A Study to Understand How the Study Medicine (PF-06823859) Works in People With Active Idiopathic Inflammatory Myopathies [Dermatomyositis (DM) and Polymyositis (PM)]

Study Overview
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Brief Summary
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The purpose of the study is to understand how the study medicine PF-06823859 works in people with idiopathic inflammatory myopathies (DM and PM). These disorders cause inflammation that weakens the muscles that are important for movement and may also cause skin rash in people with DM. This study is seeking participants who: Are 18 years of age or older. Have active DM or active PM. Are receiving a stable dose of 1 corticosteroid taken by mouth and/or 1 traditional immunosuppressant. Note: Corticosteroids and immunosuppressants are medicines that help reduce inflammation and may signal to the immune system not to attack the body. Dermatomyositis (DM) is a rare disease that causes muscle inflammation that results in muscle weakness and low muscle stamina. Patients with DM have a characteristic skin rash. Polymyositis (PM) is a rare disease that involves mainly muscle inflammation resulting in muscle weakness, that can sometimes be painful. Patients with DM and PM may have trouble going up the steps, walking or getting to a standing position. Some of the participants will receive the study medicine (PF-06823859) and some will receive placebo (which is similar to study medicine but contains no medicine in it). The study medicine or placebo will be given as an intravenous (IV) infusion (directly into the veins), which takes about1 hour; every 4 weeks from Day 1 to Week 48 of the study. Both PF-06823859 and placebo and will be given at the study site. The study will compare the experiences of people receiving study medication to those of the people who do not. This will help to see if PF-06823859 is safe and effective. Participants will take part in this study for about 13 months. During this time, participants will have 16 study visits. These visits will be performed at the study site.

Official Title
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A PHASE 3, MULTICENTER, DOUBLE-BLIND, RANDOMIZED, PLACEBO-CONTROLLED STUDY TO EVALUATE THE EFFICACY AND SAFETY OF PF-06823859 IN PARTICIPANTS WITH ACTIVE IDIOPATHIC INFLAMMATORY MYOPATHIES (INCLUDING PARTICIPANTS WITH ACTIVE DERMATOMYOSITIS OR POLYMYOSITIS)

Conditions
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Myositis

Intervention / Treatment
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* Drug: PF-06823859
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female adults (≥18 years old) Active dermatomyositis (DM) or polymyositis (PM) with age of onset 18 years old. Must be receiving a stable dose of standard of care (SOC) background medications at the time of enrollment. Exclusion Criteria: Myositis due to non-Idiopathic inflammatory myopathies (non-IIM) Existing diagnosis of inclusion body myositis (IBM) Presence of immune-mediated necrotizing myositis (IMNM) Myositis with end-stage organ involvement Active bacterial, viral or fungal infections or hospitalizations for serious infections within 60 days prior to enrollment Have cancer or a history of cancer within 5 years of screening Significant current or prior disease conditions that may interfere with the response to or safety of the study medicine, including but not l limited to: history of major organ transplant acute coronary syndrome or any history of significant cerebrovascular disease within 24 weeks of screening preexisting demyelinating disorder such as multiple sclerosis, or other severe neurological disorder major surgery within 4 weeks of screening, or scheduled to occur during the study, excluding diagnostic surgery history of any lymphoproliferative disorder such as Epstein Barr Virus, history of lymphoma, leukemia, or symptoms of current lymphatic or lymphoid disease Clinically significant depression, suicidal ideation, or previous history of suicidal behaviors Other medical or laboratory abnormality that may increase the risk of study participation Previous administration with an investigational product (drug or vaccine) within 30 days or of the first dose of study medicine Current use or incomplete appropriate washout period of any prohibited medication(s), including known exposure to anti-interferon beta (PF-06823859) or any type of anti-interferon beta therapy Prior SOC medication that does not fulfill the criteria Certain laboratory results from screening assessments that may interfere with study participation. Investigator site staff directly involved in the conduct of the study and their family members, site staff and sponsor and sponsor delegate employees directly involved in the conduct of the study and their family members

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Randomized, double-blind, placebo-controlled, parallel-group study to assess whether the study medicine will work to lessen muscle weakness and skin symptoms in adults with active polymyositis (PM) or dermatomyositis (DM). Eligible participants are required to have active disease at the time of enrollment and are required to enter the study on protocol-permitted standard of care (SOC) background medication. The study will be conducted in 2 parallel cohorts: Cohort 1 (DM) and Cohort 2 (PM).
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: PF-06823859<br>Participants will receive PF-06823859 via intravenous infusion every 4 weeks. | Drug: PF-06823859<br>* anti-interferon beta therapy<br>|
| Placebo Comparator: Placebo<br>Participants will receive placebo via intravenous infusion every 4 weeks. | Drug: Placebo<br>* Placebo for PF-06823859<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Moderate change in Total Improvement Score (TIS) | Total Improvement Score 0 to 100 with higher scores indicating a better outcome. | 24 weeks outside of the United States (US) and 52 weeks in the US | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in Manual Muscle Testing - 8 designated muscles (MMT-8) | Manual Muscle Testing (8 designated muscles) 0 to 150 with higher scores indicating a better outcome | 24 weeks outside of the US and 52 weeks in the US | 
| Change from baseline in Cutaneous Dermatomyositis Disease Area and Severity Index Activity Score (CDASI-A) in participants with dermatomyositis (DM) | Cutaneous Dermatomyositis Disease Area and Severity Index Activity Score 0 to 100 with higher scores indicating a worse outcome. Only participants with baseline CDASI-A score >14 will be assessed. | Week 24 outside the US | 
| Change from baseline in Investigator Global Assessment severity scale (IGA) in participants with dermatomyositis | Investigator Global Assessment severity scale 0 to 4 with higher scores indicating a worse outcome. Only participants with baseline IGA ≥2 will be assessed | 24 and 52 weeks in the US only | 
| Corticosteroid (CS) dose assessment | Normalized Area Under the Curve (AUC) of corticosteroid dose | 52 weeks | 
| Moderate change in Total Improvement Score | Total Improvement Score 0 to 100 with higher scores indicating a better outcome. | 24 weeks in the US and 52 weeks outside of the US | 
| Change from baseline in Patient-Reported Outcomes Measurement Information System - Physical Function (PROMIS-PF) | Patient-Reported Outcomes Measurement Information System - Physical Function 0 to 100 with higher scores indicating a better outcome | 24 weeks outside of the US and 52 weeks in the US | 
| Change from baseline in 5-D Itch Scale Score | 5-D Pruritis Scale 5 to 25 with higher scores indicating a worse outcome. Only participants with baseline CDASI-A score >14 will be assessed. | 24 weeks outside of the US and 52 weeks in the US | 
| Change from baseline in Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-F) | Functional Assessment of Chronic Illness Therapy - Fatigue 0 to 52 with higher scores indicating a better outcome | 24 weeks outside of the US and 52 weeks in the US | 
| Response in corticosteroid tapering | At least 50% reduction from baseline or reduction in corticosteroid (CS) dose to <7.5 mg/day at Week 52 for participants with baseline CS dose ≥10 mg/day. | 52 weeks US only | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Dermatomyositis, Polymyositis