The full during more than 5,400 patient-years of prospective follow-up, Diamont Thaçi, MD, PhD, reported at the virtual annual congress of the European Academy of Dermatology and Venereology.
For example, 89% of patients who had a PASI-75 response on the 100-mg dose of tildrakizumab (Ilumya) – the dose approved in the United States – at week 28 in the parent reSURFACE 1 and reSURFACE 2 trials maintained their PASI-75 response throughout the next 4½ years in the long-term extension study, as did 93% of those with a week 28 PASI-75 response on 200 mg, a dose approved elsewhere, said Dr. Thaçi, professor of dermatology and director of the Comprehensive Center for Inflammation Medicine at Lübeck (Germany) University.
The same held true for PASI-90, a response achieved by 71% of participants on 100 mg of tildrakizumab at week 28 and 66% at week 244, and by 73% of those on the 200-mg dose at week 28 and 70% at 5 years. A PASI-100 response was documented at week 28 in 29% of patients on the lower dose and 37% of those on 200 mg, with week 244 PASI-100 rates of 33% and 41%, respectively.
The long-term extension study enrolled 622 patients with moderate to severe chronic plaque psoriasis with at least a PASI-75 response to 100 mg or 200 mg of the humanized monoclonal antibody interleukin-23p19 inhibitor at week 28 in reSURFACE 1 or 2, or who were partial or nonresponders to etanercept in reSURFACE 2 and were then switched to tildrakizumab at 200 mg. Five hundred and forty-five of the 622 patients (88%) completed the full 5 years of the extension study.
Very few patients left the study because of loss of efficacy or adverse events. Indeed, the exposure-adjusted rate of drug-related serious adverse events was 0.8 cases per 100 patient-years at tildrakizumab 100 mg and 0.5 per 100 patient-years at 200 mg. Moreover, the rates of drug-related serious adverse events leading to treatment continuation were 0.3 and 0.2 per 100 patient-years at the 100-mg and 200-mg doses. Rates of treatment-emergent severe infection were 1.2 and 1.3 per 100 patient-years on the lower and higher doses. Major adverse cardiovascular events occurred at rates of 0.5 and 0.7 cases per 100 patient-years.
“I think the adverse events are generally similar to what has been seen with other biologics, but slightly less with tildrakizumab. Registries will provide a clearer picture. What’s interesting is that even if you double the dosage you don’t see an increase in side effects,” Dr. Thaçi said.
Asked what happens when a tildrakizumab responder stops taking the monoclonal antibody, he replied, “This is something very interesting we see with the IL-23 inhibitors: The disease comes back very slowly. It takes months, and sometimes years, for the patient to lose the PASI-75 or even the PASI-90 response. But we still consider that continuous treatment is probably the better way to go because we cannot be sure who will lose or regain response. At the moment we don’t have a biomarker to tell us what we should do in our daily practice.”
Dr. Thaçi reported serving as an adviser to and paid investigator for Almirall, the study sponsor, and approximately 20 other pharmaceutical companies.