ALBERT

Description: Introduction: 30% of Hodgkin Lymphoma (HL) patients are refractory or relapse (RR) after first line therapy. Salvage chemotherapy followed by high-dose chemotherapy and with Autologous Peripheral Blood Stem Cell Transplantation (APBSCT) can cure many patients, but those who are transplanted with active disease detectable by PET-CT have a very poor prognosis. Therefore, the current challenge in HL is to improve the results of the pre-transplant chemotherapy. We and others have demonstrated that the addition of Brentuximab Vedotin (BV) to chemotherapy can produce very good results. Objectives: We conducted a phase II trial to assess response rate with combined Brentuximab vedotin and ESHAP chemotherapy [BRESHAP] as 2nd line therapy for RRHL prior to APBSCT (ClinicalTrials.gov #NCT02243436). Methods: Primary efficacy endpoint was the proportion of complete responses (CR) pre-APBSCT. A prior phase I step was carried out to establish the appropriate dosis. Final treatment consisted of Brentuximab Vedotin (1.8 mg/m2/day IV, D1), Etoposide (40 mg/m2/day IV, D1-4), Solumedrol (250 mg/day IV, D1-4), High dose AraC (2 g/m2 IV, D5) and cisPlatin (25 mg/m2/day IV, D1-4). Results: Patients with relapsed or refractory classical HL (cHL) after one prior line of therapy were eligible. 66 patients were included in the trial. There were 35 females and 31 males, with a median age of 36 years (18-66). At inclusion, 40 patients were considered primary refractory, 16 as early relapses (complete remission -CR- shorter than 1 year) and 10 as late relapses. Currently, all patients have completed the pre-transplant therapy. During that period, there were 22 Severe Adverse Events (SAEs) reported in 15 patients: Fever in 13 occasions (neutropenic in seven, and non-neutropenic in six), hypomagnesemia and gastrointestinal alterations (n=2) and pneumothorax, skin lesions, left ventricular function reduction and pulmonary embolism [PE](n=1). There were 2 deaths: non-neutropenic abdominal sepsis and PE. Grade 3-4 hematologic toxicity presented in 22 cases: neutropenia (n=18), thrombocytopenia (n=12), and anemia (n=5). Grade 3-4 extrahematologic adverse events present in ≥5% of cases were non-neutropenic fever (n=8) and hypomagnesemia (n=3). All patients except three underwent stem cell mobilization after the 1st (n=15), 2nd (n=36) or 3rd (n=12) cycle using subcutaneous G-CSF 5 mcg/Kg/12 h. for 5 days. All patients collected 〉2·10e6/Kg peripheral blood CD34+ cells in all cases (median 5.75, range 2.12-33.4). The number of harvesting procedures was one in 47 patients, two in 13, three in 2 and four in 1. The transplant has been done in 61 patients, with data are available from 47: all engrafted with a median of 9&10 days for neutrophil and platelet recovery, respectively. No major events were registered during transplant period, except for one patient who died at day +110 due to pneumonia. Overall pre-transplant response was 96%, including a 70% and 26% complete and partial remission rates, respectively. Of these forty-seven patients, 37 (80%) were in metabolic CR after transplant and 3 (7%) in PR; six patients were considered as non-responders (13%) and went out of the trial. At a mean follow-up of 11 months, 7 patients have progressed, rendering a projected progression free survival of 87% at one year. Six patients have already died: three due to progression, and the three already mentioned above (PE, abdominal sepsis and pneumonia). With a mean follow-up of 11 months, the projected overall survival was 90% at one year (cause specific, 96%). Conclusions: BRESHAP is a highly effective regimen for remission induction prior to transplant in patients with refractory or relapsed Hodgkin lymphoma. The addition of BV to the conventional chemotherapy did not resulted in a higher toxicity for the pre- and post-transplant periods and it did not hamper the collection of PBSC. Disclosures No relevant conflicts of interest to declare.

Description: Key Points DLBCL patients carrying the HLA-B44 supertype have a worse progression-free and overall survival after R-CHOP-like treatment. The HLA-DRB1*01 allele increases the risk of DLBCL development.

