pentostatin and Lymphoma

Topics: Antibiotics, Antineoplastic; Antineoplastic Agents; Cladribine; Clinical Trials as Topic; Humans; Leukemia, Lymphoid; Lymphoma; Nucleosides; Pentostatin; Vidarabine

This article details both the contribution of the purine nucleoside analogs to the current management of relapsed indolent non-Hodgkin's lymphoma (NHL) and the role of pentostatin (Nipent) in that management. Of the three purine nucleoside analogs, pentostatin has received the least attention with regard to the management of indolent NHL. Although data in the literature appear to indicate that fludarabine (Fludara) and 2-chlorodeoxyadenosine (cladribine [Leustatin]) are more active in NHL, this conclusion could be flawed because many of the studies investigating pentostatin in indolent NHL have contained a large number of patients previously treated with the other purine analogs. As these agents are most likely cross-resistant, it is unfair to conclude that pentostatin is less active. Recently, there has been interest in using a new, more protracted schedule of 2 mg/m2/d of pentostatin for 5 days. Although the schedule used in the trials conducted in indolent NHL might not be optimal, pentostatin has nevertheless shown significant activity in these disorders.

Topics: Adenosine Deaminase Inhibitors; Antibiotics, Antineoplastic; Cladribine; Humans; Lymphoma; Pentostatin; Vidarabine Phosphate

Topics: Adenosine Deaminase; Antimetabolites, Antineoplastic; Antineoplastic Agents; Cladribine; Humans; Lymphoma; Lymphoma, B-Cell; Lymphoma, T-Cell, Cutaneous; Pentostatin; Vidarabine; Waldenstrom Macroglobulinemia

Topics: Adenosine Deaminase Inhibitors; Animals; Clinical Trials as Topic; Humans; Leukemia; Lymphoma; Lymphoproliferative Disorders; Pentostatin

There are three new purine analogs, fludarabine, 2'-deoxycoformycin, and 2-chlorodeoxyadenosine, all of which have major activity in the treatment of indolent lymphoid malignancies. These three agents, with cytotoxicity against dividing and resting lymphocytes, have revolutionized the treatment of these diseases and, accordingly, represent a significant therapeutic advance. The development of these drugs emanated from an enhanced understanding of purine metabolism in lymphocytes and the mechanism of lymphocytotoxicity in severe combined immunodeficiency disease. Preclinical studies and phase I clinical trials are reviewed, as are phase II studies of these three purine analogs in chronic lymphocytic leukemia, hairy cell leukemia, non-Hodgkin lymphoma, cutaneous T-cell lymphoma, and the myeloid leukemias. Potential future strategies exploring possible synergy between these purine analogs and the concurrent administration of both alkylators and biologic response modifiers are explored. The development of the purine analogs and their appropriate clinical applications exemplifies the model for rational drug design and development.

Topics: Antineoplastic Agents; Cladribine; Humans; Leukemia; Lymphoma; Pentostatin; Vidarabine

Topics: Antineoplastic Agents; Cladribine; Clinical Trials as Topic; Humans; Leukemia; Lymphoma; Molecular Structure; Pentostatin; Purine Nucleosides; Vidarabine

Several new antimetabolites have been evaluated in clinical trials in recent years. Those with the most promising activity include the structurally related purine analogs fludarabine, 2-chlorodeoxyadenosine, and 2'-deoxycoformycin. These compounds have shown impressive activity against a broad spectrum of indolent lymphoproliferative disorders, including hairy-cell leukemia, chronic lymphocytic leukemia, and low-grade non-Hodgkin's lymphomas. They may also be useful in the treatment of acute leukemias. In contrast, they lack activity against common solid tumors. They have been generally well tolerated in large clinical trials; however, each of them is myelosuppressive and immunosuppressive. It is unlikely that any one of these drugs, when used as a single agent, will provide optimal therapy for any disease other than, possibly, hairy-cell leukemia. Combinations with other cytotoxic agents and biologics are in development, and perhaps they will lead to more effective regimens in the future.

Topics: Animals; Antimetabolites, Antineoplastic; Cladribine; Clinical Trials as Topic; Drugs, Investigational; Forecasting; Humans; Immunosuppression Therapy; Leukemia; Lymphoma; Pentostatin; Purines; Vidarabine

A few enzymes of the purine degradative pathway have proved valuable in diagnosis and treatment of lymphomas and lymphocytic leukemia. Of particular interest are the enzymes adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP) and ecto-5'-nucleotidase (5NT). Intact activities of ADA and PNP have been shown to be vital for lymphoid cells. During development, lymphoid precursors go through remarkable changes in the concentrations of these enzymes and the neoplasms derived from them show a "frozen" biochemical profile similar to the corresponding normal cell of origin. Knowledge of the role of these enzymes has led to the pharmacological use of enzyme inhibitors for the specific treatment of lymphoid neoplasms. This review concerns the enzymatic make-up of normal and neoplastic lymphocytes and exploitation of this knowledge for the treatment of lymphomas. Special emphasis will be put on the clinical use of an ADA-inhibitor, deoxycoformycin.

Topics: 5'-Nucleotidase; Adenosine Deaminase Inhibitors; Antineoplastic Agents; Coformycin; Humans; Leukemia; Lymphoma; Nucleoside Deaminases; Nucleotidases; Pentostatin; Pentosyltransferases; Purine-Nucleoside Phosphorylase; Purines

Promising results in the treatment of indolent lymphomas have been reported with the use of 2'deoxycoformycin. This antimetabolite, an adenosine deaminase inhibitor, also shows particular efficacy in hairy cell leukemia. Of 65 patients treated to date, 44 have achieved complete and lasting remission after a limited course of deoxycoformycin. While results are not as striking as those in hairy cell leukemia, deoxycoformycin may also be a valuable adjunct to alkylating agents in the treatment of CLL. The drug also is being studied in the treatment of mycosis fungoides and other lymphoid neoplasms. Side effects in all neoplasms are dose- and schedule-dependent.

Topics: Humans; Leukemia, Hairy Cell; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoma; Mycosis Fungoides; Pentostatin

A new antimetabolite, 2'-deoxycoformycin (pentostatin), has striking antitumor activity in several lymphoid neoplasms. Isolated from cultured soil organisms, this purine analogue is a potent inhibitor of adenosine deaminase (ADA), and is thus selectively toxic to lymphocytes. Early clinical trials showed that high doses of pentostatin caused severe and unpredictable toxicity, but responses in refractory lymphoid malignancies were encouraging. Careful pharmacologic studies led to the definition of a safe and effective low weekly dose, at which protracted ADA inhibition occurs in neoplastic cells. The most sensitive tumor identified is hairy cell leukemia, in which durable remissions are achieved in more than 90% of patients with a relatively brief course of treatment. Other responsive diseases include chronic lymphocytic leukemia, prolymphocytic leukemia, mycosis fungoides, and acute T-cell lymphoma or leukemia. Response has been seen in acute lymphocytic leukemia, but the higher doses required are substantially more toxic. Pentostatin is valuable for treatment of indolent lymphoid malignancies and may be useful in non-cancer-related lymphocyte research.

