FDA Fast Tracks ARV-471 for Metastatic Breast Cancer

The Food and Drug Administration (FDA) granted a Fast Track designation to ARV-471 (vepdegestrant) for the treatment of adults with estrogen receptor (ER)-positive, HER2-negative locally advanced or metastatic breast cancer that was previously treated with endocrine therapy, according to Pfizer, the pharmaceutical company that is co-manufacturing the drug with Arvinas.

The FDA grants Fast Track designations to speed up the review and potential approval of therapies that show promise in treating serious conditions and fill an unmet need.

“The receipt of Fast Track designation reinforces the potential of (ARV-471) to provide an important new therapeutic option for people with ER-positive/HER2-negative breast cancer whose disease has progressed,” Dr. Roger Dansey, chief development officer, Oncology, Pfizer, said in a company-issued press release.

ARV-471 is currently being studied in the ongoing phase 3 VERITAC-2 clinical trial, which is comparing treatment with ARV-471 to Faslodex (fulvestrant) in patients with ER-positive, HER2-negative advanced breast cancer that progressed on a prior endocrine-based therapy.

According to the study’s listing on ClinicalTrials.gov, the global trial is recruiting patients who have been or will be randomly assigned to one of two groups. The first group will receive ARV-471 orally, once a day for 28 days, while the second group will receive injections of Faslodex on days 1 and 15 of cycle 1 and then day 1 of each cycle after for a 28-day cycle.

The main goal of the trial is to determine which group has a better mean progression-free survival (PFS; time from randomization until disease worsening or death). The researchers also plan on analyzing other metrics, including overall survival (OS; time from randomization to death of any cause), objective response rate (ORR; percentage of patients whose disease shrinks or disappears from treatment), duration of response, side effects, disease- and treatment-related quality of life and pain scores.

Preclinical studies — meaning those that have not been conducted in humans — showed that ARV-471 led to a 97% degradation in tumor cells, referring to the breakdown and induced misfunction of the cells. Additionally, the novel drug induced robust tumor shrinkage when used as a single agent in multiple ER-positive models and it also showed improved anti-tumor activity compared to Faslodex, which is the current standard of care for this patient population, both as a single agent and when combined with a CDK4/6 inhibitor, according to the press release.

ARV-471 is also being investigated in combination with Verzenio (abemaciclib), Kisqali (ribociclib), samuraciclib, Afinitor (everolimus) and the investigational CDK4 inhibitor, PF-07220060.

"We are focused on the persisting unmet needs of people with ER-positive/HER2-negative breast cancer and doing all that we can to expedite the development of (ARV-471) as a novel, oral ER-targeted potential therapy for this patient community,” said John Houston, Arvinas chairperson, chief executive officer and president. “We are pleased the FDA has granted Fast Track designation for (ARV-471), and we continue to believe this investigational drug has the potential to harness the body’s own natural protein disposal system to selectively and efficiently degrade and remove disease-causing proteins."

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