Call, Timothy G.

Abstract Abstract 4252 Background: Multiple recent studies have demonstrated the survival benefits of reduced intensity allogeneic stem cell transplant for high risk CLL patients. These transplant series, however, represent highly selected cases where age, co-morbidities and performance status preclude transplant in many patients with CLL. The portion of newly diagnosed CLL patients that are eventually considered for transplant is unknown, as well as the proportion that are referred for transplant evaluation; the proportion that actually receive stem cell transplant, and the reasons for not pursuing transplant in referred patients. We conducted a cohort study of newly diagnosed CLL patients to address this gap in knowledge. Methods: We used the Mayo Clinic database to identify all patients with newly diagnosed CLL seen at Mayo Clinic within 1 year of diagnosis between July of 2003 and May of 2011 (time interval during which reduced intensity allogeneic stem cell transplantation was part of routine care at Mayo Clinic). Electronic medical record and laboratory studies were reviewed to identify all patients referred for stem cell transplant evaluation (either allogeneic transplant for progressive CLL or autologous stem cell transplant for Richter's transformation). Patients referred for transplant were analyzed to determine what proportion completed transplant and, for those who were not transplanted, the reason they were not transplanted (e.g. lack of insurance approval, co-morbidity, lack of a donor, inadequate disease control, death prior to transplant or patient preference). Results: A total of 1250 patients with newly diagnosed CLL between July 2003 and May 2011 who were seen at Mayo Clinic within 1 year of diagnosis were identified. The mean age at diagnosis was 63.6 yrs and 34.2% were women. With respect to disease stage, 48.7% were Rai stage 0, 45.5% Rai stage I/II, and 5.8% Rai stage III/IV. CLL FISH analysis revealed 126 (13.6%) patients who had either del (17p) or del (11q) and 801 (86.4%) patients who had other FISH abnormalities or normal FISH results. After a median follow-up of 41 months, 425 (34%) of patients have received treatment. A total of 54 patients (4.3%) were referred for a transplant evaluation during follow-up. Of these 54 patients, 48 (3.8% overall cohort) were referred for consideration of allogenic transplant for treatment of progressive CLL and 6 (0.5%) were referred for autologous transplant for treatment of Richter's transformation. Baseline characteristics associated with subsequent transplant referral included age at diagnosis (median: 56 yrs) (p < 0.0001, Odds Ratio (OR) for each year older = 0.91, 95% Confidence Interval (CI)=(0.88, 0.95)), Rai stage (III/IV vs. 0) (p = 0.0002, OR = 22.7, 95% CI=(5.1, 102.4)) and FISH (del(11q), del(17p) vs Normal, del(13q) or Trisomy 12) (p < 0.0001, OR = 7.3, 95% CI=(3.3, 16.1)). Gender, Rai stage (I/II vs. 0), and patient residence (local vs. not local) were not significant. Among the 54 patients referred for transplant, 28 (51.9%) completed a transplant. This included 22 (45.8%) patients referred for allogenic transplant and 6 (100%) patients referred for autologous transplant. Among the 26 patients referred who did not undergo transplant, the principal reasons were patient preference (n = 6, 23.1%), patient still being evaluated for transplant as of the study end date (n = 6, 23.1%), alternative therapy chosen (n = 5, 19.2%), inadequate disease control (n = 3, 11.5%), death prior to transplant (n = 3, 11.5%), lack of insurance approval (n = 2, 7.7%), and lack of a donor (n = 1, 3.8%). Conclusion: 4.3% of the newly diagnosed CLL patients in this series were considered for stem cell transplant at some point during follow-up. Young age, high Rai stage and high risk FISH abnormalities are principal reasons for transplant referral. Only 51.9% of those considered for transplant completed transplant. The principal reasons for referral patients not completing transplant who had adequate time to follow were patient preference, alternative therapy, inadequate disease control and death prior to transplant. The remaining 6 patients (23%) are in process of transplant evaluation with longer follow required. These analyses provide first incidence data for CLL transplant referral in a cohort of newly diagnosed patients. Disclosures: Zent: Biothera: Research Funding; Genzyme: Research Funding; Genentech: Research Funding; Novartis: Research Funding; GlaxoSmithKlime: Research Funding. Shanafelt:Celgene: Research Funding; Teva/Cephalon: Research Funding; GlaxoSmith Klein: Research Funding; Genentech: Research Funding; Hospira: Research Funding; Polyphenon E International: Research Funding.

