Intralesional cemiplimab for patients with early-stage cutaneous squamous cell carcinoma: Results from a dose-escalation study with expansion cohorts
In brief
Weekly cemiplimab injections cleared tumors on pathology in 58% of patients
In this 41-patient phase 1 study of early-stage skin squamous cell cancer, weekly 5-mg injections led to a complete pathologic response in 58% of patients in the expansion cohort; the every-2-week cohort had a 67% rate. Side effects in both cohorts were grade 2 or milder, but small cohorts and variable injection technique limit conclusions. Further study is needed.
- Journal
- Journal of the American Academy of Dermatology (Q1)
- Published
- 30 October 2026
- Study design
- Phase 1 (first-in-human) trial
- Evidence level
- Level 4, Very Low (CEBM 4)
- Authors
- Michael Migden, Sherrif F Ibrahim, John Strasswimmer, Nathalie Zeitouni, Gary S Rogers, Jennifer DeSimone, et al.
- PMID
- 42962928
- DOI
- 10.1016/j.jaad.2026.10.075
Why clinicians should know about it
- Picked for Dermatology (paper of the day, 3 November 2026): Intralesional immunotherapy outcomes for early cutaneous SCC
Abstract
BACKGROUND: Non-surgical treatment of patients with early-stage (1-2 cm diameter) cutaneous squamous cell carcinoma (CSCC) remains an unmet need. This study investigates low-dose intralesional cemiplimab for these patients. OBJECTIVE: The primary objective was safety of low-dose intralesional cemiplimab. Efficacy was a secondary objective. METHODS: This was an open-label, phase 1 pilot study with dose escalation and expansion cohorts (NCT03889912). One lesion was injected per patient. Cemiplimab was initially administered at 5, 15, and 44 mg weekly, for 12 weeks. Subsequently, Expansion Cohorts A and B received 5 mg intralesional cemiplimab weekly or every 2 weeks, respectively, for 6 weeks. Visual response assessments were performed at Weeks 7 and 13, and surgery at Week 13. RESULTS: Across 41 patients, cemiplimab showed an acceptable safety profile. In Expansion Cohorts A and B, treatment-emergent adverse events were all grade ≤2. Week 13 visual and pathologic complete response rates were both 58.3% in Cohort A and 41.7% and 66.7%, respectively, in Cohort B. LIMITATIONS: The small number of participants limits generalizability. Intralesional cemiplimab administration may have been variable. CONCLUSION: Low-dose intralesional cemiplimab demonstrated efficacy against early-stage CSCC, with an acceptable safety profile. These data support further study of 5 mg intralesional cemiplimab weekly.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.