A Study of the Efficacy and Safety of Belimumab in Adults With Interstitial Lung Disease Associated With Connective Tissue Disease

Inclusion Criteria:

• Documented diagnosis of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), idiopathic inflammatory myopathy (IIM; including polymyositis,dermatomyositis, anti-synthetase syndrome), Sjogren's syndrome (pSS), or mixedconnective tissue disease (MCTD) in accordance with internationally recognizedclassification criteria

• Diagnosis of ILD on High Resolution Computed Tomography (HRCT) with disease extentof greater than or equal to (≥) 10% of the whole lung (WLILD)

• Evidence of ILD progression in the previous 24 months

• Must be currently receiving stable standard therapy to manage ILD and/or underlyingCTD, or to have failed or failed to tolerate first line standard therapy.

• Participant is capable and willing to self-administer the study medication or has acaregiver who is capable and willing to administer the study medication throughoutthe study

• A female participant is eligible to participate if she is not pregnant orbreastfeeding, and one of the following conditions applies:

• Is a woman of nonchildbearing potential (WONCBP) OR

• Is a Woman of childbearing potential (WOCBP) and using a contraceptive methodthat is highly effective, with a failure rate of less than (<)1%

• Capable of giving signed informed consent

Exclusion Criteria:

• Diagnosis of ILD other than CTD-ILD.

• Primary diagnosis of Systemic Sclerosis (SSc).

• Participants with rapidly progressive disease (absolute drop of 10% or more of FVCbetween screening and baseline visit and/or recent pulmonary hospitalisation).

• FVC ≤ 45% of predicted, or a Diffusing Capacity of the lung for Carbon Monoxide (DLco) (corrected for hemoglobin) ≤ 40% of predicted or requiring supplementaloxygen at screening

• History or presence of diffuse alveolar haemorrhage (DAH) or other confoundingpulmonary disease, signs, or symptoms

• Pulmonary arterial hypertension requiring therapy, as determined by the investigatorat, or prior to first day of dosing (Day 1)

• Dependence on continuous oxygen supplementation

• History or presence of cardiovascular, respiratory, hepatic, renal,gastrointestinal, endocrine, hematologic, or neurological disorders capable ofsignificantly altering the absorption, metabolism, or elimination of drugs;constituting a risk when taking the study intervention or interfering with theinterpretation of data

• Obstructive pulmonary disease (pre-bronchodilator Forced Expiratory Volume (FEV1) /FVC <0.7).

• Significant emphysema on screening HRCT (extent of emphysema exceeds extent of ILD)

• Confirmed Progressive multifocal leukoencephalopathy (PML) or unexplained new-onsetor deteriorating neurologic signs and symptoms

• Have evidence of moderate to severe depression, defined as PHQ-9 score ≥10, orserious current suicide risk, or any history of suicidal behavior in the last 6months and/or any suicidal ideation in the last 2 months, or who in theinvestigator's judgment, poses a significant suicide risk

• Lymphoma, leukemia, or any malignancy within the past 5 years except for basal cellor squamous epithelial carcinomas of the skin that have been resected with noevidence of metastatic disease for 3 years

• Breast cancer within the past 10 years

• Major surgery (including joint surgery) within 3 months prior to screening orplanned during the duration of the study

• An active infection, or a history of infections