Retrospective study of alemtuzumab vs ATG-based conditioning without irradiation for unrelated and matched sibling donor transplants in acquired severe aplastic anemia: a study from the British Society for Blood and Marrow Transplantation.

This retrospective national study compared the use of alemtuzumab-based conditioning regimens for hematopoietic SCT (HSCT) in acquired severe aplastic anemia with antithymocyte globulin (ATG)-based regimens. One hundred patients received alemtuzumab and 55 ATG-based regimens. A matched sibling donor (MSD) was used in 87 (56%), matched unrelated donor (MUD) in 60 (39%) and other related or mismatched unrelated donor (UD) in 8 (5%) patients. Engraftment failure occurred in 9% of the alemtuzumab group and 11% of the ATG group. Five-year OS was 90% for the alemtuzumab and 79% for the ATG groups, P=0.11. For UD HSCT, OS of patients was better when using alemtuzumab (88%) compared with ATG (57%), P=0.026, although smaller numbers of patients received ATG. Similar outcomes for MSD HSCT using alemtuzumab or ATG were seen (91% vs 85%, respectively, P=0.562). A lower risk of chronic GVHD (cGVHD) was observed in the alemtuzumab group (11% vs 26%, P=0.031). On multivariate analysis, use of BM as stem cell source was associated with better OS and EFS, and less acute and cGVHD; young age was associated with better EFS and lower risk of graft failure. This large study confirms successful avoidance of irradiation in the conditioning regimens for MUD HSCT patients.

In vivo CAMPATH-1H prevents GvHD following nonmyeloablative stem-cell transplantation.

BACKGROUND: We have investigated a novel nonmyeloablative conditioning regimen in 44 patients with hematological malignancies. The median patient age was 41 years. Many of the patients had high-risk features, including 19 patients with a previous failed transplant. METHODS: Recipient conditioning consisted of CAMPATH-1H 20 mg/day on Days -8 to -4, fludarabine 30 mg/m(2) on Days -7 to -3 and melphalan 140 mg/m(2) on Day -2. Thirty-six recipients received unmanipulated G-CSF mobilized PBSC from HLA identical siblings and eight received unmanipulated BM from MUD. GvHD prophylaxis was with CYA alone for 38 patients and CYA plus MTX for six sibling recipients. RESULTS: Forty-two of the 43 evaluable patients had sustained engraftment. Results of chimerism analysis using microsatellite PCR indicate that 18 of 31 patients studied were full donor chimeras, while the other patients were mixed chimeras in one or more lineages. At a median follow-up of 9 months (range, 3-29 months) 33 patients remain alive in CR, or with no evidence of disease progression. Seven patients relapsed or progressed post-transplant and four of them subsequently died. Four patients died from regimen-related complications. There were no cases of Grades III-IV acute GvHD. Only two patients developed Grade II acute GvHD and only one had chronic GvHD. The estimated probability of non-relapse mortality at 1 year was 11%.Results: Although longer follow-up is needed to establish the long-term remission rates, this study demonstrates that this nonmyeloablative preparative regimen is associated with durable engraftment, minimal toxicity and low incidence of GvHD.

Percutaneous isolated liver perfusion for treatment of hepatic malignancy: preliminary report.

Chemotherapy for primary or metastatic hepatic malignancy is limited by poor tumor response and dose-related systemic toxicity. As an alternative to chemotherapy infusion by vein or by the hepatic artery, the authors have developed a percutaneous technique of isolated liver perfusion that allows the regional delivery of high-dose chemotherapy to the liver with little systemic toxicity. After placement of a hepatic artery infusion catheter, an 18-F double-balloon catheter is placed into the inferior vena cava through the opposite femoral vein. Balloons are inflated above and below the hepatic veins, thus isolating hepatic venous outflow. The effluent passes through fenestrations in the catheter and is pumped through charcoal hemoperfusion filters where the drug is removed. The filtered blood is returned to the patient through the internal jugular vein. Fifteen treatments have been conducted in eight patients in a phase I dose-escalation study with use of 5-fluorouracil (5-FU). While it is premature to assess tumor response to isolated liver perfusion, the data demonstrate that the procedure is safe and is tolerated by patients. Pharmacokinetic studies show a 5-FU extraction of up to 85%, with minimal drug leakage into the systemic circulation. This technique shows potential for improving liver tumor response while decreasing systemic toxicity.

Phase II study of pulse 5-fluoro-2'-deoxyuridine and leucovorin in advanced colorectal cancer patients previously treated with chemotherapy.