Abstract Introduction T-cell prolymphocytic leukemia (T-PLL) is a rare mature T-Cell malignancy typically associated with aggressive clinical course. Leukemic T-cells demonstrate post-thymic T-cell phenotypes (Tdt-, CD1a-, CD5+, CD2+ and CD7+) and commonly are CD4+/CD8- T-cells, but co-expression of CD4+/CD8+ or CD8+/CD4- have also been observed. Rearrangement of chromosome 14 involving TCL1 locus is the cornerstone for T-PLL diagnosis which leads to overexpression of oncogene TCL1. As a binding partner for TCL1, AKT expression correlates with worse prognosis. Despite advances in identification of novel mutations, therapeutic option is limited with most patients having very short survival. Herein, we performed a detailed analysis of specific T-cell subsets affected in T-PLL and a comprehensive genomic analysis by whole exome sequencing (WES) and RNA sequencing. We also explored the preclinical efficacy of targeting AKT activation by AKT inhibitor MK2206 on leukemic T-cells isolated from T-PLL patients. Methods T-PLL leukemic cells were isolated from blood or marrow samples of T-PLL patients (n=9) and were tested for involved T-cell subsets by multicolor flow cytometric analysis. Leukemic T-cells were treated with escalating doses of MK2206 (0 to 10 µM) for about 80 hours and were assessed for their apoptosis levels using Annexin V flow cytometric analysis. Whole exome sequencing (WES) and RNA sequencing were conducted using genomic DNA and RNA isolated from purified leukemic T cells from T-PLL patients. Results Phenotypic analysis of T-cell subsets in T-PLL patients showed that leukemic T-cells in 4 untreated T-PLL patients are consistent with naïve T-cell phenotype (CD45RA+, CD45RO-, CCR7+). Leukemic T-cells in 3 of the untreated patients and in 2 of the treated patients have central memory T (CD45RA-, CD45RO+, CCR7+) and effector memory T phenotypes (CD45RA-, CD45RO+,CCR7-) respectively. MK2206 treatment was able to induce dose-dependent apoptosis on the isolated PBMC (containing > 90% leukemic T-cells) of T-PLL patients (n=4) (IC50: 5 µM). FISH analysis found a rearrangement of TCL1 locus on chromosome 14 in all T-PLL cases (n=9). Three cases have also been detected to have del (11q) involving ATM locus and one patient has both del(11q) and del(17p). Subsequent WES (n=7) and RNA sequencing (n=6) analysis revealed recently reported mutations in ATM (frame shift mutation and early stop mutation W579*) in 2 cases, JAK3 (M511I) in 2 cases and STAT5B (T628S and N642H) in 2 cases. Importantly, novel somatic mutations in gene IKZF1 (N159S), NTRK1 (R33W), AP2A2 (P514L), HDAC8 (I115R), RARB (G90W) and TNIP2 (K104Q) were detected by WES. Mutations in EML4 (L548W and F304S) and VAV3 (C282Y and splice site mutation) were also identified in 2 different T-PLL cases. RNA sequencing revealed several fusion transcripts resulting in early stop of several different genes including PTPRT, L3MBTL1, UCKL1 in one T-PLL case. Conclusion T-PLL leukemic T-cells are consistent with either naïve or central memory T-cell subsets in untreated patients. The AKT inhibitor MK-2206 was capable of inducing apoptosis and could be a potential therapeutic agent for T-PLL patients. In addition, we detected known mutations in ATM and JAK-STAT pathways. Novel mutations in genes involving DNA binding and chromatin remodeling (IKZF1, HDAC8) or kinase signal pathway (NTRK1, TNIP2, VAV3, EML4) were uncovered. These results suggest that further therapeutic approaches could be developed to target DNA binding factors or JAK-STAT or AKT-TCL1 signal pathway with an ultimate goal to improve survival of T-PLL patients. Disclosures Off Label Use: Off label use of MK2206: MK-2206 is an AKT inhibitor obtained from Selleck Chemicals and is used to treat leukemic cells in vitro to test the leukemic sensitivity to AKT inhibition. .