Topics: Adenosine Deaminase Inhibitors; Animals; Antimetabolites, Antineoplastic; Antineoplastic Combined Chemotherapy Protocols; Clinical Trials as Topic; Coformycin; Drug Evaluation; Humans; Immunosuppressive Agents; Leukemia; Lymphoma; Pentostatin; Ribonucleosides

Topics: Adult; Animals; Antibodies, Monoclonal; Burkitt Lymphoma; Cats; Cattle; Cell Differentiation; Chickens; Child; Coformycin; Disease Models, Animal; Humans; Interleukin-2; Japan; Leukemia; Leukemia, Lymphoid; Lymphoma; Lymphoproliferative Disorders; Male; Mice; Mice, Inbred AKR; Pentostatin; T-Lymphocytes

Extracorporeal photopheresis (ECP) is an immunomodulatory cellular therapy which has been shown to induce a tolerogenic state in patients with acute and chronic graft-vs-host disease. ECOG-ACRIN explored the activity of ECP as a part of a reduced intensity conditioning regimen in two multicenter trials in patients with MDS (E1902) and lymphomas (E1402). While both studies closed before completing accrual, we report results in 23 patients (17 MDS and 6 lymphoma).. Patients received 2 days of ECP followed by pentostatin 4 mg/m2 /day for two consecutive days, followed by 600 cGy of total body irradiation prior to stem cell infusion. Immunosuppression for aGVHD was infusional cyclosporine A or tacrolimus and methotrexate on day +1, +3, with mycophenolate mofetil starting on day 100 for chronic GVHD prophylaxis.. All patients engrafted, with median time to neutrophil and platelet engraftment of 15-18 days and 10-18 days respectively. Grade 3 or 4 aGVHD occurred in 13% and chronic extensive GVHD in 30%.. These studies demonstrate that ECP/pentostatin/TBI is well tolerated and associated with adequate engraftment of neutrophils and platelets in patients with lymphomas and MDS.

Topics: Adult; Allografts; Cyclosporine; Female; Graft vs Host Disease; Hematopoietic Stem Cell Transplantation; Humans; Lymphoma; Male; Methotrexate; Middle Aged; Myelodysplastic Syndromes; Pentostatin; Photopheresis; Tacrolimus; Transplantation Conditioning; Whole-Body Irradiation

Pentostatin, a novel inhibitor of adenosine deaminase, has shown activity in various lymphoid malignancies of both the T and B cell lineage. This agent has unique side effects and in general myelosuppression has been mild. Interferon has both antiviral and antineoplastic properties. This agent has shown activity in hairy cell leukemia, chronic granulocytic leukemia, low grade lymphoma, and myeloma. Side effects from interferon are in general dissimilar to those that have been seen with pentostatin and in particular myelosuppression has not been a major toxicity with low doses of interferon. This current trial explored the combination of pentostatin and interferon in hematologic malignancies. Fifteen patients were enrolled in this phase I trial at a fixed dose of pentostatin of 4 mg/m2 biweekly and interferon at doses of 0.5, 1, 2, or 4 million units/m2 of interferon. At the first three dose levels of interferon nausea and vomiting were the predominant toxicity and appeared to worsen with time on study. Fatigue also was seen at the lowest level of interferon and was severe enough to cause two individuals to discontinue the study medications. At higher dose levels of interferon, myelosuppression, nausea and vomiting, and fatigue were the predominant toxicities. One patient with hairy cell leukemia had a complete response and a second patient with T cell cutaneous lymphoma had a partial response which lasted for 6 to 7 weeks. The maximum tolerated dose of interferon with pentostatin in this patient population was four million units/m2.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Drug Evaluation; Female; Hematologic Diseases; Humans; Interferon Type I; Leukemia; Lymphoma; Male; Middle Aged; Monitoring, Physiologic; Pentostatin; Remission Induction

Thirty-seven patients with refractory lymphoma or cutaneous T-cell lymphoma were treated with 2'-deoxycoformycin (pentostatin; dCF), 5 mg/m2 intravenous (IV) bolus for 3 consecutive days of every 3-week cycle in this Eastern Cooperative Oncology Group (ECOG) trial. Included were 25 with the diagnosis of non-Hodgkin's lymphoma, three with Hodgkin's disease, eight with cutaneous T-cell lymphoma (CTCL), and one with unknown subtype, of whom 31 were considered eligible. The majority had failed at least two, but no more, conventional chemotherapy regimens. Ten (32%) of the eligible patients had a partial response (PR), including patients with nodular poorly differentiated lymphocytic (NPDL), nodular mixed (NM), diffuse poorly differentiated lymphocytic (DPDL), or diffuse histiocytic (DH), lymphoma mixed-cellularity (MC), Hodgkin's disease, and unknown subtype, and in four patients with CTCL. The overall median time to treatment failure (TTF) was only 1.3 months, but the range extended to 57.3 months. The overall response duration was 16.0 months, and the range extended to 53.4 months. Overall median survival was 2.7 months, with the range extending to 63.2 months. The majority of patients had no toxicity, but there were some instances of severe or life-threatening events. Four fatal toxicities occurred, in two patients with underlying pulmonary conditions and two with prior cardiac histories. From this study, we conclude that dCF is active in refractory lymphomas and CTCLs, should be avoided in patients with a history of serious pulmonary or cardiac diseases, and warrants consideration for incorporation of a low-dosage schedule into conventional combination chemotherapy regimens, including its use with biologic response modifiers.

Topics: Adult; Aged; Aged, 80 and over; Drug Administration Schedule; Drug Evaluation; Female; Hodgkin Disease; Humans; Injections, Intravenous; Lymphoma; Lymphoma, Non-Hodgkin; Lymphoma, T-Cell, Cutaneous; Male; Middle Aged; Pentostatin; Skin Neoplasms; Survival Rate

A new antimetabolite, 2'-deoxycoformycin (pentostatin), has striking antitumor activity in several lymphoid neoplasms. Isolated from cultured soil organisms, this purine analogue is a potent inhibitor of adenosine deaminase (ADA), and is thus selectively toxic to lymphocytes. Early clinical trials showed that high doses of pentostatin caused severe and unpredictable toxicity, but responses in refractory lymphoid malignancies were encouraging. Careful pharmacologic studies led to the definition of a safe and effective low weekly dose, at which protracted ADA inhibition occurs in neoplastic cells. The most sensitive tumor identified is hairy cell leukemia, in which durable remissions are achieved in more than 90% of patients with a relatively brief course of treatment. Other responsive diseases include chronic lymphocytic leukemia, prolymphocytic leukemia, mycosis fungoides, and acute T-cell lymphoma or leukemia. Response has been seen in acute lymphocytic leukemia, but the higher doses required are substantially more toxic. Pentostatin is valuable for treatment of indolent lymphoid malignancies and may be useful in non-cancer-related lymphocyte research.

