AN2 Therapeutics has implemented cost-saving measures after “disappointing” topline results from Phase II part of the Phase II/III trial evaluating its lead antibiotic, epetraborole.

The antibiotic’s development suffered a major setback a few months ago after AN2 voluntarily stopped enrolment in the Phase III portion of the trial. The decision followed a blinded aggregate data analysis indicating “potentially lower than expected efficacy”.

Following the news, AN2’s stock was down by over 22.7% in premarket trading today (9 August), compared to the market close on 8 August. The company’s stock has been floundering since it took a nosedive in February after AN2 announced plans to pause enrolment in the Phase III portion of the trial.

AN2 plans to cut 50% of its workforce by the end of the year. The restructuring is expected to cost approximately $2m – $3m. Furthermore, AN2’s chief medical officer, Dr Paul Eckburg, will leave the company by 30 August as part of the restructuring. The cost savings measures are expected to provide AN2 a cash runway through 2027.

With the announcement of job cuts, AN2 joins the likes of FibroGen, Aerovate Therapeutics and Allakos, all of which have reduced their headcounts after trial failures this year.

Epetraborole is a bacterial leucyl-tRNA synthetase inhibitor. AN2 licensed the therapy from Pfizer, who gained it as part of a $5.2bn acquisition of Anacor Pharmaceuticals. AN2 was evaluating epetraborole as a treatment for refractory mycobacterium avium complex (MAC) lung disease.

The placebo-controlled Phase II/III trial (NCT05327803) enrolled 80 patients with treatment refractory MAC lung disease. Although the Phase II portion met its primary endpoint of patient-reported response, there was no significant difference between the treatment and placebo arms in a “key” secondary endpoint of sputum culture conversion at six months.

Whilst AN2 has shut down the development of epetraborole in MAC lung disease, it plans to start a Phase II trial evaluating the therapy in melioidosis, a bacterial infection. Another therapy in AN2’s pipeline is AN2-502998 for the treatment of Chagas disease, an infectious illness caused by a parasite transmitted by ticks.