Clinical efficacy of tildrakizumab, an anti–IL-23p19 monoclonal antibody, in patients with chronic plaque psoriasis over two years of treatment: Results from long-term extensions to two Phase III clinical studies (reSURFACE 1 and reSURFACE 2)

Presenters: Papp K¹, Reich K², Blauvelt A³, Thaçi D⁴, Sinclair R⁵, Tyring SK⁶, Cichanowitz N⁷, Green S⁷, Li Q,⁷ La Rosa C⁷

Affiliations: ¹Probity Medical Research, Waterloo, ON, Canada; ²SCIderm Research Institute and Dermatologikum Hamburg, Hamburg, Germany; ³Oregon Medical Research Center, Portland, Oregon; ⁴Comprehensive Center for Inflammation Medicine, University Medical School Schleswig-Holstein, University of Lübeck, Lübeck, Germany; ⁵University of Melbourne, Melbourne, VIC, Australia; ⁶Department of Dermatology, University of Texas, Houston, Texas; ⁷Merck & Co., Inc., Kenilworth, New Jersey

Background/Objective: Tildrakizumab is a high-affinity, humanized, anti-IL-23p19 monoclonal antibody that has demonstrated efficacy in the treatment of chronic plaque psoriasis in two Phase III studies (reSURFACE 1 and 2). Extensions of these studies are ongoing. In this analysis, we present preliminary data evaluating maintenance of response in patients who were responders to tildrakizumab upon entering the extension periods and who maintained response a year into the extensions (a total of at least 2 years of treatment).

Methods: The reSURFACE base studies are three-part, double-blinded, randomized, placebo-controlled studies in adult patients with moderate-to-severe chronic plaque psoriasis (body surface area involvement ?10%, Physician’s Global Assessment [PGA] score ?3, and Psoriasis Area and Severity Index [PASI] ?12). Tildrakizumab 200mg and 100mg were evaluated for 64 weeks (reSURFACE 1; NCT01722331) and 52 weeks (reSURFACE 2; NCT01729754), respectively. Patients were eligible for the optional long-term extensions if they completed the base studies and achieved PASI ?50 at the end of the base studies (for reSURFACE 1 only, patients had to have received an active dose of tildrakizumab within 12 weeks of the end of the base study). Patients received the same dose of tildrakizumab (200mg or 100mg every 12 weeks) as they received at the completion of the base studies. Administration was open label after database lock for the base studies. The full analysis set (patients with at least 1 dose of extension treatment based on assigned treatment) was the primary efficacy population. The efficacy objective during the extension period was evaluation of maintenance of efficacy endpoints (i.e., proportion of PASI 50, 75, 90, and 100 responders 1 year into the extension among PASI 50, 75, 90, and 100 responders at the start of the extension) prespecified to be based on observed data. No statistical analyses were planned for comparison between doses.

Results: In reSURFACE 1, 772 patients entered, 638 completed the base study, and 506 entered the extension; in reSURFACE 2, 1,090 patients entered, 756 patients completed the base study, and 731 entered the extension. In reSURFACE 1, in patients entering the extension on tildrakizumab 200mg, PASI 50/75/90/100 was maintained by 97%/91%/82%/63% (out of 255/208/135/70 patients with data at 1 year); in patients on tildrakizumab 100mg, PASI 50/75/90/100 was maintained by 98%/90%/74%/53% (out of 219/195/121/70 patients with data at 1 year). In patients entering the extension on tildrakizumab 200 mg in reSURFACE 2, PASI 50/75/90/100 was maintained by and 97%/88%/84%/70% (out of 330/293/191/97 patients with data at 1 year); for those on tildrakizumab 100mg, PASI 50/75/90/100 was maintained by 99%/92%/84%/66% (out of 352/327/249/125 patients with data at 1 year).

Conclusion: Tildrakizumab 100mg and 200mg demonstrated maintenance of efficacy in the treatment of moderate-to-severe chronic plaque psoriasis for at least two years of treatment.

Funding: Study sponsored by Merck & Co. Analyses previously presented at the 26th European Academy of Dermatology and Venereology Congress, Geneva, Switzerland, 2017.