Topics: Adenosine Deaminase Inhibitors; Animals; Antimetabolites, Antineoplastic; Antineoplastic Combined Chemotherapy Protocols; Clinical Trials as Topic; Coformycin; Drug Evaluation; Humans; Immunosuppressive Agents; Leukemia; Lymphoma; Pentostatin; Ribonucleosides

The adenosine deaminase inhibitor 2'-deoxycoformycin (pentostatin, Nipent) has been used since 1982 to treat leukemia and lymphoma, but its mode of action is still unknown. Pentostatin was reported to decrease methylation of cellular RNA. We discovered that RNA extracted from pentostatin-treated cells or mice has enhanced immunostimulating capacities. Accordingly, we demonstrated in mice that the anticancer activity of pentostatin required Toll-like receptor 3, the type I interferon receptor, and T cells. Upon systemic administration of pentostatin, type I interferon is produced locally in tumors, resulting in immune cell infiltration. We combined pentostatin with immune checkpoint inhibitors and observed synergistic anti-cancer activities. Our work identifies pentostatin as a new class of an anticancer immunostimulating drug that activates innate immunity within tumor tissues and synergizes with systemic T cell therapies.

Topics: Animals; Antineoplastic Agents; Lymphoma; Mice; Pentostatin; RNA; Toll-Like Receptor 3

dCF (2'-deoxycoformycin) is a potent inhibitor of ADA (adenosine deaminase), an enzyme regulating intra- and extracellular concentrations of purine metabolites. ADA exists as cytosolic and extracellular forms, the latter colocalized on the cell surface with CD26. Once the surface expression of CD26 and ADA in a panel of cell lines and primary samples of T-cell leukemia/lymphoma was defined, we correlated this expression with the antiproliferative and apoptotic effect of dCF.. Surface expression of CD26 inversely correlated with the capability of dCF to inhibit cell growth and induce apoptosis both in T-cell lines and primary samples of T-cell malignancies. This conclusion was sustained by a decreased sensitivity to dCF-mediated proapoptotic and/or antiproliferative in vitro effects of: (a) leukemia/lymphoma T-cell lines expressing surface CD26/ADA complex; (b) primary CD26(+) T cell malignancies; and (c) normal T cells (CD26(+)) as compared with tumor T cells (CD26(-)) in unpurified samples from three cases of T-cell receptor gammadelta(+) T-cell malignancies characterized by a mixture of normal and neoplastic cells. This latter point was confirmed in vivo, in a patient affected by CD26(-) T-cell receptor gammadelta(+) hepatosplenic gammadelta(+) T-cell lymphomas treated on a compassionate basis with dCF. The inverse correlation between CD26 expression and sensitivity to dCF was also demonstrated in a lymphoblastic lymphoma case in which CD26 was expressed on circulating blasts at relapse but not at diagnosis, as well as in two H9 T-cell clones expressing or not expressing CD26 mRNA and protein.. This study corroborates the notion of CD26 as a marker of poor prognosis for T-cell malignancies and delineates a role for CD26 as a predictor of poor response to dCF.

Topics: Antibiotics, Antineoplastic; Apoptosis; Biomarkers, Tumor; Blotting, Western; Bone Marrow Cells; Cell Division; Cell Line; Cell Line, Tumor; Cell Survival; Cells, Cultured; Cytosol; Dipeptidyl Peptidase 4; Flow Cytometry; Humans; Leukemia; Leukemia, T-Cell; Lymphoma; Pentostatin; Prognosis; Reverse Transcriptase Polymerase Chain Reaction; RNA; T-Lymphocytes; Transfection

Topics: Adenosine Deaminase Inhibitors; Antibiotics, Antineoplastic; Autoimmune Diseases; Enzyme Inhibitors; Hematologic Neoplasms; Humans; Immunosuppressive Agents; Leukemia; Lymphoma; Pentostatin

We summarize the results of our experience over the past 15 years using pentostatin (Nipent; SuperGen, San Ramon, CA) to treat a range of mature B- and T-cell malignancies. This includes 145 patients with postthymic T-cell malignancies in whom disease subtype was found to be the most significant predictor of response, with the best response rates seen in Sézary syndrome (62%) and T-prolymphocytic leukemia (45%). However, there are no long-term survivors among patients with this group of disorders, and strategies using pentostatin in combination with other therapies, such as CAMPATH-1H, are currently being explored. Among the mature B-cell diseases, pentostatin in both standard- and low-dose regimens is effective in advanced, relapsed/refractory B-chronic lymphocytic leukaemia, showing no cross-resistance with other purine analogs such as fludarabine. Our largest series treated with pentostatin consists of 165 patients with hairy cell leukemia. The follow-up period in this group extends to more than 10 years, with a projected event-free survival rate at 5 years of 60% and an overall survival rate of 97%.

Topics: Antibiotics, Antineoplastic; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Disease-Free Survival; Drug Resistance, Neoplasm; Follow-Up Studies; Humans; Immunosuppressive Agents; Leukemia; Leukemia, B-Cell; Leukemia, Hairy Cell; Leukemia, Lymphocytic, Chronic, B-Cell; Leukemia, Prolymphocytic; Leukemia, T-Cell; Lymphoma; Lymphoma, B-Cell; Lymphoma, T-Cell; Pentostatin; Sezary Syndrome; Survival Rate; Vidarabine

In spite of the chemosensitivity seen with the initial treatment of malignant lymphoid disorders, relapse is common and death most often occurs as a result of disease progression. This is related to a multitude of resistance mechanisms associated with the various lymphoproliferative disorders. As a result, therapies targeting intrinsic drug-resistance mechanisms are evolving and have become an active area of research. In vitro studies of human chronic lymphocytic leukemia cells incubated with theophylline, a phosphodiesterase inhibitor, resulted in downregulation of bcl-2 concomitant with induction of apoptosis. We describe the preclinical basis for a novel combination therapy involving pentostatin (Nipent; SuperGen, San Ramon, CA), chlorambucil, and theophylline in the treatment of patients with relapsed chronic lymphoproliferative disorders. An ongoing study based on such justification, which is currently accruing patients, is also described. Results from this trial appear promising, and a phase II study is now being planned.

Topics: Antibiotics, Antineoplastic; Antineoplastic Agents, Alkylating; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cause of Death; Chlorambucil; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Disease Progression; Down-Regulation; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Genes, bcl-2; Humans; Immunosuppressive Agents; Leukemia; Lymphoma; Neoplasm Recurrence, Local; Pentostatin; Phosphodiesterase Inhibitors; Theophylline

Managing the infectious complications associated with pentostatin (Nipent), used alone or in combination with other agents in patients with low-grade lymphomas, poses a significant problem for clinicians. Since there is limited experience with these therapies, definitive treatment recommendations concerning prophylaxis cannot be made. The panel members discussed the use of valacyclovir (Valtrex) to provide prophylaxis for herpes zoster, trimethoprim/sulfamethoxazole for Pneumocystis, and acyclovir (Zovirax) for varicella zoster. They also considered combinations of pentostatin with agents such as interferon, rituximab (Rituxan), and chlorambucil (Leukeran) and their effect on the immune system. The biology of B and T cells was discussed, with an emphasis on clinical application.

