No effect on infant vaccine (Tripedia) titers in monkey PPND; ADA in one mother and its infant at 10 mg/kg
“Following immunization with Tripedia®, there were no treatment-related effects on development of specific titers to the vaccine components. Anti-mepolizumab antibodies were detected in one mother and its infant from the 10 mg/kg group.”
✓ VerifiedFDA pharmacology/toxicology review, p. 129Source ↗
Biodistribution & persistence
Transplacental exposure in monkeys: infant levels ~2.4x maternal, quantifiable through day 178 postpartum
“Concentrations of mepolizumab were approximately 2.4 times higher in infants than in mothers for several months post-partum. Mepolizumab was quantifiable in infant plasma samples continuing through day 178 postpartum.”
✓ VerifiedFDA pharmacology/toxicology review, p. 20Source ↗
Modality-specific risk
Eosinophil depletion and host defense, including a possible role of eosinophils in antiviral responses
“The published scientific literature provides evidence that eosinophils can play a role in the antiviral host response.”
✓ VerifiedFDA pharmacology/toxicology review, p. 5Source ↗
Anti-drug antibodies: animals
Weakly immunogenic in monkeys: ADA in 3% of animals (IV studies), enhancing clearance without adverse reactions
“In the intravenous studies, only 3% of the animals generated anti-drug antibodies, which resulted in an enhanced systemic clearance of mepolizumab and in no adverse reactions.”
Severe asthma, 100 mg: 6% (15/260) ADA; neutralizing antibodies in 1 patient; ~20% higher clearance
“In adult and adolescent patients with severe asthma receiving NUCALA 100 mg, 15/260 (6%) had detectable anti-mepolizumab antibodies. Neutralizing antibodies were detected in 1 patient with asthma receiving NUCALA 100 mg. Anti-mepolizumab antibodies slightly increased (approximately 20%) the clearance of mepolizumab.”
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