Sun Pharma’s ILUMYA gains FDA approval for active psoriatic arthritis, supported by Phase 3 INSPIRE-1 and INSPIRE-2 results showing improvements in joint and skin responses.
Written By: Kirti Kumbhar, M. Pharm (QA)
Reviewed By: Pharmacally Editorial Team
Sun Pharmaceutical announced that the US Food and Drug Administration (FDA) has approved the supplemental Biologics License Application (sBLA) for ILUMYA® (tildrakizumab-asmn) for the treatment of adults with active psoriatic arthritis (PsA). The approval expands tildrakizumab beyond its established indication for moderate-to-severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy, originally approved in the US in 2018.
ILUMYA is an interleukin-23 (IL-23) inhibitor administered exclusively by healthcare professionals. According to Sun Pharma, this administration model offers an additional option for patients who cannot self-administer treatment or may benefit from regular clinical supervision.
Psoriatic arthritis is a chronic immune-mediated inflammatory disease characterized by joint pain, swelling and stiffness, as well as inflammation at entheses, where tendons and ligaments attach to bone. Persistent inflammation can contribute to permanent joint damage. Approximately 2.4 million Americans live with the condition, while more than 15% of people with psoriasis may have undiagnosed PsA, according to the company.
INSPIRE-1 and INSPIRE-2 Supported the Approval
The approval is supported by two global, multicenter, randomized, double-blind, placebo-controlled Phase 3 studies: INSPIRE-1 (NCT04314544) and INSPIRE-2 (NCT04314531). Both evaluated tildrakizumab 100 mg in adults with active PsA over 52 weeks.
The trials addressed different treatment populations. INSPIRE-1 enrolled participants with previous anti-tumor necrosis factor (TNF) exposure, while INSPIRE-2 evaluated anti-TNF-naïve participants. Treatment was administered at Weeks 0 and 12, without the loading dose used in the plaque psoriasis regimen. The primary endpoint was the proportion of participants achieving an American College of Rheumatology 20% response (ACR20) at Week 24.
Pooled Week 24 results from 806 participants (405 receiving tildrakizumab and 401 receiving placebo) are reported in an ACR Convergence 2026 abstract (Abstract 2313). ACR20 response was achieved by 38.8% of participants receiving tildrakizumab, compared with 24.4% receiving placebo (P=0.00002).
The treatment also demonstrated improvements in key secondary endpoints. ACR50 responses were 21.5% versus 12.5% (P=0.001), while ACR70 responses were 8.6% versus 3.5% (P=0.006). Among participants with baseline body surface area involvement of at least 3%, PASI75 responses were 41.0% versus 10.9% (P<0.0001).
However, improvement in Health Assessment Questionnaire Disability Index (HAQ-DI) scores did not reach statistical significance compared with placebo (P=0.09). The abstract reports nominal P values and pooled results, with the conference presentation scheduled for November 10, 2026.
IL-23 Inhibition and the Role of Tildrakizumab
Tildrakizumab is a humanized IgG1/k monoclonal antibody that selectively binds to the p19 subunit of IL-23, preventing its interaction with the IL-23 receptor. This inhibits the release of pro-inflammatory cytokines and chemokines involved in inflammatory disease processes.
Its expansion into PsA is clinically relevant because the disease involves both musculoskeletal and skin manifestations. The observed improvements in joint and skin response measures provide clinical evidence supporting IL-23 inhibition in this setting. However, the available pooled results do not establish superiority over other biologic therapies or uniform benefits across every PsA disease domain.
Safety Profile and Prescribing Considerations
Sun Pharma reported that safety findings from INSPIRE-1 and INSPIRE-2 were consistent with ILUMYA’s established safety profile, with no new safety signals identified. The most common adverse reactions reported in PsA at an incidence of at least 3% were upper respiratory tract infections and COVID-19.
The prescribing information highlights the potential risk of infections and recommends evaluating patients for tuberculosis (TB) before treatment. ILUMYA should not be administered to patients with active TB, and latent TB should be treated before initiation. Live vaccines should be avoided during treatment. Hypersensitivity reactions, including angioedema and urticaria, have also been reported; serious allergic reactions require immediate discontinuation and appropriate treatment.
Clinical Interpretation
ILUMYA’s FDA approval for active PsA expands tildrakizumab’s clinical use and strengthens Sun Pharma’s position in the psoriatic disease market. The pooled Phase 3 results demonstrate statistically significant improvements in ACR20, ACR50, ACR70 and PASI75 responses compared with placebo at Week 24, following two doses.
However, the absence of a statistically significant HAQ-DI improvement indicates that the observed clinical responses did not translate into a significant difference across every assessed outcome. The results also do not establish comparative superiority over existing PsA biologics. The approval broadens treatment choice, while longer-term and domain-specific evidence will help clarify tildrakizumab’s place in clinical practice.
References
Sun Pharmaceutical Industries Limited. ILUMYA® (tildrakizumab-asmn) approved in the U.S. for the Treatment of Adults with Active Psoriatic Arthritis, Sun Pharmaceuticals, October 30, 2026.
Efficacy and Safety of Tildrakizumab Compared to Placebo in Subjects with Active Psoriatic Arthritis I (INSPIRE 1), ClinicalTrials.gov ID NCT04314544
Efficacy and Safety of Tildrakizumab Compared to Placebo in Anti-TNF naïve Subjects with Active Psoriatic Arthritis II (INSPIRE 2), ClinicalTrials.gov ID NCT04314531
About the Writer
Kirti Kumbhar (LinkedIn) is an M.Pharm graduate with experience in Quality Assurance at Lupin Limited and a strong interest in clinical research, regulatory affairs, and Trial Master File (TMF) management. She has developed knowledge of regulatory documentation, quality systems, compliance, and healthcare research through her professional experience. Passionate about clinical development and continuous learning, Kirti is committed to supporting high-quality healthcare documentation, regulatory excellence, and research-driven healthcare advancements.