Pfizer/Arvinas’ vepdegestrant shows promise in phase 3 breast cancer study
Pfizer and Arvinas have shared promising top-line results from a late-stage study of their investigational protein degrader vepdegestrant in a subset of breast cancer patients. The phase 3 VERITAC-2 trial has been evaluating the candidate against AstraZeneca’s endocrine therapy Faslodex (fulvestrant) in adults with oestrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer.
Patients enrolled to the trial had also experienced disease progression following prior treatment with cyclin-dependent kinase 4/6 inhibitors and endocrine therapy.
VERITAC-2 met its primary endpoint in the cohort of patients with oestrogen receptor 1 (ESR1) mutations, a common cause of acquired resistance, with vepdegestrant demonstrating a statistically significant and clinically meaningful improvement in progression-free survival (PFS) compared to Faslodex. Statistical significance in PFS improvement was not reached in the intent-to-treat population.
Megan O’Meara, interim chief development officer at Pfizer Oncology, said: “Patients with advanced ER-positive/HER2-negative metastatic breast cancer face significant clinical challenges, with limited treatment options following disease progression and the development of resistance to available endocrine therapies. This data from VERITAC-2 supports the potential of vepdegestrant to give patients whose tumours harbour ESR1 mutations additional time without disease progression, compared to Faslodex”
It is estimated that nearly 320,000 people will be diagnosed with breast cancer in the US this year, with ER-positive/HER2-negative disease accounting for approximately 70% of all cases.
Taken orally, vepdegestrant is designed to harness the body’s natural protein disposal system to specifically target and degrade the ER. The drug has already been granted fast track designation by the US Food and Drug Administration, and data from VERITAC-2 will now be shared with global regulatory authorities to potentially support regulatory filings.
John Houston, chairperson, chief executive officer and president at Arvinas, said: “The first phase 3 data readout for a PROTAC degrader represents a significant achievement and this data shows that vepdegestrant has the potential to provide clinically meaningful outcomes for thousands of patients with metastatic breast cancer whose tumours harbour ESR1 mutations.”
