AN2 Therapeutics has announced a voluntary halt of subject enrolment in the Phase III segment of a Phase II/III (EBO-301) clinical trial of epetraborole for treatment-refractory Mycobacterium avium complex (MAC) lung disease.
This decision follows a preliminary review of Phase II data, which indicated potential efficacy concerns.
The company expects to release top-line data from the ongoing Phase II stage later this year.
The superiority, double-blind, placebo-controlled study uses an adaptive design to assess the efficacy and safety of epetraborole.
It is designed to analyse epetraborole and an optimised background regimen (OBR) compared to a placebo plus OBR in patients with treatment-refractory MAC lung disease.
The Phase II portion, which completed enrolment with 80 subjects in September 2023, is designed to inform the subsequent Phase III segment.
The voluntary pause was initiated after a blinded aggregate assessment of the Phase II trial, including pooled participants from both treatment groups, suggested potentially lower than expected efficacy.
AN2 Therapeutics clarified that the pause was not prompted by any safety concerns.
Nearly 100 patients were enrolled in the Phase III section of the trial, surpassing initial enrolment projections. Patients currently participating in the trial will be permitted to continue, the company added.
In addition, the pause will allow for a more thorough evaluation of the study data. An independent Data Safety Monitoring Board (DSMB) will conduct an unblinded assessment and advise on potential modifications to the Phase III study protocol.
AN2 Therapeutics co-founder, president and CEO Eric Easom said: “Developing new therapies for patients suffering with treatment-refractory MAC lung disease, a disease with limited treatment options and low response rates to existing therapies, is a complex undertaking.
“In light of recently available blinded aggregate data, we believe our voluntary decision to pause enrolment in the Phase III part of the study will provide us the opportunity to further evaluate study data, and determine the best path forward.
“We plan to provide further details regarding the epetraborole Phase II/III clinical trial in the second quarter of 2024 following completion of our analysis.”
