Recent Updates
Recently added Catalysts

Epetraborole

Phase 2

Mycobacterium Abscessus Infection | Small molecule | Infectious Disease |AN2 Therapeutics, Inc.|Last Updated: May 6, 2026

Target and mechanism

Molecular targetLeuRS
ModalitySmall molecule

Success Probability

Subscribe to view

Market & Valuation

Subscribe to view

Trial Design

RandomizedDouble-BlindPLACEBO_CONTROLLEDDMC
Total Trials1
Total Enrollment84

FDA Designations

No designations recorded

Clinical trial landscape

Epetraborole · 3 trials · 3 indications

Phase 2 1Phase 1 2
NCT07301320Epetraborole in Patients With Mycobacterium Abscessus Lung DiseaseMycobacterium Abscessus Infection
RECRUITING84 Analytics
PHASE2RECRUITING
Epetraborole in Patients With Mycobacterium Abscessus Lung Disease
Mycobacterium Abscessus InfectionUnlock trial analytics

Study Endpoints

Primary Endpoints

Clinical Response (NTM Symptom Evaluation Instrument) at Day 84
Day 1 to Day 84

Improvement in severity of at least 50% of the symptoms present at baseline and no deterioration in severity of symptoms present at baseline

Sputum culture conversion by Day 84
Day 1 to Day 84

Defined as 3 consecutive negative cultures one month apart without intervening or subsequent positives

Decrease in semi-quantitative sputum culture counts at Day 84
Day 1 to Day 84

Defined as improvement in sputum colony count category as defined by Griffith et al, 2015

Change from baseline in Quality of Life - Bronchiectasis (QOL-B) Respiratory Domain at Day 84
Day 1 to Day 84

QOL-B Domain scores range from 0 to 100, with higher scores indicating better health-related quality of life

Change from baseline in MACrO2 PRO at Day 84
Day 1 to Day 84

MACrO2 scores range from 0 to 100, with lower scores indicating better symptom-related quality of life

Sputum culture conversion by Day 56
Day 1 to Day 56

Defined as 2 consecutive negative cultures collected one month apart without intervening or subsequent positives

Characterize the PK Profile of Epetraborole and M3: Maximum Plasma Concentration
Cohorts 1-4: Day 1 to Day 4; Cohort 5: Day 1 - Day 8

Determination of the maximum observed plasma concentration (Cmax)

Characterize the PK Profile of Epetraborole and M3: Area Under the Plasma Concentration Versus Time Curve from Time 0 to the Last Time Point Evaluated
Cohorts 1-4: Day 1 to Day 4; Cohort 5: Day 1 - Day 8

Determine the area under the plasma concentration versus time curve from time 0 to the last time point evaluated (AUC0-t)

Characterize the PK Profile of Epetraborole and M3: Area Under the Plasma Concentration Versus Time Curve from Time 0 to 24 hours
Cohorts 1-4: Day 1 to Day 4; Cohort 5: Day 1 - Day 8

Determine the area under the plasma concentration versus time curve from time 0 to 24 hours (AUC0-24)

Characterize the PK Profile of Epetraborole and M3: Area Under the Plasma Concentration Versus Time Curve from Time 0 to Infinity
Cohorts 1-4: Day 1 to Day 4; Cohort 5: Day 1 - Day 8

Determine area under the drug concentration versus time curve, from time zero to infinity (AUC0-∞)

Characterize the PK Profile of Epetraborole and M3: Apparent total plasma clearance of drug
Cohorts 1-4: Day 1 to Day 4; Cohort 5: Day 1 - Day 8

Determine the apparent total plasma clearance of drug (CL/F)

Characterize the PK Profile of Epetraborole and M3: Time to Maximum Plasma Concentration
Cohorts 1-4: Day 1 to Day 4; Cohort 5: Day 1 - Day 8

Determination the time to maximum plasma concentration (Tmax)

Characterize the PK Profile of Epetraborole: Plasma from Hemodialysis Flow
Cohort 5: Day 5

Determine the AUC from 0 to the last quantifiable concentration AUClast immediately after the end of dialysis period from inflow (arterial) line

Characterize the PK Profile of Epetraborole:Plasma from Hemodialysis Flow
Cohort 5: Day 5

Determine the AUC from 0 to the last quantifiable concentration AUClast immediately after the end of dialysis period from inflow (venous) line