Because of possibly better activity against colorectal cancer of 5-fluoro-2'-deoxyuridine [floxuridine (FUdR)] compared to 5-fluorouracil (5-FU), and because of improved therapeutic results of leucovorin (LV) modulation of 5-FU, we carried out a phase II study of systemic FUdR and LV in 5-FU-treated patients with metastatic colorectal cancer. Weekly regimens consisted of a 4-hour infusion of LV, 200 mg/m2, and at 2 hours, a 2-hour infusion of FUdR, 30 mg/kg, with weekly dose escalation, as tolerated, to a maximum of 60 mg/kg. Twenty-nine patients were treated; they had a median age of 66, most had good performance status, and all had measurable disease. All had received 5-FU, although three had received it as adjuvant therapy only. Two patients had partial responses (6.9% response rate, 95% confidence interval, 1.9-21.9%) lasting 29 and 19 weeks, and five had stable disease. Median time to progression was 8 weeks and median survival was 36.5 weeks. The median number of courses was 6.5; escalation of FUdR was carried out in 27 patients. Hematologic toxicity was minimal and gastrointestinal toxicity was most frequent, although mild. This regimen, although well tolerated, is minimally effective in previously 5-FU-treated patients with metastatic colorectal cancer.

Stability of the in vivo P388 leukemia model in evaluation of antitumor activity of natural products.

The stability of the P388 mouse leukemia model over 15 years was examined. Eleven natural products and one synthetic compound (5-FU) tested repetitively under the same conditions of dose and schedule were associated with no significant change in their activity. The P388 model, used in conjunction with other in vivo and in vitro tumor models, continues to be of value in the anticancer drug screening process.

Chemosensitivity of human tumor clonogenic cells simultaneously assayed in agar diffusion chambers and in a two-layer agar culture system.

We have compared plating efficiencies (PE) of 20 fresh and cryopreserved samples of human solid tumors, disaggregated and cloned simultaneously in a two-layer agar culture system (2LACS) and in agar diffusion chambers (ADC). A significant correlation (0.001 less than P less than 0.01, paired t test) was found between PE, confirming that the two methods reflect the same property of tumor cells: their clonogenic potential. The median PE in ADC was 1.4 and 3.3 times higher than that in the 2LACS for cryopreserved and fresh specimens, respectively. One- and two-drug doses, approximately clinically achievable concentrations, were assayed simultaneously in the ADC and in the 2LACS, respectively, on 15 tumor specimens. In this way we evaluated the effects of eight drugs, two to five for each tumor, in a static (2LACS) versus a dynamic (ADC) system. The comparison of percent survival in ADC versus that in the 2LACS at both concentrations tested showed no statistically significant rank correlation. If the data regarding cyclophosphamide and mitomycin, which produced significant cell kill in the ADC and almost none in the 2LACS, were excluded, the rank correlation was still not significant. We conclude that the widely used 2LACS is unsuitable to study cyclophosphamide and mitomycin, for which the ADC technique may be a valid alternative.

The effects of cancer chemotherapeutic agents on normal hematopoietic precursor cells: a review.

The effects of antineoplastic agents, singly or in combination, on normal hematopoietic precursor cells have been reviewed. Following a description of the assays used (e.g., spleen colony, in vitro colony, repopulating ability), the dose response and/or time response for each drug are presented by species and by assay as available. The schedule of drug administration, the time of the assay, and the proliferative state of the target population are the most important determinants. Alkylating agents, antitumor antibiotics, and 5-fluorouracil have exponential dose survival curves. "Phase-specific" agents such as antimetabolites, Vinca alkaloids, and ribonucleotide reductase inhibitors have plateaus in their dose survival curves, although the level of this plateau is different for different agents. Most drugs are more effective against rapidly proliferating cells although busulfan is less effective. Direct interspecies comparisons are possible with some of the clonogenic assays, which may allow prediction of the magnitude of human hematological toxicity for new agents or combinations.

Factors influencing hematopoietic spleen colony formation in irradiated mice. II. The effect of foreign materials.

Normal dog plasma and serum, human, rat, and Swiss-Webster mouse plasma, phytohemagglutinin, sheep red cells, mumps and influenza vaccine, fibrinogen, and endotoxin injected before irradiation led to an increased number of endogenously derived spleen colonies in irradiated mice. Spleen weight and uptake of radioactive iron and iododeoxyuridine into such spleens were also increased. The relationship between these parameters of splenic hematopoiesis was unchanged by plasma injection suggesting that, while the number of colonies was increased, the composition of individual colonies was unchanged. This conclusion was supported by studies on plethoric mice in which splenic erythropoiesis is abolished. Increased splenic hematopoiesis was accompanied by an increase in the volume of packed red blood cells 10 days after irradiation. The total volume of plasma injected, the number of days of plasma injection preceding irradiation, and the route of administration were all important variables influencing the effect of plasma injections. Crude fractions of human albumin and gamma globulin, cortisol, C57BL (maternal) and DBA (paternal) mouse plasma, and isogeneic plasma were without effect. The ineffectiveness of isogeneic and closely related allogeneic plasma rendered unlikely the hypothesis that this effect represented the presence of homeostatic hematopoietic regulating factors in plasma. The increased hematopoiesis induced with plasma appeared to be limited to the spleen, for increased bone marrow hematopoiesis was not detected. Certain observations suggested that the effect of plasma may not be due to an antigenic or an inflammatory effect. From current observations, it was unclear whether the increased colonies induced by plasma were representative of expansion of the colony-forming cell pool or of increased efficiency of growth of the fraction surviving irradiation.