Bullous disorders associated with anti-PD-1 and anti-PD-L1 therapy: A retrospective analysis evaluating the clinical and histopathologic features, frequency, and impact on cancer therapy.

BACKGROUND: Bullous disorders associated with anti-programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) therapy are increasingly reported and may pose distinct therapeutic challenges. Their frequency and impact on cancer therapy are not well established.
OBJECTIVE: To evaluate the clinical and histopathologic findings, frequency, and impact on cancer therapy of bullous eruptions due to anti-PD-1/PD-L1 therapy.
METHODS: We retrospectively reviewed the medical records of patients evaluated by the oncodermatology clinic and consultative service of Yale New Haven Hospital from 2016 to 2018.
RESULTS: We identified 9 of 853 patients who developed bullous eruptions (∼1%) that were treated with an-PD-1/PD-L1 therapy at our institution during the study period: 7 presented with bullous pemphigoid, 1 presented with bullous lichenoid dermatitis, and 1 presented with linear IgA bullous dermatosis in the context of vancomycin therapy. In all, 8 patients required systemic steroids, 5 required maintenance therapy, and 8 required interruption of immunotherapy. All 9 patients had an initial positive tumor response or stable disease, but 4 went on to develop disease progression. LIMITATIONS: This was a retrospective study from a single tertiary care center.
CONCLUSIONS: Bullous disorders developed in approximately 1% of patients treated with anti-PD-1/PD-L1 therapy at our institution and frequently resulted in interruption of immune therapy and management with systemic corticosteroids and occasionally steroid-sparing agents.