Topics: Acyclovir; Anti-Infective Agents; Anti-Infective Agents, Urinary; Antibiotics, Antineoplastic; Antibodies, Monoclonal; Antibodies, Monoclonal, Murine-Derived; Antineoplastic Agents; Antineoplastic Agents, Alkylating; Antineoplastic Combined Chemotherapy Protocols; Antiviral Agents; Chlorambucil; Encephalitis, Varicella Zoster; Herpes Zoster; Humans; Interferons; Lymphoma; Pentostatin; Pneumocystis Infections; Rituximab; Sulfamethoxazole; Trimethoprim; Valacyclovir; Valine

To review the activity of the purine analogues fludarabine, cladribine (2-chlorodeoxyadenosine [2-CdA]), and pentostatin (2'-deoxycoformycin) in the treatment of indolent lymphoid malignancies, including chronic lymphocytic leukemia, hairy cell leukemia, and indolent non-Hodgkin's lymphomas (NHLs).. Patients with previously untreated, relapsed, or refractory indolent NHL and other indolent lymphoid malignancies who have been treated with purine analogues.. Purine analogues have revolutionized the treatment of indolent lymphomas. Fludarabine induces responses in almost 50% of patients with relapsed or refractory indolent NHL and produces complete remissions (CRs) in 10% to 15% of patients. In patients receiving fludarabine as initial treatment, CRs are achieved in almost 40%, with an overall response rate of 70% and a median time to progression > 1 year. Response rates with 2-CdA in previously treated patients appear similar to those with fludarabine, although less durable. Fludarabine and 2-CdA achieve a higher number of durable responses in Waldenström's macroglobulinemia than are generally achieved with alkylating agents in this disease. Pentostatin appears to be less active in NHL. Newer purine analogues currently in clinical trials in lymphomas include gemcitabine and compound 506U. Promising activity has been reported with the combination of fludarabine, mitoxantrone, dexamethasone, and fludarabine plus cyclophosphamide. Combinations of 2-CdA with other agents are also in development. Toxicities associated with these purine analogues primarily include moderate myelosuppression, profound immunosuppression, neurotoxicity at higher than recommended doses, and a possible increase in secondary malignancies.. The purine analogues should provide the basis for new treatment strategies with the goal of curing patients with indolent NHL. For progress to continue, patients must be referred to important and innovative clinical research trials.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Cladribine; Deoxycytidine; Drug Resistance, Neoplasm; Gemcitabine; Humans; Lymphoma; Lymphoma, Non-Hodgkin; Pentostatin; Vidarabine

The adenosine deaminase (ADA) inhibitor 2'-deoxycoformycin (dCF) significantly inhibits the proliferation of leukemia and lymphoma cell lines. When cells were incubated in the presence of both dCF and 2'-deoxyadenosine (dAd), the concentration of dCF required to induce apoptosis of monocytoid leukemia cells was much lower than that required for myeloid, erythroid, or lymphoma cell lines. Among the cell lines tested, U937 cells were the most sensitive to this treatment. The concentration of dCF that effectively inhibited the proliferation of U937 cells was 1/1,000 of that required for lymphoma cell lines, on a molar basis. However, the uptake of dCF or dAd in U937 cells was comparable with that in other leukemia and lymphoma cell lines. The intracellular accumulation of dATP in U937 cells was only slightly higher than that in other leukemia cells in dCF-treated culture. Treatment with dCF plus dAd induced apoptosis in U937 cells at low concentrations, and this apoptosis was reduced by treatment with caspase inhibitors. Induction of caspase-3 (CPP32) activity accompanied the apoptosis induced by dCF plus dAd. No activation of CPP32 was observed in cytosol prepared from exponentially growing leukemia and lymphoma cells. However, dATP effectively induced CPP32 activation in cytosol from monocytoid cells, but not in that from nonmonocytoid cells, suggesting that dATP-dependent CPP32 activation is at least partly involved in the preferential induction of apoptosis in monocytoid leukemia cells. The combination of dCF and dAd may be useful for the clinical treatment of acute monocytic leukemia.

Topics: Apoptosis; Caspase 3; Caspases; Cytosol; Deoxyadenine Nucleotides; Deoxyadenosines; Enzyme Activation; Growth Inhibitors; HL-60 Cells; Humans; Leukemia; Leukemia, Monocytic, Acute; Lymphoma; Neoplasm Proteins; Pentostatin; Tumor Cells, Cultured; U937 Cells

Topics: 2-Chloroadenosine; Antibodies, Monoclonal; Deoxyadenosines; Humans; Immunoconjugates; Immunotoxins; Leukemia, Hairy Cell; Lymphoma; Pentostatin; Ricin

Permeabilized L5178Y cells were used to investigate the mechanism underlying inhibition of the repair of irradiation-induced DNA strand breaks by 2'-deoxycoformycin combined with deoxyadenosine. Permeabilized cells repaired DNA strand breaks as effectively as did intact cells, and at deoxyadenosine concentrations that produced similar levels of deoxyadenosine triphosphate (dATP), repair of DNA strand breaks was inhibited by 2'-deoxycoformycin plus deoxyadenosine to a comparable extent in both types of cells. Accompanying the increase in intracellular dATP produced by 2'-deoxycoformycin combined with deoxyadenosine was a fall in levels of deoxythymidine triphosphate (dTTP), deoxyguanosine triphosphate (dGTP), and deoxycytidine triphosphate (dCTP). The addition of dTTP, dGTP, and dCTP reversed the inhibition of DNA repair by 2'-deoxycoformycin plus deoxyadenosine, although the level of dATP was not affected. Reducing the phosphorylation of deoxy-adenosine to dATP by the addition of adenosine prevented the decrease in levels of dTTP, dGTP, and dCTP and the inhibition of DNA repair by 2'-deoxycoformycin and deoxyadenosine. In contrast, increasing the intracellular levels of dATP by the addition of 2'-deoxycoformycin together with dATP, deoxyadenosine diphosphate (dADP), or deoxyadenosine monophosphate (dAMP) had no effect on the levels of the other deoxynucleotide triphosphates and did not inhibit DNA repair. Moreover, DNA repair was not inhibited by the breakdown products of deoxyadenosine, adenine, or deoxyribose. These results suggest that inhibition of the repair of irradiation-induced DNA strand breaks by 2'-deoxycoformycin combined with deoxyadenosine requires the phosphorylation of deoxyadenosine and involves alterations in the levels of deoxynucleotide triphosphates.

