# Real‐World Safety Profile of Spesolimab in Generalized Pustular Psoriasis: Insights From Japan as Part of a Multinational Expanded Access Program (EAP)

## TL;DR

This study examines the safety of spesolimab, a treatment for generalized pustular psoriasis, in a real-world Japanese patient population.

## Contribution

The study provides real-world safety data for spesolimab in GPP patients with comorbidities and ongoing medication use.

## Key findings

- Spesolimab was well tolerated with no severe adverse events or deaths.
- Most adverse events were mild or moderate, including skin and general disorders.
- Safety findings aligned with previous clinical trial results.

## Abstract

Generalized pustular psoriasis (GPP) is a heterogeneous, systemic neutrophilic inflammatory disease, characterized by chronic symptoms and recurrent flares, which can be potentially life‐threatening. Spesolimab, an interleukin‐36 receptor antagonist, has been approved to treat GPP flares in many countries including Japan. An expanded access program (EAP) in Japan provided early access to spesolimab for patients aged 18–75 years unable to participate in a clinical trial with no other treatment options. Patients received a single dose of 900 mg intravenous spesolimab for flare treatment, with an optional second dose after 1 week if symptoms persisted. Safety was monitored for 16 weeks post‐treatment. Eleven patients (54.5% female; 51 years mean age; 26.7 kg/m2 mean body mass index) received 23 doses of intravenous spesolimab. Nine patients (81.8%) were diagnosed with GPP for > 5 years. Ten patients (90.9%) had ≥ 1 baseline medical condition. All patients used ≥ 1 concomitant medication prior to or during the spesolimab treatment period, most commonly immunosuppressants and non‐steroidal anti‐inflammatory agents. Seven patients (63.6%) experienced treatment‐emergent adverse events, all of mild or moderate intensity, including skin and subcutaneous tissue disorders, general disorders and administration site conditions. No adverse event led to treatment discontinuation or death. A potential hypersensitivity event (face edema) resolved without intervention and was not considered treatment related. Spesolimab was well tolerated in a heterogeneous patient population with GPP, including those with comorbidities and concomitant medication use. The safety profile of spesolimab aligned with the EFFISAYIL 1 clinical trial results.