John C. Byrd

Distinct types of diffuse large B-cell lymphoma identified by gene expression profiling.

Diffuse large B-cell lymphoma (DLBCL), the most common subtype of non-Hodgkins lymphoma, is clinically heterogeneous: 40% of patients respond well to current therapy and have prolonged survival, whereas the remainder succumb to the disease. We proposed that this variability in natural history reflects unrecognized molecular heterogeneity in the tumours. Using DNA microarrays, we have conducted a systematic characterization of gene expression in B-cell malignancies. Here we show that there is diversity in gene expression among the tumours of DLBCL patients, apparently reflecting the variation in tumour proliferation rate, host response and differentiation state of the tumour. We identified two molecularly distinct forms of DLBCL which had gene expression patterns indicative of different stages of B-cell differentiation. One type expressed genes characteristic of germinal centre B cells (‘germinal centre B-like DLBCL’); the second type expressed genes normally induced during in vitro activation of peripheral blood B cells (‘activated B-like DLBCL’). Patients with germinal centre B-like DLBCL had a significantly better overall survival than those with activated B-like DLBCL. The molecular classification of tumours on the basis of gene expression can thus identify previously undetected and clinically significant subtypes of cancer.

Rituximab therapy in Waldenstrom's macroglobulinemia: Preliminary evidence of clinical activity

To assess the preliminary efficacy of rituximab therapy in Waldenstroms macroglobulinemia (WM), we examined the clinical and laboratory data for all patients with WM treated on IDEC Pharmaceuticals sponsored trials and one patient treated at Walter Reed Army Medical Center. Seven symptomatic patients with WM were treated with four (n = 6) or eight (n = 1) weekly infusions of rituximab (375 mg/m2). Patients had received a median of three prior therapies (range 1-4) which included alkylator therapy in all (five patients refractory) and fludarabine in four (all refractory). Therapy was tolerated well in all patients without decrement in cellular immune function or significant infectious morbidity. Partial responses were noted in three of these patients, including two with fludarabine-refractory disease. The median progression-free survival for these patients was 6.6 months (range 2.2-29+ months). These data suggest that rituximab has clinical activity in heavily pre-treated patients with Waldenstroms macroglobulinemia. Based on these data, clinical studies of Rituximab in previously untreated and treated WM appear indicated.

Pentostatin in Steroid-Refractory Acute Graft-Versus-Host Disease

PURPOSE Acute graft-versus-host disease (aGVHD) is a major complication of allogeneic bone marrow transplantation. In steroid-refractory aGVHD, mortality is very high. Pentostatin, a potent inhibitor of adenosine deaminase, induces lymphocyte apoptosis and may be useful in the treatment of this condition. PATIENTS AND METHODS We have conducted a phase I dose escalation study of pentostatin in patients with steroid-refractory aGVHD. Twenty-three patients were enrolled. Starting dose was 1 mg/m2/d by intravenous injection for 3 days. RESULTS The maximum tolerated dose was found to be 1.5 mg/m2/d. Late infections at the 2-mg/m2/d dose level were believed to be dose limiting toxicities. Lymphopenia was universal, but the neutrophil count was generally not affected. Fevers associated with neutropenia were not observed. Otherwise, the drug was well tolerated, with only modest elevations of liver function tests and thrombocytopenia, each being observed in a single patient. Twenty-two patients were assessable for response, including 14 complete responses (63%) and three partial responses (13%). Median survival after therapy for the group was 85 days (range, 5 to 1,258 days). CONCLUSION The suggested intravenous dose for a phase II study will be 1.5 mg/m2/d for 3 days. Pentostatin has activity in patients with steroid-refractory aGVHD that is worth exploring in future trials.

Herpes virus infections occur frequently following treatment with fludarabine: results of a prospective natural history study.

We performed a prospective infectious natural history study of 21 patients with low‐grade lymphoproliferative disorders receiving fludarabine as initial (n = 5) or salvage (n = 16) therapy. 12 (57%) of these patients developed herpes zoster (n = 9), herpes simplex I (n = 1) or herpes simplex II (n = 2) infections at a median of 8 (range 1–17) months following initiation of fludarabine, with 75% of these having completed therapy. All patients with herpes zoster developed severe post‐herpetic neuralgia. Factors differentiating patients developing these infections included older age and low serum IgG or IgA. Based upon these prospective data, we conclude that herpes virus infections frequently occur following fludarabine treatment, necessitating aggressive patient education and new prophylactic strategies.

