AN2 Therapeutics Updates on EBO-301 Phase 2/3 Study of Epetraborole for Treatment-Refractory MAC Lung Disease

AN2 Therapeutics, Inc. (Nasdaq: ANTX), a biopharmaceutical company based in Menlo Park, California, has announced the topline results from the Phase 2 portion of their EBO-301 Phase 2/3 study. This study was aimed at evaluating the efficacy of epetraborole in combination with an optimized background regimen (OBR) for patients suffering from treatment-refractory Mycobacterium avium complex (MAC) lung disease.

The Phase 2 part of the study successfully met its primary goal, which was to demonstrate the potential validation of a novel patient-reported outcome (PRO) tool. Additionally, the epetraborole + OBR treatment group showed a higher PRO-based clinical response rate of 39.5% compared to 25.0% in the placebo + OBR group. However, the difference in treatment efficacy, though notable, was not statistically significant (p=0.19). Importantly, sputum culture conversion at Month 6, a critical secondary endpoint, showed minimal difference between the two groups (13.2% for the epetraborole + OBR group versus 10.0% for the placebo + OBR group, with a treatment difference of 3.4%, p=0.64).

Earlier this year, AN2 voluntarily paused the enrollment of new patients in the Phase 3 segment of the trial due to lower-than-anticipated efficacy observed in a blinded interim analysis. Following the recent topline data, the company has decided to terminate both the Phase 2 (which included 80 patients) and Phase 3 parts of the study (which had enrolled 97 patients before the pause). Notably, the decision to terminate the study was not due to safety concerns, as oral epetraborole 500 mg was generally well-tolerated.

Eric Easom, the Co-founder, Chairman, President, and CEO of AN2 Therapeutics, expressed disappointment with the results, emphasizing the high unmet need for new treatments in refractory MAC lung disease. Easom extended gratitude to the patients, investigators, study site staff, and AN2 employees involved in the study.

In light of these results, the company plans to further assess the outcomes of the EBO-301 study to guide future development decisions regarding epetraborole for Non-Tuberculous Mycobacteria (NTM) lung disease in other patient groups. In the short term, AN2 intends to accelerate research and development efforts centered on their boron chemistry platform. The company aims to restructure strategically and extend its cash runway through 2027, focusing resources on advancing its pipeline through various milestones.

AN2 Therapeutics is leveraging boron chemistry as a core element of its research and development strategy. Boron’s unique capability to form reversible covalent bonds with biological targets offers the potential to address targets that are challenging to inhibit using traditional carbon-based molecules.

Among its pipeline programs, the company plans to initiate Phase 1 clinical development for a product candidate intended to treat chronic Chagas disease, which affects an estimated 6-7 million individuals globally, including around 300,000 in the U.S. Additionally, AN2 aims to start a Phase 2 study of epetraborole for melioidosis, a severe bacterial infection and bioterrorism threat, with the objective of reducing the approximately 50% three-month mortality rate.

AN2 is also pursuing various early-stage research programs targeting infectious diseases and oncology, driven by high unmet needs. The company anticipates identifying multiple development compounds within its extended cash runway. Efforts to address global health issues, such as tuberculosis and malaria, will continue through non-dilutive funding, including support from the Gates Foundation.

AN2 Therapeutics remains committed to developing innovative treatments and advancing its boron-based drug discovery platform to address significant healthcare challenges.