Abstract INTRODUCTION: Erdheim-Chester Disease (ECD) is a rare hematologic disease manifesting as granulomatous or fibrotic infiltration of long bones and non-skeletal tissues by non-Langerhans foamy histiocytic (CD68+, CD1a-, S100-) cells. The clinical presentation can be diverse and any organ can be affected. It is estimated that less than 500 cases have been reported in the literature. METHODS: We retrospectively reviewed the medical records of patients evaluated at Mayo Clinic from January 2001 to May 2014. A tissue biopsy review by pathologists at Mayo Clinic was necessary for inclusion in the study. In all cases, the diagnosis of ECD was confirmed using clinical criteria in conjunction with histopathologic findings. Clinical data such as patient characteristics, disease presentation, management strategies, treatment responses, and survival time were collected. RESULTS: Forty-five patients with confirmed ECD were included in our study. The median age at diagnosis was 53 years (range, 32-78), while the median age of onset of symptoms prior to diagnosis was 24 months (range, 1-180). There was a male predilection with a male to female ratio of 2.4. The duration of follow-up ranged from 1-168 months (median, 20). At the time of last follow-up, 38 patients were alive and 5 were dead, while the vital statuses of 2 patients were unknown. The median and mean survival times from the time of diagnosis were 150 and 130 months respectively. The median survival time from the time of symptom onset was not reached and mean time was 154 months (Figures 1A and 1B). Bone pain was the most common presenting symptom (27%). Other common presentations included diabetes insipidus (24%), abdominal pain (22%), B symptoms (13%), visual changes (13%), renal failure/obstruction (11%), pleural effusion (9%), other neurologic symptoms (9%), ataxia (7%), pericardial effusion (7%), edema (7%), dyspnea (7%), and hypertension (7%). The organs/sites involved were bone (80%), central nervous system (59%), kidneys (56%), lungs (38%), retroperitoneum (33%), heart (22%), sinuses (22%), bone marrow (14%), adrenal glands (13%), liver (11%), spleen (11%), and skin (16%). Only 18 (40%) patients had the diagnosis established by the first biopsy. The rest required multiple biopsies before the diagnosis was confirmed (median, 2; range, 1-5). Testing for BRAF V600Ewas performed in 12 patients and 8 (67%) tested positive for the mutation. Eight patients have not required ECD-specific treatment so far. Of the 37 patients who required treatment, the median number of treatments received was 2 (range, 1-7). The systemic treatments received and their response rates are summarized in Table 1. Four patients received radiotherapy but none responded. At the time of the last follow up, 5 patients with BRAFV600E were receiving treatment with vemurafenib or dabrafenib. However, follow-up is insufficient for proper assessment of response. CONCLUSIONS: ECD is an extremely rare diagnosis as exemplified in our retrospective analysis. The diagnosis is often challenging due to protean and diverse clinical presentation as well as frequent inconclusive initial biopsies. There is usually a long-latency period of smoldering symptoms leading to definitive diagnosis. A high level of suspicion is essential in order to make the diagnosis and BRAFmutation analysis should be considered an integral part of work up even if biopsy is non-diagnostic. Traditional oncologic systemic therapies and even novel rheumatologic anti-inflammatory agents generally have limited objective activity. BRAF inhibitors offer a novel treatment option and results of prospective studies are eagerly awaited. Abstract 1405. Table 1: Summary of Response to Various Treatment Modalities in Patients with ECD Therapeutic Agent Number of Patients Treated Response (%) Complete Response Partial Response Stable Disease No response Corticosteroids 11 0 0 9 91 Methotrexate 9 0 0 11 89 Cyclophosphamide 4 0 0 25 75 2-CDA 12 8 17 25 50 Interferon-α 8 0 29 14 57 Vinorelbine 4 0 50 0 50 Tumor necrosis-α factor Inhibitors 7 0 0 14 86 Interleukin-1 Receptor Antagonists 6 17 17 0 67 Tamoxifen 2 0 50 0 50 Radiotherapy 4 0 0 0 100 Figure 1 Figure 1. Disclosures Off Label Use: We report among all treatments utilized at our institution for ECD including the use of steroids, immunosupressants, TNF blockers, interleukin-1 receptor antagonists, and BRAF inhibitors in patients with Erdheim Chester Disease. These treatments, though supported by other reports in the literature, have not been explicitly approved by the FDA for ECD..

