T. Ahmed

Phase I clinical and laboratory evaluation of topotecan and cytarabine in patients with acute leukemia.

PURPOSE To determine the maximal-tolerated dose (MTD) of topotecan with cytarabine in acute leukemia patients, and to evaluate leukemia cell apoptosis in these patients. PATIENTS AND METHODS Fifty-three patients with acute leukemia not responsive to standard therapy were treated at eight dose levels of topotecan (2.5 mg/m2/d to 7.75 mg/m2/d). Topotecan was given as a 30-minute infusion daily with cytarabine 1 g/m2/d, both for 5 days. Using a flow-cytometric technique, the percent apoptotic cells in blood and bone marrow samples was determined, and the cell cycle distribution of the leukemic cells studied. RESULTS Oropharyngeal mucositis was dose-limiting. The MTD of topotecan was 4.75 mg/m2/d for 5 days in high-risk patients and 7.0 mg/m2/d for 5 days in low-risk patients. The mean percent apoptotic cells in the peripheral blood reached a peak of 18.8%, a median of 48 hours following the first dose of topotecan. Patients with higher S-phase fractions, either before treatment or following cytarabine, were more likely to achieve bone marrow aplasia than those with lower S-phase fractions (P = .01 and P < .05, respectively). Clinical responses were seen in four of 39 patients with acute myelogenous leukemia (AML; of whom 32 had received prior high-dose cytarabine), three of six with acute lymphoblastic leukemia (ALL), and one of eight with chronic myelogenous leukemia in blast phase (CML-BP). CONCLUSION The recommended phase II dose of topotecan with intermediate-dose cytarabine is 4.75 mg/m2/d for high-risk patients and 7.0 mg/m2/d for low-risk patients. The percentage of cells in S phase was important in determining response to treatment.

Phase I clinical and pharmacokinetic evaluation of high-dose mitoxantrone in combination with cytarabine in patients with acute leukemia.

PURPOSE To determine the maximally tolerated dose of mitoxantrone in combination with cytarabine in patients with acute leukemia and advanced phases of chronic myelogenous leukemia (CML), and to assess the pharmacokinetics of high-dose mitoxantrone in this patient population. PATIENTS AND METHODS In a phase I study, 68 patients with acute myelogenous leukemia (AML), acute lymphoblastic leukemia (ALL), and accelerated- and blastic-phase CML received induction therapy consisting of cytarabine 3 g/m2 by infusion over 3 hours daily for 5 days, with escalating doses of mitoxantrone 40 to 80 mg/m2 over 1 to 2 days by intravenous infusion over 15 minutes. Mitoxantrone pharmacokinetics were evaluated by high-performance liquid chromatography (HPLC) in 15 patients given a single dose of mitoxantrone ranging from 40 to 80 mg/m2 in combination with cytarabine. RESULTS Severe, but reversible hyperbilirubinemia (> three times normal) was considered the dose-limiting toxicity, and was observed in 25% of all patients and in 35% of those who received 70 to 80 mg/m2 of mitoxantrone. Other extramedullary toxicity, including cardiac dysfunction, was mild. Myelosuppression was universal and the median time to complete remission (CR) was 28 days (range, 19 to 77). The CR rate for previously untreated and relapsed patients with AML was 85% (17 of 20) and 38% (seven of 18), respectively. Eighty-three percent (15 of 18) of patients with ALL achieved a CR, including all patients with previously untreated disease. Eight of 12 patients with advanced-phase CML achieved a CR. No significant changes in mean mitoxantrone plasma elimination rates (ie, terminal plasma half-life and total-body clearance rate) occurred as the mitoxantrone dose doubled, indicating linear pharmacokinetics. CONCLUSIONS The recommended phase II dose of mitoxantrone is 80 mg/m2 administered over 15 minutes as a single intravenous infusion in combination with cytarabine 3 g/m2/d for 5 days. At this dose, high concentrations of mitoxantrone are achievable in vivo to levels that have been shown to be extremely cytotoxic in vitro.

Cell cycle specificity of apoptosis during treatment of leukaemias.

This review summarizes our observations on the mechanism of induction of apoptosis in vitro in leukaemic cell lines and in vivo in patients with leukaemia undergoing chemotherapy, in relation to the cell cycle. Multiparameter flow cytometric methods allowed us to identify apoptotic cells and position them with respect to their cell cycle phase. Several antitumor agents of different classes have been characterized in terms of the cell cycle phase specificity of induction of apoptosis. Three types of apoptosis could be distinguished in relation to the initial damage to the cell vis-a-vis cell cycle position: (1) homo-phase apoptosis where the cells underwent apoptosis during the same phase in which they were initially affected; (2) homo-cycle apoptosis, where the cells underwent apoptosis during the same cell cycle in which they were initially affected, i.e., prior to or during the first mitosis, and (3) post-mitotic apoptosis, where cells underwent apoptosis during the cell cycle(s) subsequent to that in which the cell was initially affected, most likely at the G1 or G2 checkpoints of these cycle(s). Four ranges of drug concentration can be distinguished in vitro for most drugs, where either: (1) no immediate effects; (2) cytostasis or post-mitotic apoptosis; (3) homo-cycle or homo-phase apoptosis; or (4) necrosis are observed. Analysis of cell death of blast cells from peripheral blood or bone marrow of over 250 leukaemia patients (AML, ALL, CML in blast crisis) treated with various drugs during routine chemotherapy reveals that in the case of DNA topoisomerase inhibitors (e.g., mitoxantrone, VP-16) apoptosis is often rapid (peaks at 1-2 days after drug administration) and has features of homo-phase apoptosis. In contrast, cell death observed after administration of paclitaxel (taxol) or cytarabine (cytosine arabinoside) occurs later and has features of post-mitotic apoptosis: the cells divide but die in G1 of the subsequent cycle(s).

