Drug Update · Rheumatology

FDA Approves Subcutaneous Anifrolumab for Moderate-to-Severe SLE

August 23, 2026

FDA approval date

04/24/2026

Approved subcutaneous dose

120 mg once every week

Approved intravenous dose

300 mg every 4 weeks

BLA number for subcutaneous

761451

Clinical Perspective

Rheumatologists and other clinicians treating adults with moderate to severe SLE now have an FDA-approved subcutaneous formulation of anifrolumab that can be prescribed for patients receiving standard therapy, expanding administration options beyond the intravenous 300 mg infusion ^[2]^[3]^[5]. The approval supports weekly subcutaneous self-administration or caregiver administration using a 120 mg/0.8 mL prefilled syringe or autoinjector (SAPHNELO PEN) as described in the prescribing information ^[1]^[3]. What is the long-term safety and comparative tolerability of the subcutaneous administration route relative to the established intravenous regimen in real-world use?

Dr. Deepak Nair, MBBS, MD (General Medicine), DM (Clinical Immunology & Rheumatology) · Rheumatology

The U.S. Food and Drug Administration approved Saphnelo (anifrolumab-fnia) accessorized pre-filled syringe and autoinjector for subcutaneous use, effective 04/24/2026, authorizing marketing of 120 mg/0.8 mL prefilled syringe or autoinjector for adults with moderate to severe systemic lupus erythematosus (SLE) receiving standard therapy ^[2]^[3]. Clinicians should consult current prescribing information for full dosing guidance. The approval supplements existing intravenous labeling and adds a weekly 120 mg subcutaneous dosing option to the product’s prescribing information ^[1]^[3].

Clinical Context

Saphnelo (anifrolumab-fnia) is a human IgG1κ monoclonal antibody that binds subunit 1 of the type I interferon (IFN) receptor (IFNAR1) and inhibits type I IFN signaling, a pathway implicated in SLE pathogenesis ^[7]. The product is marketed by AstraZeneca and, under the approved license, will be supplied as an accessorized pre-filled syringe and autoinjector (SAPHNELO PEN) for subcutaneous administration in a 120 mg/0.8 mL strength, in addition to the existing intravenous 300 mg/2 mL vial formulation ^[2]^[3]. Clinicians should consult current prescribing information for full dosing guidance. Manufacturing and labeling details for the subcutaneous product are described in the FDA approval letter ^[2]. Regulatory review materials note that Saphnelo is intended for use under healthcare provider guidance and may be administered either intravenously or subcutaneously per the prescribing information ^[1]^[3].

Key Findings

Regulatory documents and product summaries report that two pivotal studies of anifrolumab 300 mg demonstrated improved clinical response versus placebo measured by composite disease activity indices. Clinicians should consult current prescribing information for full dosing guidance. In two main pivotal trials, Saphnelo 300 mg given as an add-on to standard therapy achieved a BICLA response in 47% versus 30% with placebo in one study, and 48% versus 32% with placebo in a second study, supporting efficacy in adults with moderate to severe autoantibody-positive SLE ^[4]. The FDA labeling and clinical studies synopsis describe three randomized, double-blind, placebo-controlled 52-week trials used to evaluate efficacy (Trials 1, 2 and 3), with primary endpoints including SRI‑4 in one trial and BICLA in another; the trials enrolled adults with moderate to severe SLE receiving standard therapy ^[7]. The FDA approval letter authorizes the subcutaneous 120 mg/0.8 mL prefilled syringe and autoinjector presentation for commercial distribution ^[2].

Safety & Tolerability

Serious and sometimes fatal infections have occurred in patients receiving SAPHNELO; SAPHNELO increases the risk of respiratory infections and herpes zoster and initiating treatment during an active infection should be avoided ^[1]^[3].
Serious hypersensitivity reactions including anaphylaxis and angioedema have been reported; SAPHNELO is contraindicated in patients with a history of anaphylaxis to anifrolumab-fnia ^[1]^[3].
The labeling advises caution regarding malignancy risk and recommends updating immunizations prior to initiating therapy and avoiding live or live-attenuated vaccines while on treatment ^[1]^[3].
The most common adverse reactions (incidence ≥5%) listed in the prescribing information include nasopharyngitis, upper respiratory tract infections, bronchitis, infusion-related reactions, herpes zoster and cough; adverse reactions occurring ≥2% in intravenous trials included upper respiratory tract infection (34% vs 23% placebo), bronchitis (11% vs 5.2% placebo), infusion-related reactions (9.4% vs 7.1% placebo), herpes zoster (6.1% vs 1.3% placebo), cough (5.0% vs 3.2% placebo) and respiratory tract infection (3.3% vs 1.5% placebo) ^[1]^[3]^[6].

Study Design

The safety and efficacy database described in labeling includes three 52‑week, multicenter, randomized, double-blind, placebo-controlled trials (Trials 1 [NCT01438489], Trial 2 [NCT02446912] and Trial 3 [NCT02446899]) enrolling adults with moderate to severe SLE on stable background therapy; primary endpoints included SRI‑4 in Trial 2 and BICLA in Trial 3, with common secondary endpoints such as maintenance of oral corticosteroid reduction and cutaneous response ^[7]. The EMA summary and product information reference two main pivotal studies showing the BICLA responder rates cited above, and the FDA approval letter (BLA 761451) authorizes subcutaneous presentations in 120 mg/0.8 mL format for marketing and details manufacturing and dating period conditions ^[2]^[4]^[7]. Clinicians should consult current prescribing information for full dosing guidance.

FAQ

Q1 What is Saphnelo (anifrolumab-fnia) approved for?

Saphnelo is approved for the treatment of adult patients with moderate to severe systemic lupus erythematosus (SLE) who are receiving standard therapy. The prescribing information states that efficacy has not been evaluated in patients with severe active lupus nephritis or severe active central nervous system lupus, and use is not recommended in those situations.

Q2 How does anifrolumab (Saphnelo) work?

Anifrolumab-fnia is a human IgG1κ monoclonal antibody that binds to subunit 1 of the type I interferon receptor (IFNAR1) with high specificity and affinity, inhibiting type I interferon signaling. This blockade reduces interferon‑responsive gene expression and downstream inflammatory and immunological processes implicated in SLE pathogenesis.

Q3 What is the recommended dose of Saphnelo?

The prescribing information lists two recommended dosage regimens: 300 mg administered as an intravenous infusion over a 30‑minute period every 4 weeks, or 120 mg administered as a subcutaneous injection once every week using a prefilled syringe or autoinjector (SAPHNELO PEN). Clinicians should consult current prescribing information for complete dosing guidance.

Q4 What are the most common side effects of Saphnelo?

Most common adverse drug reactions reported with SAPHNELO include nasopharyngitis, upper respiratory tract infections, bronchitis, infusion‑related reactions, herpes zoster and cough. Labeling also warns of serious infections (including COVID‑19), hypersensitivity reactions including anaphylaxis and angioedema, and advises updating immunizations prior to therapy and avoiding live or live‑attenuated vaccines while treated with SAPHNELO. Clinicians should consult current prescribing information for complete dosing guidance.

FDA Approves Subcutaneous Anifrolumab for Moderate-to-Severe SLE

Direct Clinical Takeaway & Evidence Summary

FDA Approves Subcutaneous Anifrolumab for Moderate-to-Severe SLE

Clinical Perspective

Clinical Context

Key Findings

Safety & Tolerability

Study Design

FAQ

References

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