Citations

AbstractHealth‐related quality of life (HRQoL) in patients with chronic lymphocytic leukemia (CLL) is important in guiding treatment decisions. However, the impact of CLL treatment initiation on HRQoL is unclear. We assessed HRQoL using the FACT‐Leu and EQ‐5D‐3L questionnaires in the Connect® CLL Registry, a large, US‐based, multicenter, prospective observational study of CLL patients enrolled between 2010 and 2014, prior to the introduction of novel therapies. Among 889 patients initiating first‐line therapy with chemoimmunotherapy or rituximab monotherapy, questionnaire completion rates were 95.7% and 95.8% at enrollment, and 70.8% and 69.4% at 12 months, for FACT‐Leu Total and EQ‐5D‐3L, respectively. For 849 patients completing all five FACT‐Leu components, average total scores were 135.7 at enrollment and 141.6 at 12 months. Among 526 patients with FACT‐Leu Total scores at enrollment and 12 months, clinically meaningful (≥11‐point) improvements or reductions were observed in 179 (34.0%) and 88 (16.7%) patients, respectively. Mean EQ‐5D‐3L index scores were 0.87 at enrollment and 12 months. Among 513 patients completing EQ‐5D‐3L at enrollment and 12 months, clinically meaningful (≥0.06‐point) improvements or reductions were observed in 125 (24.4%) and 116 (22.6%) patients, respectively. In the Connect® CLL Registry, HRQoL remained stable or slightly improved after 12 months of follow‐up.

e20009 Background: Although treating B-Chronic Lymphocytic Leukemia (CLL) with small molecule inhibitors has shown promise, a lasting cure for this disease has yet to be found. Further treatments directed at key molecular targets in the CLL B cell need development for patients with adverse prognostic factors, and relapsed/refractory patients. We evaluated the impact of two novel drugs with non-overlapping mechanisms of action on CLL B cells: Voruciclib, a cyclin dependent kinase (CDK) inhibitor targeting CDKs 9, 6, 4, 1 and Venetoclax a BCL-2 inhibitor. To mimic the protective effect of the CLL micro-environment these experiments were done with CLL cells cocultured in the presence of bone marrow mesenchymal stromal cells (BMSC). Methods: Voruciclib, (MEI Pharma) and Venetoclax were tested for killing activity alone and in combination against CLL cells cocultured with healthy human bone marrow MSC. CLL B cells were from untreated patients stratified on risk of disease progression. Low risk had mutated and high risk patients had unmutated IVGH genetic status. CLL cells were cultured on BMSC’s with a series of escalating doses of individual drugs and drug combinations at fixed molar ratios then Annexin/PI stained for viability testing by flow cytometry. Killing curves generated for each drug/combination were analyzed by the combination index (C.I.) approach of Chou and Talalay with Calcusyn, characterizing interactions as synergistic, additive or inhibitory. C.I. value hierarchy classes synergy as moderate (0.7-0.9), synergistic (0.3-0.7), strong (0.1-0.3) and very strong (below 0.1). Results: CLL cells with unmutated IGVH status were more sensitive to Voruciclib than mutated IGVH both with and without BMSC’s. The combination Voruciclib +Venetoclax showed synergism for all patients regardless of risk; half strongly to very strongly (Table). Similar synergistic effects were seen with relapsed/refractory patients. Conclusions: Based on these preclinical data, Voruciclib + Venetoclax is a very promising combination to improve treatment of CLL patients. We speculate that CDK9 inhibition, which regulates transcription of Mcl-1, with Bcl-2 inhibition results in potent apoptosis induction in CLL B cells. [Table: see text]

8026 Background: CLL progression and CLL-related complications (infections and second malignancies) were the leading cause of death (COD) in a prospective cohort of CLL patients (Strati, BJH 2017). The CLL-IPI integrates major clinical and molecular prognostic factors and stratifies patients into 4 risk groups with distinct prognosis. It is unknown if COD differs according to CLL-IPI risk group in patients with newly diagnosed CLL. Methods: Patients diagnosed with CLL between 1/2000-12/2019 and seen within 1 year of diagnosis were identified from the Mayo Clinic CLL database. Cumulative incidences of cause-specific death were analyzed using Gray’s test, with deaths from different causes treated as competing events and deaths from unknown causes excluded. Results: 1276 patients were included in this study. The median age at diagnosis was 63 years (range 24-92), and 880 (69%) were male. Based on CLL-IPI score, 449 (35%) had low risk disease, 443 (35%) had intermediate risk disease, and 384 (30%) had high/very high risk disease. Median follow-up time for the study was 6 years; 286 deaths occurred. The COD was CLL progression in 99 (35%), infection in 16 (6%), second malignancy in 47 (16%), CLL-unrelated in 59 (21%), and unknown in 65 (23%) patients. The rates of death due to CLL progression were higher (17.3% at 5 years; 30.3% at 10 years) than the rates due to CLL-related complications (5.7% at 5 years; 12.9% at 10 years) or due to CLL-unrelated causes (8.6% at 5 years; 16.9% at 10 years) in the CLL-IPI high/very high risk group, but not the CLL-IPI low or intermediate risk group (Table). A higher CLL-IPI risk group was associated with a higher rate of death due to CLL progression ( P < 0.001), as well as a higher rate of death due to CLL-related complications ( P = 0.013), and CLL-unrelated causes ( P < 0.001). Conclusions: Causes of death in newly diagnosed CLL patients differ according to their CLL-IPI risk group. In patients with high/very high risk CLL, improving CLL disease control with novel agents seems justified. In patients with low/intermediate risk CLL, there should be increased efforts to reverse immune dysfunction to reduce infections and second malignancies. [Table: see text]

Abstract One of the major mechanisms by which the immune system combats unpredictable foreign pathogens is to produce highly specific and effective antibodies by B cells. Somatic hypermutation (SHM) and class switch recombination (CSR) are two key events required for the production of highly specific and effective antibodies. Both SHM and CSR occur in the germinal center (GC), and are mediated by a common enzyme, activation-induced cytidine deaminase (AID) that specifically mutates the variable regions (IgV) and switch regions (IgS) of immunoglobulin genes by converting cytidines to uridines. It has been shown that in addition to the central deaminase domain, an N-terminal domain is essential to target SHM to the IgV region whereas a C-terminal domain is necessary for Ig CSR. Given its mutagenic nature, it has been postulated that AID may play causative roles in B cell lymphomagenesis. Consistent with this notion, AID is expressed and alternatively spliced in B cell tumors such as B-cell chronic lymphocytic leukemia (B-CLL) and non-Hodgkin’s lymphoma (NHL). However, it remains unclear whether post-GC malignant B cell AID expression and alternative splicing is a consequence of B cell transformation and/or is required to maintain growth and/or malignant B-cell survival, or whether post-GC AID expression and alternative splicing may also occur in normal B cells. To discriminate between these two possibilities, we analyzed AID expression and splicing in normal human B cells. Our data demonstrate that human tonsillar B cells prominently express the full-length AID transcript, and of interest, also express all four alternative transcripts that have been previously described in B-CLL and NHL B cells. To determine if all normal B cells express all of the AID transcripts, we performed limiting dilution of tonsillar B cells and used RT-PCR to detect AID expression. We surprisingly discovered that AID splicing variants are singly expressed by individual B-cells. To address the functional significance of each splicing variant, we considered the possibility that B cells expressing the alternative transcripts may be by-products of the normal GC reaction and are eliminated prior to GC exit. Conversely those B cells may contribute to the memory B cell pool if those AID variants are functional. Therefore, we examined AID expression and splicing in memory B cells using a more sensitive nested PCR approach. Our data show that AID is indeed expressed in peripheral blood memory cells but not in naïve B cells. Moreover, at least one splicing variant was expressed at levels comparable to the full-length AID transcript. Using limiting dilution, we again found that the full-length and alternatively spliced AID transcripts are singly expressed by individual memory B cells. Our results suggest that AID expression beyond the GC stage may play a role in sustaining selection pressure. Since the AID domains specific for SHM and CSR are encoded by different exons, we hypothesize that those variants may function differentially in SHM and CSR and this concept is under current study. Since each B cell only expressed one AID transcript, our data strongly suggest that SHM and CSR are coordinated in a stepwise process by generation of alternative AID splice variants that exhibit selective activity thereby allowing fine-tuning of humoral immunity.

