The PGI-S respiratory symptom is a self-reported scale to measure the severity of illness based on symptoms using a 5-point scale ranging from 1 to 5, (1=not at all, 2=mild, 3=moderate, 4=very severe, 5=extremely severe). Considering different aspects of breathing symptoms like congestion, cough, mucus, wheezing, shortness of breath, participants rated their symptom severity on the PGI-S respiratory symptom scale. Higher scores indicate greater symptom severity.

ITT Analysis Set comprises all participants who were randomized.

The PGI-S fatigue is a self-reported scale to measure the severity of illness based on symptoms using a 5-point scale ranging from 1 to 5, (1=not at all, 2=mild, 3=moderate, 4=very severe, 5=extremely severe). Participants rated the severity of their fatigue on the PGI-S fatigue scale. Higher scores indicate greater fatigue severity.

ITT Analysis Set comprises all participants who were randomized.

The QOL-B is a self-administered, PRO questionnaire used to assess symptoms, functioning, and health related quality of life in adults with lung conditions. The respiratory symptom domain of the QOL-B contains 9 items describing patient's self-assessment of her/his respiratory symptoms that affect daily life. For each of the 8 items (chest congestion, coughing, cough up mucus, shortness of breath with greater activity, wheezing, chest pain, shortness of breath when talking, woken up during night due to cough), scores ranged from 1 to 4 (1= lot, 2= moderate, 3= little, 4= not at all) and the sputum item based on the color ranged from 0=don't know,1=green with traces of blood/brownish dark,2=yellowish-green,3=clear to yellow,4=clear. The item scores were summed and then standardized on a 0 to 100-point scale to derive the domain score with higher scores representing fewer symptoms or better functioning and quality of life.

The ITT Analysis Set comprises all participants who were randomized.

The PROMIS F-SF 7a is a self-administered questionnaire assessing a range of self-reported symptoms over the past 7 days, from mild subjective feelings of tiredness to an overwhelming, debilitating, and sustained sense of exhaustion that likely decreases one's ability to execute daily activities and function normally in family or social roles. Fatigue is divided into the experience of fatigue (frequency, duration, and intensity) and the impact of fatigue on physical, mental, and social activities over 7 items. Response options are on a 5-point Likert scale, ranging from 1=never to 5=always. Total scores range from 7 to 35 and low scores represent less fatigue interference i.e., better symptoms.

The ITT Analysis Set comprises all participants who were randomized.

TRTR consists of measuring the degree to which an instrument yield reproducible score at different points in time assessed across a fixed and common time interval for all subjects. TRTR co-relations were based on the two-way mixed effect ICC coefficient estimated using the inter-rater reliability package, version 0.84.1. TRTR estimate of 0.7 and above indicated better retest reliability. TRTR was assessed among participants reporting no change on PGI-S between screening and baseline. PGI-S anchors are PRO specific, with a respiratory PGI-S (scale ranging from 1=not at all to 5=extremely severe, Higher scores=greater symptom severity) applied to the QOL-B respiratory domain (9-item scale ranging from 0 to 100, higher scores=fewer symptoms and better quality of life). As pre-specified in statistical analysis plan(SAP) for participants contributing to this outcome measure from INS-415 study,data were collected and analyzed for combined population in which ALIS and ELC groups were pooled.

As pre-specified in the SAP, to adequately power the planned modern psychometric methods (MPMs) the cross-sectional validation sample was composed of a total of 97 participants enrolled in the INS-415 study (comprising of pooled ALIS + ELC data per planned analyses) who provided item-level QOL-B Respiratory domain data and Screening/Baseline data from the first 132 participants enrolled in the INS-416 study (NCT04677569) to yield a total sample of n=229.

TRTR consists of measuring the degree to which an instrument yield reproducible score at different points in time assessed across a fixed and common time interval for all subjects. TRTR co-relations were based on the two-way mixed effect ICC coefficient estimated using the inter-rater reliability package, version 0.84.1. TRTR estimate of 0.7 and above indicated better retest reliability. TRTR was estimated using mean PROMIS F-SF 7a scores from participants who were stable as defined by a PGI-S-Fatigue change score of zero between screening and baseline. As pre-specified in the SAP, for participants contributing to this outcome measure from INS-415 study, data were collected and analyzed for combined population in which ALIS and ELC groups were pooled.

As pre-specified in the SAP, to adequately power the planned MPMs the cross-sectional validation sample was composed of a total of 98 participants enrolled in the INS-415 study (comprising of pooled ALIS + ELC data per planned analyses) who provided item-level PROMIS F-SF 7a data and Screening/Baseline data from the first 132 participants enrolled in the INS-416 study to yield a total sample of n=230.

