Arvinas-Pfizer Partner Cancer Drug Trial Shows 63% Clinical Benefit In Breast Cancer Patients - Arvinas (

On Tuesday, Arvinas Inc. (NASDAQ:ARVN) and Pfizer Inc. (NYSE:PFE) announced preliminary data from the ongoing Phase 1b portion of the TACTIVE-U sub-study of vepdegestrant in combination with abemaciclib for locally advanced or metastatic estrogen receptor-positive/human epidermal growth factor receptor 2 negative breast cancer.

These data will be presented at the 2024 San Antonio Breast Cancer Symposium.

Preliminary results from 16 patients in the Phase 1b sub-study demonstrated a tolerable safety profile for the combination of abemaciclib 150 mg twice daily (BID) with the recommended Phase 3 monotherapy dose of vepdegestrant (200mg once daily; QD).

An encouraging clinical benefit rate of 62.5% was observed among patients with both mutant ESR1 and wild-type ESR1 disease who had all been previously treated with a CDK4/6 inhibitor.

Pharmacokinetic data demonstrated no significant drug-drug interaction between vepdegestrant and abemaciclib, and no clinically meaningful effect on abemaciclib exposure was observed.

In addition to tolerability, the results demonstrated a safety profile consistent with the known properties of abemaciclib and observed data in other clinical trials for vepdegestrant.

These findings support the ongoing Phase 2 portion of the study, which is evaluating full dose abemaciclib (150mg BID) in combination with vepdegestrant (200 mg QD) in post-CDK4/6 advanced breast cancer.

Additional details on the TACTIVE-U poster presentation at SABCS are below:

Key findings included:

There was no significant drug-drug interaction, and data reflected vepdegestrant has no clinically meaningful effect on abemaciclib exposure.
Encouraging preliminary antitumor activity is observed with a clinical benefit rate of 62.5% in all CBR-eligible patients (10/16), 62.5% in patients with mutant ESR1 (5/8), and 62.5% in patients with wild-type ESR1 (5/8).
The objective response rate (ORR) in evaluable patients was 26.7% overall (4/15), 37.5% in patients with mutant ESR1 (3/8), and 14% in patients with wild-type ESR1 (1/7).

Arvinas and Pfizer continue to evaluate data from the ongoing TACTIVE-U clinical trial, including combinations of vepdegestrant plus abemaciclib, ribociclib, or samuraciclib.

Price Action: At the last check on Tuesday, PFE stock was down 1.70% at $25.66, and ARVN stock was down 1.30% at $24.76.

Read Next:

What’s Going On With Eli Lilly Stock On Tuesday?

Photo by Aunt Spray via Shutterstock

Market News and Data brought to you by Benzinga APIs

To add Benzinga News as your preferred source on Google, click here.