Eric J. Feldman

Apoptotic Cell Death During Treatment of Leukemias

The apoptosis-associated DNA strand breaks were detected in situ, in individual leukemic cells in peripheral blood and bone marrow of over 110 patients with different types of leukemia (ALL, AML, CML in blastic crisis, APL), prior to and during routine chemotherapy. The DNA strand breaks were labeled with digoxigenin- or biotin-conjugated dUTP in the reaction catalyzed by exogenous terminal deoxynucleotidyl transferase, and the cells, counterstained for DNA, were analyzed by bivariate flow cytometry. The proportion of cells with DNA strand breaks prior to therapy, most likely reflecting spontaneous apoptosis, varied from 0.1 to 16%, but in the large majority of cases was below 3%. Administration of drugs of different classes, which included DNA topoisomerase I (Topotecan) and II (mitoxantrone, VP-16) inhibitors, antimetabolite (ara-C) or microtubule poison (Taxol), all triggered the appearance of cells with extensive DNA breakage, typical of apoptosis, to up to 80%. The peak of the response, measured as maximal percent of cells with DNA strand breaks, which varied between individual patients by as much as factor 10, was generally seen between 8 to 24 h after the initial administration of DNA topoisomerase inhibitors, and somewhat later (48-72 h) during the response to Taxol or ara-C. Thus, the data show that the response to treatment with a variety of drugs, in terms of induction of apoptosis, can be conveniently measured by the present method. The prognostic value of the apoptotic index, before, as well as during treatment, is being estimated for each type of leukemia, in the ongoing prospective studies.

A loading dose/continuous infusion schedule of fludarabine phosphate in chronic lymphocytic leukemia.

Using a loading dose/continuous infusion schedule, fludarabine phosphate was administered to 51 patients with previously treated chronic lymphocytic leukemia (CLL). All patients had evidence of active disease, and the majority had advanced Rai stages. Of the 42 patients assessable for response, 22 (52%) achieved a partial response, five (12%) had stable disease, and 15 (36%) progressed. Thirteen of the 22 responders improved their Rai stages with fludarabine therapy, including six patients who achieved stage 0. Response rates for pretreatment stages III and IV were 60% and 53%, respectively. Patients with final Rai stages 0 to II had better survival than those with stages III and IV. Patients who had undergone splenectomy before starting therapy were more likely to respond. Myelosuppression was the primary toxicity and did not appear to be cumulative. Severe leukopenia and thrombocytopenia, although infrequent, were associated with several deaths in the early cycles of treatment. Nonhematologic toxicity was mild with no serious neurotoxicity noted. Infections were common with 22 minor, 18 major, and 10 fatal episodes. Fludarabine phosphate by this alternative dosing schedule is effective in refractory advanced CLL and is well tolerated by the majority of patients.

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

PURPOSEnTo determine the maximal-tolerated dose (MTD) of topotecan with cytarabine in acute leukemia patients, and to evaluate leukemia cell apoptosis in these patients.nnnPATIENTS AND METHODSnFifty-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.nnnRESULTSnOropharyngeal 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).nnnCONCLUSIONnThe 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.

PURPOSEnTo 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.nnnPATIENTS AND METHODSnIn 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.nnnRESULTSnSevere, 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.nnnCONCLUSIONSnThe 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.

Incidence and Treatment of Tumor Lysis Syndrome in Patients with Acute Leukemia

Tumor lysis syndrome (TLS) is a complication associated with electrolyte abnormalities that is observed in patients with acute leukemia who are receiving intense doses of chemotherapy. Forty-one patients with acute leukemia were treated with high-dose combination chemotherapy and were evaluated for TLS. A grading system developed for the evaluation of these patients was applied. Grade I tumor lysis was observed in 22 patients, grade II TLS in 2 patients and grade III in 1 patient. All patients were treated with intravenous fluids, mannitol, allopurinol and in some patients, aluminum-based antacids. Treatment for TLS prior to intensive chemotherapy reduced morbidity and mortality associated with high-dose chemotherapy for acute leukemias.

Adenovirus Mediated Alpha Interferon (IFN‐α) Gene Transfer into CD34+ Cells and CML Mononuclear Cells

