Nontuberculous mycobacterial (NTM) lung disease is a general term for lung infections caused by exposure to mycobacteria found in the environment. While NTM bacteria do not cause tuberculosis, they result in chronic lung infections that require aggressive and coordinated treatment. This disease affects more than 86,000 people in the U.S. and more than 220,000 worldwide.
Mycobacteria are naturally found in soil, water, and dust worldwide. Everyone inhales NTM into their lungs as part of daily life. In most people, the organisms do no harm. But in a small number of vulnerable individuals, especially those with a weakened immune system or an underlying lung disease such as CF, COPD, or bronchiectasis, the NTM organism can invade the lungs and cause infection, inflammation, and lung damage that worsens over time. NTM can be intracellular, which means it can grow and survive inside human cells, including macrophages, where they are shielded from the native immune response and traditional antibiotics.
The most common types of NTM bacteria in the U.S. are mycobacterium avium complex (MAC), mycobacterium abscessus, and mycobacterium kansasii. The standard treatment for these infections is a combination of two or more antibiotics, taken over several months. Such therapy is challenging for many patients who may have difficulty keeping up with a lengthy treatment regimen and are prone to side effects from the medications. In addition, non-eliminated mycobacteria readily develop antibiotic resistance. The need for new treatment options that are effective against both intracellular NTM and NTM biofilms without fostering antibiotic resistance is significant.
Vast is developing its inhalable nitric oxide-based drug candidate, ALX2 as a potential treatment for patients with NTM lung disease. Our lead compounds have demonstrated in vitro efficacy against multiple strains of NTM bacteria, including M. abscessus. The compounds have also proven effective in treating NTM in both acute and chronic mouse models of pulmonary infection.