Description: Introduction: Denosumab is a monoclonal antibody targeting Receptor Activator of Nuclear Factor-Kappa B Ligand (RANKL) that has been shown to reduce skeletal related events associated with bone lesions in patients with multiple myeloma and solid tumors. Results from the full primary analysis of 1718 patients with newly diagnosed multiple myeloma in an international double blind, randomized, controlled phase 3 (20090482) study that assessed the efficacy of denosumab (Dmab) vs zoledronic acid (ZA) for preventing SREs met its primary end point of non-inferiority regarding time to first SRE. The analysis of the PFS exploratory endpoint showed a clinically meaningful 10.7 months median PFS benefit (HR, 0.82; 95% CI, 0.68-0.99; descriptive P= 0.036) of Dmab vs ZA. This benefit was most pronounced in patients who were stratified into the "intent to undergo Autologous Stem Cell Transplant (ASCT)" group at randomization. Thus, we present an in-depth analysis of relevant baseline characteristics, treatment regimens and PFS outcome in patients with intent to undergo transplant receiving Dmab and ZA. Methods: Adult patients with newly diagnosed multiple myeloma (NDMM) and stratified as "intent to undergo ASCT" at randomization were included in this analysis. Patients received subcutaneous denosumab (120 mg) plus intravenous placebo or intravenous zoledronic acid (4 mg) plus subcutaneous placebo in 4-week cycles. In this subgroup, the PFS outcome was examined. Baseline characteristics and treatment regimens were compared between treatment arms. Results: 54.1% of the 1718 enrolled patients were stratified into "intent to undergo ASCT" as part of their front-line therapy, and 61.8% of "intent to undergo ASCT" did receive an ASCT. In the "intent to undergo ASCT" group, 19.6% patients had disease progression in the Dmab arm compared to 28.0% in the ZA arm (HR 0.65 (0.49-0.85)) (Figure 1). No imbalance in terms of triplet therapy use between the two study arms (TABLE 1). 55.1% in Dmab vs 52.6% in ZA arm received Triplet Therapies which included Bortezomib, Cyclophosphamide, Dexamethasone (VCD), Bortezomib, Thalidomide, Dexamethasone (VTD), Cyclophosphamide, Thalidomide, Dexamethasone (CTD), or Bortezomib, Lenalidomide, Dexamethasone (VRD). The percentage of triplet therapies used in the "intent to undergo ASCT"patients was higher than in patients with no intent to undergo ASCT. Percentage of patients with ECOG performance status 2 was 19.4% in the Dmab group vs 18.6% in the ZA group. 26.2% of patients in the Dmab arm and 25% in the ZA arm had Multiple Myeloma ISS stage III upon diagnosis. Among intent to transplant patients there was no imbalance in terms of age, performance status, ISS stage, risk status, weight, bone marrow plasma cell % between the ZA and the Dmab arm Conclusion: Results from this post-hoc subgroup analysis suggest a more profound PFS benefit in the "intent to undergo ASCT" patient subgroup. Multiple myeloma treatment received in the intent to undergo transplant subjects was similar between the denosumab and zoledronic acid arms. No significant imbalance in demographics or baseline disease characteristics was observed between the two treatment arms. Disclosures Terpos: Janssen: Honoraria, Other: Travel expenses, Research Funding; Amgen: Honoraria, Research Funding; Takeda: Honoraria, Other: Travel expenses, Research Funding; Medison: Honoraria; Genesis: Honoraria, Other: Travel expenses, Research Funding; Celgene: Honoraria. Shimizu:Medical Biological Laboratory: Consultancy; Takeda: Speakers Bureau; Daiichi: Consultancy; Amgen: Consultancy; Fujimoto: Consultancy. Willenbacher:Abbvie: Consultancy, Honoraria; Sandoz: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; oncotyrol: Employment, Research Funding; Gilead Science: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; European Commission: Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Tirol Program: Research Funding; Fujimoto: Consultancy, Honoraria; Myelom- und Lymphomselbsthilfe Österreich: Consultancy, Honoraria; Sanofi: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; IQVIA: Membership on an entity's Board of Directors or advisory committees. Glennane:amgen: Employment, Equity Ownership. Dai:Amgen: Employment, Equity Ownership. Pasteiner:Amgen: Employment, Equity Ownership. Raje:Amgen Inc.: Consultancy; Bristol-Myers Squibb: Consultancy; Celgene Corporation: Consultancy; Takeda: Consultancy; Janssen: Consultancy; Merck: Consultancy.

