IL-2, IL-6, IFN-gamma release in chimpanzees, consistent with clinical CRS; ADA to surrogate in mice
“Increases in cytokines IL-2, IL-6, and INFγ were also observed following infusion with blinatumomab in chimpanzees, a finding consistent with the cytokine release syndrome observed in the clinical trial in patients with ALL.”
✓ VerifiedFDA pharmacology/toxicology review, p. 12Source ↗
Biodistribution & persistence
Short half-life (1.5-8 h), rapid elimination with renal clearance; surrogate crosses placenta
“The mean terminal half-lives in the tested species ranged from 1.5 to 8 hours, indicating rapid elimination of the drug.”
CRS and neurotoxicity (cytokines plus VCAM-1/T-cell endothelial adhesion), B-cell depletion, infection
“It is therefore plausible that the up-regulation of both proinflammatory cytokines and VCAM-1 may at least in part contribute to neurologic adverse events seen in the blinatumomab-treated subjects (see clinical safety).”
Anti-muS103new ADA in mice, mainly at low doses; did not affect kinetics or pharmacological effect in pivotal studies
“Development of ADAs in the pivotal toxicity studies did not impact on their validity since neither the kinetics nor the pharmacological effect of muS103new or blinatumomab were affected. The occurrence of ADAs was mainly reported at low dose levels”
Less than 2% of patients had anti-blinatumomab antibodies; 7 of 9 (78%) neutralizing
“In clinical studies, less than 2% of patients treated with BLINCYTO tested positive for binding anti-blinatumomab antibodies. Of patients who developed anti-blinatumomab antibodies, 7 out of 9 (78%) had in vitro neutralizing activity.”