SpeciesAccepted with a conditionBeyond the letter
Repeat-dose toxicity only in immunodeficient nude rats, judged an inadequate toxicology model; juvenile study in a relevant species required postmarketing
Why: Additional juvenile toxicology study in a relevant species needed to characterize nerve risk in the pediatric population
“Literature cited by the Applicant using other antibodies targeting GD2 in fully immunocompetent rat or mouse models demonstrates the ability of these rodents to model the allodynia observed clinically, further suggesting that though some immune-competent rodent models may adequately predict the toxicity of the antibody the nude rat is does not, making it an inadequate toxicology model for this product.”
✓ VerifiedFDA multi-discipline review, p. 63Source ↗ “Due to the lack of changes in nociception in the nonclinical toxicology studies provided in the BLA and the age of the animals used, an additional toxicology study in juvenile animals of a relevant species is needed to adequately characterize the risk of the use of naxitamab on the central and peripheral nerves as related to the indicated pediatric population.”
✓ VerifiedFDA multi-discipline review, p. 253Source ↗ First doseVerdict not stated
Initial clinical trials supported by prior clinical data with the murine parent antibody, not by toxicology data with naxitamab
Why: Prior clinical data with the murine parent antibody
“The initial clinical trials investigating the activity and dosing of naxitamab were conducted on the basis of previous clinical data with the murine parent antibody rather than supported by toxicology data with the clinical candidate.”
✓ VerifiedFDA multi-discipline review, p. 41Source ↗ DARTAccepted
No fertility or embryo-fetal development studies
Why: Patient population primarily 5 years old or younger; fertility studies not warranted for advanced cancer · Within the guideline · Other reason
“In addition, because the age of the proposed patient population is primarily ≤5 years old, FDA did not request an embryo-fetal development study to support the use of naxitamab.”
✓ VerifiedFDA multi-discipline review, p. 42Source ↗ “Y-mAbs did not conduct dedicated studies to assess fertility or carcinogenicity and these studies are not warranted to support the development of a drug intended to treat patients with advanced cancer.”
✓ VerifiedFDA multi-discipline review, p. 42Source ↗