Giuseppe Gritti

Ibrutinib interferes with the cell-mediated anti-tumor activities of therapeutic CD20 antibodies: implications for combination therapy

The novel Bruton tyrosine kinase inhibitor ibrutinib and phosphatidyl-4-5-biphosphate 3-kinase-δ inhibitor idelalisib are promising drugs for the treatment of chronic lymphocytic leukemia and B-cell non-Hodgkin lymphoma, either alone or in combination with anti-CD20 antibodies. We investigated the possible positive or negative impact of these drugs on all known mechanisms of action of both type I and type II anti-CD20 antibodies. Pretreatment with ibrutinib for 1 hour did not increase direct cell death of cell lines or chronic lymphocytic leukemia samples mediated by anti-CD20 antibodies. Pre-treatment with ibrutinib did not inhibit complement activation or complement-mediated lysis. In contrast, ibrutinib strongly inhibited all cell-mediated mechanisms induced by anti-CD20 antibodies rituximab, ofatumumab or obinutuzumab, either in purified systems or whole blood assays. Activation of natural killer cells, and antibody-dependent cellular cytotoxicity by these cells, as well as phagocytosis by macrophages or neutrophils were inhibited by ibrutinib with a half maximal effective concentration of 0.3–3 μM. Analysis of anti-CD20 mediated activation of natural killer cells isolated from patients on continued oral ibrutinib treatment suggested that repeated drug dosing inhibits these cells in vivo. Finally we show that the phosphatidyl-4-5-biphosphate 3-kinase-δ inhibitor idelalisib similarly inhibited the immune cell-mediated mechanisms induced by anti-CD20 antibodies, although the effects of this drug at 10 μM were weaker than those observed with ibrutinib at the same concentration. We conclude that the design of combined treatment schedules of anti-CD20 antibodies with these kinase inhibitors should consider the multiple negative interactions between these two classes of drugs.

The lymphocyte to monocyte ratio improves the IPI‐risk definition of diffuse large B‐cell lymphoma when rituximab is added to chemotherapy

The peripheral blood lymphocyte to monocyte ratio (LMR) at diagnosis can be clinically relevant in patients with diffuse large B‐cell lymphoma (DLBCL). We reviewed the outcome of 1,057 DLBCL patients followed from 1984 to 2012 at four centers. LMR was analyzed as a clinical biomarker by receiver‐operating characteristic (ROC) analysis and Harrells C‐statistics. Patients were characterized by a median age of 61 years, International Prognostic Index (IPI) score of >2 in 39%, and were treated with a rituximab‐containing chemotherapy in 66%. LMR proved strongly predictive for survival in patients treated with rituximab‐based programs, but not in those receiving chemotherapy alone. Additionally, an LMR value of ≤2.6 (as determined by ROC analysis) was associated with a worst performance status, a higher lactate dehydrogenase (LDH) level, an advanced clinical stage, and a higher IPI score (P = 0.000). In patients treated with rituximab‐supplemented chemotherapy programs, an LMR value of <2.6 was found in most of the primary refractory patients (75%) which proved as the best cutoff to predict both response and survival (P = 0.018). Finally, multivariate analysis and Harrells C‐statistics confirmed the IPI‐independent role of LMR on survival (P = 0.0000). In conclusion, LMR is a potent predictor of clinical response and survival in DLBCL treated with rituximab‐containing chemotherapy. Am. J. Hematol. 88:1062–1067, 2013.

Pulmonary arterial hypertension in primary myelofibrosis is common and associated with an altered angiogenic status

Pulmonary arterial hypertension in primary myelofibrosis is common and associated with an altered angiogenic status

An Italian retrospective study on the routine clinical use of low‐dose alemtuzumab in relapsed/refractory chronic lymphocytic leukaemia patients

Low‐dose alemtuzumab has shown a favourable toxicity profile coupled with good results in terms of efficacy in relapsed/refractory chronic lymphocytic leukaemia (CLL). We conducted a multicentre retrospective study on the routine clinical use of low‐dose alemtuzumab in this patient setting. One hundred and eight relapsed/refractory CLL patients from 11 Italian centres were included in the analysis. All patients had an Eastern Cooperative Oncology Group performance status ≤2 and the majority (84%) had adenopathies <5cm. Low‐dose alemtuzumab was defined as a total weekly dose ≤45 mg and a cumulative dose ≤600 mg given for up to 18 weeks. The overall response rate was 56% (22% complete remissions). After a median follow‐up of 42·2 months, the median overall survival and progression‐free survival were 39·0 and 19·4 months, respectively. In univariate analysis, response was inversely associated with lymph node (P = 0·01) and spleen (P = 0·02) size, fludarabine‐refractoriness (P = 0·01) and del(11q) (P = 0·009). Advanced age and del(17p) were not associated with a worse outcome. Cumulative dose of alemtuzumab was not associated to response. Toxicities were usually mild and manageable; severe infections occurred in seven patients (7%) during therapy. This retrospective analysis confirms that low‐dose alemtuzumab is a valid and currently used therapeutic option for the treatment of relapsed/refractory CLL.

