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L D Piro

Publications and source records attributed to L D Piro.

At least 37 records · Page 2Linked to original sources
PubMed1994

Complete hematologic remissions in chronic-phase, Philadelphia-chromosome-positive, chronic myelogenous leukemia after 2-chlorodeoxyadenosine.

BACKGROUND: 2-Chlorodeoxyadenosine (Cladribine, Leustatin, Ortho Biotech, Raritan, NJ) (2-CdA) is a purine analog with activity in the treatment of lymphoid neoplasms. Interferon induces cytogenetic remissions in chronic myeloid leukemia (CML) and partial remissions in hairy cell leukemia, a disorder in which single courses of 2-CdA induce complete remissions. In vitro clonal growth of immature myeloid progenitors from normal marrow is markedly inhibited by 2-CdA. METHODS: 2-CdA was administered to 12 patients with Philadelphia-chromosome-positive CML, 11 chronic phase, and 1 accelerated phase, at 0.1 mg/kg/day by continuous intravenous infusion for 7 days every 28-35 days, until maximum peripheral hematologic response. RESULTS: Of 12 patients, 10 (83%) achieved complete hematologic responses and 2 (17%) partial hematologic responses after a median of two courses of 2-CdA. The median first hematologic response duration was 3 months. Of the seven patients who relapsed and were retreated with a median of two further courses of 2-CdA, five obtained responses (four complete and one partial) and two did not respond. The median second hematologic response duration was 4 months. No patient had significant Philadelphia-chromosome suppression. Reversible myelosuppression and severe cumulative T-cell immunosuppression associated with opportunistic infections in four patients were the principal toxicities. CONCLUSIONS: 2-CdA is active in CML, inducing complete hematologic responses, but the absence of cytogenetic responses and severe immunosuppression may limit its clinical use.

Adult↗
PubMed1994

2-Chlorodeoxyadenosine: a newer purine analog active in the treatment of indolent lymphoid malignancies.

OBJECTIVE: To review the structure, mechanism of action, pharmacologic features, and clinical trial results of the newer purine analog, 2-chlorodeoxyadenosine (2-CdA). DATA SOURCES AND STUDY SELECTION: English-language medical literature review of more than 70 articles. DATA SYNTHESIS: 2-Chlorodeoxyadenosine is unique compared with traditional antimetabolite drugs in that it is equally active against dividing and resting lymphocytes, which may be especially important in indolent lymphoid malignancies, such as chronic lymphocytic leukemia, because most cells in these disorders are in the resting phase. In patients with alkylator-refractory chronic lymphocytic leukemia who were treated with 2-CdA, 44% achieved a response (4% complete responses, 40% partial responses), and 54%, scored as nonresponders, had a sustained reduction in their peripheral lymphocytosis. Patients with untreated chronic lymphocytic leukemia had an 85% response rate (25% complete responses, 60% partial responses). Patients with previously treated low-grade lymphoma achieved an overall response rate of 43%. The most striking clinical effects of this drug have been seen in hairy cell leukemia, in which a single course of therapy induces complete remissions in 85% of partial remissions in 12%. Activity has also been shown in cutaneous T-cell lymphoma and the myeloid leukemias. CONCLUSIONS: 2-Chlorodeoxyadenosine is a newer purine analog with potent activity in the treatment of indolent lymphoproliferative diseases and illustrates the model for rational drug development.

Animals↗
PubMed1994

Identification of monoclonal immunoglobulins and quantitative immunoglobulin abnormalities in hairy cell leukemia and chronic lymphocytic leukemia.

Serum and urine samples from 161 cases of hairy cell leukemia (HCL) and 50 cases of chronic lymphocytic leukemia (CLL) were analyzed for monoclonal immunoglobulin (MIg) by using a combination of high-resolution protein electrophoresis, immunoelectrophoresis, and immunofixation. Quantitative immunoglobulin analysis also was performed on all serum samples. Monoclonal immunoglobulin, usually of low intensity, was identified in serum or urine in 26 (16.1%) cases of HCL compared with 27 (54%) cases of CLL. Forty-eight (29.8%) cases of HCL had an increase in one or more immunoglobulins; increases in IgG were the most frequent. In CLL, 48 (96.0%) cases had a decrease in one or more immunoglobulins, with decreases in IgG, IgA, and IgM in 76%, 68%, and 56% of the cases, respectively. The correlation between serum or urine monoclonal immunoglobulin light chain and the surface membrane light chain was 88% in CLL compared with 47.4% in HCL. These findings confirm previous observations of frequent polyclonal hyper-gamma-globulinemia in HCL, hypo-gamma-globulinemia in CLL, and weak monoclonal immunoglobulins in both disorders. The contrasting immunoglobulin abnormalities in HCL and CLL indicate distinctive biologic differences in these chronic B-cell leukemias.

