Clinical StudiesImmune Checkpoint Inhibition in Marjolin Ulcer: A Case SeriesShalhout, Sophia Z.*; Kaufman, Howard L.*; Sullivan, Ryan J.*; Lawrence, Donald*; Miller, David M.*,† Author Information *Division of Hematology/Oncology, Departments of Medicine †Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, MA This study was approved by the Mass General Brigham Institutional Review Board and was conducted in accordance with Good Clinical Practice Guidelines and the Declaration of Helskinki. The subjects involved provided consent to treatments. Consent to participate was waived for this study since the case series has been completely deidentified via the Safe Harbor Method. Reprints: David M. Miller, Division of Hematology/Oncology, Departments of Medicine, Massachusetts General Hospital, Bartlett Hall, 15 Parkman St, Room 132, Boston, MA 02114 (e-mail: [email protected]). Journal of Immunotherapy 44(6):p 234-238, July/August 2021. | DOI: 10.1097/CJI.0000000000000376 Buy Metrics Abstract Immunotherapy has revolutionized the treatment of advanced cutaneous squamous cell carcinoma. However, the role of immune checkpoint inhibitors for the treatment of Marjolin ulcer (MU), a rare cutaneous malignancy that arises from previously traumatized and chronically inflamed skin, is not well defined. Thus, efficacy and clinical response to immunotherapy in patients with MU requires further investigation. MU with squamous cell carcinoma, the most commonly associated malignancy, is highly aggressive with a greater risk for lymph node and distant metastasis compared with non-MU cutaneous squamous cell carcinoma. Often associated with nonhealing chronic wounds from burn scars, injuries, venous stasis ulcers, osteomyelitis, and radiotherapy, MU carries a poor prognosis. We conducted a retrospective study and describe a single institution experience of patients with MU treated with anti–programmed cell death protein 1 (PD-1) therapy at Massachusetts General Hospital between 2016 and 2020. Five subjects with this rare presentation met inclusion criteria and were treated with pembrolizumab (N=2) or cemiplimab (N=3). Four subjects received immunotherapy in the first-line setting. Notably, 1 patient had durable disease control for 1 year while on immunotherapy, with continued disease control after the cessation of anti-PD-1 therapy. Of the 4 patients that progressed on anti-PD-1 therapy, disease control at 5 months was achieved in 2 patients. Furthermore, 60% overall survival (3 patients) was observed in this limited cohort at 12 months after initiating anti-PD-1 therapy for MU. We describe the clinicopathologic features and clinical outcomes of our MU-SCC cohort. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.