Abstract Abstract 2342 Poster Board II-319 PURPOSE: Numerous clinical and biologic parameters are able to predict time to first treatment (TFT) and overall survival (OS) for patients with CLL. The utility of prognostic testing in CLL patients may vary based on age at diagnosis given the higher mortality from other causes among older individuals. The goals of the present study were to i) evaluate differences in natural history of CLL patients based on age at diagnosis, ii) compare survival to age-matched individuals in the general population, and iii) determine the age-stratified utility of prognostic testing. METHODS: All 2487 CLL/SLL patients diagnosed between January 1995 and June 2008 and cared for in the Mayo Clinic Division of Hematology were categorized by age at diagnosis (<55 years, 55-64 years, 65-74 years, or ≥75 years) and evaluated for differences in clinical characteristics, TFT, and OS using chi-square tests. IGHV gene mutation analysis, ZAP-70 status, CD38 status, and cytogenetics abnormalities by interphase FISH testing were performed as part of clinical and/or research studies using methods previously described by our group. Cox regression was used to evaluate the ability of prognostic parameters to predict clinical outcome stratified by age at diagnosis. Patient survival was compared to that of the age matched Minnesota population. RESULTS: When grouped by age, 593 patients were age <55, 713 age 55-64, 748 age 65-74, and 433 age ≥75 at diagnosis. As of last follow-up, 268, 282, 296, and 108 patients in these age groups have been treated, respectively and 112, 171, 254, and 199 patients have died. Survival decreased as the age at diagnosis increased (p<0.001). OS of CLL patients was significantly shorter than that of the age-matched general population for patients age <55 years (p<0.001), 55-64 years (p<0.001), and 65-74 years (p<0.001) at diagnosis but not those ≥75 years (p=0.136). Among Rai stage 0 patients, survival was also shorter than that of the age-matched general population for CLL patients age <55 years (p<0.001), 55-64 years (p<0.001), and 65-74 years (p<0.001) but not those ≥ age 75 at diagnosis (p=0.07). No statistically significant differences were observed in CD38 status, IGHV mutation status, ZAP-70 status or the frequency of common cytogenetic abnormalities on FISH based on age at diagnosis category. Consistent with prior reports, all of these parameters were powerful predictors of TFT and OS for the overall cohort on univariate analysis (all p<0.001 for both TFT and OS). Given the variation in TFT and OS based on age at diagnosis, we next evaluated the utility of these prognostic parameters for predicting TFT and OS in each age category after adjusting for stage. CD38, IGHV mutation, and ZAP-70 each predicted TFT independent of stage for all age groups (all p <0.05). FISH results predicted TFT independent of stage for patients age 55-64 and 65-74 however did not reach statistical significance for those age <55 (p=0.18) or ≥75 (p=0.07). The utility of these parameters for predicting OS independent of stage was less consistent and varied by age. IGHV predicted OS independent of stage for patients <age 55 (p<0.001), 55-64 (p=0.007), and 65-74 (p'0.001) but was not a significant predictor of OS among those ≥75 (p=0.15). CD38, ZAP-70, and FISH each predicted survival independent of stage for only 2 of the 4 age categories (ZAP-70 for age <55 and 55-64; FISH for age <55 and 65-74; CD38 for 55-64 and ≥75). CONCLUSIONS: Survival of CLL patients is shorter than that of the age-matched general population for individuals age <75 at diagnosis regardless of disease stage. In contrast, survival does not differ from the age-matched general population among CLL patients ≥age 75 at diagnosis. Prognostic testing using CD38, IGHV mutation, and ZAP-70 is useful for predicting TFT independent of stage for CLL patients of all ages (including those ≥age 75) but has less value for predicting OS particularly as the age at diagnosis increases. IGHV appeared to be the best predictor of OS independent of stage among all patients age <75. Unexpectedly, prognostic testing had little utility for predicting OS independent of stage among patients age ≥75. These findings have important implications regarding the use of prognostic tests in patients with CLL as well as the use of test results to select patients for clinical trials testing early treatment for asymptomatic individuals. Disclosures: Shanafelt: Cephalon: Research Funding; Celgene: Research Funding; Polyphenon Pharma : Research Funding; Hospira: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; Bayer Health Care Pharmaceuticals: Research Funding. Kay:Biogenc-Idec, Celgene, Genentech, genmab: Membership on an entity's Board of Directors or advisory committees; Genentech, Celgene, Hospira, Polyphenon Pharma, Sanofi-Aventis: Research Funding. Zent:Genentech, Bayer, Genzyme, Novartis: Research Funding.