Abstract CLL/SLL and other CLPD are associated with an increased risk of autoimmune hemolytic anemia (AIHA), immune thrombocytopenic purpura (ITP), pure red blood cell aplasia (PRBCA), and autoimmune agranulocytosis (AIAG). CLL patients with AIHA and ITP have advanced stage disease according to the Rai and Binet clinical classifications, implying a poor prognosis. However, previous community based studies suggest that patients with CLL and immune cytopenias could have a similar prognosis to other patients with CLL. To further define the prognostic significance of autoimmune cytopenia, we studied a cohort of patients seen at the Mayo Clinic Rochester (MCR). Methods The MCR Division of Hematology Chronic Lymphoproliferative Disease Database was used to identify patients with CLPD and autoimmune complications (AID) over a 10 year period (1 January 1995 to 30 December 2004). The clinical records of all patients with AID were thoroughly reviewed and collated with additional biological data. Results Forty-one (6%) of 665 patients with CLPD had AID. Of the patients with CLPD and AID, 21 (51%) had AIHA, 19 (46%) had ITP, 8 (20%) had PRBCA and 2 (5%) had AIAG. 17% of patients had 2 or more AID diagnoses. In 4 patients (10%) the diagnosis of AID preceded the diagnosis of CLPD, and in 7 patients (17%) the diagnoses were made concurrently. In the 32 patients with CLL, the median lymphocyte count at diagnosis was 24.8 x 109/L (5.18 – 121.8). Of 27 CLL patients who had interphase FISH analysis performed, 12 (44%) had abnormalities associated with poor prognosis CLL (17p13–11% 11q22–22%, 12+ 11%), and 15 (56%) had results associated with a more favorable prognosis (no detectable abnormalities or 13q14 deletion as the sole abnormality). CD38 was positive (&gt; 30% of cells) in 38% of 21 tested patients. 39 patients required treatment for their AID. Treatment included corticosteroids (90%), splenectomy (31%), chemotherapy (31%), and rituximab (46%). Response rates following the first treatment for AID were: AIHA 53% complete response (CR) and 26% partial response (PR); ITP 56% CR and 22% PR; PRBCA 38% CR and 38% PR; AIAG no responses. Of the 41 patients seen over the 10 year period, there were 4 deaths (2 from CLPD). Conclusions This study of a large cohort of community and referred patients showed a prevalence of AID similar to that reported in community based studies. We found an equivalent prevalence of AIHA and ITP as well as a substantial number of patients with 2 or more AID complications. This could be due in part to detailed workup of all cytopenias. In addition, 27% of patients did not have a prior diagnosis of a B cell malignancy when presenting with AID. The measured biological risk factors (FISH anomalies and CD38) suggest that CLL patients with AID do not have a higher percentage of high risk CLL. The majority of patients responded well to AID treatment. Mortality appears to be lower than CLL patients with non-autoimmune cytopenia. These preliminary data suggest that AID is a common and often presenting complication of CLL/SLL and other CLPD. Early diagnosis and management of AID could lead to improved outcomes.

