A Phase 2 Study of KZR-616 to Evaluate Safety and Efficacy in Patients With Active Polymyositis or Dermatomyositis
Condition: Polymyositis; Dermatomyositis
MeSH terms: Dermatomyositis; Polymyositis
Intervention: KZR-616; Placebo
Intervention description: Subcutaneous 30 mg weekly for 2 weeks, then 45 mg weekly for 14 weeks; Subcutaneous injection for 16 weeks
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 25.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: Myositis; Idiopathic inflammatory myopathies; Polymyositis; Dermatomyositis; Musculoskeletal Diseases; Muscular Diseases

Summary:

      This was a Phase 2 randomized, double-blind, placebo-controlled, crossover, multicenter study
      to evaluate the safety, tolerability, efficacy, pharmacokinetics (PK) and pharmacodynamics
      (PD) of treatment with KZR-616 in patients with active polymyositis (PM) or dermatomyositis
      (DM). Patients were evaluated for eligibility during the Screening Period. Eligible patients
      were stratified by diagnosis of DM or PM and randomized 1:1 to Arm A or Arm B of the study.

      During the 32-week treatment period, patients received study drug subcutaneously (SC) once
      weekly with 2 treatment periods of 16 weeks each.

      This study was conducted on an outpatient basis.
    

Eligibility criteria:

        Inclusion Criteria:

          1. Adult patients at least 18 years of age

          2. Body Mass Index (BMI) of 18 to 40 kg/m^2

          3. Diagnosis of probable or definite DM or PM by the 2017 European League Against
             Rheumatism (EULAR)/American College of Rheumatology (ACR) Classification Criteria

          4. Must have their data reviewed by an adjudication committee to confirm eligibility
             unless at least 1 of the following is present:

               1. Muscle biopsy with evidence of active myositis within the last 6 months prior to
                  or at Screening

               2. Electromyography or magnetic resonance imaging with evidence of active myositis
                  within the last 6 months prior to Screening

               3. A creatine kinase (CK) ≥4 × upper limit of normal (ULN).

          5. Must have demonstrable muscle weakness as measured by the Manual Muscle Testing-8
             muscle Groups (MMT-8) with a score ≥80/150 but ≤136/150 units and any 2 of the
             following:

               1. Physician Global Assessment (MDGA) visual analog scale (VAS) ≥2 cm

               2. Patient Global Assessment of Disease Activity (PtGADA) VAS ≥2 cm

               3. At least one muscle enzyme laboratory measurement ≥1.3 × ULN

               4. Myositis Disease Activity Assessment Tool (MDAAT) Extramuscular Global Activity
                  VAS ≥1 cm.

          6. Documented inadequate response OR have demonstrated documented toxicity or intolerance
             to prior standard of care therapies

          7. Has had age-appropriate cancer screening that is up to date and negative for evidence
             of malignancy as per local standard of care

        Exclusion Criteria:

          1. Has significant muscle damage or has a muscle damage VAS score ≥5 cm on the MDI

          2. Any other form of myositis or myopathy other than PM or DM

          3. Any condition that precludes the ability to quantitate muscle strength

          4. Has severe interstitial lung disease or has a pulmonary damage VAS score ≥5 cm on the
             Myositis Damage Index (MDI)

          5. Presence of autoinflammatory disease

          6. Use of nonpermitted medications or treatments within the specified washout periods
             prior to screening

          7. Patient has had recent serious or ongoing infection, or risk for serious infection

          8. Any of the following laboratory values at Screening:

               1. Estimated glomerular filtration rate <45 mL/min

               2. Hemoglobin <10 g/dL

               3. White blood cell (WBC) count <3.0 × 10^9/L

               4. Absolute neutrophil count (ANC) <1.5 × 10^9/L (1500/mm^3)

               5. Platelet count <100 × 10^9/L

               6. Serum AST or serum ALT >2.5 × ULN (unless considered consistent with muscle
                  origin)

               7. Serum alkaline phosphatase >2.5 × ULN

               8. Total bilirubin >1.5 × ULN (3 × ULN for patients with documented Gilbert's
                  syndrome)

               9. Thyroid stimulating hormone outside of the central laboratory normal range

              10. Immunoglobulin G (IgG) <500 mg/dL.

          9. Presence of New York Heart Association Class III or IV heart failure, or uncontrolled
             blood pressure, or prolonged QT interval

         10. Major surgery within 12 weeks before Screening or planned during the study period

         11. Clinical evidence of significant unstable or uncontrolled diseases

         12. Any active or suspected malignancy, including myeloproliferative or
             lymphoproliferative disorder, or history of documented malignancy within the last 5
             years before Screening or within 3 years of diagnosis of myositis, except
             appropriately excised and cured cervical carcinoma in situ or basal or squamous cell
             carcinoma of the skin