Synergetic effects of retrovirus IFN-alpha gene transfer and 5-FU on apoptosis of colon cancer cells.

Gene transfer has advantages in the treatment of a variety of disorders due to its selective expression within specific mammalian cells including the most primitive stem cells and cancer cells. Several investigators have reported on the clinical effects of interferon-α (IFN-α) or the combination of 5-FU plus IFN-α on patients with advanced colorectal carcinoma. Therefore, we examined the ability of a retrovirus-mediated IFN-α gene transfer to infect colon cancer cells COLO 201 and the effect of IFN-α gene expression alone or in combination with other chemotherapeutic drugs as 5-FU. IFN-α showed positive antitumor activity against COLO 201 cells, whereas 5-FU showed time- and concentration-dependent antitumor activity against COLO 201 cells. Furthermore, we demonstrated that combination therapy of IFN-α gene transfer and 5-FU resulted in enhancement of cancer cell lethality. The potentiation increased with higher concentrations of 5-FU by 1.5- to 2.1-fold. Our results suggest that retrovirus-mediated IFN-α gene transfer in COLO 201 cells resulted in functional gene expression as assessed by the levels of IFN-α mRNA and protein; furthermore, the combination of IFN-α gene transfer and 5-FU have additional effects on the induction of apoptosis. This finding provides an experimental basis for possible clinical therapy using retrovirus-mediated IFN-α gene transfer alone or in combination with other chemotherapeutic drugs for treatment of colorectal cancer.

CEPP regimen (cyclophosphamide, etoposide, procarbazine and prednisone) as initial treatment for Hodgkin lymphoma patients presenting with severe abnormal liver function

ABVD regimen (doxorubicin, bleomycin, vinblastine and dacarbazine) remains the most commonly used front-line therapy for Hodgkin lymphoma. However, atypical and extranodal presentations present challenges to initial therapy, especially in the presence of renal and liver failure. We hereby present two cases of young male patients with atypical presentation of Hodgkin lymphoma with severe abnormal liver function. Patients showed excellent response to cyclophosphamide, etoposide, procarbazine and prednisone (CEPP regimen).

Marrow Transplantation for Hodgkin's Disease: Points to Ponder

High dose chemotherapy with autologous marrow rescue has been shown to be useful in achieving long term disease free survival in patients with recurrent or relapsed Hodgkin’s disease.I4 However, high dose chemotherapy with autologous bone marrow transplantation (ABMT) is not uniformly curative and 40-70% of patients undergoing such therapy still relap~e.~.~ New treatment strategies for cohorts of patients at high risk of relapse after dose intensive therapy and ABMT need to be developed. The group at Genoa in collaboration with various investigators has been investigating the potential utility of dose intensive therapy and ABMT for patients deemed to be at high risk of relapse following standard dose therapy e.g. MOPP, ABVD or MOPP/ABVD.* Entry criteria to this multi-national trial include presence of extra-nodal disease, B symptoms, increased liver function tests and other prognostic variables. These factors have been identified as being important for prognosis after standard dose thera~y.~.’ In the experience at New York Medical College factors that influence overall and disease free survival after dose intensive therapy are not identical to variables that influence survival after standard dose therapy. While investigating the utility of dose intensive therapy for patients at risk of relapse, one should consider the impact and influence of prognostic factors that have been identified as being significant for patients undergoing dose intensive therapy. Since 1987 a series of dose intensive chemotherapy regimens were employed in the treatment of patients presenting to New York Medical College. Patients with refractory or resistant disease were eligible to receive 2

Phase I trial of ImuVert (natural membrane vesicles associated with ribosomes) in patients with advanced cancer

SummaryImuVert, a new biological response modifier, was evaluated for toxicity and potential efficacy in patients with advanced cancer. This agent consists of sized, labile, natural membrane vesicles associated with ribosomes derived fromSerratia marcescens. ImuVert induces enhanced in vitro macrophage and natural-killer-cell-mediated cytotoxicity, and has demonstrated antitumor activity in palpable animal tumor systems. A group of 39 patients with a variety of tumors, 25 men, 14 women, with a mean performance status (Karnofsky) of 80% and median age of 57 years were entered into this trial. ImuVert was administered subcutaneously weekly for a minimum of 3 weeks. A total of 183 treatments were evaluated. Flu-like systemic toxicities, including fever, chills, nausea, vomiting, diarrhea and hypotension were observed. Erythema, induration and tenderness developed at the injection sites. Myelosuppression, thrombocytopenia, anaphylaxis, rental and hepatic toxicities did not occur. All symptoms resolved within 24 h. Two patients with nodular lymphoma achieved a partial response and two minor responses were seen in patients with glioblastoma and melanoma. On the basis of ImuVerts biological activity, and tolerable toxicity it warrants further clinical investigation.

Preparation for Blood Group-Incompatible Bone Marrow Transplantation: Comparison of Two Techniques

Two similar techniques of red cell depletion of blood group-incompatible marrow prior to bone marrow transplantation were compared in 8 patients. The first method involved a single sedimentation step and removed a mean of 91% of marrow red cells and 33% of marrow nucleated cells. The second method involved multiple sedimentation steps and removed a mean of 96% of red cells and 29% of nucleated cells. Both methods can be recommended to a transfusion service newly involved in a bone marrow transplantation program.