CarcinogenicityAcceptedBeyond the letter
Carcinogenicity study waived for a chronic asthma indication
Why: No related findings in 6-month monkey study; rodent study not technically feasible · Weight of evidence · No relevant species
“The need for a carcinogenicity study was discussed with the Executive Carcinogenicity Assessment Committee and it was concluded that a carcinogenicity study was not required given the lack of related findings in the 6-month toxicology study in monkeys and since conduct of a study in rodents did not appear to be technically feasible.”
✓ VerifiedFDA pharmacology/toxicology review, p. 2Source ↗ “I agree that the decision to waive the carcinogenicity study is reasonable and the EPC for mepolizumab is appropriate.”
✓ VerifiedFDA pharmacology/toxicology review, p. 3Source ↗ DARTAcceptedBeyond the letter
Embryo-fetal development studied in mice with a surrogate antibody, not in monkeys; teratogenicity not assessed in monkey PPND study
Why: Masking of embryo-foetal toxicity by insufficient drug exposure considered unlikely · Other reason
“However, mepolizumab crosses the placental barrier and the teratogenic potential of mepolizumab was not studied in the monkey pre and post-natal study. An embryofoetal development study was conducted in mice and not in monkeys.”
✓ VerifiedEMA assessment report, p. 22Source ↗ “The potential for masking of embryo-foetal toxicity due to insufficient drug exposure was considered unlikely. This was considered acceptable by the CHMP.”
✓ VerifiedEMA assessment report, p. 22Source ↗ DARTCriticised but acceptedBeyond the letter
Small monkey PPND study (8-9 infants per group) without skeletal or visceral malformation examinations
“Infants were not examined for skeletal or visceral malformations and variations. The results of this study should be judged with caution given the limitations in study design and resources.”
✓ VerifiedFDA pharmacology/toxicology review, p. 129Source ↗ “The present study is considered adequate; however, it should be noted that this study was small with only 8 or 9 infant monkeys per group for assessment.”
✓ VerifiedFDA pharmacology/toxicology review, p. 129Source ↗ OtherAcceptedBeyond the letter
Abbreviated toxicity programme: one species and two dose levels in pivotal studies
Why: Other standard laboratory species not suitable; chosen doses adequate · No relevant species
“The applicant conducted an abbreviated toxicity programme with mepolizumab, in only one species, the cynomolgus monkey, and at two doses in the pivotal studies.”
✓ VerifiedEMA assessment report, p. 19Source ↗ “The CHMP accepted that other standard laboratory species would not have been suitable and that the doses chosen for the pivotal toxicity studies were adequate.”
✓ VerifiedEMA assessment report, p. 19Source ↗