AN2 Therapeutics shares fall after pausing lung disease study enrollment

(Reuters) -AN2 Therapeutics said on Monday it will pause further enrollment in a late-stage study testing its experimental lead drug due to potentially lower-than-expected efficacy, sending shares down 65% premarket.

It said the pause was not due to any safety concerns but because of an analysis testing its drug at the mid stage of the study.

The company was testing epetraborole, a once-daily oral drug, to potentially treat MAC lung disease which is caused by a group of bacteria called mycobacterium avium complex.

More than 86,000 Americans are affected by infectious diseases caused by these bacteria, according to Cleveland Clinic. MAC lung disease is the most common, making up nearly 80% of the infections.

AN2 has so far enrolled nearly 100 patients for the study. It had previously planned to enroll about 234 patients.

Patients already enrolled for the study during September will be allowed to continue, the company said.

AN2 said the decision to pause enrollment will give it time to further evaluate the data. It expects to provide further details on the study in the second quarter of the year.

The drug developer said an independent group of experts will conduct an assessment and recommend the next steps, which could include changes to the study's protocol.

(Reporting by Mariam Sunny And Sneha S K in Bengaluru; Editing by Krishna Chandra Eluri)