Dupilumab for bullous pemphigoid related to immune checkpoint inhibitors: a retrospective case series

BACKGROUND: Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy but are associated with treatment-limiting immune-related cutaneous adverse events (irCAEs). Immune checkpoint inhibitor-related bullous pemphigoid (irBP), a severe, blistering irCAE occurs in 0.3%-1.5% of patients receiving ICI therapy. While systemic steroids can be effective, they are associated with significant toxicity and may mitigate -immunotherapy antitumor efficacy. Consequently, steroid-sparing therapies are needed. Dupilumab, an IL-4 and IL-13 receptor antagonist, has demonstrated efficacy in non-ICI-related BP and appears promising for managing irBP. METHODS: We conducted a retrospective review of patients treated with dupilumab for irBP from April 2020 to April 2024. Clinical data, outcomes, and adverse events were assessed. Inhibitor-related bullous pemphigoid response was categorized as complete response (CR), partial response (PR), or no response (NR). RESULTS: In all, 17 patients (59% male, 82% non-Hispanic White; mean age 72.7 years) developed irBP while receiving PD-1/PDL-1 inhibitors. Sixteen patients (94%) received dupilumab for active irBP and one (6%) for prevention of recurrence. Dupilumab achieved CR of irBP for 12 patients (75%) and PR for 2 (12%) patients with active irBP. Ten (62%) achieved CR with dupilumab systemic monotherapy. Median time to first response was 19.5 days (range = 3-50). Most patients with CR (58%) failed prior oral corticosteroid therapy. The patient treated prophylactically experienced no irBP recurrence. Dupilumab was well-tolerated, with no adverse events. CONCLUSIONS: Dupilumab is a promising steroid-sparing option for irBP, achieving initial response in under 20 days for most cases. Dupilumab is a valuable tool to manage this challenging irCAE while minimizing risk related to systemic steroid treatment.