On March 21, the FDA approved Sun Pharma ’s Ilumya (tildrakizumab) for the treatment of adults with moderate to severe plaque psoriasis (PsO) who are candidates for systemic therapy or phototherapy. Ilumya marks the second interleukin-23 (IL-23) inhibitor to gain FDA approval within the past year, following the approval of J&J’s Tremfya (guselkumab) in July 2017.

These recent approvals follow an influx of IL-17 inhibitors into the US PsO market between January 2015 and February 2017, including Novartis’ Cosentyx (secukinumab), EIi Lilly’s Taltz (ixekizumab), and Valeant ’s Siliq (brodalumab). How will the IL-23 inhibitors stand up to the established IL-17 inhibitors in the US market?

The FDA approval of Ilumya was based off of the Phase III reSURFACE clinical development program, including two multicenter, double-blind, placebo-controlled trials (reSURFACE1 and reSURFACE2). In both trials, adult patients with psoriasis were randomized to receive a subcutaneous injection of Ilumya (n = 616) at Week 0 and 4 and every 12 weeks thereafter or placebo (n = 310). At Week 12, both studies met the co-primary efficacy endpoints of at least 75% of skin clearance as measured by Psoriasis Area (PASI75) and Physician’s Global Assessment score of “clear” or “minimal” (PGA 0/1). In the reSURFACE1/reSURFACE2 studies, 64%/61% and 58%/55% of patients who received Ilumya (100mg) achieved a PASI75 score and PGA 0/1 at Week 12, respectively, compared with 6%/6% and 7%/4% of patients receiving placebo.

In regards to Ilumya’s safety profile, the drug comes with a warning for hypersensitivity, infections, and tuberculosis. The most common adverse events associated with use of Ilumya are upper respiratory tract infections, injection site reactions, and diarrhea. However, Tremfya and all three marketed IL-17 inhibitors are associated with similar warnings; GlobalData does not anticipate Ilumya’s safety profile to impact its performance in the US market.

Focusing on the competition, GlobalData anticipates Sun Pharma will face an uphill battle marketing Ilumya in the US, ceding first-to-market advantage to Tremfya while also facing strong competition from the established IL-17 inhibitors. J&J has an eight-month head start marketing Tremfya in the US, while IL-17 inhibitor Cosentyx reached blockbuster status in 2016 and Taltz and Siliq are not far behind. With nine biologics now approved for the treatment of PsO in the US, not to mention biosimilars, IL-23 inhibitors, especially Ilumya, face significant challenges to establish themselves in an already overcrowded market.

Related Reports

GlobalData (2016). PharmaPoint: Psoriasis – Global Drug Forecast and Market Analysis to 2024, April 2016, GDHC119PIDR

GlobalData (2016). PharmaPoint: Psoriatic Arthritis – Global Drug Forecast and Market Analysis to 2025, November 2016, GDHC140PIDR