A Study to Assess the Safety, Tolerability, Ciliary Rescue, and Pharmacodynamics of RCT1100 in Adults with PCD

Major Inclusion Criteria:

• Healthy, adult, male or female of, 18-70 years of age, inclusive, at screening.

• Participant has clinical diagnosis of PCD and disease-causing mutations in the DNAI1gene

• Participant has a forced expiratory volume in one second (FEV1) of at least 50%predicted.

Major Exclusion Criteria:

• History or presence of clinically significant medical, surgical, clinicallaboratory, or psychiatric condition or disease.

• History of cancer, with exception of adequately treated basal cell or squamous cellcarcinoma of the skin.

• Predisposition to bleeding or clinically meaningful hemorrhagic event in the 12months prior

• Medically significant hemoptysis.

• Anticoagulation therapy for the treatment of a pulmonary embolus or has had apulmonary embolus in the last 6 months of screening.

• Active tuberculosis infection.

• 12-lead ECG with QT interval >450 msec (or >480 msec for BBB)

• Laboratory abnormalities in clinical laboratory tests at screening:

1. Serum creatinine level

2. Total bilirubin, aspartate aminotransferase or alanine aminotransferase values

3. Hematological or coagulation values outside the normal reference range

• Any medical history of disease that has the potential to cause a rise in totalbilirubin over the ULN.

• COVID-19 infection within 4 weeks of Screening or receipt of COVID-19 vaccine within 2 weeks prior to first dose of RCT1100.

• Receipt of vaccine with live virus, attenuated live virus, or live viral componentswithin 2 weeks prior to first dose of RCT1100 or to receive these vaccines duringtreatment or within 8 weeks of completion of study treatment.

Other protocol defined inclusion/exclusion criteria may apply.