The US Food and Drug Administration (FDA) issued a complete response letter (CRL) regarding the Biologics License Application (BLA) for Saphnelo (anifrolumab) for subcutaneous administration in adult patients with systemic lupus erythematosus (SLE). AstraZeneca subsequently provided the information requested in the CRL and is committed to working with the FDA to progress the application as quickly as possible.

A decision from the FDA on the updated application for Saphnelo SC is expected in the first half of 2026. Intravenous (IV) Saphnelo remains commercially available.

The original BLA submitted to the FDA by AstraZeneca was based on a planned interim analysis of the Phase III TULIP-SC trial evaluating the subcutaneous administration of Saphnelo, which met the primary endpoint. The safety profile observed in the TULIP-SC trial was consistent with the known clinical profile of Saphnelo administered as an intravenous (IV) infusion.^1-4

In December 2025, AstraZeneca announced the approval of Saphnelo in the European Union (EU) for subcutaneous administration in adult patients with moderate to severe SLE. Since then, the full analysis of the TULIP-SC trial also demonstrated the subcutaneous administration of Saphnelo met the primary endpoint of reduction in disease activity. These results were published in Arthritis & Rheumatology in January 2026. 

Saphnelo IV infusion is approved for the treatment of moderate to severe SLE in more than 70 countries worldwide including the US, EU and Japan. To date, more than 40,000 patients globally have been treated with Saphnelo.⁵

Notes

Financial considerations 
AstraZeneca acquired global rights to Saphnelo through an exclusive license and collaboration agreement with Medarex, Inc. in 2004. The option for Medarex to co-promote the product expired on its acquisition by Bristol-Myers Squibb (BMS) in 2009. Under the agreement, updated in 2025, AstraZeneca will pay BMS a mid-teens royalty for sales in the US.  

Systemic lupus erythematosus
SLE is an autoimmune disease in which the immune system attacks healthy tissue in the body.⁶ It is a chronic and complex disease with a variety of clinical manifestations that can impact many organs and can cause a range of symptoms, including pain, rashes, fatigue, swelling in joints and fevers.^6-9

Over 3.4 million people globally are affected by SLE.¹⁰ Living with SLE can be painful, debilitating, and have a profound impact on patients' mental and financial wellbeing.^9,11-15 An estimated 50% of people with SLE have irreversible organ damage within five years of diagnosis due to long-term corticosteroid use and disease activity.^11,16 Even a small reduction in daily steroid use (for example 1mg/day) can lower the risk of organ damage.¹⁷

TULIP-SC
TULIP-SC was a Phase III, multicentre, randomised, double-blind, placebo-controlled study to evaluate the efficacy and safety of a subcutaneous administration of anifrolumab versus placebo in participants aged 18 to 70 years with moderate to severe SLE while receiving standard therapy (oral corticosteroids, antimalarial, and/or immunosuppressants).¹⁸

The reduction of disease activity was measured using the British Isles Lupus Assessment Group based Composite Lupus Assessment (BICLA) at week 52.¹⁸ The BICLA requires improvement in all organs with disease activity at baseline with no new flares.¹⁸

Participants (367) were randomised 1:1 to receive 120mg subcutaneous dose of anifrolumab or placebo administered via a pre-filled, single-use syringe.¹⁸ A planned interim analysis was conducted when the first 220 participants reached week 52.¹⁸ The trial also includes an open-label extension period of 52 weeks for participants who completed the 52-week treatment period.¹⁸

Saphnelo
Saphnelo (anifrolumab) is a first-in-class, fully human monoclonal antibody that binds to subunit 1 of the type I interferon (IFN) receptor, blocking the activity of type I IFN.^2,19 Type I IFNs, such as IFN-alpha, IFN-beta and IFN-kappa, are cytokines involved in regulating the inflammatory pathways implicated in SLE.^20-25

Saphnelo IV is the first biologic with remission data in SLE from a four-year placebo-controlled Phase III trial (TULIP-LTE) and was measured with the DORIS criteria for remission.^26,27 DORIS is measured as clinical SLEDAI-2K, or "Systemic Lupus Erythematosus Disease Activity Index 2000" score of 0, physician global assessment <0.5, prednisolone/ equivalent dose of OCS dose of ≤5 mg per day and stable maintenance doses of immunosuppressants, including biologics.²⁸

Saphnelo continues to be evaluated in diseases where type I IFN plays a key role, including Phase III trials in cutaneous lupus erythematosus, myositis, systemic sclerosis and lupus nephritis.^29-32     

AstraZeneca in Respiratory & Immunology
Respiratory & Immunology, part of AstraZeneca BioPharmaceuticals, is a key disease area and growth driver to the Company.

AstraZeneca is an established leader in respiratory care with a 50-year heritage and a growing portfolio of medicines in immune-mediated diseases. The Company is committed to addressing the vast unmet needs of these chronic, often debilitating, diseases with a pipeline and portfolio of inhaled medicines, biologics and new modalities aimed at previously unreachable biologic targets. Our ambition is to deliver life-changing medicines that help eliminate COPD as a leading cause of death, eliminate asthma attacks and achieve clinical remission in immune-mediated diseases.

AstraZeneca
AstraZeneca (LSE/STO/NYSE: AZN) is a global, science-led biopharmaceutical company that focuses on the discovery, development, and commercialisation of prescription medicines in Oncology, Rare Diseases, and BioPharmaceuticals, including Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca's innovative medicines are sold in more than 125 countries and used by millions of patients worldwide. Please visit astrazeneca.com and follow the Company on Social Media @AstraZeneca.

Contacts
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References

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1. Fanouriakis A, et al. EULAR recommendations for the management of systemic lupus erythematosus: 2023 update. Ann Rheum Dis. 2024;83(1):15-29. 
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