Therapy of refractory/relapsed acute leukemia with cytosine arabinoside plus tetrahydrouridine (an inhibitor of cytidine deaminase)--a pilot study.
Thirty two patients with refractory or recurrent acute leukemia or blast crisis of chronic myelocytic leukemia were treated with 1-beta-D-arabinofuranosylcytosine (Ara-C), 100 mg/m2 [group I (n = 15)] or 200 mg/m2 [group II (n = 18)], and tetrahydrouridine (THU) 350 mg/m2, given concurrently as a 3 h continuous intravenous infusion at 12 h interval for eight doses. Two of 13 (15.3%) evaluable patients in group I achieved a complete response, both of whom had acute myelocytic leukemia. In group II, seven of 14 evaluable patients (50%) obtained objective responses--six with complete responses (42.8%) and one with partial response (7%). Myelosuppression was seen in all patients with a median duration of 32.5 days (group I) and 36.3 days (group II), respectively. Non-hematologic toxicity consisted of nausea, vomiting, diarrhea, conjunctivitis, skin rash, hepatocellular toxicity, hemorrhage, and renal toxicity. Pharmacokinetic studies revealed, for group I, mean peak plasma Ara-C levels at 3 h (Cp3h) of 1254 ng/ml, area under the curve (AUC) 4651 ng x h/ml, total body clearance (TBC) 32.65 l/h/m2, renal clearance (RC) 7.04 l/h/m2 with a mean of 12.36% of the injected amount of Ara-C excreted unchanged in urine over the first 24 h. The corresponding mean values for group II are Cp3h 3305 ng/ml, AUC 15080 ng x h/ml, TBC 20.48 l/h/m2, RC 7.02 l/h/m2 and 26.23%. Ara-C 200 mg/m2 combined with THU gave serum Ara-C levels and response rates comparable to those achieved with high dose Ara-C (HiDAC) (greater than or equal to 1 g/m2). Central nervous system toxicity associated with HiDAC was not seen. Pharmacokinetics for uracil arabinoside (Ara-U) in patients treated with Ara-C 200 mg/m2 plus THU, were comparable to values seen with Ara-C for Cp3h, AUC and 24 h urine, amounting to 3160 ng/ml, 21717 ng x h/ml and 23.62% whereas TBC was significantly lower (p less than 0.001) for Ara-U than for Ara-C (3.02 versus 20.48 l/h/m2).
Kreis
W
W
Don Monti Division of Oncology, Department of Medicine, North Shore University Hospital, Cornell University Medical College, Manhasset, New York 11030.
Budman
D R
DR
Chan
K
K
Allen
S L
SL
Schulman
P
P
Lichtman
S
S
Weiselberg
L
L
Schuster
M
M
Freeman
J
J
Akerman
S
S
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D003561:Cytarabine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D004334:Drug Administration Schedule; D004341:Drug Evaluation; D005260:Female; D006801:Humans; D007938:Leukemia / Q000188:drug therapy*; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D013767:Tetrahydrouridine / Q000008:administration & dosage
D003561:Cytarabine; D013767:Tetrahydrouridine