Abstract Abstract 4410 BACKGROUND Autoimmune cytopenia occurs in 5%-10% of patients with CLL. Treatment for patients with both autoimmune cytopenia and progressive CLL is challenging due to poor tolerance of myelosuppression, and the risk of exacerbation of autoimmune cytopenia by purine analogues. METHODS We identified 20 patients from our CLL database of approximately 3000 patients who were treated with a chemoimmunotherapy regimen of rituximab, cyclophosphamide, vincristine, and prednisone (R-CVP) for both autoimmune cytopenia and progressive CLL from January 2000-December 2008 at Mayo Clinic Rochester. RESULTS Autoimmune cytopenia responded in 19 patients (14 CR and 5 PR) with a median time to progression (TTP) of 13.6 months (range 5 – 29). Five patients remain in sustained remission at last follow up (range 15 – 30 months) and 4 patients have had recurrent autoimmune cytopenia requiring re-treatment. Six patients required maintenance corticosteroid therapy after completing R-CVP. Progressive CLL responded to treatment in 17 patients (9 CR/CCR, 8 PR by NCI-WG 1996 criteria) with a median TTP of 6.3 months (range 1-40 months). Fourteen patients have required additional treatment for progressive CLL at a median of 5.4 months (range 4-22 months). Five patients have not required additional treatment for either CLL or autoimmune cytopenia at 15 -30 months after completing treatment. R-CVP treatment toxicity included 3 patients with grade 3-4 infections, 2 with grade 1 peripheral neuropathy, and one with grade 3 drug-induced pneumonitis. No patient required blood cell transfusions after the completion of cycle 1 of therapy. CONCLUSIONS Although R-CVP is an effective and tolerable therapy for patients with simultaneous autoimmune cytopenia and progressive CLL requiring therapy, the duration of response is suboptimal. Clinical trials testing alternative treatment strategies are needed for this patient population. Disclosures: Zent: Genentech, Bayer, Genzyme, Novartis: Research Funding. Shanafelt:Cephalon: Research Funding; Celgene: Research Funding; Polyphenon Pharma : Research Funding; Hospira: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; Bayer Health Care Pharmaceuticals: Research Funding. Kay:Biogenc-Idec, Celgene, Genentech, genmab: Membership on an entity's Board of Directors or advisory committees; Genentech, Celgene, Hospira, Polyphenon Pharma, Sanofi-Aventis: Research Funding.

Abstract Abstract 3928 Background: Accumulating data support the critical role of PI3K/Akt in CLL B cell receptor (BCR) mediated signal transduction, cell proliferation and survival. In addition recent preclinical and clinical studies indicate that specific PI3K blockade results in robust preclinical and clinical efficacy in CLL. In our model system of CLL B cell-stromal cultures which feature their interaction, platelet derived growth factor (PDGF) present in CLL culture medium drives VEGF production through PI3K/Akt activation in stromal cells (Blood. 2010. 116:2984). Indeed Akt was found to be activated in leukemic cells during the CLL-stroma interaction (Leuk Res. 2008. 32:1565). Therefore, we hypothesized that Akt inhibition should promote CLL B cell apoptosis and abrogate BCR mediated cytokine production. MK2206 is an orally bioavailable highly specific allosteric Akt inhibitor. It has been tested in patients with refractory solid tumors and was demonstrated to be safely administered in a phase I trial. Therefore the goal of this study was to test the preclinical efficacy of MK2206 on both the survival and the BCR mediated cytokine production of CLL leukemic B cells. Methods: Peripheral blood mononuclear cells isolated from CLL patients (n=37) were treated with escalating concentrations of MK2206 (1–16 μM) for 24 hours, 48 hours or 72 hours. The levels of leukemic B cell viability were tested using an (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay. The potential impact (antagonistic/additive/synergistic) of Bendamustine in combination with MK2206 was also tested by using the MTT assay. We used the Calcusyn system to calculate the effect of drug interactions. The combination index (CI) as calculated by the program usually indicates synergy when ≤ 0.8 and indicates additive outcomes when between 0.8–1.2. A CI >1.2 indicates antagonism. Downstream signals of Akt activation in CLL B cells were evaluated by testing their expression of Mcl-1, 4EBP1 and p70S6K using immunoblot. The impact of Akt inhibition