Abstract The prognostic power of immunoglobulin (Ig) somatic mutation status in B cell chronic lymphocytic leukemia (B-CLL) is widely appreciated and has served as the rationale to systematically determine this molecular feature in B-CLL patients. Consistent with other reports, our study of Ig mutation status in a large cohort of B-CLL patients (n=599) found the most commonly used Ig heavy chain variable (VH) region gene was VH 1–69. The VH1–69 gene is of particular interest as there are numerous reports demonstrating that VH1–69 expressing B-CLL cells predominantly express the 51p1-like allele in an unmutated (UM) form and it is frequently associated with use of the D gene segment, D3-3; the J gene segment, JH6; and a relatively long third, complementarity-determining region (CDR3). Despite molecular definition of a commonly used form of VH1–69 in B-CLL, the clinical significance of CLL B cell usage of this prototypic form of VH1–69 remains to be determined. The goal of this study, therefore, was to perform a molecular and clinical analysis on our cohort of B-CLL patients expressing the VH1–69 gene. Our cohort consisted of 19 females and 55 males, with 89.5% expressing UM Ig VH. The 51p1-like allele was present in 75.7% of patients and the predominant D region used was D3 (64.7%). Patients in our cohort were classified by Rai risk as follows: 20 low (28.2%), 40 intermediate (56.3%), and 11 high (15.5%). For those patients with Rai stage available, analysis of specific D and J regions resulted in 16 D3-3/JH6 (26.7%); 14 D3-3/non-JH6 (23.3%); 16 non-D3-3/JH6 (26.7%); and 14 non-D3-3/non-JH6 (23.3%). Despite observing an overwhelming majority of leukemic cells with UM Ig VH, and the known relationship between mutation status and disease progression, it is interesting that our cohort included almost 30% with a low Rai risk. Of note, Ig VH mutation status did not segregate with Rai risk group or VH1–69 allele use (although few patients overall were mutated). However, an UM Ig VH status was associated with a CDR3 length &gt;20 (p = 0.001) and with use of the JH6 segment (p = 0.003). When mutation status was analyzed in concert with specific use of the D3-3 allele, no relationship emerged; however, when this D region allele was analyzed for JH6 vs non-JH6 usage, combination of the D3-3 allele with JH6 was significantly associated with an UM Ig VH status (p = 0.004). Moreover, when J and D segment usage was analyzed in concert with Rai stage group, a significant (p = 0.019) relationship emerged between paired use of D3-3 and a JH6 segment and advanced (intermediate/high) Rai stage. Strikingly, only 1 of 18 VH1–69 patients with low Rai risk for whom D and J data were available expressed the specific combination of D3-3 and JH6. Although analysis of a larger cohort is clearly required to more formally and fully evaluate these relationships, to our knowledge, this is the first suggestion that D and J usage in VH1-69 expressing B-CLL patients correlates with advanced stages of disease. Because Ig VH usage is not believed to change over the course of disease, it is tempting to speculate that VH1–69 B-CLL patients that do not express the prototypic VH1–69 receptor may have a more favorable disease course. In summary, these data add further support to the notion that there is selection for specific Ig receptors in B-CLL and that the antigenic specificity of certain receptors may be associated with risk of progression.

