title: Multicenter prospective trial evaluating the tolerability of imatinib for Japanese patients with chronic myelogenous leukemia in the chronic phase: does body weight matter?
abstract: Imatinib at a daily dose of 400 mg is the standard treatment for chronic myelogenous leukemia in the chronic phase. However, the feasibility of this dose for small Japanese adults has not been clarified. We prospectively investigated the toxicity and efficacy of this dose in adult Japanese patients. Among the 89 evaluable patients with a median body weight of 62.8 kg, imatinib therapy was held in 40 subjects (45%), due to Grade 3-4 toxicities in 30 patients (75%) and Grade 2 toxicities at the discretion of the attending physician in 10 patients (25%). However, treatment was resumed and the dose was gradually increased until 62 of the 89 patients tolerated a maintenance dose of 400 mg. Older age and lower body weight were significant independent risk factors for discontinuation of imatinib. After a median follow-up period of 31 months, 84 patients were alive without progression. The complete cytogenetic response rate was 60 and 90% at 6 months and 1 year after starting imatinib, respectively. Older patients and those with a lower body weight were less likely to achieve a complete cytogenetic response. These findings suggest that the body weight has a significant influence on the toxicity and efficacy of imatinib in patients with a small body size, although dose reduction in proportion to weight may result in an inadequate response to imatinib.
authors.affiliation: Division of Hematology, Saitama Medical Center, Jichi Medical University, Saitama, Japan. ycanda-tky@umin.ac.jp
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Kanda
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Okamoto
authors.forename: Tetsuzo
authors.initials: T
authors.lastname: Tauchi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kizaki
authors.forename: Koiti
authors.initials: K
authors.lastname: Inokuchi
authors.forename: Mariko
authors.initials: M
authors.lastname: Yabe
authors.forename: Kenji
authors.initials: K
authors.lastname: Yokoyama
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ito
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Kimura
authors.forename: Masaaki
authors.initials: M
authors.lastname: Higashihara
authors.forename: Masami
authors.initials: M
authors.lastname: Bessho
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ando
authors.forename: Shigeru
authors.initials: S
authors.lastname: Chiba
authors.forename: Mineo
authors.initials: M
authors.lastname: Kurokawa
authors.forename: Kazuo
authors.initials: K
authors.lastname: Oshimi
authors.forename: Kazuo
authors.initials: K
authors.lastname: Dan
authors.forename: Kazuma
authors.initials: K
authors.lastname: Ohyashiki
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ikeda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001549:Benzamides; D001835:Body Weight; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D000068877:Imatinib Mesylate; D007564:Japan; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000009:adverse effects*; D047428:Protein Kinase Inhibitors / Q000009:adverse effects*; D011743:Pyrimidines / Q000009:adverse effects*; D012074:Remission Induction; D055815:Young Adult
chemical_list: D001549:Benzamides; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D000068877:Imatinib Mesylate