Description: In MM patients relapsing after MRD-negativity, the disease could reemerge from immature cells or from undetectable MRD. However, it remains unknown if immature cells have the same genetic background as MM plasma cells (PCs), as well as the amount of MRD that persists below the limit of detection (LOD) of next-generation techniques. To obtain further insight, we compared the biological landscape of MM PCs at diagnosis to that of CD34 progenitors, B cells and normal PCs isolated from patients with negative MRD by next-generation flow (NGF) after treatment. We performed whole-exome sequencing (WES, mean depth: 90x) with the 10XGenomics Exome Solution for low DNA-input as well as deep NGS of B-cell receptor immunoglobulin (BcR IG) gene rearrangements (mean, 69,975 sequences), in a total of 68 cell-samples isolated from the bone marrow (BM) of 7 MM patients with MRD-negativity by EuroFlow NGF after induction with VRD and auto-transplant (GEM2012MENOS65 trial). Patients with negative MRD were intentionally selected to avoid contamination with MM PCs during sorting of CD34 progenitors, B-cell precursors, mature B cells and normal PCs after induction and transplant. We investigated in these populations the presence of somatic mutations and clonotypic BcR Ig rearrangements detectable in MM PCs sorted at diagnosis, using peripheral blood T cells as germline control. We also performed WES in matched diagnostic MM PCs and MRD cells persisting after VRD induction in 14 cases as control. In another 6 patients with untreated MM, we performed single-cell RNA and BcR IG sequencing (scRNA/BcRIGseq) of total BM B cells and PCs (n=16,380) to investigate before treatment, if the clonotypic BcR IG sequence of MM PCs was detectable in other B cell stages defined by their molecular phenotype. We used multidimensional flow cytometry (MFC) to investigate the frequency of B cell clonality in BM samples from a larger series of 195 newly-diagnosed MM patients, prospectively enrolled in the GEM-CLARIDEX trial. Somatic mutations present in diagnostic MM PCs were detectable in the lymphopoiesis of 5/7 patients achieving MRD-negativity after treatment. In one case, out of 55 mutations present in diagnostic MM PCs, a single mutation in PCSK1N (VAF: 0.30) was detectable in normal PCs. In the other four patients, a total of 85 mutations were present in MM PCs and up to 10 (median VAF, 0.16) were found all the way from CD34 progenitors into B-cell precursors, mature B cells and normal PCs, but not in T cells. Of note, most mutations were reproducibly detected in each cell type after induction and after transplant. All somatic mutations shared by MM PCs and normal cells were non-recurrent, and genes recurrently mutated in MM (eg. ACTG1, ATM, DIS3, FAM46C, KRAS, LTB, MAX, TRAF3) were found in MM PCs but never in normal cells. Copy number alterations (CNA) were found only in MM PCs. By contrast, up to 513/827 (62%) mutations and 48/67 (72%) CNA were detectable in matched diagnostic MM PCs and persistent MRD cells, indicating that the few somatic variants present in normal cells were unlikely related to contaminating MRD below NGF's LOD. Accordingly, MM clonotypic BcR IG rearrangements were detectable in normal PCs (4/7patients) and in immature B cells (5/7 patients) but at much lower frequencies (mean of 0.02% in both). Of note, 9 additional clonotypes (mean 8.4%) were found in MM PCs of 5/7 patients (range, 1-3). scRNR/BcRIGseq unveiled that clonotypic cells were confined mostly but not entirely within PC clusters, and that in 1 patient another clonotype was detectable in mature B cells. Accordingly, using MFC we found in a larger series that 25/195 (13%) of newly-diagnosed MM patients display B-cell clonality (median of 0.7% BM clonal B cells, range 0.02%-6.3%). In conclusion, we show for the first time that MM patients bear somatic mutations in CD34 progenitors that specifically differentiate into the B cell lineage, likely before the disease onset. Because diagnostic, MRD (and relapse) MM PCs display great genetic similarity, these results suggest that undetectable MRD

