Press Release

February 10, 2022

AN2 Therapeutics Reports Phase 1b Data for Oral Epetraborole

– Epetraborole was well tolerated with a predictable PK profile that supports continued development of oral, once-daily dosing

– Dosage selected for pivotal Phase 2/3 study to start in first half of 2022

Menlo Park, CA – February 10, 2022 – AN2 Therapeutics, Inc., a clinical-stage biopharmaceutical company focused on developing treatments for rare, chronic, and serious infectious diseases with high unmet needs, today announced topline results from its Phase 1b dose-ranging study of oral epetraborole. AN2 Therapeutics is developing epetraborole as a once-daily, orally administered treatment for patients with non-tuberculous mycobacterial (NTM) lung disease, with an initial focus on treatment-refractory Mycobacterium avium complex (MAC) lung disease. 

The Phase 1b double-blind, placebo-controlled, dose-ranging study was designed to evaluate the safety, tolerability, and pharmacokinetics (PK) of oral epetraborole administered to healthy volunteers at doses ranging from 250 mg to 1,000 mg for 28 days. Results showed that epetraborole was generally well tolerated, with no severe or serious adverse events. PK was shown to be generally linear and predictable, consistent with previous studies.  
“We believe the Phase 1b results further validate data from previous studies with epetraborole and demonstrate that it is well tolerated when dosed for 28 days,” said Paul Eckburg, M.D., Chief Medical Officer of AN2 Therapeutics. “These results, coupled with data available from our non-clinical efficacy and chronic toxicology studies completed earlier this year, provide us with additional confidence in dose selection for our pivotal Phase 2/3 trial, which we plan to initiate in the first half of this year in patients with treatment-refractory MAC lung disease.”  

“Epetraborole has the potential to meet many of the characteristics of an ideal target product profile. It has demonstrated high levels of efficacy in animal models of NTM infection, it works via a novel mechanism of action, and is well tolerated with a once-daily oral treatment for patients with NTM lung disease. There is only one approved therapy in the United States for patients with pulmonary NTM, and patients and physicians need better options,” said Eric Easom, President and Chief Executive Officer of AN2 Therapeutics. “Novel oral antibiotics are urgently needed that have the potential to improve therapeutic efficacy, safety and tolerability for this underserved patient population.”

For more information on the epetraborole Phase 1b study design, visit and search NCT04892641.

About Epetraborole

Epetraborole is a novel, once-daily, orally administered investigational treatment for patients with chronic NTM lung disease. The U.S. Food and Drug Administration has granted Qualified Infectious Disease Product (QIDP) and Fast Track designations for epetraborole in treatment-refractory MAC lung disease.

About AN2 Therapeutics, Inc.

AN2 Therapeutics, Inc. is a clinical-stage biopharmaceutical company developing treatments for rare, chronic, and serious infectious diseases with high unmet needs. AN2 is developing epetraborole, a novel, once-daily oral treatment for patients with NTM lung disease, a rare, chronic and progressive infectious disease caused by bacteria known as mycobacteria that leads to irreversible lung damage and can be fatal. For more information, visit

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