AstraZeneca Plc demonstrated encouraging clinical results from the Phase 3 TULIP-SC study evaluating subcutaneous (SC) delivery of anifrolumab, marketed as Saphnelo, in patients 18 to 70 years old diagnosed with moderately to severely active, autoantibody-positive systemic lupus erythematosus (SLE). The detailed results, released Tuesday, build upon initial topline data shared in September 2025, substantiating the therapeutic benefits observed with SC administration relative to placebo.
The TULIP-SC trial revealed that 56.2% of participants receiving Saphnelo via subcutaneous injection achieved a clinically meaningful reduction in disease activity at Week 52, surpassing the 37.1% response seen in the placebo cohort. This outcome aligns closely with findings from AstraZeneca’s previous investigations of the antibody therapy.
Sharon Barr, the company’s executive vice president of BioPharmaceuticals Research and Development, emphasized that this robust data reinforces the differentiated mechanism of action driving Saphnelo’s clinical impact. By selectively targeting the type 1 interferon receptor pathway, the treatment not only meaningfully reduces lupus disease activity but also introduces the advantage of self-administration through the SC formulation, enhancing patient convenience and potentially adherence.
Further interpreting these results, Barr highlighted how Saphnelo contributes to improved remission rates and supports significant reductions in oral corticosteroid use, underscoring AstraZeneca’s broader goal of transforming therapeutic approaches to lupus management. This marks an important development given the chronic and complex nature of the disease, along with the challenges associated with long-term steroid therapy.
Safety findings reported in the trial were consistent with the established profile of Saphnelo administered intravenously, suggesting the SC formulation does not introduce new or unexpected risks. The overall incidence of adverse events occurred at comparable rates between the treatment and placebo groups, supporting the tolerability of the subcutaneous option.
In addition to the primary endpoint of disease activity reduction, Saphnelo demonstrated positive effects across a range of secondary and exploratory measures. Nearly 29.0% of patients achieved remission as defined by Definitions Of Remission In SLE (DORIS), and 40.1% reached low-level disease activity benchmarks. The therapy also delayed the time to first flare in a numerical sense, indicating potential protective benefits against disease exacerbations.
The TULIP-SC full analysis confirmed and expanded upon the interim results, sustaining statistical significance and reinforcing confidence in the observed benefits. Importantly, the study also demonstrated the possibility of tapering to low doses of oral corticosteroids (≤7.5 mg/day) while maintaining disease control, an important milestone in reducing corticosteroid-related adverse effects in lupus patients.
Globally, Saphnelo administered via intravenous infusion holds regulatory approval for moderate to severe SLE in over 70 countries, encompassing major markets such as the United States, European Union, and Japan. Regulatory assessments are ongoing in additional territories, including China. The subcutaneous formulation has already been approved in the European Union and is under regulatory review in multiple countries, including the US and Japan.
To date, more than 40,000 patients worldwide have received Saphnelo treatment, reflecting its growing clinical adoption. AstraZeneca obtained global rights to Saphnelo through a licensing and collaboration deal with Medarex Inc. in 2004. While Medarex previously held an option to co-promote the drug, this right expired following the company’s acquisition by Bristol-Myers Squibb Co. in 2009. Under the licensing agreement, AstraZeneca is obligated to pay Bristol-Myers mid- to low-teen royalties on sales, subject to geographic factors.
In response to the TULIP-SC results, AstraZeneca shares experienced a modest increase, rising 0.58% to $91.75 during premarket trading on Tuesday, according to Benzinga Pro data.
Key Points:
- Phase 3 TULIP-SC trial confirms subcutaneous anifrolumab significantly reduces SLE disease activity compared to placebo.
- Saphnelo offers meaningful clinical benefits including increased remission rates and substantial reduction in oral corticosteroid use.
- The safety profile of subcutaneous administration aligns with established intravenous infusion data, showing balanced adverse event rates.
- Regulatory approval for intravenous Saphnelo exists in over 70 countries; subcutaneous form approved in EU and under review elsewhere.
Risks and Uncertainties:
- Regulatory decisions for subcutaneous Saphnelo pending in key markets including the United States and Japan.
- Potential market access challenges and competition within the lupus treatment landscape remain to be observed.
- Royalties to Bristol-Myers Squibb represent ongoing financial obligations dependent on geographic sales performance.
- Long-term safety and efficacy in broader patient populations require continued monitoring beyond trial results.