WSMC was estimated via change scores computed between Baseline and end of study (EOS) (Month 7). The estimated WSMC threshold of 14.81 points for the QOL-B Respiratory Symptom score (9-item scale ranging from 0 to 100, higher scores=fewer symptoms and better quality of life) as derived from anchor-based methods supplemented with eCDF curves was used for analysis. The percentage of participants and confidence intervals were estimated by standardized logistic regression with treatment group and history of mycobacterium avium complex (MAC) lung infection as factors in the model. Missing change from baseline at Month 7 was imputed by multiple imputation. The mean of all imputed values was used to derive response according to WSMC. Response rate was expressed in terms of percentage of participants and the percentages are rounded off to the nearest decimal.

The ITT Analysis Set comprises all participants who were randomized.

WSMC was estimated via change scores computed between Baseline and EOS (Month 7). The percentage of participants and confidence intervals were estimated by standardized logistic regression with treatment group and history of MAC lung infection as factors in the model. Missing change from baseline at Month 7 was imputed by multiple imputation. The mean of all imputed values was used to derive response according to WSMC. The estimated WSMC threshold of -4.00 points for the PROMIS Fatigue score as derived from anchor-based methods supplemented with eCDF curves was used for analysis. Response rate was expressed in terms of percentage of participants and the percentages are rounded off to the nearest decimal.

The ITT Analysis Set comprises all participants who were randomized.

Culture conversion by Month 6 was defined as no MAC growth on agar media and broth media in all sputum cultures at 2 consecutive visits up to Month 6. Percentage of participants and confidence intervals were estimated by standardized logistic regression with treatment group and history of MAC lung infection as factors in the model. For the purpose of the estimation missing conversion status by Month 6 was imputed by multiple imputation. Percentages are rounded off to the nearest decimal.

The ITT Analysis Set comprises all participants who were randomized.

The QOL-B is a self-administered, PRO questionnaire used to assess symptoms, functioning, and health related quality of life in adults with lung conditions. The respiratory symptom domain of the QOL-B contains 9 items describing patient's self-assessment of her/his respiratory symptoms that affect daily life. For each of the 8 items (chest congestion, coughing, cough up mucus, shortness of breath with greater activity, wheezing, chest pain, shortness of breath when talking, woken up during night due to cough), scores ranged from 1 to 4 (1= lot, 2= moderate, 3= little, 4= not at all) and the sputum item based on the color ranged from 0=don't know,1=green with traces of blood/brownish dark,2=yellowish-green,3=clear to yellow,4=clear. The item scores were summed and then standardized on a 0 to 100-point scale to derive the domain score with higher scores representing fewer symptoms or better functioning and quality of life. Positive change from baseline indicates improvement.

The ITT Analysis Set comprises all participants who were randomized.

The PROMIS F-SF 7a is a self-administered questionnaire assessing a range of self-reported symptoms over the past 7 days, from mild subjective feelings of tiredness to an overwhelming, debilitating, and sustained sense of exhaustion that likely decreases one's ability to execute daily activities and function normally in family or social roles. Fatigue is divided into the experience of fatigue (frequency, duration, and intensity) and the impact of fatigue on physical, mental, and social activities over 7 items. Response options are on a 5-point Likert scale, ranging from 1=never to 5=always. Total scores range from 7 to 35 and low scores represent less fatigue interference i.e., better symptoms.

The ITT Analysis Set comprises all participants who were randomized.

Time to first culture conversion was the number of months between first study drug intake and date of the first negative culture at or before Month 6 after adjustment for non-productivity. Participants without conversion at or before Month 6 are considered censored at the last visit with available culture assessment at or before Month 6.

The ITT Analysis Set comprises all participants who were randomized. Overall number analyzed is the number of participants with culture conversion who had data available for analyses.

Time to first negative culture was the number of months from the date of first dose of study drug(s) to the date of first MAC culture negative post-baseline. Participants without negative culture were considered censored at the last visit with available culture assessment or at Month 7 whichever occurred first.

The ITT Analysis Set comprises all participants who were randomized. Overall number analyzed is the number of participants with a negative culture.

The ITT Analysis Set comprises all participants who were randomized.

Culture conversion for this outcome measure was defined as MAC culture negative at 2 consecutive visits before or at Month 5 during the treatment period. The positive culture was defined as at least 1 MAC positive culture in agar media or positive cultures in broth media in at least 2 consecutive visits. Percentages are rounded off to the nearest decimal.

The ITT Analysis Set comprises all participants who were randomized. Overall number analyzed is the number of participants who had conversion before or at Month 5 with data available for analyses.

Culture conversion for this outcome measure was defined as MAC culture negative at 2 consecutive visits before or at Month 5 during the treatment period. The positive culture was defined as at least 1 MAC positive culture in agar media or positive cultures in broth media in at least 2 consecutive visits. Percentages are rounded off to the nearest decimal.

The ITT Analysis Set comprises all participants who were randomized. Overall number analyzed is the number of participants who had conversion before or at Month 5 with data available for analyses.

An adverse event (AE) is defined as any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. TEAEs are AEs that occurred on or after the date of first dose of study drugs and within 28 days after the end of treatment.

The Safety Analysis Set comprises all participants who were randomized and received at least 1 dose of ALIS, ELC, azithromycin or ethambutol.