Refer a Patient

Have a Patient with DM Who May Be Interested in the Flex Study?

The Flex Study is enrolling approximately 180 adult participants across North America, Europe, and Asia Pacific.

This is a phase 2 study (Part A) that leads to a phase 3 study (Part B). The total duration of participation is between 104 and 128 weeks, depending on which part of the study participants are enrolled in. Both parts consist of a screening period, study treatment period, and open-label extension period. Participants who complete the last visit in the treatment period may have the opportunity to receive the investigational medication in the open-label extension period.

The investigational medication, ravulizumab, is a monoclonal antibody that is being compared to standard of care on reducing symptoms in patients with DM. Participants will be assigned at random to receive either the investigational medication or the placebo. Neither the participant nor the study team will know which study treatment option has been assigned, but in case of an emergency, they can quickly find out. Both the investigational medication and the placebo are administered as IV infusions.

Primary Objective

The primary objective of the Flex Study is to evaluate the effectiveness and safety of the investigational medication compared to standard of care on reducing symptoms in adults with DM.

Eligibility Criteria

Key Inclusion Criteria

  • Male or female subjects at least 18 years of age
  • Body weight ≥ 30 kg at the time of Screening
  • Diagnosis of definite or probable DM that meets 2017 ACR/EULAR classification criteria
  • Participants have had an inadequate response or are intolerant to 2 or more DM treatments
    • Those who are currently receiving treatment with glucocorticoids or immunosuppressive therapies (ISTs) may be eligible to participate if they are on a stable dose entering the study or complete a washout period (this will depend on the treatment)
  • Disease severity: Participants who show disease severity at Screening using the following criteria:
    • MMT-8 of ≤ 142 (out of 150 maximum) and 2 additional IMACS CSMs out of 5 at Screening, such as:
      • Patient Global Activity assessment of ≥ 2.0 cm on a 10 cm VAS
      • Physician Global Activity assessment of ≥ 2.0 cm on a 10 cm VAS
      • HAQ disability index with ≥ 0.25
      • Elevation of at least 1 of the muscle enzymes (which includes creatine kinase [CK], aldolase, lactate dehydrogenase [LDH], alanine aminotransferase [ALT], and aspartate aminotransferase [AST]) at ≥ 1.3 times the upper limit of normal (ULN)
      • Global extramuscular disease activity score with ≥ 2.0 cm on a 10 cm VAS (this measure is the physician’s composite evaluation and is based on assessments of activity scores on the constitutional, cutaneous, skeletal, gastrointestinal, pulmonary, and cardiac scales of the MDAAT)
  • Participants must meet 1 of the following criteria to ensure enrollment of active disease rather than weakness due to muscle damage
    • Muscle or skin biopsy with evidence of active pathological findings of DM within the last 6 months prior to or at Screening
    • Electromyography evidence of active myositis within the last 6 months prior to Screening
    • Magnetic resonance imaging (MRI) muscle evidence of active myositis within the last 6 months prior to Screening
    • At least 1 muscle enzyme (CK, LDH, aldolase, AST, ALT) in the IMACS panel ≥ 2 times ULN at Screening
    • Active DM skin rash characterized by inflammatory changes (CDASI Activity Score ≥ 7) at Screening
  • Vaccinated against N meningitidis within 3 years prior to initiating ravulizumab as per national and local guidelines – participants must receive the vaccination at least 2 weeks before first study intervention, and the sponsor recommends national and local guidelines for prophylactic antibiotics to also be followed
  • Participants who have been diagnosed with cancer within the last 3 years need to have appropriate negative cancer screening as per local standard of care within 6 months before Screening (basal or squamous cell skin cancer or carcinoma in situ of the cervix needs to have been excised and cured at least 3 months before Screening)

Key Exclusion Criteria

  • Cancer-associated myositis, defined as the diagnosis of myositis within 3 years of the diagnosis of cancer
  • Evidence of active malignant disease or malignancies diagnosed within the previous 3 years including hematological malignancies and solid tumors (except basal or squamous cell skin cancer or carcinoma in situ of the cervix, which needs to have been excised and cured at least 3 months before Screening)
  • Participants with other forms of myositis: Clinical diagnosis of inclusion body myositis, polymyositis, necrotizing myopathy, drug-induced myositis/myopathy, anti-synthetase syndrome without DM, cancer-associated myositis (myositis diagnosed within 3 years either before or after a diagnosis of malignancy except squamous cell cancer of skin, basal cell cancer, carcinoma in situ lesions anywhere, or cervical carcinoma in situ), myositis with overlap connective tissue disease such as SLE, rheumatoid arthritis, or systemic sclerosis
    • Participants with secondary Sjogren’s syndrome are allowed
  • History of N meningitidis infection, HIV infection, hypersensitivity to murine proteins, advanced clinically symptomatic interstitial lung disease, or drug and/or alcohol abuse
  • Previously or currently treated with a complement inhibitor

Additional eligibility criteria apply.