TY - JOUR
T1 - Idarubicin monotherapy in multiply pretreated leukemia patients: Response in relation to P-glycoprotein expression
AU - Nüssler, V.
AU - Gieseler, F.
AU - Zwierzina, H.
AU - Gullis, E.
AU - Pelka-Fleischer, R.
AU - Diem, H.
AU - Abenhardt, W.
AU - Schmitt, R.
AU - Langenmayer, I.
AU - Wohlrab, A.
AU - Kolb, H. J.
AU - Wilmanns, W.
PY - 1997
Y1 - 1997
N2 - The aim of the study was to test whether fractionated (weekly) idarubicin administration to multiply pretreated leukemia patients is effective and tolerable for outpatient treatment, and whether idarubicin alone can overcome P-glycoprotein (P-gp)-related resistance. P-gp was assessed with an immunocytological technique using the monoclonal antibody 4E3.16. P-gp expression was characterized as a percentage of P-gp-positive blasts. Additionally, the function of P-gp was determined with the rhodamine-123 (R-123) accumulation test in combination with or without verapamil and expressed as the R123 accumulation ratio. Fractionated idarubicin (12 mg/m2/week) was given to 36 acute myelogenous leukemia (AML) patients, 12 acute lymphoblastic leukemia (ALL) patients, and eight chronic myelogenous leukemia (CML) patients in blast crisis. Furthermore, 11 AML and four ALL patients were treated with fractionated daunorubicin at a dose of 50 mg/m2/week. All patients had been pretreated with drugs inducing P-gp-related resistance including daunorubicin and/or doxorubicin or vindesine (CML patients). Of 71 pretreated patients, 51 (72%) had a P-gp value between 25 and 98%. Six of these patients with increased P-gp expression had a nonpumping P-gp; four of them were CD34 positive. Of 51 patients with increased P-gp expression, 30 (59%) were CD34 positive. With regard to idarubicin monotherapy, overall response was 33/56 (59%) patients, and 23/33 (70%) responding patients showed a P-gp expression between 25 and 95%. All idarubicin-responding patients with high P-gp expression before treatment showed a clear reduction of P-gp-positive blasts. No patients with P-gp expression between 34 and 85% treated with fractionated daunorubicin showed response or reduction of P-gp-positive blasts in bone marrow. This study demonstrates that P-gp-related resistance can be overcome in multiply pretreated leukemia patients with idarubicin alone, and that the protocol used here is tolerable for outpatient treatment.
AB - The aim of the study was to test whether fractionated (weekly) idarubicin administration to multiply pretreated leukemia patients is effective and tolerable for outpatient treatment, and whether idarubicin alone can overcome P-glycoprotein (P-gp)-related resistance. P-gp was assessed with an immunocytological technique using the monoclonal antibody 4E3.16. P-gp expression was characterized as a percentage of P-gp-positive blasts. Additionally, the function of P-gp was determined with the rhodamine-123 (R-123) accumulation test in combination with or without verapamil and expressed as the R123 accumulation ratio. Fractionated idarubicin (12 mg/m2/week) was given to 36 acute myelogenous leukemia (AML) patients, 12 acute lymphoblastic leukemia (ALL) patients, and eight chronic myelogenous leukemia (CML) patients in blast crisis. Furthermore, 11 AML and four ALL patients were treated with fractionated daunorubicin at a dose of 50 mg/m2/week. All patients had been pretreated with drugs inducing P-gp-related resistance including daunorubicin and/or doxorubicin or vindesine (CML patients). Of 71 pretreated patients, 51 (72%) had a P-gp value between 25 and 98%. Six of these patients with increased P-gp expression had a nonpumping P-gp; four of them were CD34 positive. Of 51 patients with increased P-gp expression, 30 (59%) were CD34 positive. With regard to idarubicin monotherapy, overall response was 33/56 (59%) patients, and 23/33 (70%) responding patients showed a P-gp expression between 25 and 95%. All idarubicin-responding patients with high P-gp expression before treatment showed a clear reduction of P-gp-positive blasts. No patients with P-gp expression between 34 and 85% treated with fractionated daunorubicin showed response or reduction of P-gp-positive blasts in bone marrow. This study demonstrates that P-gp-related resistance can be overcome in multiply pretreated leukemia patients with idarubicin alone, and that the protocol used here is tolerable for outpatient treatment.
UR - http://www.scopus.com/inward/record.url?scp=1842336294&partnerID=8YFLogxK
U2 - 10.1007/s002770050258
DO - 10.1007/s002770050258
M3 - Journal articles
C2 - 9063374
AN - SCOPUS:1842336294
SN - 0939-5555
VL - 74
SP - 57
EP - 64
JO - Annals of Hematology
JF - Annals of Hematology
IS - 2
ER -
