ClinicalTrials.gov record NCT06455449

A Study to Investigate the Efficacy and Safety of Anifrolumab Administered as Subcutaneous Injection and Added to Standard of Care Compared With Placebo Added to Standard of Care in Adult Participants With Idiopathic Inflammatory Myopathies (Polymyositis and Dermatomyositis)

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Sep 17, 2026

A Multicenter, Parallel-group, Double-blind, 2-Arm, Phase III Study to Investigate the Efficacy and Safety of Anifrolumab Administered as Subcutaneous Injection and Added to Standard of Care Compared With Placebo Added to Standard of Care in Adult Participants With Idiopathic Inflammatory Myopathies (Polymyositis and Dermatomyositis)

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.
Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.
PhasePhase 3A later-stage study, usually with more participants, designed to give stronger evidence about how well a treatment works and how safe it is. It often compares the treatment with standard care or a placebo, and results may support an application for approval.
Age18 years old to 75 years old
SexAll
LocationArgentina, Australia, Austria, Belgium, Brazil, Bulgaria, Canada, Chile, China, Czechia, Denmark, France, Germany, Hungary, India, Israel, Italy, Japan, Mexico, Netherlands, Poland, Puerto Rico, South Korea, Spain, Sweden, Taiwan, United Kingdom, United States, Vietnam
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This randomized, double-blind study compares weekly subcutaneous anifrolumab plus standard of care with matched placebo plus standard of care in adults with moderate-to-severe polymyositis or dermatomyositis. The blinded treatment period lasts 52 weeks, with a primary outcome measured at Week 52; after that, all participants receive open-label anifrolumab for an additional 52 weeks. The study evaluates disease activity and safety while participants remain on their background treatments.

What it is studying. The study investigates the efficacy and safety of adding once-weekly subcutaneous anifrolumab to standard of care, compared with placebo, on overall disease activity in adults with moderate-to-severe polymyositis or dermatomyositis.

What the researchers hope to learn. To evaluate whether subcutaneous anifrolumab added to standard treatment affects overall disease activity and to assess its safety profile in polymyositis and dermatomyositis. Key measured outcomes include a Total Improvement Score response at 52 weeks, muscle strength tests, corticosteroid dose use, skin disease measures, and cumulative corticosteroid exposure.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

The purpose of this multicenter, randomized, placebo-controlled and double-blind study is to evaluate the efficacy and safety of subcutaneous anifrolumab compared with placebo on the overall disease activity in participants with moderate to severe Idiopathic Inflammatory Myopathies (IIM) [polymyositis (PM) or dermatomyositis (DM)] while receiving standard of care (SoC) treatment.

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Combination product
  • Anifrolumab (blinded)
  • Anifrolumab (unblinded, open label)
Other
  • Placebo

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

  • Capable of giving informed consent.
  • 18 - 75 years old
  • Body weight ≥40 kg
  • Must have "probable" or "definite" diagnosis of PM or DM according to the 2017 ACR/EULAR classification criteria for adult myositis.
  • Moderate or severe disease activity per core set measurements.
  • Currently receiving oral prednisone or other polymyositis or dermatomyositis treatments at a stable dose.
  • No history of active tuberculosis or severe COVID-19.
  • Male and female participants must follow contraception guidelines.

Exclusion criteria

  • Participants with documented inclusion body myositis (IBM), immune mediation necrotizing myositis (IMNM), juvenile myositis (if diagnosed within 10 years prior to signing the ICF), drug-induced myositis, cancer associated myositis, amyopathic DM, and non inflammatory myopathies (eg, muscular dystrophies).
  • PM and DM patients at a high risk of malignancy.
  • Participants with rapidly progressive interstitial lung disease.
  • Participants with severe muscle damage or permanent weakness due to non-PM or non-DM conditions (i.e. stroke) as per the investigator's opinion.
  • Any history of severe case of herpes zoster infection
  • History of cancer (except adequately treated basal cell carcinoma or cervical cancer in-situ), immunodeficiency, HIV, HBV, active HCV .
  • Any clinical cytomegalovirus or Epstein-Barr virus infection that has not completely resolved within 12 weeks prior to signing the ICF.
  • Opportunistic infection requiring hospitalization or IV antimicrobial treatment within 3 years prior to randomization.
  • Recent non-opportunistic infection requiring hospitalization or anti-infective treatment.
  • Recent or concurrent enrollment in another clinical study with an investigational product.
  • Lactating, breastfeeding, or pregnant females or females who intend to become pregnant or begin breastfeeding

