Phase I study of combination drug purging for autologous bone marrow transplantation

The impact of recent vincristine on human hematopoietic progenitor cell collection in pediatric patients with central nervous system tumors

BACKGROUND

Central nervous system (CNS) malignancies represent 20% of all childhood cancers. To improve outcomes in infants and children with high-risk disease, treatment can include adjuvant chemotherapy and early autologous peripheral blood human progenitor cell collection (AHPCC), followed by high-dose chemotherapy and stem cell rescue. In many protocols, postoperative chemotherapy includes the administration of weekly vincristine (VCR) between induction chemotherapy cycles, regardless of scheduled AHPCC. We observed anecdotal AHPCC failures in children receiving midcycle VCR (MC-VCR).

STUDY DESIGN AND METHODS

The study was an 8-year retrospective chart review of all children with a CNS malignancy and who underwent AHPCC. Information included patient demographic and clinical data, mobilization regimen, VCR administration, product yields, infusion toxicity, and patient charges. Data were analyzed relative to MC-VCR administration. Graphics and statistical analysis (t-test, chi-square, linear regression) were performed with commercial software.

RESULTS

Twenty-four patients and 47 AHPCCs were available for analysis. Nine patients (37%) received MC-VCR within 7 days of scheduled AHPCC. MC-VCR was associated with delayed marrow recovery (17.9 days vs. 14.9 days, p=0.0012), decreased median peripheral CD34 counts (75 × 10(6) CD34/L vs. 352 × 10(6) CD34/L, p=0.03), decreased median CD34 yields (2.4 × 10(6) CD34/L vs. 17.8 × 10(6) CD34/kg, p=0.08), more AHPCCs per mobilization (2.9 vs. 1.1, p=0.01), and an increased rate of remobilization (33% vs. 6%). Mean patient charges were 2.5× higher in patients receiving MC-VCR than controls (p=0.01).

CONCLUSION

MC-VCR should be withheld before scheduled AHPCC to optimize CD34 collection.

Long-term follow-up of intensive ara-C-based chemotherapy followed by bone marrow transplantation for adult acute lymphoblastic leukemia: impact of induction Ara-C dose and post-remission therapy

We report single institution outcome of brief, intensive ara-C-based chemotherapy using bone marrow transplantation as primary intensification for untreated adult patients with acute lymphoblastic leukemia (ALL). Overall disease-free and overall survival were inferior to those reported with prolonged chemotherapy modeled on pediatric protocols. Survival and disease-free survival were superior for patients receiving allogeneic BMT compared with chemopurged autologous transplant or maintenance chemotherapy (patients ineligible for or declining BMT). In multivariate analysis, non-L2-FAB, higher ara-C dose, absence of CNS disease, non-Ph1+ karyotype, allogeneic BMT, T cell phenotype, and younger age were associated with improved disease-free survival. Autologous BMT was not superior to chemotherapy, and appears unlikely to provide adequate curative treatment for most adult ALL patients if not followed by maintenance.

Addition of etoposide to initial therapy of adult acute lymphoblastic leukemia: a combined clinical and laboratory study

The role of high-dose etoposide in the initial treatment of newly diagnosed adult ALL was assessed in a combined clinical and laboratory study. Therapy on protocol JH8802 consisted of two induction modules, module 1 containing prednisone, vincristine, high-dose etoposide and L-asparaginase (L-asp), followed by module 2 containing cytarabine (Ara-C) and daunorubicin (DNR). Patients achieving a complete remission (CR) underwent bone marrow transplantation (BMT) or intensive maintenance therapy. Results were compared to the preceding protocol (JH8302), which was similar except for omission of etoposide and L-asp. The CR rate following module 1 was 45% on protocol JH8802 and 9% on protocol JH8302 (p < 0.0002). Nonetheless, the two protocols had similar CR rates following module 2 (69% on protocol JH8302; 77% on JH8802) and indistinguishable survivals. Laboratory investigations performed on blasts harvested prior to chemotherapy revealed two factors that could potentially contribute to decreased etoposide sensitivity in ALL blasts. A flow microfluorimetry-based assay of nuclear DNR accumulation detected small P-glycoprotein (Pgp)-mediated decreases in drug accumulation in a quarter of the samples. Western blotting demonstrated that topoisomerase II was present in all samples but was diminished in amount compared to the Molt3 human ALL cell line. Immunoperoxidase staining with affinity-purified antibodies revealed that topo II alpha, the target for etoposide, was detectable in only a minority of the blasts (median 7.5%, range < 1-35%) at diagnosis. These observations raise the possibility that alterations in drug accumulation and diminished target enzyme levels might both limit the long-term efficacy of a single course of high dose etoposide administered early in the treatment of adult ALL.

