Laura Gallur

Rituximab in the management of chronic immune thrombocytopenic purpura: an effective and safe therapeutic alternative in refractory patients

Rituximab induces B-cell depletion; therefore, it has been used in the treatment of immune thrombocytopenic purpura (ITP). The aim of this retrospective study was to evaluate the effectiveness of rituximab in the treatment of 89 patients with chronic ITP refractory to several treatments. All the patients had platelet counts <30 x 10(9)/l. They had received a median of five (2-13) previous treatments, and 47 had undergone splenectomy. Rituximab was administered i.v. at 375 mg/m(2) in four weekly doses in 77 patients, and 12 patients received 1-6 doses. Forty-nine patients (55.1%) reached platelet counts >50 x 10(9)/l; 41 (46%) achieved a complete response (CR; platelets >100 x 10(9)/l), and eight (9%) obtained a partial response (platelets 50-100 x 10(9)/l). Overall, 31 patients (35%) maintained response, including 15 patients in whom splenectomy failed, with a median follow-up of 9 months (2-42), 12 for more than 1 year. The unique predictor of a maintained response was to reach a CR. Heavily treated patients (more than three different previous treatments, including any corticosteroids) and those with longer ITP duration (>10 years from diagnosis) had a worse response. Non-splenectomized patients had a better early response rate than those splenectomized. Rituximab was well tolerated, with two fever episodes following infusion and two reports of skin rash. Rituximab induced clinical responses in multi-treated refractory ITP patients with little toxicity and should be considered as an early therapeutic option in this setting, even as an alternative to splenectomy in selected patients.

Relationship between minimal residual disease measured by multiparametric flow cytometry prior to allogeneic hematopoietic stem cell transplantation and outcome in children with acute lymphoblastic leukemia

Background The presence of minimal residual disease detected by polymerase chain reaction techniques prior to allogeneic hematopoietic stem cell transplantation has proven to be an independent prognostic factor for poor outcome in children with acute lymphoblastic leukemia. Design and Methods The aim of this study was to ascertain whether the presence of minimal residual disease detected by multiparametric flow cytometry prior to allogeneic hematopoietic stem cell transplantation is related to outcome in children acute lymphoblastic leukemia. Minimal residual disease was quantified by multiparametric flow cytometry at a median of 10 days prior to hematopoietic stem cell transplantation in 31 children (age range, 10 months to 16 years) with acute lymphoblastic leukemia. Thirteen patients were transplanted in first remission. Stem cell donors were HLA-identical siblings in 8 cases and matched unrelated donors in 23. Twenty-six children received a total body irradiation-containing conditioning regimen. According to the level of minimal residual disease, patients were divided into two groups: minimal residual disease-positive (≥0.01%) (n=10) and minimal residual disease-negative (<0.01%) (n=21). Results Estimated event-free survival rates at 2 years for the minimal residual disease-negative and -positive subgroups were 74% and 20%, respectively (P=0.004) and overall survival rates were 80% and 20%, respectively (P=0.005). Bivariate analysis identified pre-transplant minimal residual disease as the only significant factor for relapse and also for death (P<0.01). Conclusions The presence of minimal residual disease measured by multiparametric flow cytometry identified a group of patients with a 9.5-fold higher risk of relapse and a 3.2-fold higher risk of death than those without minimal residual disease. This study supports the strong relationship between pre-transplantation minimal residual disease measured by multiparametric flow cytometry and outcome following allogeneic hematopoietic stem cell transplantation and concur with the results of previous studies using polymerase chain reaction techniques.

Long-term follow-up of dose-adjusted EPOCH plus rituximab (DA-EPOCH-R) in untreated patients with poor prognosis large B-cell lymphoma. A phase II study conducted by the Spanish PETHEMA Group

This prospective multi‐institutional phase II study was designed to assess the efficacy and safety of dose‐adjusted EPOCH (etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin) plus rituximab (DA‐EPOCH‐R) in untreated patients with poor prognosis large B‐cell lymphomas. Eighty‐one patients diagnosed with diffuse large B‐cell lymphoma (DLBCL, n = 68), primary mediastinal DLBCL (n = 6) and follicular lymphoma Grade 3b (n = 7), with an age‐adjusted International Prognostic Index >1, were eligible for analysis. Median age was 60 years (range: 21–77). Sixty‐five patients (80·2%) achieved complete response. After a median follow‐up time of 64 months, 10‐year event‐free survival and overall survival (OS) were 47·8% and 63·6%, respectively. None of the studied clinical and biological characteristics were associated with poorer outcome. Interestingly, patients with BCL6 rearrangement achieved a 10‐year OS of 100%, while patients with BCL2 rearrangement exhibited a poorer outcome compared to activated B‐cell tumours and germinal centre B‐cell without BCL2 rearranged tumours. Results achieved with DA‐EPOCH‐R showed a good long‐term outcome and a tolerable toxicity profile in high‐risk large B cell lymphoma patients. Outcome was not affected by tumour cell proliferation or by cell of origin, highlighting the requirement of new biological markers for patient subclassification of high‐risk DLBCL patients.

Abstract 1344: ZAP-70 enhances migration of malignant B lymphocytes toward lymphoid organs in a Burkitt lymphoma xenograft model

Chronic Lymphocytic Leukemia (CLL) is a lymphoproliferative disease characterized by the accumulation and proliferation of mature B-lymphocytes in the blood, bone marrow and secondary lymphoid organs. CLL patients with adverse outcome prognosis can be identified by the presence of a high ZAP-70 expression. ZAP-70, a protein tyrosine kinase that plays a crucial role in cellular activation in T and NK cells, has been related to aggressive features of the CLL cells, such as higher migrative capacity in vitro. In order to analyze the consequences of ZAP-70 ectopic expression in an in vivo model, we stably transfected a Burkitt cell line (Raji) with a vector expressing a ZAP-70-GFP fusion protein. Raji transfectants showed constitutively active ZAP-70 protein. Subsequently, thirty-four 8-week old SCID mice were inoculated intravenously with 5 x10 6 cells from each cell line (control Raji-GFP, 12 mice; Raji-ZAP-70-GFP, 9 mice). Mice were euthanized when hind legs paralysis, dyspnea, or tumor growth was observed. Organs were obtained to quantify the percentage of GFP-positive cells present in each organ by flow cytometry. Median survival of mice injected with the ZAP-70 cell line did not differ from that observed in the control mice (16 days, p=0.658). Percentage of GFP positive cells was analyzed by flow cytometry in different tissue compartments (Table 1). We observed a significantly higher percentage of infiltrating GFP-positive cells in the bone marrow from mice injected with ZAP-70 expressing cell line (58.8%±6.08 vs 4.2%±1.4, p Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1344. doi:1538-7445.AM2012-1344