Saphnelo (anifrolumab)
An investigational treatment for Dermatomyositis.
The same compound appears under different names depending on the context. Here is how to identify Anifrolumab wherever you encounter it, plus the key facts at a glance.
- Generic name
- Anifrolumab
- Brand name
- Saphnelo
- Development code
- MEDI-546
- Drug class
- Monoclonal antibody (anti-IFNAR1)
- Manufacturer
- AstraZeneca
- How it's taken
- For lupus, anifrolumab is approved as an IV infusion of 300 mg every 4 weeks, and since April 2026 in the U.
Originally approved for lupus, this antibody blocks the receptor that all type I interferons use to trigger inflammation. It is being tested in a Phase 3 trial in dermatomyositis and polymyositis.
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How Anifrolumab works
Anifrolumab blocks the interferon-alpha receptor (IFNAR1) on cells. Interferon-alpha is a key driver of inflammation in dermatomyositis and other autoimmune conditions. By blocking this receptor, the drug prevents interferon from activating immune cells and triggering inflammatory cascades.
Mechanism: Blocks the type I interferon receptor (IFNAR1)
Side effects and safety
Potential side effects include infections, headache, nausea, and fatigue. Because it targets the interferon signaling pathway, it can affect immune responses. Patients should be monitored for signs of infection during treatment.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Anifrolumab
For lupus, anifrolumab is approved as an IV infusion of 300 mg every 4 weeks, and since April 2026 in the U.S. as a 120 mg weekly injection under the skin using a pen. The JASMINE myositis trial uses the weekly injection under the skin.
Clinical trial results
The Phase 3 JASMINE trial (NCT06455449) is testing weekly anifrolumab injected under the skin against placebo in about 240 adults with moderate to severe dermatomyositis or polymyositis. It is recruiting, with main results expected around 2027. The drug is already approved for systemic lupus erythematosus.
Main registered trial: NCT06455449 on ClinicalTrials.gov. Check it for the current status, sites and contacts before asking about enrollment.
Development history
Anifrolumab (MEDI-546) was developed by AstraZeneca as a fully human monoclonal antibody. It was first approved for lupus in 2021 and is now being tested in dermatomyositis and other autoimmune conditions based on the strong anti-interferon rationale.
Explore Dermatomyositis trials
Other Dermatomyositis treatments
Common questions about Anifrolumab
▸What is Anifrolumab (Saphnelo)?
Originally approved for lupus, this antibody blocks the receptor that all type I interferons use to trigger inflammation. It is being tested in a Phase 3 trial in dermatomyositis and polymyositis.
▸How does Anifrolumab work?
Anifrolumab blocks the interferon-alpha receptor (IFNAR1) on cells. Interferon-alpha is a key driver of inflammation in dermatomyositis and other autoimmune conditions. By blocking this receptor, the drug prevents interferon from activating immune cells and triggering inflammatory cascades.
▸What are the side effects of Anifrolumab?
Potential side effects include infections, headache, nausea, and fatigue. Because it targets the interferon signaling pathway, it can affect immune responses. Patients should be monitored for signs of infection during treatment.
▸How is Anifrolumab taken?
For lupus, anifrolumab is approved as an IV infusion of 300 mg every 4 weeks, and since April 2026 in the U.S. as a 120 mg weekly injection under the skin using a pen. The JASMINE myositis trial uses the weekly injection under the skin.
▸Is Anifrolumab FDA approved?
Anifrolumab is currently in phase 3 clinical trials for Dermatomyositis. It has not yet received FDA approval.
▸Is anifrolumab already approved for another condition?
Yes. Anifrolumab (Saphnelo) is approved for systemic lupus erythematosus (SLE). It is now being studied in the Phase 3 JASMINE trial for dermatomyositis and polymyositis.
▸How does anifrolumab work?
Anifrolumab blocks the type I interferon receptor, shutting down a key inflammatory pathway that is overactive in both lupus and dermatomyositis. This targeted approach may reduce the autoimmune attack on skin and muscle tissue.
▸How is anifrolumab administered?
For lupus, anifrolumab can be given as an IV infusion every 4 weeks or, since April 2026 in the U.S., as a weekly self-injection under the skin. The JASMINE trial in myositis tests the weekly injection under the skin.
▸Why is the interferon pathway relevant to dermatomyositis?
Type I interferons are overproduced in dermatomyositis and drive much of the inflammatory damage to skin and muscle. Blocking this pathway with anifrolumab targets a root cause of the disease rather than broadly suppressing the immune system.
Sources and references
Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.
- ClinicalTrials.gov. JASMINE: anifrolumab in idiopathic inflammatory myopathies. https://clinicaltrials.gov/study/NCT06455449
- AstraZeneca · 2026-04-27. Saphnelo approved in the US for subcutaneous self-administration. https://www.astrazeneca.com/media-centre/press-releases/2026/saphnelo-self-administration-approved-in-the-US.html