Effect of first-line treatment on second primary malignancies and Richter's transformation in patients with CLL

This study aimed to assess the frequency of and the contributing factors for second primary malignancies (SPMs) and Richter's transformations (RTs) following first-line treatment of chronic lymphocytic leukemia within four phase II/III trials of the GCLLSG evaluating fludarabine (F) vs F+cyclophosphamide (FC), chlorambucil vs F, FC without or with rituximab, and bendamustine+R (BR). Among 1458 patients, 239 (16.4%) experienced either an SPM (N=191) or a RT (N=75). Solid tumors (N=115; 43.2% of all second neoplasias) appeared most frequently, followed by RTs (N=75; 28.2%). Patients showed a 1.23-fold increased risk of solid tumors in comparison to the age-matched general population from the German cancer registry. Age>65 (hazard ratio (HR) 2.1; P<0.001), male sex (HR 1.7; P=0.01), co-morbidities (HR 1.6; P=0.01) and number of subsequent treatments⩾1 (HR 12.1; P<0.001) showed an independent adverse prognostic impact on SPM-free survival. Serum thymidine kinase>10 U/l at trial enrollment (HR 3.9; P=0.02), non-response to first-line treatment (HR 3.6; P<0.001) and number of subsequent treatments⩾1 (HR 30.2; P<0.001) were independently associated with increased risk for RT.

Next-generation sequencing and real-time quantitative PCR for minimal residual disease detection in B-cell disorders

In this study, we compared immunoglobulin heavy-chain-gene-based minimal residual disease (MRD) detection by real-time quantitative PCR (RQ-PCR) and next-generation sequencing (NGS) to assess whether NGS could overcome some limitations of RQ-PCR and further increase sensitivity, specificity, accuracy and reproducibility. In total, 378 samples from 55 patients with acute lymphoblastic leukemia (ALL), mantle cell lymphoma (MCL) or multiple myeloma (MM) were investigated for clonotype identification, clonotype identity and comparability of MRD results. Forty-five clonotypes were identified by RQ-PCR and 49 by NGS. Clonotypes identified by both tools were identical or >97% homologous in 96% of cases. Both tools were able to routinely reach a sensitivity level of 1 × E-05. A good correlation of MRD results was observed (R=0.791, P<0.001), with excellent concordance in 79.6% of cases. Few discordant cases were observed across all disease subtypes. NGS showed at least the same level of sensitivity as allele-specific oligonucleotides-PCR, without the need for patient-specific reagents. We conclude that NGS is an effective tool for MRD monitoring in ALL, MCL and MM. Prospective comparative analysis of unselected cases is required to validate the clinical impact of NGS-based MRD assessment.

Next-generation sequencing and real-time quantitative PCR for minimal residual disease detection in B-cell disorders

In this study, we compared immunoglobulin heavy-chain-gene-based minimal residual disease (MRD) detection by real-time quantitative PCR (RQ-PCR) and next-generation sequencing (NGS) to assess whether NGS could overcome some limitations of RQ-PCR and further increase sensitivity, specificity, accuracy and reproducibility. In total, 378 samples from 55 patients with acute lymphoblastic leukemia (ALL), mantle cell lymphoma (MCL) or multiple myeloma (MM) were investigated for clonotype identification, clonotype identity and comparability of MRD results. Forty-five clonotypes were identified by RQ-PCR and 49 by NGS. Clonotypes identified by both tools were identical or >97% homologous in 96% of cases. Both tools were able to routinely reach a sensitivity level of 1 × E-05. A good correlation of MRD results was observed (R=0.791, P<0.001), with excellent concordance in 79.6% of cases. Few discordant cases were observed across all disease subtypes. NGS showed at least the same level of sensitivity as allele-specific oligonucleotides-PCR, without the need for patient-specific reagents. We conclude that NGS is an effective tool for MRD monitoring in ALL, MCL and MM. Prospective comparative analysis of unselected cases is required to validate the clinical impact of NGS-based MRD assessment.