by MK2206 on cytokine production in response to B-cell receptor ligation with anti-IgM was also tested using a multiplex cytokine analysis (Invitrogen) in a time-course experiment. Results: MK2206 treatment induced concentration- and time-dependent apoptosis in CLL leukemic cells. At 72 hours, the IC50 of MK2206 in the experiments using CLL leukemic cells in vitro is ∼8 mM. MK2206 incubation at 1 or 5 mM cultured with CLL B cells over a 48-hour period abolished of Akt and p70S6K phosphorylation while native PARP was cleaved into the 85 kD polypeptide fragment. However, the expression level of the upstream signal molecule, PI3K, was not changed. Among the CLL patients tested (n = 37), we did not find any difference in sensitivity to MK2206 induced apoptosis based on critical prognostic factors of CD38, ZAP-70, IGHV and del(17p) status. Importantly, we detected synergistic or additive activity between MK2206 and Bendamustine in 11 tested CLL samples when these combinations were used to treat CLL cells in vitro for 72hrs. Thus the median CI value for this group of patients was 0.8 (0.1 – 1.1). Six were found to have CI ≤ 0.8 and five fell within the additive CI values (0.8 – 1.2). Production of immune or chemotactic cytokines (e.g. CCL3, CCL4, MCP-1, IL-1Ra, IL-8 and IL-2R) at 24 hour incubation increased significantly above baseline when CLL cells were stimulated anti-IgM. Akt inhibition with MK2206 selectively abrogated upregulation of CCL3, CCL4, MCP-1 and IL-2R production, but not for IL-8 or IL-1Ra secretion. MK2206 also abolished BCR mediated Akt activation and decreased Erk activation. Conclusion: MK2206, a robust and selective Akt inhibitor, induced significant in vitro apoptosis of CLL B-cells in vitro. Preclinical evidence of a synergistic effect between MK2206 and Bendamustine was also observed independent of prognostic risk. MK2206 abolished BCR mediated Akt activation and selectively abrogates BCR mediated production of cytokines that may promote apoptotic resistance. These findings support the use of MK2206 in treating CLL and indeed we have initiated a phase I/II trial of MK2206 in combination with Bendamustine and Rituximab for relapsed CLL patients(N1087, October 2011). Acknowledgments: This study was funded by the NCI-K23, NCCTG and CLL Global Foundation. Disclosures: Shanafelt: Cephalon: Research Funding; Genentech: Research Funding. Kumar:Genzyme: Research Funding; Novartis: Research Funding; Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Honoraria. Kay:Celgene: Research Funding.

Abstract Abstract 1379 Background: Although chemoimmunotherapy (CIT) has substantially improved response rates, treatment free survival, and overall survival in patients with chronic lymphocytic leukemia (CLL), only 40–50% of patients achieve a complete remission and the majority have residual disease when evaluated using sensitive assays for minimal residual disease (MRD). While this observation created interest in consolidation therapy, previous alemtuzumab based consolidation trials have demonstrated excess morbidity/mortality. We conducted a lenalidomide based consolidation trial for patients with previously untreated CLL who received 6 cycles of induction with pentostatin, cyclophosphamide and rituximab (PCR). Methods: Eligible patients were previously untreated and had CLL in need of treatment according to the NCI-WG criteria (Blood 111:5446). Treatment schema consisted of 6 cycles of pentostatin (2 mg/m2), cyclophosphamide (600 mg/m2) and rituximab (375 mg/m2) given every 21 days (Blood 109:405). All patients completing 6 cycles of PCR, underwent complete restaging and evaluation for MRD using sensitive flow cytometry (Leukemia 21:956). Following restaging and adequate recovery of blood counts, patients received 6 mos of lenalidomide consolidation by continuous daily administration. The starting lenalidomide dose was 5 mg/day with escalation to 10 mg/day after the first cycle as tolerated. Patients again underwent complete restaging and MRD evaluation after 6 mos of lenalidomide. At the time of this restaging, MRD negative patients entered observation. Those with residual disease continued on lenalidomide and underwent repeat MRD assessment every 3 mos with cessation of lenalidomide when an MRD negative state achieved. Results: 45 patients were enrolled at Mayo Clinic between 3/2008 and 11/2009. 