Adult↗
PubMed1994

The Scripps Clinic experience with 2-chlorodeoxyadenosine in the treatment of hairy cell leukemia.

Follow-up data is now available on 144 patients with hairy cell leukemia treated with 2-chlorodeoxyadenosine (2-CdA) at the Scripps Clinic. Of 144 patients followed for a median of 14.2 months, 123 (85%) obtained complete responses, 17 (12%) partial responses, 3 (2%) did not respond and 1 patients was unevaluable. So far, only 4 patients have relapsed at a median of 36 months. Fever was the major toxicity occurring in 43% of patients. Five patients resistant (3 patients) or intolerant (2 patients) to 2'-deoxycoformycin were also treated. Of these 5 patients, 4 obtained complete responses, including 2 patients resistant to 2'-deoxycoformycin, and 1 patient a partial response, suggesting a possible lack of cross-resistance between 2'-deoxycoformycin and 2-CdA in hairy-cell leukemia. More than 200 patients have been treated with 2-CdA worldwide with 82% obtaining complete remission and 12% partial remissions. Serial peripheral blood immunophenotypic analyses have documented the absence of circulating hairy cells. When bone marrow biopsies were examined using sensitive immunohistochemical staining techniques, residual hairy cells were detected in 25-50% of morphologic complete responders. Patients will need to be observed longitudinally to determine if this staining is predictive of relapse. A double-blind, placebo-controlled study of pentoxifylline, a modulator of tumor necrosis factor-alpha and other cytokines, was performed in 2-CdA-treated hairy cell leukemia patients to determine whether the incidence of neutropenic fever would be reduced. Although pentoxifylline resulted in less febrile, hospital and antibiotic therapy days than placebo, only the number of days in the hospitalized patients achieved statistical significance. 2-CdA is emerging as the treatment of choice for hairy cell leukemia given the high percentage of long-lasting, complete responses that follow a single course of therapy.

Cladribine↗
PubMed1994

Purine metabolism of lymphocytes. Targets for chemotherapy drug development.

The unique metabolic profile that renders lymphoid cells sensitive to purine deoxynucleosides also accounts for the response of chronic lymphoid malignancies to purine analogues. Consistent with earlier observations in children with adenosine deaminase deficiency, a profound and relatively selective lymphocyte depletion results from treatment with drugs that elevate or mimic deoxyadenosine. Three such agents available for clinical use are 2-chlorodeoxyadenosine, 2'-deoxycoformycin, and fludarabine phosphate. In addition to a review of the relevant biochemistry and cellular pharmacology of these agents in target lymphoid cells, this article reviews the current clinical response data in leukemias and lymphoma.

Animals↗
PubMed1993

The newer purine analogs. Significant therapeutic advance in the management of lymphoid malignancies.

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.

Antineoplastic Agents↗
PubMed1993

Complete remissions in hairy cell leukemia with 2-chlorodeoxyadenosine after failure with 2'-deoxycoformycin.

OBJECTIVE: To determine whether clinical cross-resistance and intolerance exists between the nucleosides 2'-deoxycoformycin (DCF) and 2-chlorodeoxyadenosine (2-CdA) in the treatment of patients with hairy cell leukemia despite similar structures and mechanisms of action. DESIGN: Phase II clinical study. SETTING: Referral cancer center. PARTICIPANTS: Five patients with hairy cell leukemia who had been previously treated with DCF. INTERVENTION: Single course of 2-CdA at 0.1 mg/kg body weight per day for 7 days by continuous intravenous infusion. RESULTS: Of five patients, three were resistant to and two were intolerant of (having had life-threatening toxic reactions) DCF therapy. Four patients obtained a complete response with a median follow-up period of more than 11 months. The other patient in whom splenectomy, interferon, and DCF treatments were unsuccessful had a partial response lasting 2 months and subsequently died of Streptococcus pneumoniae bacteremia. Three of the four patients with complete responses remain in unmaintained remission, whereas the fourth has progressive splenic enlargement with stable hematologic parameters. The median leukocyte count increased from 2.0 x 10(9)/L to 3.8 x 10(9)/L, the median absolute neutrophil count increased from 0.56 x 10(9)/L to 2.73 x 10(9)/L, the median hemoglobin level increased from 112 g/L to 140 g/L, and the median platelet count increased from 55 x 10(9)/L to 123 x 10(9)/L. Two patients had culture-negative neutropenic fever associated with treatment. CONCLUSIONS: 2-Chlorodeoxyadenosine induced complete responses in patients with hairy cell leukemia resistant to DCF, suggesting a lack of cross-resistance. Also, 2-CdA is not prohibitively toxic in patients intolerant of DCF.

