Protection against fludarabine neurotoxicity in leukemic mice by the nucleoside transport inhibitor nitrobenzylthioinosine

AA Adjei, L Dagnino, MMY Wong… - Cancer chemotherapy and …, 1992 - Springer
AA Adjei, L Dagnino, MMY Wong, ARP Paterson
Cancer chemotherapy and pharmacology, 1992Springer
Fludarabine phosphate (F-ara-AMP, Fludara) is rapidly converted in the circulation to
fludarabine (F-ara-A) and is among the most effective single agents in the treatment of
chronic lymphocytic leukemia. Although current treatment protocols are well tolerated,
severe neurotoxicity was a consequence of high-dose F-ara-AMP regimens used in early
phase I trials against adult acute leukemia. The present study showed that in mice implanted
with leukemia L1210, fatal neurotoxicity, which initially manifested as hind-limb paralysis …
Summary
Fludarabine phosphate (F-ara-AMP, Fludara) is rapidly converted in the circulation to fludarabine (F-ara-A) and is among the most effective single agents in the treatment of chronic lymphocytic leukemia. Although current treatment protocols are well tolerated, severe neurotoxicity was a consequence of high-dose F-ara-AMP regimens used in early phase I trials against adult acute leukemia. The present study showed that in mice implanted with leukemia L1210, fatal neurotoxicity, which initially manifested as hind-limb paralysis, was a consequence of high-dose-F-ara-AMP treatment. However, the incidence of neurotoxicity was reduced by the coadministration of NBMPR-P, the 5′-phosphate of nitrobenzylthioinosine, a potent inhibitor of thees equilibrative nucleoside transport (NT) system. NBTGR-P, the 5′-phosphate of nitrobenzylthioguanosine (also a potent NT inhibitor) similarly prevented F-ara-AMP neurotoxicity in this experimental system. Treatment with F-ara-AMP/NBMPR-P combinations was more effective with respect to the fractional yield of “cured” mice than were the same treatment regimens without NBMPR-P.
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