Testing a Novel Combination Treatment (Arm D) Versus Standard of Care for Intensive Phase Treatment for Mycobacterium Abscessus Pulmonary Disease in People With or Without Cystic Fibrosis in the Finding the Optimal Regimen for Mycobacterium Abscessus Treatment (FORMaT) Adaptive Platform Trial

The goal of this clinical trial is to learn if a new combination antibiotic treatment (Arm D) works to treat a rare lung condition called mycobacterium abscessus pulmonary disease in people of any age and sex, when compared to the standard treatments. It will also learn about the safety of this new combination antibiotic treatment when compared to the standard treatments. The main questions it aims to answer are:

* How well does Arm D treat mycobacterium abscessus pulmonary disease? * What side effects does Arm D cause when used to treat mycobacterium abscessus pulmonary disease? Researchers will compare Arm D to the current standard of care treatments to see if Arm D treats mycobacterium abscessus pulmonary disease better and if it will cause less side effects.

Participants will:

* Be screened and recruited to the FORMaT adaptive platform trial (NCT04310930) * Be given Arm D for 4 weeks or standard of care treatments for 6 weeks. * Be reviewed by the study doctors weekly for checkups and tests. * Provide respiratory samples (sample coughed up from the chest), respond to quality-of-life questionnaires, have CT lung scans and blood tests.