Atypical Stevens–Johnson syndrome caused by pembrolizumab in the treatment of metastatic melanoma – Are corticosteroids a safe treatment option?

Pembrolizumab is a humanized monoclonal antibody that targets programmed cell death receptor-1. Stevens–Johnson syndrome (SJS) secondary to pembrolizumab has rarely been described in the treatment of malignant melanoma (MM). A 62-year-old woman developed a widespread bullous eruption following administration of her third dose of pembrolizumab for the treatment of MM. A skin biopsy showed sub-epidermal bulla formation with lymphocytic infiltrate and a necrotic roof, consistent with a SJS/toxic epidermal necrolysis (TEN) disorder. Intravenous methylprednisolone was administered. Upon cessation of oral prednisolone, there was a recrudescence of the eruption. A repeat skin biopsy confirmed recurrent SJS. Following a prolonged taper with oral prednisolone, there was no further relapse of SJS. Severe cutaneous adverse reactions such as SJS/TEN have been reported with pembrolizumab and can be associated with significant morbidity and even mortality. High-dose systemic corticosteroids are frequently used in its treatment. Concerns about the potential negative effect of high-dose steroids have re-surfaced, given the observed reduced overall survival in patients with MM. Due to difficulties in performing studies in this population, the benefits and risk of steroids should be considered on a case-by-case basis.