Circulating and progenitor endothelial cells are abnormal in patients with different types of von Willebrand disease and correlate with markers of angiogenesis.

von Willebrand disease (VWD) is the most common inherited bleeding disorder and is caused by quantitative or qualitative defects of von Willebrand factor (VWF). VWF, synthesized by endothelium and megakaryocytes (MK), circulates in plasma and is present in subendothelium and platelets. Circulating endothelial cells (CEC) and progenitor endothelial cells (EPC) have been recently proposed as markers of peripheral and bone marrow‐derived angiogenesis. To evaluate the association of CEC/EPC with known inherited defects of cellular and circulating VWF, we have measured the number of CEC/EPC together with cytokines involved in angiogenesis in different VWD types. A group of 74 patients was composed by the following VWD types: VWD1 (n = 22), VWD2A (n = 9), VWD2B (n = 19), VWD2M (n = 17), and VWD3 (n = 7). Healthy individuals (n = 20) were used as controls. CEC (CD146+, CD31+, and CD45−) and EPC (CD34+, CD133+, and CD45−) were evaluated by flow cytometry. Circulating serum levels of VEGF, E‐selectin, P‐selectin, EPO, and TPO were determined by ELISA. CEC, VEGF, E‐selectin, and EPO were higher and EPC lower in VWD patients than in controls (P < 0.01). Among the five groups of VWD patients and controls, a significant difference was found for CEC (one‐way ANOVA: P = 0.005), EPC (P = 0.001), E‐Selectin (P < 0.0001), EPO (P = 0.021), and TPO (P = 0.004): the latter was high in VWD3 patients. In VWD1, we found an inverse relationship between CEC and VWF:Ag levels (P = 0.048; R2 = 0.19). Based on these data, CEC are increased in VWD and are associated with the high levels of cytokines involved in angiogenesis (up‐regulation). EPC are decreased, suggesting down‐regulation of bone marrow‐derived angiogenesis in VWD. Am. J. Hematol. 2011.

Randomized trial comparing R-CHOP versus high-dose sequential chemotherapy in high-risk patients with diffuse large B-cell lymphomas

Purpose The benefit of high-dose chemotherapy with autologous stem-cell transplantation (ASCT) as first-line treatment in patients with diffuse large B-cell lymphomas is still a matter of debate. To address this point, we designed a randomized phase III trial to compare rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP)-14 (eight cycles) with rituximab plus high-dose sequential chemotherapy (R-HDS) with ASCT. Patients and Methods From June 2005 to June 2011, 246 high-risk patients with a high-intermediate (56%) or high (44%) International Prognostic Index score were randomly assigned to the R-CHOP or R-HDS arm, and 235 were analyzed by intent to treat. The primary efficacy end point of the study was 3-year event-free survival, and results were analyzed on an intent-to-treat basis. Results Clinical response (complete response, 78% v 76%; partial response, 5% v 9%) and failures (no response, 15% v 11%; and early treatment-related mortality, 2% v 3%) were similar after R-CHOP versus R-HDS, respectively. After a median follow-up of 5 years, the 3-year event-free survival was 62% versus 65% ( P = .83). At 3 years, compared with the R-CHOP arm, the R-HDS arm had better disease-free survival (79% v 91%, respectively; P = .034), but this subsequently vanished because of late-occurring treatment-related deaths. No difference was detected in terms of progression-free survival (65% v 75%, respectively; P = .12), or overall survival (74% v 77%, respectively; P = .64). Significantly higher hematologic toxicity ( P < .001) and more infectious complications ( P < .001) were observed in the R-HDS arm. Conclusion In this study, front-line intensive R-HDS chemotherapy with ASCT did not improve the outcome of high-risk patients with diffuse large B-cell lymphomas.

Low-dose alemtuzumab-associated immune thrombocytopenia in chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is frequently complicated during its course by autoimmune disorders (from 2 to 12% of cases), such as autoimmune hemolytic anemia (AIHA) and immune thrombocytopenic purpura (ITP). In particular, ITP has been reported in about 2–5% of CLL population. Recently, Cuker et al. reported the occurrence of ITP in 6/216 patients with relapsing-remitting multiple sclerosis in a phase 2 clinical trial of annual alemtuzumab. Alemtuzumab is an anti-CD52 monoclonal antibody used in CLL both as first-line treatment and in relapsed/refractory patients. We evaluated a cohort of 64 consecutive patients affected by relapsed-refractory CLL treated with low-dose alemtuzumab and we observed a incidence of ITP higher than predicted. Our data, associated with the report of Cuker et al., seem to suggest an important role of alemtuzumab in the pathogenesis of ITP which could be related to its induced dysregulation of T-lymphocyte activity.

