Updated NTM guidelines recommend newer therapy for treatment-refractory MAC pulmonary infection

7 July, 2020

A newer therapy that acts like a Trojan horse to attack bacteria should be reserved for patients with certain treatment-refractory lung infections, according to updated nontuberculous mycobacterial (NTM) pulmonary disease guidelines developed by the European Respiratory Society (ERS), the Infectious Diseases Society of America (IDSA), the American Thoracic Society (ATS) and the European Society of Clinical Microbiology and Infectious Disease (ESCMID). The guidelines are published in the European Respiratory Journal and Clinical Infectious Diseases.

The therapy, amikacin liposome inhalation suspension, was approved by the Food and Drug Administration (FDA) in September 2018 to treat people with treatment-refractory Mycobacterium avium complex (MAC), a common cause of NTM pulmonary disease. The antibiotic amikacin is encased in fat globules called liposomes and inhaled into the lungs, where it is released into cells to attack the bacteria. The new guidelines recommend that the treatment should only be given to MAC patients who have not improved after at least six months of standard therapy.

“Infectious diseases and pulmonary specialists have the expertise to treat these complex NTM pulmonary disease patients, who often require 12-18 months of therapy, sometimes including intravenous treatment,” said Charles L. Daley, MD, lead author of the guidelines and chief of the division of mycobacterial and respiratory infections at National Jewish Health, Denver. “It is likely many patients are being undertreated and others overtreated. The new guidelines should help provide clarity for diagnosis and treatment.”

The new guidelines update the 2007 guidelines, for the first time employing the methodical Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, which specifies the quality and weight of the evidence for diagnosis and treatment. The previous guidelines covered a large amount of material making them complex and difficult to follow. The new guidelines are more focused and provide easier guidance to ensure more patients are treated appropriately, he said.

The guidelines recommend three sputum specimens be obtained at least a week apart and at least two be positive to confirm the person has NTM pulmonary disease. About half of people with the disease do not require antibiotics, at least initially, said Dr. Daley. When it is necessary, treatment typically involves a combination of antibiotics.

MAC is one of more than 190 species and subspecies of mycobacteria, many of which can cause NTM pulmonary disease in humans and can become chronic. While NTM are found in the environment and can be inhaled, few people develop the disease. However, NTM pulmonary disease has increased from 7 per 100,000 people in 2008 to 12 per 100,00 people in 2015, according to one study. The majority of those with NTM pulmonary disease are women, most of whom are 65 and older and have underlying lung disease.

“Many patients can be cured of the infection, but their underlying lung disease remains incurable,” said Richard J. Wallace Jr., MD, FIDSA, co-author of the guidelines and chairman of the department of microbiology and director of the microbacterial clinical and research laboratory, University of Texas Health Science Center, Tyler. “Other patients can’t be cured of their NTM infection, but can be stabilized with treatment.”