EuroFlow standardization of flow cytometer instrument settings and immunophenotyping protocols

The EU-supported EuroFlow Consortium aimed at innovation and standardization of immunophenotyping for diagnosis and classification of hematological malignancies by introducing 8-color flow cytometry with fully standardized laboratory procedures and antibody panels in order to achieve maximally comparable results among different laboratories. This required the selection of optimal combinations of compatible fluorochromes and the design and evaluation of adequate standard operating procedures (SOPs) for instrument setup, fluorescence compensation and sample preparation. Additionally, we developed software tools for the evaluation of individual antibody reagents and antibody panels. Each section describes what has been evaluated experimentally versus adopted based on existing data and experience. Multicentric evaluation demonstrated high levels of reproducibility based on strict implementation of the EuroFlow SOPs and antibody panels. Overall, the 6 years of extensive collaborative experiments and the analysis of hundreds of cell samples of patients and healthy controls in the EuroFlow centers have provided for the first time laboratory protocols and software tools for fully standardized 8-color flow cytometric immunophenotyping of normal and malignant leukocytes in bone marrow and blood; this has yielded highly comparable data sets, which can be integrated in a single database.

Addition of rituximab to fludarabine and cyclophosphamide in patients with chronic lymphocytic leukaemia: a randomised, open-label, phase 3 trial

BACKGROUND

On the basis of promising results that were reported in several phase 2 trials, we investigated whether the addition of the monoclonal antibody rituximab to first-line chemotherapy with fludarabine and cyclophosphamide would improve the outcome of patients with chronic lymphocytic leukaemia.

METHODS

Treatment-naive, physically fit patients (aged 30-81 years) with CD20-positive chronic lymphocytic leukaemia were randomly assigned in a one-to-one ratio to receive six courses of intravenous fludarabine (25 mg/m(2) per day) and cyclophosphamide (250 mg/m(2) per day) for the first 3 days of each 28-day treatment course with or without rituximab (375 mg/m(2) on day 0 of first course, and 500 mg/m(2) on day 1 of second to sixth courses) in 190 centres in 11 countries. Investigators and patients were not masked to the computer-generated treatment assignment. The primary endpoint was progression-free survival (PFS). Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00281918.

FINDINGS

408 patients were assigned to fludarabine, cyclophosphamide, and rituximab (chemoimmunotherapy group) and 409 to fludarabine and cyclophosphamide (chemotherapy group); all patients were analysed. At 3 years after randomisation, 65% of patients in the chemoimmunotherapy group were free of progression compared with 45% in the chemotherapy group (hazard ratio 0·56 [95% CI 0·46-0·69], p<0·0001); 87% were alive versus 83%, respectively (0·67 [0·48-0·92]; p=0·01). Chemoimmunotherapy was more frequently associated with grade 3 and 4 neutropenia (136 [34%] of 404 vs 83 [21%] of 396; p<0·0001) and leucocytopenia (97 [24%] vs 48 [12%]; p<0·0001). Other side-effects, including severe infections, were not increased. There were eight (2%) treatment-related deaths in the chemoimmunotherapy group compared with ten (3%) in the chemotherapy group.

INTERPRETATION

Chemoimmunotherapy with fludarabine, cyclophosphamide, and rituximab improves progression-free survival and overall survival in patients with chronic lymphocytic leukaemia. Moreover, the results suggest that the choice of a specific first-line treatment changes the natural course of chronic lymphocytic leukaemia.

FUNDING

F Hoffmann-La Roche.

Standardized MRD flow and ASO IGH RQ-PCR for MRD quantification in CLL patients after rituximab-containing immunochemotherapy: a comparative analysis