Topics: Adenosine; Animals; Cell Membrane Permeability; Deoxyadenosines; DNA Damage; DNA Repair; DNA, Neoplasm; Lymphoma; Mice; Mice, Inbred DBA; Nucleotides; Pentostatin; Phosphorylation; Tumor Cells, Cultured

Topics: Biological Transport; Carrier Proteins; Humans; Leukemia; Lymphocytes; Lymphoma; Membrane Proteins; Nucleoside Transport Proteins; Pentostatin; Thioinosine; Tumor Cells, Cultured

Topics: Adult; Antineoplastic Combined Chemotherapy Protocols; Drug Resistance; Female; Humans; Lymphoma; Male; Pentostatin; T-Lymphocyte Subsets

Autologous bone marrow transplantation may contribute to the treatment of several types of lymphoreticular malignancies. Recent studies have suggested that a combination of chemoseparation and immunoseparation may be more effective than either modality alone in eliminating malignant cells from human bone marrow. In this report an immunotoxin has been prepared by conjugating pokeweed antiviral protein (PAP) to the 3A1 murine monoclonal antibody that recognizes a 40 kD (CD7) determinant expressed by most T cell acute lymphoblastic leukemias and a majority of normal mature peripheral T cells. When HSB-2 T lymphoma cells were mixed with normal human bone marrow and incubated with 3A1-PAP and 100 microM chloroquine, approximately 3 logs of clonogenic T cells could be eliminated from a 20-fold excess of bone marrow. Treatment of cell mixtures with 2'deoxycoformycin (2'-dCF) and deoxyadenosine (dAdo) eliminated 2 logs of clonogenic tumor cells. The use of 3A1-PAP and chloroquine with dCF/dAdo was more effective than either single modality, eliminating up to 6 logs of HSB-2 tumor cells in optimal experiments. Anti-tumor activity of the combined treatment extended to T leukemia cells taken directly from patients. Although 3A1-PAP reduced CFU-GM by only 13% and BFU-E by 36%, the addition of 2'-dCF and dAdo was more toxic for normal marrow precursors, further reducing CFU-GM, GEMM and BFU-E as well as preventing recovery of CFU-GM in long-term bone marrow culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Antiviral Agents; Bone Marrow; Cell Line; Cell Separation; Chloroquine; Deoxyadenosines; Hematopoietic Stem Cells; Humans; Immunotoxins; Leukemia, T-Cell; Lymphoma; N-Glycosyl Hydrolases; Pentostatin; Plant Proteins; Ribosome Inactivating Proteins, Type 1; Stem Cells; T-Lymphocytes; Tumor Stem Cell Assay

Pentostatin (2'-deoxycoformycin) is a unique antineoplastic agent that has proven valuable in the treatment of a number of lymphoid malignancies. Dose-limiting toxicities observed in clinical trials include central nervous system (CNS) effects and acute renal failure. Information regarding the incidence, duration, and severity of nausea and vomiting from published reports is conflicting and insufficient to provide recommendations for optimal supportive measures. We report the results of a phase I study where pentostatin was associated with a 20% incidence of vomiting following courses one and two (pentostatin alone). The third course of pentostatin administered concurrently with alpha interferon resulted in a 29% incidence of vomiting and by course four had increased to 50%. Grade of severity was similarly increased, and nausea and vomiting was the dose-limiting toxicity in 6 of 15 patients. Forty-two percent of all episodes of vomiting were delayed in onset (onset 24 hr after drug administration) and in over 80% of cases persisted for greater than 48 hr in duration. Potential mechanisms that may account for these findings, as well as recommendations regarding antiemetic therapy are provided.

Topics: Adult; Aged; Drug Therapy, Combination; Humans; Incidence; Interferon Type I; Lymphoma; Middle Aged; Pentostatin; Vomiting

Growth-inhibitory activity of 2'-deoxycoformycin (DCF) and 9-beta-D-arabinofuranosyladenine (Ara-A) used either singly or in combination was assessed in 30 human cultured cell lines (seven T-cell, nine B-cell, five non-T,non-B and nine myeloid cell lines) derived from leukemias and lymphomas. DCF had little activity even at 100 microM on any of the cell lines, while Ara-A had an obvious inhibitory effect on them, especially on non-T,non-B cell lines at 10 microM or less. Lymphoid cell lines were apparently more sensitive to the combined use of Ara-A and DCF than myeloid cell lines. DCF potentiated the antiproliferative activity of Ara-A not only in T-cell lines with high adenosine deaminase (ADA) activity, but also in some other cell lines with low ADA activity. DCF was stable in the culture medium, but Ara-A in the medium containing cultured cells was rapidly inactivated. DCF completely inhibited the inactivation of Ara-A in the medium containing P12/ICH or NALM-6, but not in the medium containing Daudi. This suggests that there is some unknown mechanism(s) of inactivation of Ara-A other than ADA in Daudi, which was insensitive to Ara-A in the presence of 1 microM DCF. The capacity of DCF to inhibit degradation of Ara-A in the medium containing these cultured cells correlated with the level of Ara-A sensitivity potentiated by DCF. In all seven T-cell lines, seven of the nine B-cell lines, all five non-T,non-B cell lines, and only three of nine myeloid cell lines, the IC50 value for Ara-A decreased to 5 microM or less in the presence of 1 microM DCF. These results suggest that the combination of DCF and Ara-A may be effective against various types of lymphoid malignancies and some myeloid leukemias.

Topics: Adenosine Deaminase; Antineoplastic Agents; Cell Division; Coformycin; Drug Stability; Drug Synergism; Humans; Leukemia; Lymphoma; Pentostatin; Ribonucleosides; Tumor Cells, Cultured; Vidarabine

Deoxyadenosine is known to be toxic to both proliferating and resting lymphocytes that lack adenosine deaminase (ADA) activity. We now show that human monocytes are also highly sensitive in vitro to nanomolar concentrations of deoxyadenosine plus the ADA inhibitor deoxycoformycin, and to the ADA-resistant analogue 2-chlorodeoxyadenosine (CdA). Monocytes exposed to deoxyadenosine or to CdA in vitro accumulate massive DNA damage detectable within 1 hour. The DNA damage in monocytes exposed to CdA is associated with a decrease in protein synthesis and with inhibitions of phagocytosis and IL-6 secretion. However, unlike lymphocytes with similar DNA damage, the monocytes show no significant NAD or ATP depletion until cell viability declines. The selective toxicity of CdA to monocytes was confirmed by in vivo studies. In almost all patients receiving CdA infusion chemotherapy for cutaneous lymphoma, the blood monocytes counts fell to near 0 during one week of therapy. Our results suggest that CdA and related compounds may have potential clinical use in the therapy of immune disorders associated with monocyte/macrophage activation.