Clonal selection of CD56+ t(8;21) AML blasts: further suggestion of the adverse clinical significance of this biological marker?

Although patients with acute myelogenous leukaemia (AML) and t(8;21)(q22;q22) have a favourable prognosis, a subset die despite receiving appropriate treatment. Recent reports suggest that expression of the CD56 antigen might predict for both extramedullary disease and poor outcome in these patients. We describe a patient who presented with CD56‐negative t(8;21) AML who achieved a complete remission and was subsequently treated with three consolidative courses of high‐dose cytarabine therapy. She relapsed 9 months later with extramedullary and bone marrow involvement of CD56‐positive t(8;21) AML. This case demonstrates clonal evolution and provides further support that blast expression of CD56 might be an unfavourable prognostic factor in t(8;21) AML.

Mixed-Type Autoimmune Hemolytic Anemia following Fludarabine Treatment in a Patient with Chronic Lymphocytic Leukemia/Small Cell Lymphoma

Background and objectives: Mixed-type autoimmune hemolytic anemia (AIHA) is a rare complication of chronic lymphocytic leukemia (CLL). We report a patient with small lymphocytic lymphoma (phenotypic CLL) who developed symptomatic anemia 3 weeks after her fifth cycle of fludarabine, a T cell immunosuppressant. Materials and methods: An antibody screen and panel, direct antiglobulin test, rapid acid eluate, rabbit erythrocyte stroma (RESt) adsorption, and autoadsorption were performed. Results: Warm and cold autoantibodies were detected. Prompt treatment with corticosteroids and minimal blood transfusions led to marked improvement. Conclusion: Normally, T cells suppress polyclonal lymphocytes that produce autoantibodies. Suppression of T cells in this patient, in addition to the underlying disease process, may explain this mixed-type AIHA, the first reported case to occur following fludarabine treatment.

A dose-finding study of liposomal daunorubicin with CVP (COP-X) in advanced NHL

BACKGROUND Standard therapy for lymphoma consists of a cyclophosphamide (C), doxorubicin, vincristine (V), and prednisone (P) (CHOP) combination regimen. Liposomal daunorubicin (DaunoXome) is an alternative to doxorubicin for patients with lymphoma because of its more favorable safety profile and potentially more selective uptake in lymphoma. The objectives of this study were to determine the maximum tolerated dose (MTD) of liposomal daunorubucin with CVP (COP-X) and the tolerability of the regimen in patients with indolent lymphoma. PATIENTS AND METHODS Patients with low-grade and intermediate-grade lymphoma having adequate cardiac, hepatic, and renal function were enrolled. Patients received C 750 mg/m2, V 1.4 mg/m2 (maximum 2.0 mg), and liposomal daunorubicin 50-100 mg/m2 i.v. on day 1 and P 100 mg p.o. on days 1-5. MTD was the liposomal daunorubicin dose associated with 20% dose-limiting toxicity (ANC < 500/mm3 for > 5 days or febrile neutropenia). RESULTS Twenty patients, median age 59 years, were treated. The liposomal daunorubicin MTD combined with CVP was 70-80 mg/m2, depending on patient population. No significant non-hematologic toxicity occurred. Response rate was 44% (2 complete and 5 partial responses). CONCLUSIONS A liposomal daunorubicin dose of 80 mg/m2 in the COP-X regimen was well tolerated with little nonhematologic toxicity.

Pancreatitis during therapy of acute myeloid leukemia: Cytarabine related?