Adult↗
PubMed1993

Diagnostic application of two-color flow cytometry in 161 cases of hairy cell leukemia.

Recent immunophenotypic studies of hairy cell leukemia (HCL) have suggested specific patterns of immunoreactivity that may aid in diagnosis. We studied peripheral blood (PB) from 161 cases of HCL using two-color direct immunofluorescence flow cytometry and an extended panel of antibody combinations. Circulating hairy cells were identified by immunophenotypic features in 92% of the cases and could be detected even when representing < or = 1% of circulating lymphocytes. The 133 cases with > or = 2% detectable hairy cells were analyzed in detail. HCL showed a uniform and unique B-cell phenotype, with each of the following features identified in 99% to 100% of cases: (1) positive staining for B-ly7, coexpressed with CD19; (2) very intense, uniform expression of CD11c, with CD19; (3) moderately intense staining for CD25, with CD19; (4) very intense staining for CD22; (5) moderate to very intense staining for CD20; and (6) moderately intense monoclonal surface Ig. Phenotypic variability existed in expression of CD10 (26%) and CD5 (4%). Based on these features, HCL was easily distinguished from 50 cases of chronic lymphocytic leukemia (CLL). Although CLL exhibited frequent expression of CD11c (74%) and CD25 (68%), the intensity of staining was significantly less than HCL. Furthermore, CLL was uniformly positive for CD5 and showed weak staining for CD20, CD22, and surface Ig. B-ly7 proved to be the most specific marker, reacting with 100% of HCL cases, but absent in all cases of CLL. We conclude that two-color flow cytometry with specific antibody combinations is an efficacious method for characterization and sensitive detection of hairy cells in PB. Application of the phenotypic criteria described should help to increase accuracy in diagnosis of HCL.

Antigens, CD↗
PubMed1993

Relationship of deoxycytidine kinase and cytoplasmic 5'-nucleotidase to the chemotherapeutic efficacy of 2-chlorodeoxyadenosine.

The agent 2-chlorodeoxyadenosine (2-CdA) has chemotherapeutic activity in hairy cell leukemia (HCL) and in refractory chronic lymphocytic leukemia (CLL). The cytotoxic activity of 2-CdA requires the intracellular accumulation of 2-CdA nucleotides. Deoxycytidine kinase (dCK) and cytoplasmic 5'-nucleotidase (5'-NT) are the principal enzymes that phosphorylate 2-CdA and dephosphorylate 2-CdA 5'-monophosphate, respectively. The net accumulation of 2-CdA nucleotides may therefore depend on both dCK and 5'-NT. The purpose of the present experiments was to determine if there is a relationship between pretreatment levels of dCK and 5'-NT in HCL and in CLL cells, and the clinical outcome of 2-CdA treatment. As measured by a direct immunoassay for dCK in 25 CLL patients, and by a 5'-NT activity assay in 23 patients, mean dCK levels were significantly higher in 2-CdA responders than in nonresponders (P < .01), whereas mean 5'-NT levels were significantly lower in 2-CdA responders than in nonresponders (P < .05). Mean dCK levels were higher in six HCL 2-CdA responders than in one nonresponder, whereas mean 5'-NT levels were lower in the 2-CdA responders than in the nonresponder. These results suggest that both dCK and 5'-NT are determinants of 2-CdA responsiveness.

5'-Nucleotidase↗
PubMed1993

2-Chlorodeoxyadenosine dose escalation in nonhematologic malignancies.