Abstract Background: Results of conventional cytogenetic studies on specimens processed without B-cell mitogens are usually normal in B-CLL: this observation is often attributed to lack of mitotic B-CLL cells. Using metaphase FISH with D13S319, we now have evidence that these apparently normal mitotic B-CLL cells often exhibit submicroscopic interstitial deletions in 13q14. This observation indicates B-CLL cells do divide in unstimulated cultures, but the abnormal metaphases are not detected because the abnormalities are submicroscopic and represent a low percentage of proliferating cells. Methods: We studied 12 patients with B-CLL who had normal metaphases by conventional cytogenetics, but abnormal interphase nuclei by FISH with D13S319. This cohort consisted of 7 females and 5 males who ranged in age from 50 to 87 years. Clinical information was available for 11 patients: Rai stages were 0, I, II, III, or IV for 6, 1, 1, 2, and 1 patients, respectively; 8 patients received treatment and 3 have died. Conventional cytogenetic studies and metaphase FISH were done on bone marrow specimens that were processed by standard 24 and 48-hour unstimulated cultures with Chang Medium BMC. Interphase FISH studies were done on blood or bone marrow (collected within 3 days of specimens for conventional cytogenetic studies) using probes to detect anomalies of chromosomes 6, 11, 12, 13, 14 and 17. For each patient, metaphase FISH was done with commercial probes from Vysis Inc., Downers Grove, IL for D13S319/13q34 using leftover fixed cells from conventional cytogenetics studies. Results: Metaphase FISH results were normal for 3 bone marrow specimens: the remaining 9 specimens had 1.9 to 13.8% metaphases with interstitial deletions of 13q14. One patient had a cytogenetically visible chromosome 13 deletion in 2.2% of metaphases. In the remaining 8 specimens, the size of the abnormal 13 was similar to the normal 13 homolog and other acrocentric chromosomes. By comparison, interphase FISH revealed 13 to 93% nuclei with 13q-x1 or 13q-x2. Seven patients had additonal anomalies in their interphase nuclei; 3 had 11q-, 2 had 17p-, 1 had +12 and 1 had +IGH. Conclusions: This investigation indicates that metaphase FISH detects submicroscopic deletions in chromosome 13 as well as infrequent mitotic B-CLL cells in patients who have normal conventional cytogenetic results. Therefore, metaphase FISH is a novel and useful technique to detect abnormal mitotic cells in B-CLL in cultures without special B-cell mitogens. The prognostic significance of abnormal metaphase FISH results is still under investigation. We speculate that this method will allow for identification of more aggressive proliferating disease even in so-called “favorable” prognostic groups based on interphase FISH results.

Abstract Background: Non-Hodgkin lymphoma (NHL) is a malignancy of lymphocytes, and may develop in the setting of inflammation and immune dysfunction. Small scale evaluations have suggested that common genetic variation in candidate genes related to immune function may predispose to the development of NHL. Here we report a comprehensive analysis of variants within genes associated with immunity and inflammation and risk of NHL. Methods: We used ParAllele’s Immune and Inflammation panel of 9,412 single nucleotide polymorphisms (SNPs) from 1,450 immune/inflammation genes as a discovery tool in a clinic-based study of 458 NHL cases and 484 frequency matched controls seen at the Mayo Clinic from 2002–2005. The panel included 537 coding non-synonymous SNPs (nsSNPs), with the remainder of the SNPs selected as tags from HapMap (tagSNPs) to provide coverage of the candidate genes (r2 = 0.8 and minor allele frequency &gt;0.05). To assess the association of individual SNPs with risk of NHL, we calculated Odds Ratios (ORs) and 95% confidence intervals, adjusted for age and gender. The most prevalent homozygous genotype was used as the reference group, and each polymorphism was modeled individually as having a log-additive effect in the regression model. Associations between haplotypes from each gene and the risk of NHL were calculated using a score test implemented in HAPLO.SCORE. We also modeled the main effects for all independent (r2 &lt;0.25) SNPs from a gene in a multivariate logistic regression model. Results: The mean age at diagnosis was 60 years for cases and 58% were male; in controls the mean age at enrollment was 61.6 years and 55% were male. In the gene analyses, the strongest findings (p≤0.001 from multiple SNP logistic regression or haplotype analysis) were for cAMP responsive element binding protein 1 (CREB1; p=0.0004), fibrinogen alpha chain (FGA; p=0.0006), TNF receptor-associated factor 1 (TRAF1; p=0.001), dual specificity phosphatase 2 (DUSP2; p=0.001), and fibrinogen gamma chain (FGG; p=0.001). In the nsSNP analyses, the strongest findings (p≤0.01) were for integrin β3 (ITGB3) L59P (OR=0.64, 0.50–0.83), Beta-1,3-N-acetylglucosaminyltransferase 3 (B3GNT3) H328R (OR=0.72, 0.57–0.91), transporter 2, ATP-binding cassette (TAP2) T665A (OR=1.32, 1.07–1.63), HLA-B associated transcript 2 (BAT2) V1895L (OR=0.60, 0.42–0.85), and complement component 7 (C7) T587P (OR=1.39, 1.07–1.80). Conclusions. Our results suggest that genetic variability in genes associated with antigen processing (CREB1 and TAP2), lymphocyte trafficking (B3GNT3), immune activation (TRAF1, BAT2), complement and coagulation pathways (FGA, FGG, ITGB3, C7), and MAPK signaling (DUSP2) may be important in the etiology of NHL, and should be pursued in replication studies.

