乌鸦传媒

SAN DIEGO -- A pair of antibiotic drug regimens performed equally well at eliminating Mycobacterium xenopi pulmonary infection, the randomized CaMoMy trial showed.

In an intention-to-treat analysis, the 6-month sputum conversion rate was 93.2% among patients who received rifampin and ethambutol plus clarithromycin compared with 82.1% among those who received the two base drugs plus moxifloxacin (P=0.11), reported Claire Andréjak, MD, PhD, of University Hospital Amiens in France, at the American Thoracic Society annual meeting.

In the per-protocol analysis, conversion rates were 90.2% versus 80%, respectively (P=0.17).

There was no difference between the groups in terms of tolerance (P=0.55), and the most severe adverse events were linked to rifampicin and ethambutol.

The regimens are "an avenue to treat these patients, even if the prognosis seems to be very poor" with these infections, Andréjak said.

She told 乌鸦传媒 that M. xenopi causes pulmonary infection mainly in patients with chronic respiratory diseases, such as those with chronic obstructive pulmonary disease (COPD). Outcomes are often poor, with research suggesting a 5-year mortality rate of 69%.

Theodore K. Marras, MD, MSc, of the University of Toronto and Toronto Western Hospital, told 乌鸦传媒 that the M. xenopi bacteria progressively eat holes in the lungs. It can be unclear whether patients succumb to the infection or their underlying pulmonary disease, said Marras, who was not involved in the study.

Treatment guidelines from 2020 are based on an interim analysis of this study and recommend rifampicin and ethambutol with clarithromycin or moxifloxacin, Andréjak said. Previously, guidelines were based on management of Mycobacterium avium complex infections.

In this study, "the sputum conversion rate was very much higher than expected, even in very severe patients," she said. "There was no difference in terms of efficacy or tolerance between the two arms, so it's possible to start with one regimen and to switch, if necessary, to the other regimen."

As for which treatment to choose first, Andréjak said medical professionals can base their decisions on comorbidities or the potential for drug interactions.

Marras noted that it appears that the two regimens are "pretty equivalent," and "it's reassuring that this is supportive of the international guidelines."

The study's findings suggest that clinicians can consider either option and perhaps even consider combining all four drugs in patients with severe disease, he said.

The drugs are not expensive, he added. They're generally well-tolerated, although they can cause gastrointestinal problems and pose other risks.

For the , Andréjak and colleagues recruited adult patients who had not been previously treated for M. xenopi and didn't have contraindications for clarithromycin, moxifloxacin, rifampicin, or ethambutol. Mean age was 59, and 72.3% were men; patients had a mean of three positive tests at baseline, with a positive smear in 44%. More than 90% were smokers, 87.3% had chronic respiratory diseases (mainly COPD 74.7%), and 20% had immunosuppression.

As for other outcomes at 6 months, proportions of patients with anorexia dropped from 28% at baseline to 19.2%, weight loss from 48.3% to 15.4%, and fatigue from 58.5% to 34.6%.

The researchers will continue tracking patients for 5 years, Andréjak said. Meanwhile, the French ministry of health has funded a study to evaluate whether adding amikacin (Arikayce) to the existing three-drug regimens can speed up the healing process, she noted.

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