Low dose alemtuzumab in patients with fludarabine-refractory chronic lymphocytic leukemia

Abstract Alemtuzumab has been shown to be effective in poor-prognosis chronic lymphocytic leukemia (CLL); treatment, however, has been associated with significant toxicity. With the aim of seeking better tolerability, we treated 39 patients with fludarabine-refractory CLL subcutaneous alemtuzumab 10 mg three times a week, for 18 weeks. In 18 randomly selected patients, after obtaining lymphocyte count reduction by 1 Log, the antibody was administered once weekly at the dose of 30 mg. Overall response rate was 44%, including 8% complete remissions. Median overall survival and progression free survival were 29.1 and 10.3 months, respectively. Treatment was well tolerated, severe non-CMV infection occurred in 7% of the patients. CMV reactivation was detected in 27% of the patients, with only one case of CMV disease. No deaths occurred during therapy. In conclusion, low-dose alemtuzumab shows a promising safety profile coupled with satisfactory effectiveness in this category of poor prognosis CLL patients.

Rate of primary refractory disease in B and T-cell non-Hodgkin's lymphoma: correlation with long-term survival.

Background Primary refractory disease is a main challenge in the management of non-Hodgkin’s Lymphoma (NHL). This survey was performed to define the rate of refractory disease to first-line therapy in B and T-cell NHL subtypes and the long-term survival of primary refractory compared to primary responsive patients. Methods Medical records were reviewed of 3,106 patients who had undergone primary treatment for NHL between 1982 and 2012, at the Hematology Centers of Torino and Bergamo, Italy. Primary treatment included CHOP or CHOP-like regimens (63.2%), intensive therapy with autograft (16.9%), or other therapies (19.9%). Among B-cell NHL, 1,356 (47.8%) received first-line chemotherapy with rituximab. Refractory disease was defined as stable/progressive disease, or transient response with disease progression within six months. Results Overall, 690 (22.2%) patients showed primary refractory disease, with a higher incidence amongst T-cell compared to B-cell NHL (41.9% vs. 20.5%, respectively, p<0.001). Several other clinico-pathological factors at presentation were variably associated with refractory disease, including histological aggressive disease, unfavorable clinical presentation, Bone Marrow involvement, low lymphocyte/monocyte ration and male gender. Amongst B-cell NHL, the addition of rituximab was associated with a marked reduction of refractory disease (13.6% vs. 26.7% for non-supplemented chemotherapy, p<0.001). Overall, primary responsive patients had a median survival of 19.8 years, compared to 1.3 yr. for refractory patients. A prolonged survival was consistently observed in all primary responsive patients regardless of the histology. The long life expectancy of primary responsive patients was documented in both series managed before and after 2.000. Response to first line therapy resulted by far the most predictive factor for long-term outcome (HR for primary refractory disease: 16.52, p<0.001). Conclusion Chemosensitivity to primary treatment is crucial for the long-term survival in NHL. This supports the necessity of studies aimed to early identify refractory disease and to develop different treatment strategies for responsive and refractory patients.

Italian real life experience with brentuximab vedotin: results of a large observational study on 40 relapsed/refractory systemic anaplastic large cell lymphoma

Between November 2012 and July 2014, in accordance with national law 648/96, brentuximab vedotin was available in Italy for patients with relapsed systemic anaplastic large cell lymphoma outside a clinical trial context. A large Italian observational retrospective study was conducted on the use of brentuximab vedotin in everyday clinical practice to check whether clinical trial results are confirmed in a real-life context. The primary endpoint of this study was best response; secondary endpoints were the overall response rate at the end of the treatment, duration of response, survival and safety profile. A total of 40 heavily pretreated patients were enrolled. Best response was observed after a median of four cycles in 77.5%: globally, 47.5% patients obtained a complete response, 64.2% in the elderly subset. The overall response rate was 62.5%. At the latest follow up, 15/18 patients are still in complete remission (3 with consolidation). The progression-free survival rate at 24 months was 39.1% and the disease-free survival rate at the same time was 54% (median not reached). All the long-term responders were aged <30 years at first infusion. The treatment was well tolerated even in this real-life context and no deaths were linked to drug toxicity. Brentuximab vedotin induces clinical responses quite rapidly, i.e. within the first four cycles of treatment in most responders, thus enabling timely use of transplantation. For patients ineligible for transplant or for those in whom a transplant procedure failed, brentuximab vedotin may represent a feasible effective therapeutic option in everyday clinical practice.