Study description and what participation involves

The registry record has no detailed description beyond the summary above.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Participants are randomized to receive weekly subcutaneous injections of either blinded anifrolumab or matched placebo added to their standard of care for 52 weeks. Study visits will include repeated disease assessments used in the trial (for example muscle strength testing, skin activity scores for DM, recording of corticosteroid dose, and core set patient/physician assessments and function questionnaires) and safety monitoring. At Week 52 all participants (whether they received placebo or anifrolumab) will receive open-label anifrolumab once weekly for an additional 52 weeks. The study requires adherence to contraception rules and avoidance of pregnancy or breastfeeding during participation.

How the study is structured. Adults are randomly assigned to one of two groups: weekly subcutaneous anifrolumab plus standard of care, or matched placebo plus standard of care. The trial is double-blind (participants, care providers, investigators, and outcome assessors are masked) during the 52‑week randomized phase. At Week 52 there is an open-label period in which all participants receive anifrolumab once weekly for another 52 weeks.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • Some participants receive a placebo. How is that decided, and what happens for placebo-group participants when the study ends?
  • The listed sites are in Argentina, Australia, Austria, Belgium, Brazil, Bulgaria, Canada, Chile, China, Czechia, Denmark, France, Germany, Hungary, India, Israel, Italy, Japan, Mexico, Netherlands, Poland, Puerto Rico, South Korea, Spain, Sweden, Taiwan, United Kingdom, United States, Vietnam. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on dermatomyositis

This trial is also listed on this site under polymyositis.

Clinical trials59 trials listed for dermatomyositisEvery trial the registry lists for dermatomyositis, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in dermatomyositis researchLatest monthly update: September 2026. Includes: Upadacitinib case reports. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start
Jun 20, 2024
Primary completion
Jan 10, 2028 (estimated)
Study completion
Apr 9, 2029 (estimated)
Target enrollment
240 participants (estimated)
Last updated on registry
Sep 24, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
AstraZeneca

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites (237)

  • Research SiteNot Yet Recruiting

    Phoenix, Arizona, 85032 · United States

  • Research SiteRecruiting

    Irvine, California, 92617 · United States

  • Research SiteRecruiting

    Aurora, Colorado, 80045 · United States

  • Research SiteRecruiting

    Denver, Colorado, 80230 · United States

  • Research SiteRecruiting

    New Haven, Connecticut, 06519 · United States

  • Research SiteWithdrawn

    Washington D.C., District of Columbia, 20037 · United States

  • Research SiteRecruiting

    Boca Raton, Florida, 33486 · United States

  • Research SiteWithdrawn

    Boynton Beach, Florida, 33472 · United States

  • Research SiteWithdrawn

    Gainesville, Florida, 32603 · United States

  • Research SiteRecruiting

    Margate, Florida, 33063 · United States

Terms used on this page · explanations by MedicalUpdates.ai

randomized
Participants are assigned to the study groups by chance, like a coin toss, rather than chosen by the doctor or the participant. This is done so the groups are comparable.
placebo-controlled
A study design in which one group receives a placebo so that the study treatment's effects can be compared with no active treatment.
double-blind
Two types of people involved in the study do not know which intervention a participant is receiving. The ClinicalTrials.gov record specifies who is masked, for example participants, care providers, investigators or outcome assessors.
placebo
A treatment that looks like the study treatment but contains no active ingredient. Some participants receive it instead of the study treatment, usually without knowing which they got.
standard of care
Treatment generally considered appropriate for a condition in a particular clinical setting. It can vary by patient, place and over time. In many studies the new treatment is added to, or compared with, standard of care.
informed consent
The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
prednisone
Steroid medicines, such as prednisone, that reduce inflammation. Studies often require a stable dose at entry or measure whether the study treatment allows the dose to be reduced.
stable dose
A dose that has not changed for a defined period before the study starts. Studies may require this so that background treatment is relatively stable when study measurements begin.
enrollment
The number of participants a study plans to include, or has included. 'Estimated' means the planned number; 'actual' means the number who joined.
investigational product
A treatment that is being tested and has not been approved for this use. It may be approved for a different condition. Being studied does not mean it works or is available outside the study.
Inclusion Criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion Criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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