Phase 2 Study of Rapcabtagene Autoleucel in Myositis

Key Inclusion Criteria:

1. Men and women, aged ≥ 18 and ≤75 years, with a diagnosis of probable or definitemyositis according to American College of Rheumatology/European League AgainstRheumatism 2017 (ACR/EULAR 2017) criteria

2. Participants who had inadequate response to prior therapy

3. Diagnosed with active disease

4. Participant must meet criteria for severe myositis

Key Exclusion Criteria:

1. Any condition during Screening that could prevent a complete washout of medicationsor could otherwise make the participant ineligible for anti-CD19 CAR-T therapy andfurther participation in the study

2. BMI at Screening of ≤17 or ≥40 kg/m2

3. Severe muscle damage at Screening

4. Inadequate organ function

5. Hypersensitivity and/or contraindications to any product (including its ingredients)to be given to the participant as per the study protocol

6. Other inflammatory and non-inflammatory myopathies

7. Any medical conditions that are not related to IIM that would jeopardize the abilityof the participant to tolerate CD19 CAR-T cell therapy

Other protocol-defined inclusion/exclusion criteria may apply.