizer (PFE)) and its partner Arvinas (Arvinas (ARVN)) got some good news on Monday: the FDA approved their breast cancer drug VEPPANU (vepdegestrant) ahead of schedule. Shares of both companies edged up on the news.
The approval covers a specific group of patients: those with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-), advanced or metastatic breast cancer that has an ESR1 mutation. The drug is for patients whose disease has progressed after at least one line of endocrine therapy.
VEPPANU is a first-of-its-kind PROTAC therapy. PROTACs are a relatively new class of drugs that work by hijacking the cell's protein disposal system to degrade disease-causing proteins. In this case, it targets the estrogen receptor. The drug was discovered by Arvinas and developed jointly with Pfizer.
The approval came before the FDA's assigned PDUFA date of June 5, 2026, which is always a nice surprise. It's a big deal for Pfizer as it continues to build out its oncology pipeline.
Phase 3 Data Shows Real Improvement
The FDA's decision was based on data from the VERITAC-2 Phase 3 trial, which compared vepdegestrant to fulvestrant, a standard endocrine therapy. In patients with an ESR1 mutation, vepdegestrant showed a statistically significant and clinically meaningful improvement in progression-free survival (PFS). It reduced the risk of disease progression or death by 43% compared to fulvestrant.
Median PFS was 5 months in the vepdegestrant group versus 2.1 months in the fulvestrant group. That's more than double. Overall survival data wasn't mature yet — only 16% of patients in this group had died at the time of the analysis — so we'll have to wait for longer-term results.
Companion Diagnostic Gets the Green Light Too
On the same day, the FDA also approved Guardant Health's (Guardant Health (GH)) Guardant360 CDx liquid biopsy test as a companion diagnostic for VEPPANU. That means doctors can use a simple blood test to identify patients with ESR1 mutations who might benefit from the drug, rather than needing a tissue biopsy.
Price Action: Arvinas shares were up 1.62% at $10.10, and Pfizer shares were up 0.32% at $26.41 at the time of publication on Monday.
