The full results from AstraZeneca’s phase 3 Tulip-SC trial build on the interim results that earned the drug a European approval last month.
Fresh off of a European approval for a subcutaneous version of Saphnelo, AstraZeneca is doubling down on the benefits of the self-administered drug formulation in lupus patients with a positive phase 3 showing.
In the phase 3 Tulip-SC trial, 56.2% of patients with systemic lupus erythematosus (SLE) who received a subcutaneous dose of Saphnelo experienced a reduction in disease activity at week 52, the company reported Tuesday. In the placebo group, the result was 37.1%.
The readout adds more detail to the trial’s prior interim analysis, which confirmed a statistically significant result for subcutaneous Saphnelo and a safety profile on par with the currently marketed intravenous infusion version.
Subcutaneous Saphnelo also met the bar across a range of secondary endpoints in the trial, many of which use the British Isles Lupus Assessment Group-based Composite Lupus Assessment (BICLA) as a measure of disease activity.
AstraZeneca found that more patients (41.5%) achieved a faster BICLA response with SC Saphnelo than with placebo, and that those in the treatment group had a longer delay to their first disease flare-up.
Additional pre-specified secondary and exploratory endpoints, 40.1% of patients on treatment attained low-level disease activity and 29% achieved DORIS remission at week 52, as did 14.7% on placebo.
Recently revised treatment guidance for SLE positions DORIS remission, which is a remission definition established by the DORIS Task Force, as the primary goal of care, AstraZeneca notes.
“These results reinforce Saphnelo’s unique approach of targeting the type 1 interferon receptor to reduce disease activity, with the added convenience of subcutaneous self-administration,” Sharon Barr, EVP of R&D at AstraZeneca, said in a company release. “The TULIP-SC findings build on the compelling body of evidence for Saphnelo, which has helped patients achieve remission and significantly reduce reliance on oral corticosteroids—further reinforcing our ambition to transform lupus care.”
Tapering toward chronic oral corticosteroids (OCS) discontinuation is another recent addition to lupus treatment recommendations, putting AZ’s results in line with the key changes to the global standards, the company explained in the release.
Saphnelo, as an IV infusion, won FDA approval in 2021, breaking a 10-year treatment drought in SLE after GSK’s 2011 nod for Benlysta. The nod came after a phase 3 trial found that Saphnelo didn’t outperform placebo on a disease response measure called the SLE Responder Index 4, prompting AZ to pivot to the BICLA marker for its next study.
Over 3.4 million people globally are impacted by SLE, and the disease is one of the leading causes of death in young women in the U.S., according to the company. AZ hopes to reach more of those patients through its more convenient, subcutaneous version of Saphnelo.
European regulators were the first to approve Saphnelo as a once-weekly, pre-filled pen in December, while regulatory applications in other countries, including the U.S. and Japan, are under review.
The new formulation could be key to catching up with GSK’s Benlysta, which was approved as a self-injectable treatment option in 2017. With a ten-year lead on Saphnelo, Benlysta remains the one to beat in the SLE field, touting blockbuster sales in 2024 compared to Saphnelo’s $474 million.
However, Spherix Global Insights analysts note that the lupus treatment landscape is “poised for evolution,” noting that Biogen’s experimental litifilimab is an “especially strong competitor” to the two existing offerings from AZ and GSK.