Topics: 2-Chloroadenosine; Cladribine; Deoxyadenosines; DNA Damage; Humans; In Vitro Techniques; Lymphoma; Monocytes; Pentostatin; T-Lymphocytes

2'-Deoxycoformycin, a potent inhibitor of adenosine deaminase, was administered to three patients with cutaneous T cell lymphoma refractory to multiple treatment modalities. Patient 1, who received 5 mg/m2/day for 3 days at 35- to 71-day intervals, has achieved a complete remission greater than 16 months in duration. Patient 2 had progressive disease despite two courses of 2'-deoxycoformycin at a dose of 5 mg/m2/day for 3 days at 28-day intervals. The third patient, who was treated with 4 mg/m2 2'-deoxycoformycin weekly to biweekly, had an initial response, but the disease progressed after eight treatments. Only one patient had any side effects: Patient 1 developed reversible episcleritis, mild elevation of liver enzymes, and persistent nausea and vomiting. In red blood cells of all patients, there was near complete inhibition of adenosine deaminase (91% to 96%) and S-adenosylhomocysteine hydrolase (89% to 95%) activities with treatment. In peripheral blood lymphocytes, adenosine deaminase was inhibited by 85% to 98% and S-adenosylhomocysteine hydrolase by 51% to 88%. The deoxyadenosine triphosphate level, reflected by the total cellular adenine deoxyribonucleotide measurement in erythrocytes, was noted to be modestly elevated during treatment, with the highest level in the patient who demonstrated the only complete response and the only toxic effects. Low-dose 2'-deoxycoformycin appears to be safe but may be an insufficiently intensive regimen to treat refractory cutaneous T cell lymphoma. With proper biochemical monitoring, higher doses may be both safe and more effective.

Topics: Adenosine Deaminase; Adenosine Deaminase Inhibitors; Adenosylhomocysteinase; Aged; Antineoplastic Agents; Coformycin; Erythrocytes; Humans; Hydrolases; Lymphoma; Male; Middle Aged; Neoplasm Staging; Pentostatin; Ribonucleosides; Skin Neoplasms; T-Lymphocytes

Knowledge of the vital role of the purine degradative enzyme adenosine deaminase (ADA) in the differentiation of T and B lymphocytes has stimulated interest in the pharmacologic inhibition of ADA as specific cytotoxic therapy for lymphoproliferative diseases. 2'-Deoxycoformycin (DCF) is a tight-binding ADA-inhibitor and has shown activity in T and B cell neoplasms. In this phase-II study, the efficacy and toxicity of DCF in chronic T and B cell neoplasms is investigated. We report the preliminary results of treatment in 27 patients (8 with Sézary syndrome, 11 with B-chronic lymphocytic leukemia (CLL), and 8 with hairy cell leukemia (HCL)), who were refractory to conventional therapy. DCF was applied at a dosage of 4 mg/m2 weekly x 3, then 4 mg/m2 every other week x 3. Three of the 8 patients with Sézary syndrome and 3 of the 11 patients with B-CLL attained a partial remission. One complete and 7 partial remissions have been achieved thus far in the 8 patients with HCL refractory to interferon alpha treatment. Other than nausea in 10 patients (mainly grade 1 and 2), transient skin rash in 4 patients and Herpes infections in 4 patients (mainly grade 2), no other major toxicities were observed. Thus DCF is highly active in hairy cell leukemia that did not respond to interferon alpha, and shows moderate activity in refractory Sézary syndrome and B-CLL.

Topics: Antineoplastic Agents; B-Lymphocytes; Coformycin; Drug Evaluation; Humans; Leukemia; Leukemia, Hairy Cell; Leukemia, Lymphoid; Lymphoma; Pentostatin; Ribonucleosides; Sezary Syndrome; Skin Neoplasms; T-Lymphocytes

The adenosine deaminase inhibitor deoxycoformycin was used in low doses to treat 19 patients with clinically aggressive T cell malignancy with a mature membrane phenotype. The patients comprised eight with prolymphocytic leukaemia, two with chronic lymphocytic leukaemia, four with adult T cell leukaemia-lymphoma, three with Sézary syndrome, and two with T cell lymphoma. Two thirds of the patients had been resistant or minimally responsive to combination chemotherapy. Complete remission was obtained in five patients (two with prolymphocytic leukaemia and one each with chronic lymphocytic leukaemia, adult T cell leukaemia-lymphoma, and Sézary syndrome) and partial remission in two others. Unmaintained complete remission lasting more than one year was seen in three patients. Responses were obtained only in patients with CD4+,CD8-membrane markers (seven out of 10), and no responses were recorded in any of the nine patients with a different phenotype. In this series remission appeared to correlate with the membrane phenotype of the neoplastic cell and not with the cytopathological diagnosis. Future studies should establish the biochemical basis for the greater sensitivity of CD4+ lymphoid cells to deoxycoformycin.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Cell Membrane; Coformycin; Cyclophosphamide; Deltaretrovirus Infections; Doxorubicin; Female; Follow-Up Studies; Humans; Leukemia; Leukemia, Lymphoid; Lymphoma; Male; Middle Aged; Pentostatin; Phenotype; Prednisone; Prognosis; Ribonucleosides; Sezary Syndrome; T-Lymphocytes; Vincristine

Chemoseparation and immunoseparation techniques have been combined to eliminate malignant clonogenic T lymphoma cells from human bone marrow. Incubation with 5 microM 2'-deoxycoformycin and 500 microM deoxyadenosine has eliminated 2 logs of HSB-2 T lymphoma cells from a 20-fold excess of irradiated human bone marrow. Multiple incubations with 3A1 antibody and rabbit complement eliminated approximately 2 logs of HSB-2 cells from similar mixtures. Used in combination, the 2 techniques eliminated up to 4 logs of T lymphoma cells. Incubation of normal human bone marrow under similar conditions failed to affect growth of granulocyte-macrophage colony-forming cell units, burst-forming erythroid units, or multipotential erythroid-granulocyte-megakaryocyte-macrophage colony-forming hematopoietic progenitor cells units.

Topics: Antibodies, Monoclonal; Antigens, Differentiation, T-Lymphocyte; Antigens, Surface; Bone Marrow; Bone Marrow Transplantation; Cell Line; Cell Separation; Coformycin; Complement System Proteins; Deoxyadenosines; Hematopoietic Stem Cells; Humans; Lymphoma; Pentostatin; Ribonucleosides; T-Lymphocytes; Tumor Stem Cell Assay

The nucleotide content of the various blood cells and the urinary excretion of purine and pyrimidine metabolites were studied in a patient with a T-cell lymphoma (early T-cell phenotype) before and during treatment with deoxycoformycin (dCF; given intravenously [iv] during 3 days, biweekly). During and after the administration of dCF, high amounts of dATP were found in the lymphoid cells and the erythrocytes (maximally, 480 pmol/10(6) lymphocytes and 5.5 nmol/10(6) erythrocytes), but not in the polymorphonuclear leukocytes. The amount of dATP in the erythrocytes, however, was significantly lower than described in the literature. During each administration of dCF, the number of blast cells in the peripheral blood rose initially, followed by a rapid decrease. After three courses, a hematologic remission was achieved and maintained for 6 weeks; then an autologous bone-marrow transplantation was performed. During the first dCF course a large amount of deoxyadenosine was found in the urine. During the second course, this excretion was much lower, but still higher than in healthy individuals. In the patient described, dCF showed a highly specific toxicity for the immature T-lymphoblast; hardly any changes were seen in the numbers of the other hematopoietic cells, both in the blood and in the bone marrow.

