ABSTRACT Mucous membrane pemphigoid (MMP) following anti‐programmed cell death‐1 (PD‐1) therapy is rare but increasingly reported. Management of high‐ and low‐risk MMP in this setting and the potential oncologic trade‐offs remain poorly defined. We performed a narrative synthesis of all published cases of anti‐PD‐1‐associated MMP, following MEDLINE, Embase, and PubMed Central searches from January 2014 to June 2025. Fifteen cases from thirteen reports met the inclusion criteria, with a median MMP latency period of 12.5 weeks. The oral mucosa was frequently involved and was the index site in 84.6% (11/13). Ocular involvement was observed in only one patient and resolved with topical corticosteroids (TCS). Anti‐PD‐1 therapy was successfully continued in three low‐risk cases with systemic steroid treatment. Overall, doxycycline plus TCS produced the best low‐risk response: 5/10 low‐risk patients were treated with doxycycline plus TCS; all five achieved complete remission (CR) at least at one anatomic site (3/5 CR at all sites, 2/5 CR with partial response (PR) at different sites). High‐risk MMP required escalation with methotrexate, rituximab, and/or intravenous immunoglobulin (IVIg). Of the patients, 86.7% (13/15) experienced CR or PR of MMP, and a single recurrence was reported. Tumor control (CR or PR) was maintained in 72.7%, with one relapse following anti‐PD‐1 therapy cessation. Anti‐PD‐1‐associated MMP is typically oral‐predominant and, unlike classic MMP, has infrequent ocular involvement. Management and therapeutic responses differed by site of involvement. Discontinuation of anti‐PD‐1 is not always required. When anti‐PD‐1 therapy continuation is clinically prioritized, a systemic steroid‐based regimen can stabilize MMP and facilitate completion of immunotherapy.
Dienes et al. (2026) studied this question.