Rituximab-containing regimens are becoming a therapeutic standard in chronic lymphocytic leukemia (CLL), so that a validation of flow cytometric minimal residual disease (MRD) quantification (MRD flow) in the presence of this antibody is necessary. We therefore compared results obtained by real-time quantitative (RQ)-PCR to MRD flow in 530 samples from 69 patients randomized to receive chemotherapy or chemotherapy plus rituximab. Quantitative MRD levels assessed by both techniques were closely correlated irrespective of therapy (r=0.95). The sensitivity and specificity of MRD flow was not influenced by the presence of rituximab. With 58.9% positive and 26.4% negative samples by both techniques, 85.3% of assessments (452/530) were qualitatively concordant between MRD flow and RQ-PCR. Discordant samples were typically negative by MRD flow and simultaneously positive close to the detection limit of the PCR assays, indicating a higher sensitivity of PCR for very low MRD levels. However, 93.8% of all samples were concordantly classified by both methods using a threshold of 10(-4) to determine MRD positivity. MRD flow and PCR are equally effective for MRD quantification in rituximab-treated CLL patients within a sensitivity range of up to 10(-4), whereas PCR is more sensitive for detecting MRD below that level.

A comprehensive genetic and histopathologic analysis identifies two subgroups of B-cell malignancies carrying a t(14;19)(q32;q13) or variant BCL3-translocation

The biologic and pathologic features of B-cell malignancies bearing a translocation t(14;19)(q32;q13) leading to a fusion of IGH and BCL3 are still poorly described. Herein we report the results of a comprehensive cytogenetic, fluorescence in situ hybridization (FISH), molecular and histopathological survey of a large series of B-cell malignancies with t(14;19) or variant translocations. A total of 56 B-cell malignancies with a FISH-proven BCL3 involvement were identified with the translocation partners being IGH (n=51), IGL (n=2), IGK (n=2) and a non-IG locus (n=1). Hierarchical clustering of chromosomal changes associated with the t(14;19) indicated the presence of two different groups of IG/BCL3-positive lymphatic neoplasias. The first group included 26 B-cell malignancies of various histologic subtypes containing a relatively high number of chromosomal changes and mostly mutated IgVH genes. This cluster displayed three cytogenetic branches, one with rearrangements in 7q, another with deletions in 17p and a third one with rearrangements in 1q and deletions in 6q and 13q. The second group included 19 cases, mostly diagnosed as B-cell chronic lymphocytic leukemia (B-CLL), and characterized by few additional chromosomal changes (e.g. trisomy 12) and unmutated IgVH genes. In conclusion, our study indicates that BCL3 translocations are not restricted to B-CLL but present in a heterogeneous group of B-cell malignancies.

International standardized approach for flow cytometric residual disease monitoring in chronic lymphocytic leukaemia

The eradication of minimal residual disease (MRD) in chronic lymphocytic leukaemia (CLL) predicts for improved outcome. However, the wide variety of MRD techniques makes it difficult to interpret and compare different clinical trials. Our aim was to develop a standardized flow cytometric CLL-MRD assay and compare it to real-time quantitative allele-specific oligonucleotide (RQ-ASO) Immunoglobulin heavy chain gene (IgH) polymerase chain reaction (PCR). Analysis of 728 paired blood and marrow samples demonstrated high concordance (87%) for patients off-therapy. Blood analysis was equally or more sensitive than marrow in 92% of samples but marrow analysis was necessary to detect MRD within 3 months of alemtuzumab therapy. Assessment of 50 CLL-specific antibody combinations identified three (CD5/CD19 with CD20/CD38, CD81/CD22 and CD79b/CD43) with low inter-laboratory variation and false-detection rates. Experienced operators demonstrated an accuracy of 95.7% (specificity 98.8%, sensitivity 91.1%) in 141 samples with 0.01-0.1% CLL. There was close correlation and 95% concordance with RQ-ASO IgH-PCR for detection of CLL above 0.01%. The proposed flow cytometry approach is applicable to all sample types and therapeutic regimes, and sufficiently rapid and sensitive to guide therapy to an MRD-negativity in real time. These techniques may be used as a tool for assessing response and comparing the efficacy of different therapeutic approaches.

