Sun Pharmaceutical Industries has submitted a supplemental Biologics License Application to the US FDA seeking approval for ILUMYA (tildrakizumab-asmn) for the treatment of adults with active psoriatic arthritis. The agency has accepted the application for review, with a regulatory action date expected by October 29, 2026, the company said. ILUMYA is a humanized monoclonal antibody that selectively binds the p19 subunit of interleukin-23, inhibiting downstream inflammatory signaling. If approved, this would represent a new indication for the drug, which has been available in the United States since 2018 for moderate-to-severe plaque psoriasis, with subsequent label expansions for scalp and nail psoriasis in 2024 and 2025, respectively.
The filing seeks approval based on a 100 mg dose of tildrakizumab in adults with active psoriatic arthritis. Sun Pharma has not disclosed whether it requested priority review or any accelerated regulatory pathway. The company characterized ILUMYA as the only healthcare-provider-administered IL-23 biologic, a distinction it frames as a potential differentiator in a therapeutic area where self-administered subcutaneous injections are the norm. No details regarding proposed dosing frequency for the psoriatic arthritis indication have been disclosed publicly, though in psoriasis the drug is administered every twelve weeks after loading doses.
The application rests on data from two Phase III trials, INSPIRE-1 and INSPIRE-2, both 52-week, global, multicenter, randomized, double-blind, placebo-controlled studies. INSPIRE-1 enrolled 508 participants with active psoriatic arthritis, while INSPIRE-2 enrolled 296 anti-TNF-naïve patients. The primary endpoint for both was the proportion of patients achieving ACR20 response, a standard composite measure of joint tenderness, swelling, and patient-reported outcomes. Top-line results reported in July 2025 indicated that tildrakizumab met the primary endpoint in both studies, though the company has not yet released specific response rates, secondary endpoint data, or detailed safety findings. Sun Pharma has stated that further results will be presented at a future medical congress.
Tildrakizumab would, if approved, become the third selective IL-23p19 inhibitor available for psoriatic arthritis in the United States, joining guselkumab (Tremfya, Johnson & Johnson) and risankizumab (Skyrizi, AbbVie). The psoriatic arthritis treatment landscape has expanded considerably in recent years, with the US FDA approving bimekizumab (Bimzelx, UCB), a dual IL-17A/F inhibitor, for the indication in September 2024, and deucravacitinib (Sotyktu, Bristol Myers Squibb), a selective TYK2 inhibitor, in March 2026. These join established classes including TNF inhibitors, IL-17A inhibitors, JAK inhibitors, and the PDE4 inhibitor apremilast. Despite this array of options, a substantial proportion of patients fail to achieve minimal disease activity or remission, and treatment selection is guided by the predominant disease domain, comorbidity profile, and safety considerations. IL-23 inhibitors as a class are generally associated with a favorable tolerability profile relative to JAK inhibitors, which carry boxed warnings for cardiovascular events and malignancy, and IL-17 inhibitors, which are linked to candidiasis and contraindicated in inflammatory bowel disease. The absence of published efficacy data from the INSPIRE trials makes it difficult to assess how tildrakizumab will compare with guselkumab and risankizumab, both of which have disclosed full Phase III results in psoriatic arthritis.
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