All-Oral Bedaquiline Regimen for Refractory MAC Lung Disease

"All-Oral Bedaquiline Regimen for Refractory MAC Lung Disease" takes up the question of what comes next when standard MAC therapy fails.

Dr. Losier turns to a study addressing refractory MAC, generally defined as persistent sputum cultures after six months of guideline-based multidrug therapy. Current international guidelines offer limited evidence-based options at this stage, typically the addition of inhaled liposomal amikacin. Aminoglycosides, whether parenteral or inhaled, carry side effects that can limit their use, which is why bedaquiline, with a distinct mechanism of action, is being explored as an alternative that may be better tolerated in certain patients.

The study was a multi-center, randomized, open-label, active-controlled Phase 2/3 trial enrolling patients with refractory MAC. Participants were stratified to a bedaquiline-containing combination with clarithromycin and ethambutol, or to a rifamycin-containing comparator regimen. The primary endpoint was sputum culture conversion at week 24, with durable conversion, safety, and tolerability as secondary endpoints. Dr. Losier highlights the all-oral design as an important feature, since it can reduce the burden and toxicity associated with parenteral aminoglycoside therapy or other refractory regimens.

Results showed meaningful culture conversion with the bedaquiline-containing regimen compared with the comparator, alongside an acceptable safety and tolerability profile. There were no new safety signals beyond bedaquiline's known profile, though Dr. Losier stresses that QTc monitoring remains important given the drug's potential for QT prolongation.

Her key takeaway is that this all-oral regimen represents a new potential alternative for refractory MAC, a setting with few therapeutic options. It may be especially attractive for older or frail patients, or those with comorbidities who cannot tolerate aminoglycoside therapy. She is careful to frame bedaquiline as an emerging strategy rather than a broad replacement for rifamycins, noting the field still needs more data on durability, resistance, and optimal combinations before this approach becomes standard practice.

Up next, in "Early Data on Inhaled Clofazimine for MAC and NTM," Dr. Losier reviews early data on delivering an old antimycobacterial drug straight to the lung.