Decreased plasma drug levels after repeat dosing attributed to ADA formation
“The sponsor attributed the decreases in plasma drug levels following repeat dosing to ADA formation (no individual animal ADA data were provided).”
✓ VerifiedFDA pharmacology/toxicology review, p. 60Source ↗
Biodistribution & persistence
TCR: staining of neurons and innervated tissues in human, monkey and rat, plus unexpected kidney tubular epithelium binding
“A tissue cross-reactivity study assessing galcanezumab binding positively stained select human, monkey, and rat tissues that were consistent with the association of CGRP with neurons and innervated tissues; however, specific binding was also observed in tissues not expected to express CGRP (i.e., tubular epithelium of the kidney).”
✓ VerifiedFDA pharmacology/toxicology review, p. 11Source ↗
Modality-specific risk
Cardiovascular risk of long-term CGRP antagonism (loss of vasodilation), especially with cardiovascular risk factors
“Because of the potent vasodilatory properties of CGRP, concerns were raised regarding long-term antagonism of the CGRP in humans, particularly in patients with cardiovascular risk factors.”
✓ VerifiedFDA pharmacology/toxicology review, p. 5Source ↗
Anti-drug antibodies: animals
Suspected ADA reduced exposure in 1 high-dose female (6-week) and several 2 mg/kg females (6-month) monkeys
“The reduced galcanezumab serum concentrations due to suspected ADAs observed in 1 female exposed to the highest dose level (100 mg/Kg) in the 6-week study, and in a number of female monkeys in the 6-month study in the lowest dose level (2 mg/kg), were recorded after Days 36 and 176, respectively, outside the cardiovascular/neurovascular timepoints assessment.”
ADA 4.8% (33/688) in controlled studies up to 6 months; 32 of 33 neutralizing
“In controlled studies with EMGALITY up to 6 months (Study 1, Study 2, and Study 3), the incidence of anti-galcanezumab-gnlm antibody development was 4.8% (33/688) in patients receiving EMGALITY once monthly (32 out of 33 of whom had in vitro neutralizing activity).”
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