Gene transfer or gene therapy has advantages in the treatment of a variety of disorders due to its selective expression within specific mammalian cells. Interferon‐α (IFN‐α) has been used in the management of leukemia but its diverse adverse activities with multiple potential side effects, possibly unrelated to therapeutic targets, may negatively influence the ability of IFN‐α to treat this disorder. Therefore, we examined the ability of adenovirus (Ad)‐IFN‐α gene construct to transfect normal (CD34+ cells) and chronic myelogenous leukemia (CML) bone marrow mononuclear cells (BMMNC) and the transient overexpression of IFN‐α in these cells. Ad‐cytomegalovirus promoter driven IFN‐α (AdCMV‐IFN‐α) at multiple doses was assessed to transfect highly purified CD34+ cells in liquid culture, and optimal transduction of CD34+ cells was achieved using 120 plaque forming units. Flow cytometric determinations revealed that there was no significant difference in cell viability for the 4 h or 24 h transfection periods. Immunoassay of IFN‐α produced by CD34+ cells shows that IFN‐α levels increased several fold in transfected cells. Transient expression of the IFN‐α gene did not suppress proliferation of CD34+ progenitors as indicated by BFU‐E or colony forming units‐granulocyte‐macrophage (CFU‐GM) growth. Reverse transcriptase/polymerase chain reaction analysis of RNA from CD34+ harvested CFU‐GM progenitor cells demonstrated transient IFN‐α mRNA expression. Similarly, CML BMMNC were transfected with AdCMV‐IFN‐α under similar conditions as described for CD34+ cells. BMMNC cells exposed to adenovirus for 24 h and 48 h were found to express IFN‐α at a substantial level. This in vitro data suggest that Ad‐mediated gene transfer of IFN‐α into hematopoietic stem cells can be achieved and that the IFN‐α gene can be translated into its specific mRNA in CD34 progenitor cells.

Amsacrine is safe and effective therapy for patients with myocardial dysfunction and acute leukemia

The role of amsacrine in inducing remission in patients with cardiac disease and acute leukemia was evaluated. There were 17 patients with acute myelogenous leukemia (AML), six with acute lymphocytic leukemia (ALL), and one with biphenotypic leukemia. In this series of 24 patients whose disease had relapsed and who had reduced left ventricular ejection fraction, nine had a complete remission, seven with AML and two with ALL. In addition, four of six with newly diagnosed acute leukemia and reduced left ventricular ejection fraction also responded. Among nine patients who underwent endomyocardial biopsy, none had morphologic changes of sufficient degree to account for drug‐induced heart failure. Patients with preexisting arrhythmias received amsacrine without incident if their serum potassium level was higher than 4.0 mEq/1 at the time of drug administration. Amsacrine is safe and effective therapy for patients with acute leukemia and cardiac disease.

Marrow storage techniques: a clinical comparison of refrigeration versus cryopreservation.

Fifty-three patients were evaluated for a comparison of the efficacy, safety, and cost efficiency of bone marrow (BM) transplanted after either refrigeration or cryopreservation. Thirty-eight patients had BM stored at 4 degrees C for an average of 3 days and 15 patients had cryopreserved BM stored for an average of 56 days. The average number of cells harvested was 3.8 x 10(8)/kg. The time to WBC recovery greater than 1 x 10(9)/l was 17 days refrigerated and 23 days for cryopreserved BM. The time to platelet recovery greater than 20 x 10(9)/l was 24 days for refrigeration storage and 51 days for cryopreserved BM. Four of 38 patients with refrigerated vs. 4/15 patients with cryopreserved BM experienced delayed engraftment (p less than 0.05). Refrigeration storage requires no special equipment, is cheaper than and presents a safe and viable alternative to cryopreserved BM in reconstituting hemopoiesis following high-dose chemo-radiotherapy.

Acute Promyelocytic Leukemia: A 5-Year Experience with New Antileukemic Agents and a New Approach to Preventing Fatal Hemorrhage

Forty-six induction courses were administered to 32 patients with acute promyelocytic leukemia. There were 28 males and 18 females with a median age of 39.5 (range 19-68). Twelve patients were previously untreated, 32 were in relapse, and 2 were refractory to primary induction chemotherapy. Heparin 7.5-10 units/kg/h by continuous infusion, 4-6 units of platelets and 1-2 units of fresh-frozen plasma (FFP) every 12 h were given to all patients. Previously untreated patients received either daunorubicin, idarubicin or mitoxantrone in combination with cytarabine (Ara-C). For relapsed and refractory patients, regimens included amsacrine with high-dose cytarabine (Amsa/HiDac), homoharringtonine (HHT) alone, or with Ara-C, mitoxantrone and bisantrene. Hemorrhagic complications occurred in only 1 out of 46 courses (2%). Complete remission rates (CR) were as follows: previously untreated 83% (10/12), relapsed 66% (21/32), primary refractory 50% (1/2). Amsa/HiDac resulted in a 71% (10/14) CR and HHT-based regimens achieved a 46% (6/13) CR. These regimens are effective and the value of their incorporation into primary therapy should be studied. The use of heparin with platelet and FFP transfusions every 12 h reduces the risk of hemorrhage during induction therapy.

Graft‐versus‐host disease: Possible higher risk for African American patients

Race is not generally recognized as a factor in the severity or incidence of graft‐versus‐host disease (GVHD) after allogeneic bone marrow transplantation. The impression that African American patients had more frequent and severe GVHD prompted this retrospective survey.