Reduced expression of C1q-mRNA in monocytes from patients with systemic lupus erythematosus

Inherited C1q deficiency is associated strongly with the development of systemic lupus erythematosus (SLE). The aim of our study was to evaluate the ability of monocytes from SLE patients without inherited C1q deficiency to up-regulate C1q-mRNA upon stimulation. Furthermore, we wanted to elucidate the physiological stimulus for up-regulation of C1q-mRNA. Peripheral blood mononuclear cell (PBMC)-derived monocytes from 10 SLE patients, 10 patients with rheumatoid arthritis (RA) and 10 healthy controls (HC) were stimulated with dexamethasone (DXM), interferon-gamma or both. Additionally, purified monocytes from HC were stimulated with interleukin (IL)-10. C1q-mRNA expression was measured by quantitative reverse transcription-polymerase chain reaction (RT-PCR). C1q protein was detected using the standard alkaline phosphatase/anti-alkaline phosphatase (APAAP) technique. SLE monocytes were significantly less able to up-regulate C1q-mRNA when compared to RA or HC. IL-10 was identified as an important stimulus for C1q synthesis. In SLE patients there is a significant functional impairment of monocytes to synthesize C1q upon stimulation. As C1q is linked to the process of recognition and removal of apoptotic cells, this relative C1q deficiency is likely to contribute to the reduced phagocytosis of apoptotic material observed in SLE and thereby might be a central pathogenetic factor.

Consolidation with alemtuzumab in patients with chronic lymphocytic leukemia (CLL) in first remission--experience on safety and efficacy within a randomized multicenter phase III trial of the German CLL Study Group (GCLLSG)

Patients with CLL responding to initial chemotherapy with fludarabine alone (F) or in combination with cyclophosphamide (FC) were randomized for treatment with alemtuzumab (30 mg i.v. TIW, 12 weeks) or observation. Of 21 evaluable patients, 11 were randomized to alemtuzumab before the study was stopped due to severe infections in seven of 11 patients. These infections (one life-threatening pulmonary aspergillosis IV; four CMV reactivations III requiring i.v. ganciclovir; one pulmonary tuberculosis III; one herpes zoster III) were successfully treated and not associated with cumulative dose of alemtuzumab. In the observation arm, one herpes zoster infection II and one sinusitis I were documented. At 6 months after randomization, two patients in the alemtuzumab arm converted to CR, while three patients in the observation arm progressed. After alemtuzumab treatment, five of six patients achieved a molecular remission in peripheral blood while all patients in the observation arm remained MRD-positive (P=0.048). At 21.4 months median follow-up, patients receiving alemtuzumab showed a significant longer progression-free survival (no progression vs mean 24.7 months; P=0.036). In conclusion, a consolidation therapy with alemtuzumab is able to achieve molecular remissions and longer survival in CLL, but a safe treatment regimen needs to be determined.

Rearranged T-cell receptor beta genes represent powerful targets for quantification of minimal residual disease in childhood and adult T-cell acute lymphoblastic leukemia

Current MRD studies in T-cell acute lymphoblastic leukemia (T-ALL) mainly use T-cell receptor gamma, delta and SIL-TAL1 gene rearrangements as MRD-PCR targets. However, low frequency or limited diversity of these markers restricts the number of evaluable patients, particularly because two markers are recommended for MRD monitoring. Hence, we developed a new strategy implementing the TCR beta (TCRB) locus for MRD quantification. The frequency and characteristics of complete and incomplete TCRB rearrangements were investigated in 53 childhood and 100 adult T-ALL patients using the BIOMED-2 multiplex PCR assay. Clonal rearrangements were identified in 92% both childhood and adult T-ALL (Vbeta-Dbeta-Jbeta rearrangements in 80%, Dbeta-Jbeta rearrangements in 53%). Comparative sequence analysis of 203 TCRB recombinations revealed preferential usage of the 'end-stage' segment Jbeta2.7 in childhood T-ALL (27%), whereas Jbeta2.3 was most frequently involved in adult T-ALL (24%). In complete rearrangements, three downstream Vbeta segments (19-1/20-1/21-1) were preferentially used. Subsequently, a TCRB real-time quantitative PCR assay to quantify MRD with 13 germline Jbeta primer/probe combinations and allele-specific oligonucleotides was developed and applied to 60 clonal TCRB rearrangements. The assay allowed the detection of one leukemic cell within at least 10(4) polyclonal cells in 93% of cases and will be of high value for future MRD studies.