Description: Multiple myeloma (MM) pathogenesis has been explained for many years by the cancer biology dogma introduced by Peter Nowell: first, a single plasma cell would be immortalized by an error in the immunoglobulin genes rearrangement process; then, a progressive stepwise acquisition of somatic cell mutations would induce a sequential selection and domination by the fittest clone. In line with this idea of “myeloma stability”, SNP arrays studies in diagnostic-relapse paired samples have revealed the presence of common clonal characteristics. Biologically, the M-protein remains usually constant across MM evolution and further, the variable domain of the rearranged immunoglobulin heavy chain genes (or CDR3 region) has been used as a patient-specific myeloma fingerprint in minimal residual disease (MRD) studies. However, massive genome studies with Next Generation Sequencing (NGS) have challenged this concept, showing a significant intraclonal heterogeneity at diagnosis with the possible presence of several clonal progenitors or tumor-initiating cells. In this study, we have characterized and compared the CDR3 region in 52-paired samples from 26 MM patients aiming: 1) to assess mono-clonality in MM evolution through the analysis of the CDR3 sequence and, 2) to validate ASO RQ-PCR approaches for MRD in MM, based on the constancy and specificity of the CDR3 region. Samples were obtained at diagnosis and progression (19 pairs) or at 2 different timepoints of progressive disease (7 pairs). Median time between sampling was 2 years. M-protein subtype remained stable in all pairs but 1, associated with a light-chain escape phenomenon. All samples proceeded from bone marrow (BM) except for 2 pairs, composed by BM and extramedullary disease (spleen and testes). Two major cytogenetic changes were identified: increased 13q14 deletion (from 7 to 54%) in 1 pair and increased 17p (p53) deletion (from 5 to 87%) in a further one. Treatments administered between sampling included most of the current approaches used in MM (data not shown). Genomic DNA isolation, PCR amplification and sequencing were performed following conventional methods. Germline VH, DH and JH segments were identified by comparison with public databases. CDR3 region was first identified in all samples and then compared between the two samples in the 26 pairs: the sequence of nucleotides was constantly identical in each pair, including those associated with major cytogenetic changes, a light-chain escape, extramedullar vs. BM infiltration and relapsed (and therefore, treatment selected) vs. refractory disease. Therefore, we can first conclude that the main tumor clone in MM retains a specific signature across all stages of disease evolution that allows the identification of samples as evolutionary related. This major clone signature is not modified by clinical or biological changes in the disease nor under different treatment pressures and would thus identify disease relapse and progression. Our results have also a clear impact on the validity of molecular MRD techniques. The high rate of complete responses (up to 50-60%) currently achieved in MM has prompted the use of new techniques for disease assessment. Today, ASO RQ-PCR, based on the use of specific primers and probes complementary of the VDJH rearrangement, continues to be the most sensitive approach. One pitfall of this technique would be the potential instability of PCR targets over time, which would induce false negative results. In B-cell precursor ALL, this is estimated to happen in 30-40% of cases but has not been deeply evaluated in MM yet. With the present study, we can also conclude that the junction region of the VDJH rearrangement in MM constantly identifies the myeloma cells responsible for relapse and therefore can be used as a reliable target for MRD assessment by ASO RQ-PCR and more recently, by NGS methods. If the CDR3 region remains stable, the novel concept of clonal tiding in MM should not be interpreted as a poly- or oligoclonal but subclonal. In MM, tides can be subclonal, but the ocean remains monoclonal. Disclosures No relevant conflicts of interest to declare.