Topics: Child; Chromatography, High Pressure Liquid; Coformycin; Deoxyadenine Nucleotides; Erythrocytes; Humans; Lymphoma; Male; Pentostatin; Purines; Pyrimidines; Ribonucleosides; T-Lymphocytes

2'Deoxycoformycin (dCF) specifically inhibits adenosine deaminase (ADA) and causes selective cytotoxicity of normal and malignant T cells. In clinical trials, dCF caused rapid lysis of malignant T lymphoblasts. Although dCF has been associated with dose-limiting nonhematopoietic toxicities, myelosuppression has not been observed. Since dCF is relatively nontoxic to hematopoietic stem cells, we tested dCF for utility in the ex vivo purging of malignant T lymphoblasts from remission leukemic bone marrow for autologous bone marrow transplantation. We found that T lymphoblast cell lines were sensitive to dCF (plus deoxyadenosine [dAdo]) under conditions that did not ablate human hematopoietic colony-forming cells. Moreover, combined pharmacologic (dCF plus dAdo) and immunologic (anti-T cell monoclonal antibodies [McAb] plus complement) purging resulted in additive reduction in clonogenic T lymphoblasts. These results provide the basis for a clinical trial of bone marrow transplantation using combined pharmacologic/immunologic purging of T lymphoblasts from patients' harvested autologous marrow.

Topics: Antibodies, Monoclonal; Antineoplastic Agents; Cell Line; Coformycin; Colony-Forming Units Assay; Complement System Proteins; Deoxyadenosines; Humans; Lymphocyte Depletion; Lymphoma; Pentostatin; Ribonucleosides; T-Lymphocytes

Pentostatin (dCF), an inhibitor of adenosine deaminase, has shown activity in the treatment of several lymphoid malignancies, even in the earliest phase I trials. An analysis of the first 300 patients treated in such trials shows a high incidence of severe infection (8%) during the relatively brief period of treatment. Of 24 patients in whom infection was diagnosed, 17 had no evidence of myelosuppression. The causative organisms included viruses, fungi, and bacteria of both high and low pathogenicity. Two-thirds of the infections were fatal. It is suggested that dCF may cause a syndrome similar to severe combined immunodeficiency during the course of treatment. Patients treated with dCF who show evidence of infection, even in the absence of neutropenia, should receive vigorous and rapid diagnostic evaluation to establish the cause of their infection, and aggressive treatment of suspected organisms.

Topics: Adolescent; Adult; Aged; Bacterial Infections; Child; Coformycin; Drug Evaluation; Female; Herpes Zoster; Humans; Leukemia; Lymphoma; Male; Middle Aged; Mycoses; Neoplasms; Pentostatin; Ribonucleosides

Topics: Adenosine; Adenosine Kinase; Animals; Cell Line; Coformycin; Drug Resistance; Lymphoma; Methionine Adenosyltransferase; Mice; Pentostatin; S-Adenosylhomocysteine; S-Adenosylmethionine

A new cytotoxic drug, 2'-deoxycoformycin, has been shown to be highly active in the treatment of lymphocytic leukemias and lymphomas, particularly T cell acute lymphoblastic leukemia, in which the drug, used as a single agent, can induce CRs in patients who have failed to respond to a wide variety of other compounds. Further work is required to elucidate the cause of the renal failure that has occurred in some patients, but prescribed within the dose range of the patients reported in this paper, toxicity is acceptable in consideration of the results achieved and the prognosis of this highly malignant group of diseases.

Topics: Acute Kidney Injury; Adenosine Deaminase Inhibitors; Adolescent; Adult; Aged; Antineoplastic Agents; Child; Child, Preschool; Coformycin; Female; Humans; Leukemia; Leukemia, Lymphoid; Lymphoma; Male; Middle Aged; Mycosis Fungoides; Pentostatin; Ribonucleosides; T-Lymphocytes

Topics: Antineoplastic Agents; Coformycin; Drug Administration Schedule; Drug Evaluation; Humans; Injections, Intravenous; Leukemia; Lymphoma; Pentostatin; Ribonucleosides

Topics: Adenosine Deaminase; Adenosine Deaminase Inhibitors; Azepines; Biological Transport, Active; Cell Line; Coformycin; Dilazep; Dipyridamole; Enzyme Reactivators; Erythrocytes; Humans; Leukemia; Lymphoma; Mathematics; Nucleoside Deaminases; Nucleosides; Pentostatin; Platelet Aggregation; Ribonucleosides

A patient from the Caribbean area with active T-cell lymphoma-leukaemia was primarily treated with deoxycoformycin (DCF), 5 mg/m2 i.v. on 3 consecutive days, followed by 5 mg/m2 i.v. weekly. A complete remission was attained and maintained during several weeks with DCF. A single consolidation course with other cytostatics was then given. The patient continues in complete remission without further therapy, 24 months after diagnosis, 17 months after the last cytostatic drugs. T-cell lymphoma-leukaemia has a bad prognosis with conventional anti-lymphoma therapy but was exquisitely sensitive to DCF in this patient.

Topics: Adult; Antineoplastic Agents; Coformycin; Deltaretrovirus; Drug Administration Schedule; Female; Humans; Leukemia; Lymphoma; Pentostatin; Retroviridae Infections; Ribonucleosides; T-Lymphocytes

Transplantable BALB/c and AKR lymphomas of different cell surface immunologic phenotypes have distinctive patterns of response to the ADA inhibitor DCF in vivo and in vitro. BAL 9, a lymphoma of the Lyt-1+,2+ T cell phenotype, was the most sensitive to DCF in vivo, and its DNA synthesis was inhibited more than 95% when cultured in the presence of dAr and DCF in vitro. This was correlated with a 10-fold increase in dATP content. The ADA and AMPDA activities were both high. Two lymphomas of the Lyt-1-,2+ T cell phenotype, BAL 5 and AKTB - lt , as well as two B cell phenotype lymphomas, A20 .3 and AKTB -lb, were all moderately inhibited in their in vivo growth if enough DCF was administered. However, their DNA synthesis in vitro was only inhibited 8 to 24% by dAr and DCF, there was only a twofold increase in the accumulation of dATP, and ADA and AMPDA activities were both low in the two BALB/c lymphomas tested. BAL 13, the only lymphoma of the Lyt-1+,2- phenotype examined, was completely resistant to DCF in vivo and in vitro. When cultured in the presence of dAr and DCF there was a transient increase in dATP content, followed by an abrupt decline. AMPDA activity was five to seven times greater than in the other lymphomas tested. ADA activity was moderate. The activities of 5' nucleotidase and of adenosine kinase were low and approximately equal in all the BALB/c lymphomas. These results suggest that the response to DCF by lymphomas of various immunologic phenotypes can be correlated with their nucleoside metabolism. The sensitivity of BAL 9 and the resistance of BAL 13 to DCF are correlated with their tendency to accumulate dATP and with their AMPDA and ADA activity ratios. The moderate sensitivity to DCF in vivo of the other T and B cell lymphomas, however, could not be clearly explained by any of the in vitro parameters thus far investigated, and this suggests that mechanisms inhibiting lymphoma proliferation other than dATP accumulation may be operating.