PURPOSE: We performed a dose-escalation study of 2-chlorodeoxyadenosine (2-CdA) in solid tumors to determine the maximum-tolerated dose (MTD) and define its toxicity profile at higher doses. PATIENTS AND METHODS: Twenty-one patients, seven with malignant astrocytoma, twelve with metastatic melanoma, and two with metastatic hypernephroma, were enrolled onto the study. Patients were entered onto cohorts that received 0.10, 0.15, or 0.20 mg/kg/d of 2-CdA by continuous intravenous infusion for 7 days every 28 days. 2-CdA levels were determined by radioimmunoassay. In tumor tissue samples, deoxycytidine kinase (dCK) levels were measured by both enzyme activity and immunoreactive protein analysis. RESULTS: Of seven patients treated with 2-CdA at 0.1 mg/kg/d, one experienced grade 3 or 4 myelotoxicity. Of 11 patients treated at 0.15 mg/kg/d, four experienced myelotoxicity, two after a single course of 2-CdA. All three patients who received 2-CdA at 0.2 mg/kg/d experienced myelosuppression. Neurologic events occurred in two patients, both with malignant melanoma. Two of seven patients (28.6%) with astrocytomas obtained partial responses with a median duration of 8 months. 2-CdA penetrated the blood-brain barrier. An association was found between dCK levels as measured by enzymatic activity and immunoreactive proteins, but this did not correlate with 2-CdA tumor responsiveness. CONCLUSION: The MTD for 2-CdA delivered as a 7-day intravenous infusion in patients with nonhematologic malignancies was determined to be 0.1 mg/kg/d, the same as the MTD for patients with hematologic malignancies. There was no clinical correlation with dCK expression and response to 2-CdA. The responses noted in patients with malignant astrocytoma warrant further phase II study.

Adult↗
PubMed1993

2-Chlorodeoxyadenosine in the treatment of hairy cell leukemia and chronic lymphocytic leukemia.

More than 450 patients with hairy cell leukemia have been treated at the Scripps Clinic. Of 144 patients followed for a median of 14.2 months (range, 8.1-70 months), 123 (85%) obtained complete responses, 17 (12%) partial responses, 3 (2%) did not respond, and 1 patient was unevaluable. So far, 4 patients have relapsed at a median of 36 months (range, 12-48 months). Fever was the principal toxicity occurring in 43% of patients. Five patients resistant (3 patients) or intolerant (2 patients) to deoxycoformycin were also treated. Of these 5 patients, 4 obtained complete responses, including 2 patients resistant to deoxycoformycin, and 1 patient a partial response, suggesting a possible lack of cross-resistance between deoxycoformycin and 2-CdA in hairy cell leukemia. Other single-institution studies have documented similar response rates and toxicities. Ninety patients with advanced chronic lymphocytic leukemia were treated with 2-CdA administered either as a 0.1 mg/kg/day 7-day continuous intravenous infusion or as a 0.028-0.14 mg/kg/day 2-hour bolus for 5 consecutive days. Four patients (4%) obtained complete responses and 36 patients (40%) partial responses, using NCI-sponsored Working Group guidelines. Of the 50 patients who were non-responders, 27 (54%) had a > or = 50% sustained reduction in the absolute lymphocyte count. The ratio of deoxycytidine kinase to cytoplasmic 5'-nucleotidase was predictive of 2-CdA responsiveness. Fourteen patients with fludarabine-failed chronic lymphocytic leukemia were also treated. No responses were achieved and 2 patients had progressive disease. Six patients had a > or = 50% reduction in the absolute lymphocyte count.(ABSTRACT TRUNCATED AT 250 WORDS)

Cladribine↗
PubMed1992

2-Chlorodeoxyadenosine: an active agent in the treatment of cutaneous T-cell lymphoma.

Cutaneous T-cell lymphomas are disfiguring malignant lymphoproliferative disorders for which standard therapy has been principally palliative. 2-Chlorodeoxyadenosine (2-CdA), a new purine analogue resistant to degradation by adenosine deaminase that has substantial activity against lymphoid neoplasms, was administered to 16 patients with cutaneous involvement by T-cell lymphoma. All patients had failed topical treatment modalities and/or systemic therapies. Fifteen patients were evaluable; one patient was not evaluable due to incomplete therapy and follow-up. The overall response rate was 47%. Three of 15 patients (20%) achieved complete responses and four of 15 patients (27%) achieved partial responses. The median duration of response was 5 months. One patient remains in unmaintained complete remission at 52+ months. Therapy was well tolerated. Myelosuppression was the principal toxicity encountered, occurring in 8 of 15 (53%) patients. 2-CdA is an effective new agent for the treatment of cutaneous T-cell lymphoma and warrants further study both as a single agent and in combination regimens.

2-Chloroadenosine↗