Description: Abstract 1630 The management of recurrent or refractory Hodgkin's lymphoma (HL) remains challenging. Previous published data have suggested that infiltrating normal B lymphocytes in classic HL lesions may contribute to the survival of Hodgkin and Reed-Sternberg cells in vivo. The objective of this prospective, multicenter, phase II trial was to investigate the activity of an anti-CD20 monoclonal antibody, ofatumumab, in combination to a standard platinum-based salvage regimen, ESHAP (O-ESHAP) followed by high-dose chemotherapy and autologous stem cell transplantation (ASCT) for patients with classical HL failing to first line chemotherapy. Forty- five patients (25 M / 21 F, median age 34 years, range 18–66) were enrolled in the study between June 2010 and June 2012. Treatment consisted on three cycles of ESHAP plus ofatumumab 1,000 mg days 1 and 8 on first cycle and day 1 on second and third cycles. At the time of study entry, 66% of patients had III-IV Ann Arbor stage, 16% bulky disease, 18% B symptoms, 40% extranodal HL and 52% ≥3 involved nodal areas. We respect to response to first-line therapy, 46% patients had achieved a completed response (CR) and then relapsed, 6% had a partial remission (PR), whereas the remaining 48% were primary refractory. Eighty-one percent patients have received 3 cycles of O-ESHAP as scheduled, three patients 2, and five 1 cycle (1 patient due to toxicity, 1 patient's decision, 2 HL progression, and 4 treatments ongoing). Grade 3–4 WHO hematological toxicity was observed in 16%, 19%, and 20% after cycles 1, 2, and 3, respectively. Non-hematological toxicity was reported in 32%, 10%, and 20%, respectively. Overall response (OR) rate was 63% (49% CR and 14% PR). Response to O-ESHAP according to prior response to first-line chemotherapy is shown in table 1. Adequate PBSCs collection was achieved in 94% mobilized patients. Twenty-six out of 33 patients have already proceeded to ASCT. Two patients died of neutropenic sepsis after ASCT and HL progression, respectively. Preliminary results of this ongoing trial suggest that addition of ofatumumab to ESHAP is safe and has a promising clinical activity in patients with relapsed/refractory HL candidates to ASCT. Table 1. Response to O-ESHAP according to previous response to first-line treatment Response to first-line chemotherapy Relapsed or partial response (n=17) Refractory (n=16) Response after O-ESHAP OR 16 (94%) 7 (44%) CR 14 (82%) 3 (22%) PR 2 (12%) 4 (22%) Refractory 1 (6%) 9 (56%) Disclosures: No relevant conflicts of interest to declare.

Description: Introduction VDJH usage description in B-cell hematological malignancies has brought new insights into the clonal differentiation and clinical implications for certain pathologies, improving patients' care, although no correlation has been made in MM. We present the largest-to-date VDJH gene repertoire analysis in MM, consisting in biological and clinical data from 413 patients. This database was used to comprehensively investigate the characteristics of VDJH rearrangements: gene segment usage, somatic hypermutation (SHM), CDR3 characterization, and immunoglobulin stereotyped clusters assessment. We also investigated the potential relationship of these molecular features with the outcome. Methods Newly diagnosed MM patients were included in the study. All were managed according to the recommendations of the GEM-PETHEMA Spanish MM group, including the inclusion of most patients in the GEM2000 and GEM2005 schemes. Monoclonal assessment was carried out with FR1 VH-JH amplification, following the BIOMED-2 methods. Moreover, 113 cases were also analyzed by NGS using the LymphoTrack IGH FR1 assay (Invivoscribe Tech, San Diego, CA). VDJH usage and mutational status were analyzed with IMGT-V-Quest. ClustalX2.0 was used to perform clustering analysis with CDR3 regions from our cohort and 1117 additional sequences obtained from IMGT/LIGM-DB corresponding to unique rearrangements from both normal and tumor human B cells. Molecular and clinical data were used to perform survival studies. Results The overall VDJH detection rate was 92.5% (382/413), including 376 patients with only one detectable rearrangement, five with a biallelic rearrangement, and one with a biclonal rearrangement, also detectable by flow cytometry. Thus, 388 rearrangements where detected: 362 were productive, and 26 unproductive. Gene segments were identified in productive rearrangements. VH repertoire in MM reflected its normal counterpart, with IGHV3 being the predominant selected family, followed by IGHV4, IGHV1, IGHV2 and IGHV5. IGHD and IGHJ segment usage showed a skewed distribution, with IGHD2 and IGHD3 families accounting for 55.5% of cases, and IGHJ4 and IGHJ6 accounting for 70.8%. SHM level could be identified in 349/362 productive sequences (mean: 9.16%, SD 3.95) with statistically significant differences between certain IGHV families, namely IGHV2 was less hypermutated than IGHV1 or IGHV4. We could also collect other rearrangement features: nucleotide addition by TdT appeared in 92.5% for N1 and 88.6% for N2, with evidence of exonuclease activity in all cases. CDR3 mean length was 16±4 aminoacids (median 15, range 6-29), with preference for Gly, Ala, Asp, Tyr (~10% each one). The R/S mutation ratio was 2.39 for CDRs versus 1.74 for FWRs, showing the high influence of antigen selection over the former. No stereotyped clusters were found in our cohort. Relationship between these finding and clinical evolution was done through univariate and multivariate analyses. A shorter Progression-Free Survival (PFS) related to well-known clinical factors: presence of plasmacytomas, poor performance status or ISS stages, response to therapy, and poor-risk cytogenetics (p

Description: Key Points C1013G/CXCR4 acts as an activating mutation in WM leading to enhanced tumor growth, and as an inducer of drug resistance. BMS936564/MDX1338, a novel anti-CXCR4 moAb, successfully targets WM cells, either C1013G/CXCR4 mutated or wild-type.

