This double-blind, randomized, placebo-controlled, multinational, multicenter, parallel-group, Phase 3, 2-arm, study will investigate the efficacy and safety of belumosudil compared with placebo, both administered on top of azithromycin and standard-of-care regimen of immunosuppression in male or female participants at least 1 year after bilateral lung transplant, who are at least 18 years of age and who have evidence of progressive CLAD despite azithromycin therapy.

Study details include:

The study duration will be up to 31 weeks for participants not entering the open-label extension (OLE) period and up to 57 weeks for participants entering the OLE period but not the long-term OLE.

The treatment duration will be up to 26 weeks for participants not entering the OLE period and up to 52 weeks for participants entering the OLE period but not the long-term OLE.

The number of visits will be up to 10 visits for participants not entering the OLE period and up to 16 visits for participants entering the OLE period but not the long-term OLE.

For participants who enter the long-term OLE, treatment and study participation will continue with visits every 12 weeks per protocol specifications.

Inclusion Criteria:

• Participant ≥1 year post bilateral lung transplantation at the time of screening
• Participants presenting with CLAD Stage 1 or 2: FEV1 from >50% to 80% of post-transplant baseline at screening and at randomization
• Participants who have received at least 8 weeks of azithromycin (≥250 mg/day, at least 3 times a week) prior to randomization

Exclusion Criteria:

• FEV1 ≤50% of the post-transplant baseline value (CLAD 3 and 4)
• Lung function decline that can be explained by non-CLAD causes including but not limited to acute lung allograft rejection (>A1), antibody-mediated rejection, airway stenosis, or tracheobronchomalacia

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.

Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org