Top Unmet Needs in MAC Pulmonary Disease Management

Welcome back to another AJMC Post-Conference Perspectives series. In "Top Unmet Needs in MAC Pulmonary Disease Management," Ashley Losier, MD opens the series by outlining the top unmet needs in Mycobacterium avium complex (MAC) pulmonary disease.

Dr. Losier identifies three to four unmet needs in MAC and NTM pulmonary disease that framed her review of ATS 2026 data. The first is better risk stratification: knowing which patients need treatment and when to start it. She explains that NTM is a relatively common isolated organism, especially in patients with bronchiectasis, but not every positive culture indicates true, fully defined NTM pulmonary disease. A confirmed diagnosis requires clinical symptoms such as cough and sputum production, radiographic abnormalities, and supportive microbiologic data. Dr. Losier argues clinicians need better tools to distinguish patients who require treatment from those who can be safely monitored, particularly since delaying therapy in some patients risks progression to more extensive, harder-to-treat disease.

Her second unmet need centers on more effective, better-tolerated treatment options. Current guideline-based therapy relies on three drugs: the macrolide azithromycin, ethambutol, and rifampin. Even with this regimen, Dr. Losier notes culture conversion rates remain suboptimal, particularly in patients with severe or extensive disease such as fibrocavitary disease or refractory infection. She calls for regimens that are both more effective and easier for patients to tolerate over prolonged courses of therapy.

Dr. Losier's third, hybrid unmet need addresses how the field measures treatment success. She argues for shifting some emphasis toward patient-reported outcomes and quality-of-life metrics, layered on top of traditional culture conversion data. She also flags a need to optimize how culture conversion itself is measured, since microbiologic culture, while still the gold standard, remains an imperfect and sometimes inconsistent tool. Better diagnostic options, she suggests, could help refine this process going forward. Together, these three priorities, risk stratification, treatment tolerability, and outcome measurement, set the stage for the ATS 2026 abstracts reviewed across this series.

The next episode in this series, "New Registry Data on MAC Pulmonary Disease Outcomes," turns to new registry data on who develops MAC pulmonary disease and how it behaves.