Topics: Adenosine Deaminase; Animals; Azacitidine; Body Weight; Coformycin; Deoxyadenosines; DNA; Lymphoma; Mice; Mice, Inbred AKR; Mice, Inbred BALB C; Neoplasm Transplantation; Nucleoside Deaminases; Organ Size; Pentostatin; Phenotype; Ribonucleosides; Spleen; T-Lymphocytes; Thymus Gland

Pentostatin (2'-deoxycoformycin, DCF) was administered to 17 patients with a variety of lymphoid neoplasms, both T- and B-cell, that were refractory to conventional treatments. Several responses and 2 complete remissions occurred. Toxic effects were less severe than previously described: this may be attributable to relatively low doses of DCF or to precautions taken to prevent tumour lysis syndrome. DCF appears valuable as a second-line treatment in non-Hodgkin's lymphomas and as initial treatment in T-cell chronic lymphocytic leukaemia and mycosis fungoides. Although myelosuppression is mild, immunosuppression and superinfection are potential hazards of treatment with DCF. The ocular toxicity of DCF, previously described as conjunctivitis, appears to be a keratitis of moderate severity which requires further study.

Topics: Adult; Coformycin; Female; Herpes Zoster; Humans; Keratitis; Lymphoma; Male; Pentostatin; Ribonucleosides

Leukemic cells incubated in vitro with 2'-deoxyadenosine (dAdo) plus an inhibitor of adenosine deaminase, 2'-deoxy-coformycin (DCF), show different metabolic responses depending on the histologic and immunologic type of the leukemia. Leukemic cells were obtained from 54 patients with acute lymphoblastic leukemia (ALL), 9 with myeloid or nonlymphoblastic leukemia, 3 with chronic lymphocytic leukemia (CLL), and 3 with lymphoma. There was a wide variation in the LD50, the concentration of dAdo that caused 50% inhibition of the incorporation of 3H-thymidine into cells in the presence of 20 microM DCF. T-cell leukemia specimens were much more sensitive to dAdo than were specimens of pre-B-ALL and null-ALL. In leukemic cells that had been incubated with 14C-dAdo plus DCF, a good correlation was observed between the LD50 and the ratio of 14C-deoxyATP to ATP (correlation coefficient for the fit to a hyperbola = 0.853). The accumulation of deoxyATP by the leukemic cell specimens was correlated best with the activity of ecto-ATPase, less well with cytoplasmic 5'-nucleotidase and deoxyadenosine kinase, and poorly with adenosine deaminase and ecto-5'-nucleotidase. The clinical response to DCF therapy of a patient with T-ALL and another with pre-B-ALL was consistent with the in vitro metabolic response of their cells to DCF and dAdo.

Topics: Adenosine Deaminase; Adolescent; Deoxyadenine Nucleotides; Deoxyadenosines; Humans; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid; Leukemia, Myeloid, Acute; Leukocytes; Lymphocytes; Lymphoma; Male; Nucleotidases; Pentostatin; Thymidine; Vidarabine

Deoxycoformycin (DCF) is an inhibitor of adenosine deaminase (ADA). Twenty-one courses of DCF were administered to 13 patients ranging in age from 15 to 78 yr. Eight patients had T-cell disorders, and five patients had non-T-cell malignancies. The i.v. bolus dose was escalated from 5 to 30 mg/sq m/day, and the duration of the courses ranged from 1 to 5 days. The DCF plasma half-life ranged from 4.9 to 6.2 hr and was independent of dose. The dose-limiting toxicities involved the central nervous system (CNS) and the kidneys. Other toxicities included bronchitis, decreases in hematocrit, arthralgias, and myalgias. Mortality was encountered in three patients. These toxic effects may have been secondary to the accumulation of the metabolites adenosine and deoxyadenosine. Deoxyadenosine and adenosine were both detectable in plasma (10(-6) M) and in urine (10(-3) M). Two partial remissions were observed: one in a patient with T-cell ALL and another in a patient with mycosis fungoides. Minimal responses characterized by either declines in peripheral blast counts or partial resolution of adenopathy were observed in five other patients. No responses were observed in six patients. These observations suggest that DCF is effective in the treatment of T-cell lymphoid malignancies.

Topics: Adenosine; Adenosine Deaminase Inhibitors; Adenosine Kinase; Adolescent; Adult; Aged; Bronchitis; Coformycin; Coma; Conjunctivitis; Deoxyadenosines; Female; Humans; Kidney Diseases; Leukemia, Lymphoid; Lymphoma; Male; Middle Aged; Mycosis Fungoides; Nucleoside Deaminases; Pentostatin; Phosphotransferases; Phosphotransferases (Alcohol Group Acceptor); Ribonucleosides

A deficiency of adenosine deaminase, an enzyme important in purine nucleoside catabolism, is associated with a severe combined immunodeficiency disease in children. Inhibition of this enzyme in vitro and in vivo results in an impairment in lymphoblast proliferation. We have investigated the pharmacologic inhibition of this enzyme by 2'-deoxycoformycin in 15 patients with hematologic malignancies. Biochemical consequences of the administration of this agent were closely monitored in erythrocytes, nucleated peripheral blood and bone marrow cells, serum, and urine. A marked rise in erythrocyte dATP was accompanied by a depletion of ATP in those patients exhibiting toxicity. Most patients excreted large amounts of deoxyadenosine but not adenosine in the urine. Serum deoxyadenosine rose in patients demonstrating a marked decrease in cell mass. The biochemical disturbances and clinical toxicity, including hepatic, renal, and conjunctival abnormalities, were usually reversible. Central nervous system toxicity, which potentially was the most serious consequence, was associated with high erythrocyte dATP/ATP ratios and high levels of cerebrospinal fluid deoxyadenosine. In patients with lymphoma and leukemia, objective responses were observed but were short-lived. Patients with chronic lymphocytic leukemia receiving weekly low doses of the drug demonstrated minimal toxicity and some efficacy. The chemotherapeutic potential o 2'-deoxycoformycin, as either a single agent or in combination with Ara-A, merits further exploration.

Topics: Adenosine Deaminase; Adenosine Triphosphate; Adolescent; Adult; Child; Coformycin; Erythrocytes; Humans; Leukemia; Leukocytes; Lymphoma; Middle Aged; Nucleosides; Pentostatin; Remission, Spontaneous; Ribonucleosides