44 patients were eligible for treatment: 71% male, median age 65 (range: 44–78); intermediate Rai risk 61%; high Rai risk 39%. On prognostic testing 32% were CD38+, 52% Zap-70 +, 52% IGHV unmutated, and 16% had high risk FISH (del 17p13; del 11q22). 38 of 44 eligible patients (86%) completed 6 cycles of PCR induction. Adverse events deemed at least possibly related to PCR induction included 19 (43%) patients with grade 3+ hematologic toxicity and 9 (20%) with grade 3+ non-hematologic toxicity. The Overall response rate to induction was 98% with 15 CR/CRi, 3 CCR, 9 nPR, and 16 PR. Four patients with CR were also MRD negative at the completion of induction. Of 38 patients who completed induction, 34 initiated lenalidomide consolidation. Thus, by protocol intent to treat analysis, 34/44 (77%) patients starting CIT with PCR were able to receive consolidation therapy. The remaining patients were unable to initiate consolidation due to: failure to complete induction (6 patients), disease progression (1), adverse event (1) and patient refusal (2). Among the 34 patients who initiated consolidation, the median number of cycles of lenalidomide received was 5.5 (range: 1–19). Adverse events deemed at least possibly related to lenalidomide consolidation included 22 (65%) patients with grade 3+ hematologic toxicity and 4 (12%) with grade 3+ non-hematologic toxicity. Among the 34 patients who received at least 1 cycle of lenalidomide, 4 patients have improved the quality of their response to date with 11 patients still on lenalidomide at the time of this report. After median follow-up of 16 mos, 42/44 patients are alive and median duration of response has not been reached. To date 3/44 (7%) of patients have progressed to require additional treatment. Finally, since eligibility was nearly identical to our historic trial of PCR without lenalidomide consolidation, we compared the 44 patients in the present trial to the 64 patients previously treated on our PCR trial (Blood 109:405). Demographic and prognostic characteristics of the patients in the two studies were similar. With the caveat it represents comparison across phase II trials, the proportion of patients free of retreatment at 12 mos was 97% (95%CI: 91–100) for PCR-L vs. 78% (95%CI: 68–89) for PCR (Figure 1). Conclusion: We report here the first results of lenalidomide based consolidation for CLL patients receiving first-line CIT induction. Although lenalidomide consolidation appears to improve the quality of response and prolong time to retreatment, longer follow-up is necessary to determine the clinical benefit of this strategy. Disclosures: Shanafelt: Celgene: Research Funding; Hospira: Research Funding; Genentech: Research Funding. Off Label Use: Lenalidomide. Kay:Celgene: Research Funding; Hospira: Research Funding; Genentech: Research Funding.

AbstractBackgroundHuman pegivirus (HPgV) is a single-strand RNA virus belonging to the Flaviviridae. Although no definitive association between HPgV infection and disease has been identified, previous studies have suggested an association of HPgV viremia with risk of lymphomas.MethodsWe conducted a systematic review and meta-analysis, including 1 cohort study and 14 case-control studies, assessing the association of HPgV viremia with adult lymphomas. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model, overall and by geographic region and lymphoma subtype.ResultsThe overall OR for lymphoma was 2.85 (95% CI, 1.98–4.11), with statistically significantly elevated ORs observed in 8 of 15 studies. There was a small amount of heterogeneity among studies (I2 = 28.9%; Q = 18.27, P = .16), and the funnel plot provided no evidence for publication bias. The strongest association with lymphoma risk was observed for studies from Southern Europe (OR, 5.68 [95% CI, 1.98–16.3]), whereas weaker ORs (with 95% CIs) were observed for studies from North America (2.24 [1.76–2.85]), Northern Europe (2.90 [.45–18.7), and the Middle East (2.51 [.87–7.27]), but all of similar magnitude. Participants with HPgV viremia had statistically significantly increased risks (OR [95% CI]) for developing diffuse large B-cell (3.29 [1.63–6.62]), follicular (3.01 [1.95–4.63]), marginal zone (1.90 [1.13–3.18]), and T-cell (2.11 [1.17–3.89]) lymphomas, while the risk for Hodgkin lymphoma (3.53 [.48–25.9]) and chronic lymphocytic leukemia (1.45 [.45–4.66]) were increased but did not achieve statistical significance.ConclusionsThis meta-analysis supports a positive association of HPgV viremia with lymphoma risk, overall and for the major lymphoma subtypes.

