Short course infusional idarubicin plus intermittent cytarabine and etoposide for refractory hematologic malignancies: clinical and preliminary pharmacological results.

BACKGROUND AND OBJECTIVE: Idarubicin (IDA) is relatively immune to the multidrug resistance P-gp mechanism that is frequently expressed in recurrent and refractory hematologic malignancies. Owing to rapid metabolism in vivo, a continuous infusion (CI) of IDA might prolong exposure time to the parent drug rather than its more P-gp susceptible alcohol metabolite. For this reason we developed a brief retreatment schedule incorporating CI IDA in order to obtain clinical as well as preliminary pharmacological data in patients with refractory leukemias and lymphomas. DESIGN AND METHODS: Eligible patients had either advanced-stage acute myeloid or lymphoid leukemias (AML, ALL) or high-grade non-Hodgkin's lymphomas (NHL) which failed curative-intent frontline or salvage regimens in use at our institution during the study period (July-October 1992). CI IDA 5 mg/m2/d was employed together with intermittent (every 8 hours) intermediate-dose cytarabine (500 mg/m2) and etoposide (200 mg/m2); all drugs were given for 2-4 days. A preliminary pharmacokinetic evaluation of CI IDA was carried out in three patients, including a comparison with bolus delivery in one. The in vitro effects of CI-type vs bolus-type IDA delivery in terms of intracellular IDA accumulation and related pro-apoptotic activity were assessed in P-gp- and P-gp+ human leukemic CEM cells by means of cytofluorimetry (IDA fluorescence intensity = FI, annexin V expression), with and without the addition of P-gp inhibitor cyclosporin A (CsA). RESULTS: Complete (2) or partial (4) responses were achieved in a total of 12 patients (17% and 33%, respectively), despite prior treatments with anthracyclines (100% of cases) and cytarabine-etoposide (33% of cases). Hematological toxicity caused the duration of treatment to be reduced from 4 days to 2 days after the first 4 patients. The procedural death rate was 42% (5/12), which was probably related in part to the sum of adverse prognostic characteristics: median patient age 55 years, two-thirds of cases having previously failed second/third-line regimens. The pharmacokinetic study showed an increased plasma AUC value with CI IDA in one patient (2.9-fold increase vs bolus delivery) due to the prolonged presence of low IDA plasma levels (10-20 ng/mL vs 50 ng/mL), as seen in two other cases as well. On the other hand, the in vitro study did not prove to be in favor of CI IDA because the FI threshold (> 1500 units) associated with increased apoptosis of P-gp+ cells (> 10%) was achieved only with bolus-type IDA exposure (50 ng/mL for 30') plus CsA. INTERPRETATION AND CONCLUSIONS: This short regimen demonstrated activity against end-stage leukemias and lymphomas and might prove to be more effective and less toxic in younger patients and in those with less advanced disease. In view of the results from plasma pharmacokinetics and in vitro intracellular IDA accumulation and apoptosis assays in lymphoblastic CEM cells, CI IDA 5 mg/m2/day may not represent a better therapeutic option than a rapid bolus injection, particularly in P-gp+ neoplasms. If obtaining an adequate intracellular drug concentration is the primary treatment goal, a higher CI IDA dosage, the addition of a P-gp down-regulator such as CsA and others, and in vivo study focusing on tumor samples from patients could all be helpful.

Localized resectable neuroblastoma: results of the second study of the Italian Cooperative Group for Neuroblastoma.

PURPOSE: To optimize treatment for children with localized resectable neuroblastoma in 21 Italian institutions using a common protocol based on previous experience. PATIENTS AND METHODS: Between January 1985 and December 1992, 152 children aged 0 to 15 years with nondisseminated neuroblastoma were entered onto this study following complete resection of tumor without tumor rupture (TR) (stage 1), or resection with minimal tumor residue, and/or tumor infiltration of regional lymph nodes (LN+), and/or TR (stage 2). Of 144 assessable children, 69 were classified as having stage 1 disease and 75 as stage 2. Of stage 2 children, 49 had low-risk (LR) characteristics (age, 0 to 11 months or 1 to 15 years but negative lymph nodes and no TR). Stage 1 and stage 2 LR children did not receive adjuvant therapy. The remaining 26 stage 2 children had high-risk (HR) characteristics (age, 1 to 15 years with LN+ and/or TR) and received adjuvant chemotherapy for 6 months. RESULTS: Of 144 children, three died of therapy-related complications and 19 relapsed, of whom six died of disease. The estimated 5-year overall survival (OS) rate was 93% and the event-free survival (EFS) rate was 83%. Of 69 stage 1 children, one died postoperatively and five relapsed (one local and four disseminated, two of whom died), for 94% OS and 90% EFS rates. Of 49 stage 2 LR children, six relapsed (four local and two disseminated); relapses occurred in five of 20 infants with LN+, in one of four infants with TR, and in none of the remaining 25 children. One child died of disease and one of toxicity, for 96% OS and 85% EFS rates. Of 26 stage 2 HR children, eight relapsed (three of 20 with LN+, three of four with TR, and two of two with LN+ and TR), of whom three died of disease and one of toxicity, for 87% OS and 61% EFS rates. CONCLUSION: Our data confirm the overall good prognosis of children with localized resectable neuroblastoma. LN+ and TR predisposed to relapse at all ages, but infants tended to have a less aggressive course after relapse. Stage 1 and 2 LR children had 94% and 96% OS rates, respectively, which justifies a policy of no adjuvant chemotherapy. Eight of 26 children with stage 2 HR relapsed despite 6 months of chemotherapy; for these children, more intensive chemotherapy may be required.

Intensive retreatment of adults and children with acute lymphoblastic leukemia.

Twenty-three patients (16 adults) failing their first or subsequent (n = 8) intensive treatment for de novo acute lymphoblastic leukemia (ALL) and chronic myeloid leukemia lymphoid blast phase (n = 2) were managed with protocol POG 8201, originally introduced in relapsed ALL of childhood. In this programme, a four-drug induction phase is followed by early consolidation with teniposide-cytarabine, intrathecal chemotherapy, continuation weekly chemotherapy alternating teniposide-cytarabine with vincristine-cyclophosphamide, and periodic reinduction courses. Fourteen adults and five children with ALL achieved a complete response (CR) (86 per cent). The highest response rate (100 per cent) was obtained in 12 patients treated at first relapse after an initial CR of greater than 18 months (p = 0.07). Median duration of CR was 8 months in adults and 11 months in children. A longer than previous one CR (inversion) was obtained in four cases. Four ALL patients were successfully transplanted from a matched sibling after 3-11 months from achievement of CR. Median overall survival in adults with ALL was 11 months, significantly longer than for 40 comparable cases treated intensively but without rotational continuation therapy in previous years (p less than 0.001). This regimen is applicable to adults with relapsed ALL, where prolongation of survival may allow time for effective salvage with bone marrow transplantation.