Why Is Infectious Disease-Focused AN2 Therapeutics Stock Sinking Today?

AN2 Therapeutics Inc ANTX has voluntarily paused Phase 3 enrollment in the Phase 2/3 trial (EBO-301) evaluating epetraborole in treatment-refractory Mycobacterium Avium Complex (MAC) lung disease, pending further data review. 

The double-blind, placebo-controlled trial has two arms comparing epetraborole plus optimized background regimen (OBR) versus placebo plus OBR. 

The voluntary pause was instituted following a blinded aggregate analysis of the ongoing Phase 2 study, including pooled patients from both treatment arms, which showed potentially lower-than-expected efficacy. The decision was not due to safety concerns. 

The Phase 2 part of the trial is intended to inform the Phase 3 part. The company continues to expect to announce topline data from the Phase 2 part of the trial in the summer of 2024.

The company’s decision to pause enrollment enables time to further evaluate study data and for the independent Data Safety Monitoring Board (DSMB) to conduct an unblinded assessment and recommend next steps, which could include changes to the Phase 3 part of the study protocol. 

The Phase 2 part of the trial completed enrollment in September 2023 with 80 patients. 

The Phase 3 part has enrolled nearly 100 patients. Patients already enrolled in the Phase 2/3 trial will be allowed to continue.

The company’s cash and investments of $150.2 million on September 30, 2023, are anticipated to fund operations through summer 2025.

Price Action: ANTX shares are down 72.6% at $5.48 during the premarket session on the last check Monday.

Photo via Darko Stojanovic from Pixabay