Description: Background The C-X-C chemokine receptor type 4 (CXCR4) plays a crucial role in modulating the biology of B-cell lymphoproliferative disorders. Recent whole genome sequencing studies have identified unique CXCR4 mutations in 29% of the 55 evaluated patients with Waldenstrom Macroglobulinemia (WM). In this study, we sought to better define the mutation status of CXCR4 in B-cell malignancies and define the functional role of this mutation in the progression of WM in vivo. Methods Allele-specific(AS) PCR has been performed on bone marrow (BM)-derived tumor cells of patients with WM (n: 131); IgM monoclonal gammopathy of undetermined significance (MGUS; n: 40); as well as in patients with diffuse large cell lymphomas (DLBCL; n: 75), splenic marginal zone lymphoma (SMZL; n: 14), B-chronic lymphocytic leukemia (B-CLL; n: 37), hairy cell leukemia (HCL; n: 35), multiple myeloma (MM; n: 36), IgA/IgG MGUS (n: 22), lymphoplasmacytic lymphoma without WM criteria (n: 13), and amyloidosis (n: 6). CXCR4-loss and -gain of function studies have been performed on WM cells stably expressing either shRNA-CXCR4, CXCR4-ORF-GFP-tagged or scramble-RFP-tagged (generated via lentivirus-based infection). A mutagenesis kit has been used to generate the C1013GCXCR4 mutant protein (C1013GCXCR4) in WM cells, via lentivirus-based infection. CXCR4-knock-in or C1013GCXCR4-mutated cells and the corresponding controls have been injected i.v. into SCID/Bg mice and tumor dissemination has been evaluated ex vivo by immunohistochemistry IHC (human-CD20; -CXCR4). C1013GCXCR4-mutated cells have been characterized at mRNA levels (U133 plus2) using GSEA. A novel human anti-CXCR4 mAb (BMS-936564/MDX-1338; Bristol Myers Squibb, NY) has been tested in vitro (cell proliferation, MTT, adhesion and migration to primary WM BM mesenchymal stromal cells) and in vivo (10mg/kg i.p. x3-4/week). Tumor growth has been evaluated by IHC ex vivo (hCD20; hCXCR4) and by immunofluorescence. Results We examined the mutational status of C1013GCXCR4 and confirmed the presence of this specific mutation in 28% of the 131 cases evaluated. The mutation was also detected at the stage of IgM-MGUS (20%); while it was present in a minority of patients with DLBCL (1%) and SMZL (7%). Remarkably, it was absent in all MM (n=36) and IgA/IgG MGUS patients (n=22), and it was not detected in healthy subjects (n=32). The functional relevance of the C1013G-CXCR4 variant was next examined in vivo. Mice injected with C1013GCXCR4-cells presented with a significant dissemination of tumor cells, demonstrating involvement of liver, bone marrow, lymph nodes, kidney and lung. IHC showed the presence of CXCR4+ and CD20+ cells in all the tissues examined; and quantification of CXCR4 and CD20 positivity was higher in C1013GCXCR4-cells-, compared to parental(p)-WM cell-injected mice (NIS Elements software, Nikon, Melville, NY; P