FDA Approves Anifrolumab-fnia Autoinjector for SLE Self-Administration, Offering Subcutaneous Option

The FDA has approved anifrolumab-fnia (Saphnelo; AstraZeneca) for subcutaneous (SC) self-administration via the Saphnelo Pen, a once-weekly autoinjector, for the treatment of adult patients with moderate to severe systemic lupus erythematosus (SLE) receiving standard therapy. The approval marks a significant shift in how this first-in-class type I interferon (IFN) receptor antagonist can be delivered, moving beyond the clinic-based, monthly intravenous (IV) infusion that has been available since 2021.¹

Anifrolumab works by binding to subunit 1 of the type I IFN receptor, blocking the activity of type I IFNs, including IFN-α, IFN-β, and IFN-κ—cytokines that are centrally implicated in SLE's inflammatory pathways. The IV formulation has already been approved in more than 70 countries and has been used to treat upward of 40,000 patients globally.¹

TULIP-SC Trial: Key Evidence Supporting Approval

The FDA's decision was based on results from the phase 3 TULIP-SC trial (NCT04877691), a multicenter, randomized, double-blind, placebo-controlled study evaluating SC anifrolumab in adults aged 18 to 70 years with moderate to severe, autoantibody-positive SLE on background standard therapy. The 367 participants were randomly assigned 1:1 to receive anifrolumab 120 mg or placebo SC once weekly for 52 weeks.²

The primary end point, which was the proportion of patients achieving a British Isles Lupus Assessment Group–based Composite Lupus Assessment (BICLA) response at week 52, was met. In the full analysis, approximately 56.2% of patients receiving SC anifrolumab achieved a BICLA response at week 52 vs 37.1% in the placebo group. The BICLA requires improvement across all organ systems with active disease at baseline, while permitting no new flares.²

Beyond the primary end point, patients in the anifrolumab group also outperformed placebo in both definition of remission in SLE, or DORIS (treatment difference = 14.2%; P = .0012), and low lupus disease activity state (treatment difference = 14.1%; P = .0038) at week 52. Serious adverse events occurred in 11.9% of anifrolumab patients vs 10.4% in the placebo group; herpes zoster was reported more frequently in the active treatment arm but at low overall rates.²

The safety profile observed in TULIP-SC was consistent with that of the IV formulation, based on the well-established TULIP-1 and TULIP-2 programs, and no new safety signals were identified.¹

Aligning With Updated Treatment Guidelines

The approval arrives at a pivotal moment for SLE management. The 2025 American College of Rheumatology (ACR) guideline for the treatment of SLE emphasizes uniform treatment with hydroxychloroquine, limiting duration of glucocorticoid use, and early introduction of conventional and/or biologic immunosuppressive therapies to achieve remission or low-level disease activity. Anifrolumab is one of only 2 FDA-approved biologics specifically indicated for SLE, alongside belimumab (Benlysta; GSK).³

The updated ACR guidelines now identify DORIS as the treatment target and set a new glucocorticoid goal of 5 mg/d or less—with 0 mg/d being ideal—while encouraging early introduction of steroid-sparing immunosuppressants and biologics. The TULIP-SC data align directly with these targets, demonstrating that SC anifrolumab can support oral corticosteroid reduction while sustaining disease control.³

What the Saphnelo Pen Means for Patients and Pharmacists

The approval of an SC autoinjector represents more than a formulation change; it fundamentally reshapes access. Patients previously required monthly visits to a clinic or infusion center for IV administration. The Saphnelo Pen allows for once-weekly, 120-mg SC dosing that patients can self-administer at home or with caregiver support.¹

SLE disproportionately affects Asian, Black, and Hispanic populations and is among the leading causes of death in young women in the US. Greater flexibility in administration could help reduce barriers to treatment in these communities, many of whom may face challenges related to time off work, transportation, or clinic access.¹

Pharmacists dispensing the Saphnelo Pen should counsel patients on proper injection technique, storage requirements, and the recognition of hypersensitivity reactions, including anaphylaxis, which represents a contraindication in those with a known history. Live and live-attenuated vaccines should be avoided during treatment, and the drug is not recommended in combination with other biologics, including B-cell–targeted therapies. Patients with a history of recurrent or severe infections warrant close monitoring, as respiratory infections and herpes zoster represent notable risks.¹

Looking Ahead

Anifrolumab SC was developed to enable at-home self-administration and potentially increase treatment accessibility, with the 120-mg once-weekly dose selected based on pharmacokinetic modeling showing exposure comparable to the approved 300-mg IV monthly dose. AstraZeneca continues to evaluate anifrolumab in phase 3 trials across other type I IFN-driven diseases, including cutaneous lupus erythematosus, myositis, systemic sclerosis, and lupus nephritis.^1,2

As SLE treatment continues to evolve toward personalized, treat-to-target strategies, the SAPHNELO Pen offers pharmacists a new touchpoint to support patient education, adherence, and self-management—key pillars of optimal long-term outcomes in this challenging, complex disease.

REFERENCES

1. SAPHNELO approved in the US for subcutaneous self-administration as a new autoinjector for the treatment of systemic lupus erythematosus. News release. AstraZeneca. April 27, 2026. Accessed April 27, 2026. https://www.astrazeneca-us.com/media/press-releases/2026/SAPHNELO-approved-in-the-US-for-subcutaneous-self-administration-as-a-new-autoinjector-for-the-treatment-of-systemic-lupus-erythematosus.html

2. Manzi S, Bruce IN, Morand EF, et al; TULIP‐SC investigators. Efficacy and safety of subcutaneous anifrolumab in systemic lupus erythematosus: a randomized, phase 3 study. Arthritis Rheumatol. Published online December 29, 2025. doi:10.1002/art.70041

3. Sammaritano LR, Askanase A, Bermas BL, et al. 2025 American College of Rheumatology (ACR) guideline for the treatment of systemic lupus erythematosus. Arthritis Rheumatol. Published online November 4, 2025. doi:10.1002/acr.25690