Background
Phase 2, open-label, multicenter, single-arm EMPOWER-BCC-1. N=84 locally advanced basal cell carcinoma (laBCC; group 2) who progressed on or were intolerant to hedgehog inhibitor (HHI) therapy (vismodegib or sonidegib), or had ≤stable disease after ≥9 months on HHI. No standard therapy existed for laBCC after first-line HHI failure prior to 2021. Cemiplimab (anti-PD-1).
Interventions and follow up
Treatment: Cemiplimab 350 mg IV every 3 weeks for up to 93 weeks (single-arm)
Primary endpoint: ORR by independent central review
mFollow up: 15 months (median, IQR 8–18)
Primary endpoint: ORR by independent central review
mFollow up: 15 months (median, IQR 8–18)
Results
ORR: 31% (26/84; 95% CI 21–42)
Complete response rate: 6% (5/84)
Partial response rate: 25% (21/84)
Complete response rate: 6% (5/84)
Partial response rate: 25% (21/84)
Adverse events
Grade 3–4 TEAE: 48%
Most common grade 3–4: hypertension 5%, colitis 5%
Serious TEAE: 35%
Treatment-related deaths: None
Immune-related: colitis, hepatitis, endocrinopathies (PD-1 class effects)
Most common grade 3–4: hypertension 5%, colitis 5%
Serious TEAE: 35%
Treatment-related deaths: None
Immune-related: colitis, hepatitis, endocrinopathies (PD-1 class effects)
Conclusions
Cemiplimab achieved 31% ORR including 6% CR in laBCC after HHI failure — a population with no prior standard second-line option. Established cemiplimab as the first FDA-approved second-line therapy for laBCC and demonstrated PD-1 blockade can overcome BCC's immunosuppressive microenvironment.
Key Limitations
Single-arm, nonrandomized; no comparator. Small N (84); ORR surrogate endpoint. Substantial grade 3–4 toxicity (48%); locally advanced cohort only — metastatic BCC data limited.
Clinical Context
Cemiplimab FDA-approved (2021) for laBCC previously treated with or unsuitable for a hedgehog inhibitor; ESMO-endorsed second-line option after HHI failure. Hedgehog inhibitors (vismodegib, sonidegib) remain first-line for advanced BCC.