Characterize the PK Profile of Epetraborole and M3 in Urine: Cumulative drug excreted in urine over time
Cohorts 1-4: Day 1 to Day 4

Determine the cumulative amount excreted over all time intervals (0 to T), calculated as the sum of all amounts excreted from each interval (t1-t2)

Characterize the PK Profile of Epetraborole and M3 in Urine: Unchanged drug excreted in urine during the time interval
Cohorts 1-4: Day 1 to Day 4; Cohort 5: Day 1 - Day 8

Determine the fraction of unchanged drug excreted in urine during the time interval (expressed in %, calculated) for parent drug only

Characterize the PK Profile of Epetraborole and M3 in Urine: Renal Clearance
Cohorts 1-4: Day 1 to Day 4; Cohort 5: Day 1 - Day 8

Determine renal clearance (Ae(0-t)/ AUC0-T) for parent drug only

Characterize the PK Profile of Epetraborole and M3 in Dialysate: Concentration in full dialysate
Cohort 5: Day 5

Determine amount of drug measured in the whole dialysate volume during dialysis period

Characterize the PK Profile of Epetraborole and M3 in Urine: Dialysis clearance
Cohort 5: Day 5

Determine the Dialysis clearance over the dialysis period

Evaluate the Incidence of Treatment Emergent Adverse Events at Baseline and Through Study Completion
Cohorts 1-4: Day 1 to Day 4; Cohort 5: Day 1 - Day 8

Incidence, relatedness, and severity of adverse events

Evaluate Changes in Clinical Laboratory Tests from Baseline Through Study Completion
Cohorts 1-4: Day 1 to Day 4; Cohort 5: Day 1 - Day 8

Incidence of changes in clinical laboratory measurements from baseline

Evaluate Change in Vital Signs from Baseline Through Study Completion
Cohorts 1-4: Day 1 to Day 4; Cohort 5: Day 1 - Day 8

Incidence of changes in blood pressure, pulse, respiratory rate, and temperature

Evaluate Changes in 12-lead ECG Measurements from Baseline Through Study Completion
Cohorts 1-4: Day 1 to Day 4; Cohort 5: Day 1 - Day 8

Incidence of changes in 12-lead ECG parameters from baseline

Evaluate Physical Examination Abnormalities from Baseline Through Study Completion
Cohorts 1-4: Day 1 to Day 4; Cohort 5: Day 1 - Day 8

Incidence of physical exam abnormalities

Characterize the PK Profile of Epetraborole: Maximum Plasma Concentration
From Day 1 to follow-up visit through last follow-up visit (7 days after last dose)

Determination of the maximum plasma concentration (Cmax)

Characterize the PK Profile of Epetraborole: Minimum Steady State Plasma Concentration During a Dosage Interval
From Day 1 to follow-up visit through last follow-up visit (7 days after last dose)

Determination of the minimum steady state plasma drug concentration during a dosage interval (Cmin)

Characterize the PK Profile of Epetraborole: Time to Maximum Plasma Concentration
From Day 1 to follow-up visit through last follow-up visit (7 days after last dose)

Determination the time to maximum plasma concentration (Tmax)

Characterize the PK Profile of Epetraborole: Area Under the Plasma Concentration Versus Time Curve from Time 0 to the Last Time Point Evaluated
From Day 1 to follow-up visit through last follow-up visit (7 days after last dose)

Determine the area under the plasma concentration versus time curve from time 0 to the last time point evaluated (AUC0-t) with the plasma concentration at time "t" being the last measurable concentration

Characterize the PK Profile of Epetraborole: Area Under the Plasma Concentration Versus Time Curve from Time 0 to Infinity
From Day 1 to follow-up visit through last follow-up visit (7 days after last dose)

Determine area under the drug concentration versus time curve, from time zero to infinity (AUC0-inf)

Characterize the PK Profile of Epetraborole: Last Quantifiable Concentration
From Day 1 to follow-up visit through last follow-up visit (7 days after last dose)

Determine the actual time of last quantifiable concentration used in the determination of AUC0-last (Tlast)

Characterize the PK Profile of Epetraborole: Terminal Half-Life
From Day 1 to follow-up visit through last follow-up visit (7 days after last dose)

Determine the apparent terminal half-life (t½)

Characterize the PK Profile of Epetraborole: Terminal Elimination Rate Constant
From Day 1 to follow-up visit through last follow-up visit (7 days after last dose)