Abstract The monoclonal antibodies (MoAb) alemtuzumab and rituximab have proven efficacy in the treatment of CLL. In addition, alemtuzumab is effective in patients with defective p53 function responding poorly to purine analogue therapy. The action of both MoAb is not completely understood. Proposed mechanisms include complement dependent cytotoxicity (CDC), antibody dependent cellular cytotoxicity (ADCC), and direct induction of apoptosis of CLL B cells. We have done correlative studies on CLL B cells from patients enrolled in a trial of alemtuzumab and rituximab in “high risk” early stage previously untreated CLL to determine: 1. Role of apoptosis induction and CDC in each MoAb and 2. If the addition of rituximab to alemtuzumab increases their in vitro cytotoxicity. Patients and Methods: Patients with early stage, previously untreated, high risk CLL are treated with subcutaneous alemtuzumab (dose escalation over 3 days then 30 mg Mon-Wed-Fri for 4 weeks) and rituximab (375 mg/m2/dose weekly from day 8 x 4 doses). High risk disease was defined as one or more of the following features of the CLL B cell clone: (1) 17p13−; (2) 11q22−; (3) unmutated IgVH (&lt; 2%) and either CD38+ or ZAP-70+. Blood B lymphocytes collected prior to the start of therapy were tested for response to MoAb in vitro. Cells were cultured at 2 x 106/ml in AIM-V medium using standard conditions. Alemtuzumab and rituximab were used at 20 μg/ml and complement as 10% of 40 CH50 units/ml human serum. The impact of the MoAb was measured by counting viable cells (trypan blue negative) and measuring early apoptosis (annexin V) and cell death (cell membrane permeability to propidium iodide) using flow cytometry at 1 hour, and then daily for 3 days. Results: Treatment caused rapid resolution of lymphocytosis in all 7 patients and 3 patients were negative for circulating CLL cells using a highly sensitive 3 color flow cytometry (CD5+/CD19+/CD79b-) after therapy. All patients had a clinical response (2 CR, 5 PR). Alemtuzumab and complement were rapidly cytotoxic to most CLL cells. Mean cell viability was 39% (sd: 8%) after 1 hour of incubation. Cytotoxicity was similar in all samples irrespective of FISH defects, IgVH mutation status, and in vitro resistance to F-ara-A (n = 3). Alemtuzumab was inactive in the absence of complement for all samples. Rituximab alone and together with complement did not induce cytotoxicity or apoptosis. However, the addition of rituximab to alemtuzumab and complement did increase CDC where the number of viable cells was significantly lower at 1, 24, 48, and 72 hours incubation (p = 0.075, 0.047, 0.031, 0.027, respectively, for pairwise comparisons). CLL cells surviving alemtuzumab CDC subsequently had a lower level of apoptosis than control cells, implying a selection for resistant cells. Alemtuzumab CDC on this residual population was not increased at higher concentrations of alemtuzumab or complement. This mechanism of CDC resistance is currently under investigation. Conclusion: These data suggest that alemtuzumab CDC is an important mechanism of action in patients with CLL. However, alemtuzumab CDC kills only about 61% of CLL cells in vitro, and the surviving cells are more resistant to spontaneous apoptosis. This suggests that cells that survive alemtuzimab CDC contribute to disease progression or relapse. We intend to elucidate the mechanism of this resistance using our in vitro model with the hope that treatment strategies can be deployed to remove this residual CLL B cell clone.