Anti-drug antibodies in 53% of monkeys in 26-week study (92%, 33%, 33% at 2, 10, 50 mg/kg)
“ADAs were detected in 19/36 (53%) monkeys dosed with REGN2810 including 11/12 (92%), 4/12 (33%), and 4/12 (33%) monkeys dosed with 2, 10, and 50 mg/kg REGN2810, respectively.”
✓ VerifiedFDA multi-discipline review, p. 40Source ↗
Biodistribution & persistence
No distribution, metabolism or excretion studies; tissue cross-reactivity study used to assess target distribution
“Traditional distribution, metabolism, and excretion studies were not conducted with cemiplimab because it is a monoclonal antibody; however, consistent with ICH S6(R1), the Applicant did include a tissue cross reactivity assay to assess distribution of the target”
✓ VerifiedFDA multi-discipline review, p. 38Source ↗
Modality-specific risk
Immune-mediated adverse reactions such as pneumonitis, predicted by PD-1 blockade
“Based on clinical trials done to support the approval of cemiplimab in the proposed patient population, toxicities associated with cemiplimab are primarily immune-mediated adverse reactions, such as pneumonitis, that are predicted by its mechanism of action.”
✓ VerifiedFDA multi-discipline review, p. 30Source ↗
Anti-drug antibodies: animals
ADA in 53% of monkeys in the 26-week study (92%, 33%, 33% at 2, 10, 50 mg/kg), inversely related to dose
“ADAs were detected in 19/36 (53%) monkeys dosed with REGN2810 including 11/12 (92%), 4/12 (33%), and 4/12 (33%) monkeys dosed with 2, 10, and 50 mg/kg REGN2810, respectively.”
✓ VerifiedFDA multi-discipline review, p. 40Source ↗
Anti-drug antibodies: patients
2% of patients developed anti-cemiplimab antibodies; no clinically significant effect on PK
“During a treatment period ranging from 8 to 19 months in 5 clinical studies, 2% (22/1029) of LIBTAYO-treated patients developed anti-cemiplimab-rwlc antibodies. There was no clinically significant effect of anti-cemiplimab-rwlc antibodies on PK of cemiplimab-rwlc.”
In vitro whole-blood cytokine release far below alemtuzumab/TGN1412 controls; no effects on monkey TDAR, lymphocyte subsets or serum cytokines; ADA in some monkeys