Highest in liver and kidney, then bone marrow and spleen; urinary excretion
“The highest concentration of imetelstat was seen in the liver and kidney, followed by the bone marrow and spleen.”
✓ VerifiedFDA multi-discipline review, p. 42Source ↗
Modality-specific risk
Oligonucleotide class effects: thrombocytopenia/cytopenias, complement activation, coagulation (aPTT); mitigated by 2-h infusion
“The general toxicities observed in rodents and/or non-rodents with imetelstat dosing were cytopenias (most notably thrombocytopenia), complement activation, and coagulation abnormalities.”
✓ VerifiedFDA multi-discipline review, p. 56Source ↗
Main pharmacology-related risk is increased susceptibility to infections (C5 inhibition); no complement activation by the aptamer in monkeys; panuveitis with Lucentis combination