Repeat SC dosing in rabbits caused severe systemic immune-complex (type III) hypersensitivity; ADA in monkeys and rabbits
“Repeated SC injection of ALXN1210 caused a severe immunological reaction in rabbits, indicative of a systemic, type III hypersensitivity response with an immune complex etiology.”
✓ VerifiedFDA multi-discipline review, p. 47Source ↗
Biodistribution & persistence
Human TCR: staining of proteinaceous material plus cytoplasmic staining, considered likely inaccessible in vivo
“However, with the exception of the staining of proteinaceous material, all staining observed in this study was cytoplasmic in nature, and it is unlikely that the cytoplasm and cytoplasmic structures would be accessible to the test article in vivo.”
✓ VerifiedFDA multi-discipline review, p. 47Source ↗
Modality-specific risk
Serious meningococcal infection risk from terminal complement inhibition, as with eculizumab
“There is a serious risk of meningococcal infections with eculizumab and there is an ongoing REMS program for eculizumab.”
✓ VerifiedFDA multi-discipline review, p. 31Source ↗
Anti-drug antibodies: animals
ADA in 75-100% of treated monkeys; less than dose-proportional AUC likely from ADA-driven clearance
“Cmax increased in a dose proportional manner, whereas AUC increased in a less than proportional manner, probably due to the presence of anti-human antibodies that could increase the clearance. ADAs were found in 75-100% of the ALXN1210 treated animals.”
Treatment-emergent ADA in 1/219 (0.5%) PNH and 1/71 (1.4%) aHUS patients; non-neutralizing
“In clinical studies with ULTOMIRIS, treatment-emergent antibodies to ravulizumab-cwvz were detected in 1 of 219 (0.5%) patients with PNH [see Clinical Studies (14.1) ] and 1 of 71 (1.4%) patients with aHUS [see Clinical Studies (14.2) ] . In these 2 patient populations, the observed ADA were non-neutralizing with no apparent impact on PK, safety, or efficacy.”
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