Inhibits ribonucleotide reductase.
A synthetic purine nucleoside with an affinity for lymphoid cells.
As a prodrug it must be phosphyrylated by deoxyadenosine kinase prior to activation.
The intracellular accumulation of the active metabolite of this drug, 2-chlorodeoxyadenosine triphosphate, results in disruption of cellular metabolism, inhibition of DNA synthesis and repair, and subsequent apoptosis (Beutler E).
Accumulation of cladribine nucleotide produces reduction in CD4+ and CD8+ cells and effects CD19+ B cells.
Causes a reduction in the levels of proiinflammatory cytokines and serum and cerebrospinal fluid chemokines, adhesion molecule expression, and in mononuclear migration.
Preferentially affects lymphocytes.
Oral cladribine significantly reduces relapse rate, disability progression, MRI abnormalities at 96 weeks (CLARITY Study Group).
In its original study 12 patients treated with hairy cell leukemia with a single seven day infusion, 11 obtained an complete remission and one a partial response.
Standard dosing is 0.1 mg per kilogram infusion per day for seven days.
Cladribine administration intravenous continuous infusion (0.1 mg/kg) for 7 days, intravenous infusion (0.14 mg/kg/day) over 2 hours on a 5-day regimen, or alternatively subcutaneously (0.1–0.14 mg/kg/day) on a once-per-day or once-per-week regimen.
Cladribine tablets approved for treatment of adults with relapsing hairy cell leukemia.