Osamu Asai

Phase I/II study of humanized anti-CD33 antibody conjugated with calicheamicin, gemtuzumab ozogamicin, in relapsed or refractory acute myeloid leukemia: final results of Japanese multicenter cooperative study

The primary objective of this study was to investigate the tolerability, efficacy and pharmacokinetic profile of gemtuzumab ozogamicin (GO) in patients with relapsed and/or refractory CD33-positive acute myeloid leukemia (AML). Patients received 2-h infusions of GO twice with an interval of approximately 14 days. Tolerability was assessed using the National Cancer Institute Common Toxicity Criteria Version 2.0. Samples for pharmacokinetics were taken on day 1 and day 8 of the first treatment cycle. The dose was increased stepwise and, in each cohort, patients were treated at the same dose. Forty patients, median age 58 years (range 28–68) were treated; 20 and 20 patients were enrolled to the phase I and II parts, respectively. In the phase I part, dose-limiting toxicities (DLTs) were hepatotoxicities, and the recommended dose was established as 9 mg/m2 given as two intravenous infusions separated by approximately 14 days. The pharmacokinetic study revealed that Cmax and AUC were equivalent to those of non-Japanese patients. In the phase II part, complete remission was observed in 5 patients, and one patient had complete remission without platelet recovery. Four of these 6 in remission and one in the phase I are long-term survivors (alive for at least 44 months). GO is safe and effective as a single agent among Japanese CD33-positive AML patients. Remission lasted longer in a subset of patients than in non-Japanese patients in earlier studies. Further studies of this agent are warranted to establish standard therapy.

Pseudo-Gaucher Cell Proliferation Associated with Myelodysplastic Syndrome

We report an extremely rare case of pseudo-Gaucher cell proliferation with myelodysplastic syndrome (MDS). A 77-year-old Japanese man was referred to our hospital with splenomegaly and thrombocytopenia, and subsequent bone marrow aspiration revealed infiltrates of foamy vacuolated macrophages without any evidence of other morphologic abnormalities. A karyotype analysis showed the presence of 46,XY,del(20)(q11) in 20 of 20 examined bone marrow cells. We performed a splenectomy, and the resulting pathologic findings revealed massive infiltration of foamy vacuolated macrophages, which were morphologically compatible with Gaucher cells. The activities of β-glucosidase and acid sphingomyelinase were within normal ranges; therefore, the foamy vacuolated macrophages were considered pseudo-Gaucher cells. A diagnosis of MDS, subclassified as refractory anemia, was then made according to World Health Organization classification guidelines. Pseudo-Gaucher cell proliferation and infiltration might therefore be observed in other patients presenting with MDS.

Aclarubicin plus behenoyl cytarabine and prednisolone for previously treated acute myeloid leukemia patients.

This study analysed the clinical outcome of salvage therapy consisting of aclarubicin (ACR) plus behenoyl cytarabine (BHAC) and prednisolone (PSL) for patients with acute myeloid leukemia (AML). ACR was administered at a dose of 13 mg/m2 per day for 14 days; BHAC, at 130 mg/m2 per day for 14 days; and PSL was administered orally at a dose of 60 mg/m2 per day for 5 days. Of 47 patients, 25 (53.2%) achieved CR. The CR rates of patients in whom induction failed was 55% and that of relapsed patients was 51.9%. Four patients received allogeneic hematopoietic stem cell transplantation after achieving CR. Five patients achieved long-term survival without relapse. The 10-year relapse-free and overall survival rates were 20% and 10.6%, respectively. ACR in combination with BHAC showed a substantial anti-leukemic efficacy in previously treated AML patients and the role of ACR and BHAC may be considered while devising strategies for AML treatments.

Intensified Daunorubicin in Induction Therapy and Autologous Peripheral Blood Stem Cell Transplantation in Postremission Therapy (Double-7 Protocol) for Adult Acute Myeloid Leukemia

To investigate whether an intensified dose of daunorubicin (DNR) in induction therapy and autologous peripheral blood stem cell transplantation (PBSCT) in the postremission period are effective treatments, we used a Double-7 protocol to treat adult patients with de novo acute myeloid leukemia (excluding M0 and M3). Induction therapy consisted of 40 mg/m2 of DNR intravenous drip infusion for 7 days and 200 mg/m2 of ara-C by continuous infusion for 7 days (7 + 7 DC regimen). Patients who achieved complete remission (CR) were given high-dose chemotherapy with autologous PBSCT in postremission therapy. Of the 22 assessable patients, 16 attained CR (73%). Disease-free survival (DFS) and overall survival (OS) at 3 years were 61.2% and 48.1%, respectively. Nine of the CR patients underwent PBSCT without therapy-related mortality. Patients in a favorable cytogenetic group (n = 7) attained 100% CR and long-term survival (71.4% DFS and 85.7% OS at 3 years). Thus, intensified DNR administration of 280 mg/m2 (40 mg/m2 per day for 7 days) in induction therapy for adult patients younger than 60 years of age might be optimal or at least comparable with the new anthracyclines such as idarubicin. In addition, autologous PBSCT in postremission therapy might improve DFS and OS, at least for patients in a favorable cytogenetic group, such as those with a t(8;21) abnormality.Int J Hematol. 2002; 76: 436-445.