Arvinas, Pfizer's ARV-471 Shows Clinical Benefit Rate Of 40% In Pretreated Breast Cancer Patients

Arvinas Inc ARVN and Pfizer Inc PFE posted updated data from Phase 1 dose-escalation trial of ARV-471 for locally advanced or metastatic ER-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer (ER+/HER2-).
ARV-471 demonstrated antitumor activity in CDK4/6 inhibitor-pretreated patients with a clinical benefit rate (CBR) of 40% in 47 evaluable patients.
The heavily pretreated patient group had a median of four prior therapies.
Three patients exhibited confirmed partial responses (PR) among the 38 patients with response evaluation criteria in solid tumors (RECIST) measurable lesions and at least one on-treatment tumor assessment.
ARV-471 continues to demonstrate a favorable tolerability profile. Robust ER degradation was observed at all dose levels, reaching an 89% reduction of ER.
ARV-471 is expected to enter two Phase 3 registrational clinical trials in 2022.
Related Link: Arvinas, Pfizer Announce $2.4B Licensing Agreement For Protein-Degrader Based Breast Cancer Therapy.
Price Action: ARVN shares are down 3.24% at $69.80, PFE stock is down 0.20% at $51.98 during the market session on the last check Friday.