BACKGROUND Acute pancreatitis in acute myeloid leukemia (AML) has been rarely associated with cytarabine therapy. This report attempts to characterize this toxicity. PATIENTS AND METHODS Criteria for pancreatitis was prospectively defined. Seven patients with pancreatitis were identified from an AML database and a clinical study at two tertiary care centers (n = 134). Their records were retrospectively reviewed. RESULTS Seven patients with pancreatitis complicating AML therapy were identified. Median age was 36 (range 25-73) years. Median amylase was 184 (range 77-552) U/l and median lipase was 1026 (range 630-6087) U/l. The patients had received high dose bolus cytarabine (2 g/m2 i.v. bolus every 12 hours; n = 2), and continuous infusion cytarabine followed by high-dose cytarabine (100 mg/m2 i.v. CI days 1-7 then 2 g/m2 i.v. bolus every 12 hours days 8-10; n = 2), or standard dose continuous infusion cytarabine (200 mg/m2/d; n = 3) prior to developing pancreatitis. Pancreatitis occurred at a median of 10 days following day one of cytarabine administration with resolution at a median of 11 days after initial diagnosis. Six patients did not suffer major complications. One patient died of causes unrelated to pancreatitis. Five of six patients was rechallenged and all remained free of pancreatitis. One patient subsequently did develop pancreatitis on a later rechallenge. CONCLUSIONS Pancreatitis in the setting of AML therapy may be an infrequent and self-limited toxicity of cytarabine. A schedule dependent toxicity with cytarabine was not identified.

Carboxyamido-triazole (CAI)--a novel "static" signal transduction inhibitor induces apoptosis in human B-cell chronic lymphocytic leukemia cells.

Signal transduction is a key mechanism by which both proliferative and apoptotic processes of B-cell chronic lymphocytic leukemia (CLL) cells are mediated. Carboxyamido-triazole (CAI) is a cytostatic signal transduction inhibitor currently being tested in phase II clinical trials. Based on this, we investigated the in vitro activity of CAI in mononuclear cell isolates from patients with B-CLL (n = 11). Viability, utilizing the MTT assay, was assessed at varying concentrations (0.01–100 μM) of CAI for 4 days. The CAI concentration required for 50% inhibition of cell viability (LC50), determined by the tetrazolium dye (MTT) assay, at 4 days was 53.5 μM (range 29–74.6; 95% CI × 14.8). Cells from 6 of 11 patients (3 of whom were clinically fludarabine refractory) had a 27 percent (range 11–43) mean decline in viability at 10 μM after a 4 day drug exposure, a concentration readily attainable in humans. To assess if loss of viability was due to apoptosis, we incubated cells from 4 additional CLL patients with media or CAI (10 μM) for 4 days. Annexin-V/propidium iodine labeling subsequently demonstrated CAI significantly (p = 0.049) induces apoptosis (40.1%; 95% CI × 18.1) as compared to media matched control cells (18.3%; 95% CI × 11.2). These data provide evidence that CAI can induce apoptosis in human CLL cells in vitro at drug concentrations attainable in vivo. These findings justify phase n studies of CAI in patients with B-CLL.

Concurrent pernicious anemia and myelodysplastic syndrome

Abstract.Megaloblastic anemia (MA) due to vitamin B12 deficiency is a reversible form of ineffective hematopoiesis. Myelodysplastic syndrome (MDS) is an acquired, irreversible disorder of ineffective hematopoiesis, characterized by stem cell dysfunction as a consequence of DNA damage manifested in part by karyotype anomalies. Importantly, MA and MDS are generally considered mutually exclusive diagnoses. We report the case of a 73-year-old woman with a profound macrocytic anemia, monocytosis and neurologic symptoms. Low cobalamin levels and the presence of anti-intrinsic-factor antibodies definitively established a diagnosis of pernicious anemia. Replacement therapy resulted in resolution of neurologic findings and macrocytosis; however, the anemia and monocytosis persisted. Bone marrow biopsy revealed trilineage myelodysplasia, which together with the peripheral monocytosis suggested a diagnosis of chronic myelomonocytic leukemia. Karyotype analysis revealed a clone with 45, XX, +der(1;7)(q10;p10)–7 [20]. Eighteen months after documented vitamin B12 replenishment her MDS transformed to terminal acute myeloid leukemia with the same clonal abnormality. Reversible cytogenetic abnormalities have been observed with MA, occasionally including karyotypes typically associated with MDS or myeloid leukemias. These abnormalities, like the anemia, resolve with vitamin replacement. This case suggests that MA and MDS can occur simultaneously; clinicians should be aware that this phenomenon occurs. Whether acquired karyotype abnormalities from the MA were related to the MDS and subsequent myeloid leukemia in this woman is a speculative but intriguing consideration that is discussed.