Combination of two anti-CD5 monoclonal antibodies synergistically induces complement-dependent cytotoxicity of chronic lymphocytic leukaemia cells.

The treatment of chronic lymphocytic leukaemia (CLL) has been improved by introduction of monoclonal antibodies (mAbs) that exert their effect through secondary effector mechanisms. CLL cells are characterized by expression of CD5 and CD23 along with CD19 and CD20, hence anti-CD5 Abs that engage secondary effector functions represent an attractive opportunity for CLL treatment. Here, a repertoire of mAbs against human CD5 was generated and tested for ability to induce complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC) both as single mAbs and combinations of two mAbs against non-overlapping epitopes on human CD5. The results demonstrated that combinations of two mAbs significantly increased the level of CDC compared to the single mAbs, while no enhancement of ADCC was seen with anti-CD5 mAb combinations. High levels of CDC and ADCC correlated with low levels of Ab-induced CD5 internalization and degradation. Importantly, an anti-CD5 mAb combination enhanced CDC of CLL cells when combined with the anti-CD20 mAbs rituximab and ofatumumab as well as with the anti-CD52 mAb alemtuzumab. These results suggest that an anti-CD5 mAb combination inducing CDC and ADCC may be effective alone, in combination with mAbs against other targets or combined with chemotherapy for CLL and other CD5-expressing haematological or lymphoid malignancies.

Chemoimmunotherapy with ofatumumab in combination with CHOP in previously untreated follicular lymphoma.

An international, Phase II trial was conducted to assess two doses of ofatumumab, a human CD20 monoclonal antibody, combined with cyclophosphamide (750 mg/m(2) ), doxorubicin (50 mg/m(2) ), prednisone (100 mg days 3-7) and vincristine (1·4 mg/m(2) ) (O-CHOP), as frontline treatment for follicular lymphoma (FL). 59 patients with previously untreated FL were randomized to ofatumumab 500 mg (n = 29) or 1000 mg (n = 30) day 1, with CHOP on day 3 every 3 weeks for six cycles. Median duration of FL was 0·1 years for both dose groups; 34% and 38% of patients had high-risk Follicular Lymphoma International Prognostic Index (FLIPI) scores in the 500- and 1000-mg dose groups, respectively. Overall response rate was 90% for the 500-mg group and 100% for the 1000-mg group. 62% of patients achieved complete response (CR)/unconfirmed CR (CRu). 76% of patients with FLIPI score 3-5 attained CR/CRu. Longer follow-up time is needed for analysis of survival end points. The most common Common Terminology Criteria grade 3-4 investigator-reported adverse events were leucopenia (29%) and neutropenia (22%). No deaths have been reported. O-CHOP was safe and efficacious in patients with previously untreated FL, including high-risk FLIPI groups. This trial was registered at www.clinicaltrials.gov (NCT00494780).

Immunohistochemical double-hit score is a strong predictor of outcome in patients with diffuse large B-cell lymphoma treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone.

PURPOSE: Approximately 5% of diffuse large B-cell lymphomas (DLBCLs) are double-hit lymphomas (DHLs) with translocations of both MYC and BCL2. DHLs are characterized by poor outcome. We tested whether DLBCLs with high expression of MYC protein and BCL2 protein share the clinical features and poor prognosis of DHLs. PATIENTS AND METHODS: Paraffin-embedded lymphoma samples from 193 patients with de novo DLBCL who were uniformly treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) were studied using immunohistochemistry for MYC, BCL2, CD10, BCL6, and MUM1/interferon regulatory factor 4, and fluorescent in situ hybridization (FISH) for MYC and BCL2. RESULTS: FISH analysis identified DHL in 6% of patients, who showed the expected poor overall survival (OS; P = .002). On the basis of immunohistochemical MYC and BCL2 expression, a double-hit score (DHS) was assigned to all patients with DLBCL. The DHS-2 group, defined by high expression of both MYC and BCL2 protein, comprised 29% of the patients. DHS 2 was significantly associated with lower complete response rate (P = .004), shorter OS (P < .001), and shorter progression-free survival (PFS; P < .001). The highly significant correlation with OS and PFS was maintained in multivariate models that controlled for the International Prognostic Index and the cell-of-origin subtype (OS, P < .001; PFS, P < .001). DHS was validated in an independent cohort of 116 patients who were treated with R-CHOP. CONCLUSION: The immunohistochemical DHS defined a large subset of DLBCLs with double-hit biology and was strongly associated with poor outcome in patients treated with R-CHOP.

Up-front autologous stem-cell transplantation in peripheral T-cell lymphoma: NLG-T-01.

