# Discovery of Novel Nontuberculous Inhibitors

> **NIH NIH R15** · CREIGHTON UNIVERSITY · 2021 · $363,750

## Abstract

Project Summary/Abstract
Non-tuberculous mycobacteria (NTM) are widespread pathogens found in the environment and cause
progressive lung disease as well as skin and soft tissue, central nervous system and disseminated infections.
NTM infections rates are rising globally and have emerged as important human pathogens globally. The
specific pathogens responsible for these infections are part of one of two species, i) Mycobacterium abscessus
(M. abscessus) complex (MABSC) and ii) Mycobacterium avium (M. avium) complex. The M. abscessus
complex comprises the subspecies M. abscessus, M. massiliense and M. bolletii, has emerged as a significant
global threat causing an increasing number of pulmonary infections among patients with structural lung
disease such as chronic obstructive pulmonary disease, bronchiectasis and cystic fibrosis (CF). Of particular
concern, patients with CF co-infected with an MABSC pathogen are often untreatable despite years of
combination therapy resulting in 60-70% treatment failures. Therefore, novel anti-NTM agents with potent
activity against MABSC strains that can shorten treatment time, decrease resistance rates with improved
efficacy are strongly needed.
We have discovered a novel series of indole-2-carboxamides (IC) that have potent minimum inhibitor
concentration (MIC) values of 0.0039 - 8 µg/ml against various slow- and fast-growing NTM of clinical interest,
including M. abscessus, M. massiliense, M. bolletii and M. chelonae. In addition, ICs are effective in vitro and
in mice, demonstrating their safe and effective profile. However, ICs are lipophilic and are poorly water soluble
resulting in poor oral absorption. To circumvent this poor pharmacokinetic property, we propose to design
novel amino-acid based IC analogs and develop drug-loaded liposomes, which are a safe and effective option
to formulate poorly soluble ICs. Novel analogs will be evaluated for antimycobacterial activity and active
compounds will undergo a series of ADMETox assays to determine putative PK/PD action. IC- and IC-analog-
loaded liposomes will be designed for inhalation administration and be engineered to be preferentially taken up
by macrophages, where NTM pathogens reside in infected patients. This will be accomplished through
synthesis of ICs, production of drug-loaded liposomes and characterization of drug release and macrophage
uptake. Liposomes will be produced using thin film hydration method with subsequent IC-loading using
passive trapping methods. The lamellarity of the liposomes will be monitored by 31P NMR and confirmed with
cryo-TEM. Drug-release studies will be performed to ensure therapeutic IC concentrations are released
(concentrations above MIC values). Finally, IC-loaded liposomes with optimized drug-release will be subjected
to macrophage uptake studies. This will be performed using a fluorescent labeled IC loaded liposome and
macrophages expressing GFP to visualize uptake and TEM.

## Key facts

- **NIH application ID:** 10291635
- **Project number:** 1R15AI164443-01
- **Recipient organization:** CREIGHTON UNIVERSITY
- **Principal Investigator:** Elton Jeffrey North
- **Activity code:** R15 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $363,750
- **Award type:** 1
- **Project period:** 2021-07-19 → 2025-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10291635

## Citation

> US National Institutes of Health, RePORTER application 10291635, Discovery of Novel Nontuberculous Inhibitors (1R15AI164443-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10291635. Licensed CC0.

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