The selective uptake of benzoporphyrin derivative mono-acid ring A results in differential cell kill of multiple myeloma cells in vitro

High-dose chemotherapy (HDCT) and autologous bone marrow/blood stem cell transplantation are an effective combination for treating a number of malignant disorders. The contamination of the autograft by malignant cells may be a reason for recurrences in spite of this treatment, for instance, in multiple myeloma. Therefore, we evaluated the use of photodynamic therapy (PDT) using the photosensitizer benzoporphyrin derivative mono-acid ring A (BPD-MA) on multiple myeloma cells in comparison to the components of the normal bone marrow (NBM) and peripheral blood apheresis product. Flow cytometry was used to measure differential BPDMA uptake of NBM components: namely lymphocytes, monocytes, granulocytes and enriched hematopoietic stem cell (CD34+) populations and also the multiple myeloma cell lines OCI-MY7 and OCI-MY4. When each population was measured individually, the order of uptake was [OCI-MY7/MY4] > [CD34+] > [granulocytes] = [monocytes] >> [lymphocytes]. Further, clonogenic assay was used to demonstrate surviving fractions for OCI-MY7, OCI-MY4 and NBM in vitro. The LD90 for OCI-MY7 and OCI-MY4 was between 10 and 20 ng/mL BPD-MA whereas this concentration did not show any significant cell kill for the colony-forming units-granulocyte/macrophage (CFU-GM) and burst-forming units-erythrocyte (BFU-E). When the NBM was "contaminated" with multiple myeloma cells in vitro, the LD90 for OCI-MY7 in this cell mixture was shifted to between 40 and 80 ng/mL BPD-MA. However, at 40 ng/mL BPD-MA at least 50% of normal CFU-GM and BFU-E colonies survived. For CFU-GM and BFU-E derived from the enriched CD34+ cell population, BPDMA up to a concentration of 80 ng/mL did not significantly reduce the surviving fractions. We have observed a 3-4 log therapeutic window with differential cell kill when comparing multiple myeloma cell lines to the components of the NBM and apheresis product in vitro. We conclude, that BPD-MA is a molecule potentially useful as an ex vivo purging agent.

Cytokines and bone marrow transplantation

This article summarizes the various current uses of cytokines, and bone marrow and peripheral blood stem cell transplantation for cancer treatment. Interferons, interleukin-2 and hematopoietic growth factors are extensively used for the treatment of hematopoietic as well as nonhematopoietic malignancies, either as the main therapeutic agents or as an adjuvant. Research on gene therapy using cytokines is in progress. Stem cell transplantation is also discussed in the context of gene therapy of cancer. Gene therapy is expected to become a future modality in cancer treatment.

Recombinant human deoxyribonuclease for hematopoietic stem cell processing

Numerous reagents are used in the collection processing and storage of hematopoietic progenitor cells for transplantation. To decrease potential variations in the final component for transplantation, these reagents should be uniform in safety, potency, and efficacy. Pharmaceutical-grade reagents are ideal but often are not available. Recently, recombinant human deoxyribonuclease (DNase) was approved for the treatment of patients suffering from the pulmonary complications of cystic fibrosis. We tested this pharmaceutical for toxicity to hematopoietic progenitor cells. These cells were exposed to a range of incubation concentrations for both the recombinant enzyme and bovine DNase previously used in this laboratory. No loss of nucleated cells or hematopoietic progenitors was observed after short-term incubation (1 h) or with direct addition to the culture medium. No incremental toxicity was observed in using recombinant enzyme with murine anti-B cell antibodies and rabbit complement in an immunologic purge technique. A variable effect on cell recovery after thawing of cryopreserved bone marrow cells was observed for both enzyme sources. These data suggest that the pharmaceutical-grade, recombinant human DNase may substitute for previously used reagent-grade protein from animal sources.

Autologous bone marrow transplantation

Autologous bone marrow transplantation has become a very popular and successful treatment for many patients with lymphomas and other malignancies. The current indications, pretreatment regimes, and laboratory manipulations are discussed as well as the application of gene transfer to eliminate selected genetic diseases and detect disease relapse.

Comparison of progenitor cell concentration techniques: continuous flow separation versus density-gradient isolation

Bone marrow harvests were processed using two techniques; 20 mononuclear cell concentrations (MNC) were prepared on the COBE Spectra and compared to 10 light-density cell fractions isolated using the COBE 2991. Both procedures recovered essentially the same percentage of nucleated cells (22 versus 21%) and gave progenitor cell recoveries of 132 and 100% of the CFU-GM and 101 and 104% of the CD34+ cells in the MNC and light-density products, respectively. The advantage of the Spectra MNC concentrate is that it was prepared with reagents approved for injection by the Food and Drug Administration. However, the average hematocrit on the MNC concentrate was 4%, while it was unmeasurable in the light-density cell fractions. This difference is significant only when bone marrows require purging with 4-hydroperoxycyclophosphamide or erythrocytes otherwise interfere with processing. The Spectra procedure recovered a larger percentage of MNC cells and had less contamination with mature granulocytes than did the density-gradient technique. When erythrocytes do not affect the bone marrow processing protocol, a Spectra MNC concentrate is a safe substitute for a light-density cell preparation.