The US Food and Drug Administration (FDA) has expanded the indication of tildrakizumab-asmn (Ilumya) to include adults with active psoriatic arthritis (PsA). This expansion, approved on October 30, adds to the existing approval for moderate-to-severe plaque psoriasis.
Tildrakizumab selectively inhibits interleukin (IL)-23, a cytokine involved in inflammatory and immune responses. It was first FDA-approved in March 2018 for adults with moderate-to-severe plaque psoriasis who are candidates for systemic therapy or phototherapy.
Tildrakizumab’s Mechanism of Action
Tildrakizumab is a humanized IgG1 monoclonal antibody that binds the p19 subunit of IL-23, blocking its interaction with the IL-23 receptor. This helps disrupt the inflammatory pathway, providing a therapeutic approach to managing the musculoskeletal and cutaneous manifestations of PsA.
For adult patients with active PsA and coexistent moderate-to-severe plaque psoriasis, the recommended dosing mirrors that for plaque psoriasis alone: 100 mg subcutaneously at weeks 0 and 4, followed by every 12 weeks thereafter.
The approval of tildrakizumab for PsA was supported by two Phase 3 INSPIRE trials, which evaluated the efficacy and safety of tildrakizumab in adults with active PsA. The trials demonstrated significant improvements in ACR20, ACR50, and ACR70 response rates compared to placebo.
Evidence Supporting the Approval
In a pooled analysis of 806 participants, tildrakizumab was associated with significantly higher ACR20 (38.8% vs 24.4%; P = 0.00002), ACR50 (21.5% vs 12.5%; P = 0.001), and ACR70 (8.6% vs 3.5%; P = 0.006) response rates than placebo. Improvements in skin psoriasis were also observed, with 41% of patients receiving tildrakizumab achieving a PASI 75 response compared to 10.9% receiving placebo (P < .0001).
The most common adverse reactions associated with tildrakizumab in PsA are upper respiratory infections and COVID-19. No new safety signals were reported in the INSPIRE phase 3 program relative to the established psoriasis safety profile.
With this approval, tildrakizumab is now an additional treatment option for adults with active PsA. Its place in clinical practice will become clearer as clinicians gain experience with its use and additional long-term and real-world data become available. Tildrakizumab joins other IL-23 inhibitors, including guselkumab (Tremfya) and risankizumab (Skyrizi), in the treatment of PsA.
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As tildrakizumab becomes more widely used, it will be important to compare its efficacy and safety to other IL-23 inhibitors, as well as to assess its effects on physical function and structural progression. The every-12-week maintenance dosing and healthcare professional administration of tildrakizumab may also influence treatment adherence and patient preferences.
The INSPIRE trials demonstrated significant improvements in ACR20 response rates, with 38.8% of patients achieving this milestone. This improvement was observed in both TNF inhibitor-naïve and TNF inhibitor-experienced patients, suggesting that tildrakizumab may be an effective treatment option for a range of patients with PsA.
Treatment Considerations in Psoriatic Arthritis
Individualized therapy is essential because patients differ in their disease severity and manifestations. Some individuals may lose efficacy over time or experience inadequate responses to biologics targeting TNF, IL-17, or IL-23.
Clinical Application and Safety
Participants in the INSPIRE-1 and INSPIRE-2 trials were randomized to receive either the drug or a placebo for 24 weeks. The INSPIRE-1 trial focused on patients previously exposed to TNF inhibitors, while the INSPIRE-2 trial evaluated those who were TNF inhibitor-naïve. Those in the placebo group switched to the active treatment at 24 weeks and continued through Week 52.
Stable doses of certain concomitant medications were permitted during these trials. These included leflunomide, methotrexate, nonsteroidal anti-inflammatory drugs, low-potency opioids, and low-dose oral corticosteroids equivalent to 10 mg of prednisone or less per day.
Trial data showed a pooled difference in the HAQ-Disability Index physical function score of -0.05. This result was not statistically significant.
Label warnings and precautions include the risk of increased infections and hypersensitivity. The guidance recommends pretreatment screening for tuberculosis and avoiding live vaccines.
Sun Pharmaceutical Industries submitted the supplemental biologics license application for PsA in March 2026. Previous applications in April 2024 and December 2025 incorporated data on nail and scalp psoriasis into the prescribing information.