Determine apparent terminal elimination rate constant (Kel)

Secondary Endpoints

Patient Global Impression of Change (PGI-C) at Day 84
Day 1 to Day 84
Patient Global Impression of Severity (PGI-S) at Day 84
Day 1 to Day 84
Physician Visual Analog Scale (VAS) - Global at Day 84
Day 1 to Day 84
Unlock Study Endpoints

Study Design & Arms

AllocationRANDOMIZED
MaskingQUADRUPLE
ModelPARALLEL
PurposeTREATMENT

Treatment Arms

ArmTypeDescription
High Dose EpetraboroleEXPERIMENTALThis arm is a daily treatment regimen of a 750mg oral dose of Epetraborole.
Low Dose EpetraboroleEXPERIMENTALThis arm is a daily treatment regimen of a 500mg oral dose of Epetraborole.
High Dose PlaceboPLACEBO_COMPARATORThis arm is a daily treatment regimen of a placebo, matching the high dose experimental arm.
Low Dose PlaceboPLACEBO_COMPARATORThis arm is a daily treatment regimen of a placebo, matching the low dose experimental arm.
Open LabelEXPERIMENTALAll subjects in Cohorts 1-4 receive 500 mg epetraborole once; Subjects on Cohort 5 receive 500 mg epetraborole twice
Epetraborole for Dose RangingEXPERIMENTALEpetraborole hydrochloride 250 mg, 500 mg, 750 mg, or 1000 mg PO q24h or 500 mg or 1000 mg PO q48h
Placebo for Dose RangingPLACEBO_COMPARATORMatching placebo for dose ranging
Epetraborole for Food EffectEXPERIMENTALFood effect cohort, single dose in fed and fasted conditions, dosage to be determined based on pharmacokinetics data obtained from previous cohorts
Placebo for Food EffectPLACEBO_COMPARATORFood effect cohort, single dose in fed and fasted conditions, dosage to be determined based on pharmacokinetics data obtained from previous cohorts

Interventions

NameTypeDescription
EpetraboroleDRUGHigh-dose intervention (750mg daily)
PlaceboDRUGPlacebo intervention (matching the high-dose experimental intervention)
Unlock Study Design Details

Eligibility Criteria

Age Range18 Years to N/A
SexALL
Healthy VolunteersNo
Study Sites1

Inclusion Criteria: 1. Male or female patients who are 18 years of age or older. 2. Willing and able to provide written informed consent. 3. Patients with MABc lung disease, meeting the following (a) Microbiological, (b) Clinical, (c) Radiographic a. Microbiological criteria: i. Documentation o...

Countries:United StatesAustralia
Unlock Eligibility Criteria

Frequently asked questions about Epetraborole

What is Epetraborole used for?

Epetraborole is an investigational small molecule being studied for the treatment of Mycobacterium abscessus lung disease, a chronic and difficult-to-treat infection. It is also being evaluated in healthy volunteers and in people with renal insufficiency to understand how the drug is processed by the body.

What does Epetraborole target?

Epetraborole targets leucyl-tRNA synthetase (LeuRS), an enzyme essential for protein synthesis in bacteria. By inhibiting LeuRS, the drug is designed to disrupt bacterial protein production, which may help treat infections caused by Mycobacterium abscessus.

Who makes Epetraborole?

Epetraborole is being developed by AN2 Therapeutics, Inc., a biopharmaceutical company traded on the NASDAQ under the ticker symbol ANTX.

What phase is Epetraborole in?

Epetraborole is in clinical development. It has completed Phase 1 trials in healthy volunteers and in people with renal insufficiency, and is currently being studied in a Phase 2 trial for Mycobacterium abscessus lung disease. It is not yet approved by the FDA.

What clinical trials is Epetraborole in?

Epetraborole is being studied in three clinical trials. NCT07301320 is a Phase 2 trial in patients with Mycobacterium abscessus lung disease, currently recruiting in the United States. NCT05283746 is a completed Phase 1 trial in subjects with renal insufficiency. NCT04892641 is a completed Phase 1 trial in healthy volunteers in Australia.

Is Epetraborole the same as other drugs?

Epetraborole is a distinct investigational drug and no alternative names have been reported. It is a small molecule that targets LeuRS, a mechanism that is not shared by most approved antibiotics, making it a unique candidate in development for Mycobacterium abscessus infections.