Tildrakizumab Moves Toward New Indication With sBLA Acceptance for Active Psoriatic Arthritis

Today, Sun Pharma announced that the US FDA has accepted for review a supplemental biologics license application (sBLA) seeking approval of tildrakizumab (Ilumya) for the treatment of adults with active psoriatic arthritis (PsA).¹ A Prescription Drug User Fee Act target action date of October 29, 2026, has been assigned. As 1 in 3 patients with psoriasis develop PsA, the indication would expand the clinical use of the IL-23 inhibitor beyond dermatology into the broader spectrum of psoriatic disease.

"For many people living with psoriatic disease, joint symptoms often add another layer of burden," says Rick Ascroft, CEO of Sun Pharma North America. "As we continue to strengthen Sun Pharma's innovative portfolio, we look forward to working with the FDA throughout the review process. As the only [health care provider]–administered IL-23 biologic, our ambition is that Ilumya becomes a differentiated first-choice advanced systemic treatment for active [PsA]."¹

The INSPIRE Phase 3 Program

This sBLA submission is based on data from 2 global phase 3 clinical trials—INSPIRE 1 (NCT04314544) and INSPIRE 2 (NCT04314531)—which evaluated the efficacy and safety of tildrakizumab 100 mg in adults with active PsA. Both studies were 52-week, multicenter, randomized, double-blind, single-dose, placebo-controlled trials designed to assess clinical outcomes in patients with active disease. More than 800 eligible patients with active PsA were enrolled at clinical sites in the US, Europe, and Asia. In INSPIRE 1, participants had previously been treated with an anti–tumor necrosis factor (TNF agent, whereas in INSPIRE 2, participants were naive to anti-TNFs. Patients were randomly assigned to receive either tildrakizumab 100 mg or placebo and were granted permission to use stable doses of concomitant methotrexate or leflunomide, if needed. Tildrakizumab was administered every 12 weeks.

The primary end point for both studies is the proportion of participants achieving American College of Rheumatology 20% response criteria (ACR20) at week 24. This is defined as improvement in the number of tender and swollen joints, along with 20% improvement in 3 criteria, including patient global assessment, physician global assessment, functional ability measure (Health Assessment Questionnaire Disability Index), visual analog pain scale, and erythrocyte sedimentation rate or C-reactive protein. The end point was met in both INSPIRE 1 and INSPIRE 2. Secondary efficacy end points at 24 weeks were ACR50, ACR70, and Psoriasis Area Severity Index 75. Top-line results from the studies were reported in mid-2025, with additional details expected to be presented at upcoming scientific congresses.²

“These top-line results reinforce the therapeutic potential of Ilumya as a treatment option for patients with active [PsA]. We extend our sincere gratitude to the patients, health care professionals, and administrators whose contributions made the studies possible,” Marek Honczarenko, MD, PhD, senior vice president and head of global specialty development at Sun Pharma, said in an earlier statement.²

Mechanism of Action and Current Indications

Tildrakizumab is a humanized IgG1κ monoclonal antibody that selectively targets the p19 subunit of IL-23, a key cytokine involved in the inflammatory pathways underlying psoriasis and related immune-mediated conditions. By blocking IL-23 signaling, the therapy reduces downstream production of pro-inflammatory cytokines and chemokines associated with chronic inflammation. The biologic is currently approved in the US for adults with moderate to severe plaque psoriasis who are candidates for systemic therapy or phototherapy.

According to the company, the drug has supported nearly 140,000 patients worldwide since its approval, with durable skin clearance and a well-characterized safety profile through 5 years of clinical follow-up. It has also received marketing authorization from more than 55 worldwide health authorities since its original approval, including in India, Japan, the European Union, China, Australia, and Canada. Scalp and nail plaque psoriasis sBLAs were approved in April 2024 and December 2025, respectively.

References

1. Sun Pharma announces US FDA acceptance of supplemental biologics license (sBLA) application for Ilumya (tildrakizumab-asmn) for the treatment of adults with active psoriatic arthritis. News release. Sun Pharmaceutical Industries. March 16, 2026. Accessed March 16, 2026. https://www.prnewswire.com/news-releases/sun-pharma-announces-us-fda-acceptance-of-supplemental-biologics-license-sbla-application-for-ilumya-tildrakizumab-asmn-for-the-treatment-of-adults-with-active-psoriatic-arthritis-302714083.html

2. Sun Pharma’s phase 3 clinical studies evaluating tildrakizumab 100 mg (Ilumya) in active psoriatic arthritis meet their primary endpoint. News release. Sun Pharma. July 21, 2025. Accessed March 16, 2026. https://sunpharma.com/blog/sun-pharmas-phase-3-clinical-studies-evaluating-tildrakizumab-100-mg-ilumya-in-active-psoriatic-arthritis-meet-their-primary-endpoint/