PURPOSE: Systemic peripheral T-cell lymphomas (PTCLs) respond poorly to conventional therapy. To evaluate the efficacy of a dose-dense approach consolidated by up-front high-dose chemotherapy (HDT) and autologous stem-cell transplantation (ASCT) in PTCL, the Nordic Lymphoma Group (NLG) conducted a large prospective phase II study in untreated systemic PTCL. This is the final report, with a 5-year median follow-up, of the NLG-T-01 study. PATIENTS AND METHODS: Treatment-naive patients with PTCL age 18 to 67 years (median, 57 years) were included. Anaplastic lymphoma kinase (ALK) -positive anaplastic large-cell lymphoma (ALCL) was excluded. An induction regimen of six cycles of biweekly CHOEP (cyclophosphamide, doxorubicin, vincristine, etoposide, and prednisone) was administered (in patients age > 60 years, etoposide was omitted). If in complete or partial remission, patients proceeded to consolidation with HDT/ASCT. RESULTS: Of 166 enrolled patients, 160 had histopathologically confirmed PTCL. The majority presented with advanced-stage disease, B symptoms, and elevated serum lactate dehydrogenase. A total of 115 underwent HDT/ASCT, with 90 in complete remission at 3 months post-transplantation. Early failures occurred in 26%. Treatment-related mortality was 4%. At 60.5 months of median follow-up, 83 patients were alive. Consolidated 5-year overall and progression-free survival (PFS) were 51% (95% CI, 43% to 59%) and 44% (95% CI, 36% to 52%), respectively. Best results were obtained in ALK-negative ALCL. CONCLUSION: Dose-dense induction followed by HDT/ASCT was well tolerated and led to long-term PFS in 44% of treatment-naive patients with PTCL. This represents an encouraging outcome, particularly considering the high median age and adverse risk profile of the study population. Therefore, dose-dense induction and HDT/ASCT are a rational up-front strategy in transplantation-eligible patients with PTCL.

Cytogenetic findings in adult secondary acute myeloid leukemia (AML): frequency of favorable and adverse chromosomal aberrations do not differ from adult de novo AML.

During a 15-year period, 161 adult patients were diagnosed with secondary acute myeloid leukemia (s-AML) in the region of Southern Denmark. In 73 patients, the AML diagnosis was preceded by myelodysplastic syndrome (MDS-AML), in 31 patients by an antecedent hematologic disease, and in 57 patients by treatment with chemotherapy and/or irradiation (t-AML). Cytogenetic analysis was carried out in 93%, of which 61% had clonal chromosome aberrations. MDS-AML correlated to a normal karyotype (P < 0.001). t-AML correlated to abnormal clones with numerical and structural aberrations (P = 0.03), five or more unrelated aberrations (P = 0.03), marker chromosomes (P = 0.006), abnormal mitoses only (P = 0.01), female sex (P < 0.001), and -7 (P = 0.006). Centromeric breakage correlated to a complex karyotype (P = 0.01). The frequencies of aberrations in s-AML patients were compared with an age-matched group of de novo AML patients diagnosed in the same area and period. In this comparison, s-AML only correlated to -7 (P = 0.02). In 42 patients, we found that MDS patients with an abnormal karyotype were more likely to show cytogenetic evolution during progression to AML than MDS patients with a normal karyotype (P = 0.01). We conclude that population-based cytogenetic studies of adult s-AML and age- and sex-matched de novo AML show comparable distributions of chromosome abnormalities.

Cytogenetic findings in adult de novo acute myeloid leukaemia. A population-based study of 303/337 patients.

During a 10-year period (1992-2001) in the region of Southern Denmark, 337 patients aged 15 years or older (range 16-93 years, median 67 years) were diagnosed with acute myeloid leukaemia (AML). Cytogenetic analysis was carried out in 90%, of whom 53% had clonal chromosome aberrations. Some 24% and 31% had only numerical or structural abnormalities respectively. The remaining patients showed both types of abnormalities. Ploidy levels in decreasing order were: pseudodiploidy, 41%; hyperdiploidy, 32%; and hypodiploidy, 27%. Pseudodiploidy characterizes type M3 (70%) and hypodiploidy M6 (56%). Recurrent cytogenetic abnormalities--t(8;21), t(15;17) and inv(16)--were found in 3.3%, 3.3% and 2.0% of all patients respectively. Prognostically intermediate and adverse aberrations were found in 39% and 44%, respectively, of those with an abnormal karyotype. Rare recurrent aberrations were found in two patients in this material. A previously described non-recurrent abnormality was found to be recurrent in one patient [der(20)t(11;20)(q13.2;p13)]. New, previously undescribed abnormalities were found in 41 patients. Statistically significant correlations were found between t(15;17) and young age (P < 0.001), inv(16) and young age (P < 0.006), -17 and M6 (P = 0.007), and M6 and complex karyotype with five or more unrelated aberrations (P = 0.004). We conclude that this truly population-based cytogenetic study of adult AML showed distributions of chromosome abnormalities that differ from those described so far.