Abstract CLL is a clinically heterogeneous disease with wide ranging disease course. A novel CLL-IPI based on Rai/Binet stage, IGHV-mutation status, TP53 mutation/deletion, B2M level, and age was developed to stratify patients into 4 risk groups, with a c-statistic of 0.75. Next-generation sequencing has identified ~60 genes recurrently mutated in CLL, some of which are associated with poor overall survival, whereas the clinical effect of most genes is still unknown. Herein, we examine whether somatic mutations in these putative driver genes are associated with time to first treatment (TTT), and whether they add prognostic value beyond CLL-IPI. Based on the 2008 International Workshop CLL criteria, we identified 100 CLL and 96 high-count monoclonal B-cell lymphocytosis (MBL) newly diagnosed from the Mayo Clinic CLL biobank. Pre-treatment peripheral blood mononuclear cells were collected &lt;2 years of diagnosis and tumor DNA was extracted from sorted CD5+/CD19+. We sequenced the coding regions of 61 recurrently mutated CLL driver genes using a custom SureSelect panel, with 24 samples per flow cell in Illumina HiSeq 4000. The average coverage depth was &gt;1000X. Somatic mutations were called using MuTect2 in tumor-only mode. To remove germline variants, variants were eliminated based on minor allele frequencies &gt;0.01%, identified in 1000 Genomes Project, ExAC and/or ESP6500 databases, unless present in known mutation hotspots or COSMIC. After filtering, high/moderate impact mutations were analyzed using Cox regression, to estimate hazard ratios (HR) and 95% confidence intervals (CI) to test for associations with TTT. Among 196 patients the most commonly mutated genes were TP53 (11%), ATM (10%), SF3B1 (10%), NOTCH1 (9%), CHD2 (8%), and BIRC3 (7%). The median follow-up was 8.7 years, and 73 patients were subsequently treated. ATM (HR=3.27, CI:1.8-6.1, P=0.0002) and NOTCH1 (HR=2.41, CI:1.3-4.6, P=0.008) were associated with TTT. When evaluating the total number of mutated genes, we found 32%, 29%, and 39% patients had ≥2, 1, or 0 genes mutated, respectively, and this was associated with shorter TTT (HR=1.74, CI:1.3-2.4, P=0.0005) adjusting for sex and CLL-IPI with a c-statistic=0.8 (CI: 0.75-0.84). When stratified by CLL-IPI, the association held for low (N=99, HR=1.88, CI:1.1-3.4, P=0.03) and intermediate risk (N=54, HR=1.87, CI:1.1-3.2, P=0.03) but not high/very high risk (N=35, HR=1.07, CI:0.6-1.9, P=0.83). We demonstrated that the total number of CLL putative driver genes with high or moderate impact mutations provided prognostic information in newly diagnosed CLL/MBL beyond CLL-IPI. Moreover, even among those with low or intermediate CLL-IPI risk, the total number of somatic mutations separated those patients who progressed. Sequencing the CLL driver genes at time of diagnosis could be a potential biomarker for outcome prediction. Citation Format: Geffen Kleinstern, Daniel R. O’Brien, Brian F. Kabat, Kari G. Chaffee, Aaron D. Norman, Timothy G. Call, Sameer A. Parikh, Jose F. Leis, Wei Ding, James R. Cerhan, Neil E. Kay, Susan L. Slager, Esteban Braggio. Somatic mutations within chronic lymphocytic leukemia (CLL) putative driver genes are associated with outcomes beyond the CLL international prognostic index (CLL-IPI) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4466.

Background:We have previously reported that ∼50% of CLL patients (pts) experience rapid flare of disease when they discontinue ibrutinib therapy due to progression of disease (CLL or Richter's transformation [RT]) (Hampel et al, JCO suppl, 2018). This lead to the clinical practice of overlapping venetoclax with ibrutinib for combination therapy in this setting to prevent ibrutinib withdrawal.Aims:To evaluate the role of continuing ibrutinib beyond the start of salvage venetoclax in pts who have progression of disease on ibrutinib monotherapy, both in preventing ibrutinib withdrawal associated with ibrutinib discontinuation and in disease response.Methods:We identified all CLL pts at Mayo Clinic (3/2017–11/2018) who had disease progression on ibrutinib therapy, where venetoclax was added as subsequent treatment while ibrutinib was continued. CLL‐specific characteristics, treatment timeline and toxicities, and disease course following combination therapy were ascertained. All pts started venetoclax according to the weekly ramp‐up per the package instructions.Results:Eighteen pts treated with the addition of venetoclax to ibrutinib therapy were identified; indications were CLL progression (n = 13) and RT (n = 5). BTK or PLCG2 mutations were present in 8/13 pts. Median duration of follow‐up was 9.6 months after the start of combination therapy.The target venetoclax dose was reached by 5 weeks in 13 pts; reasons for delaying or stopping dose escalation included diarrhea (n = 2), sepsis (n = 2), and neutropenia (n = 1). No patient experienced a disease flare during venetoclax ramp‐up.The median duration of combination ibrutinib and venetoclax therapy was 3 months (range, 0–14 months). Of 18 pts who started combination therapy with ibrutinib and venetoclax, ibrutinib was discontinued in 10 pts. Reasons included hematopoietic stem cell transplant (n = 2), planned stop after adequate disease control (n = 4), financial reasons (n = 1), toxicity (neutropenia n = 1, immune thrombocytopenia/bleeding risk n = 1), and death (n = 1). Only 1 patient experienced ibrutinib withdrawal, which occurred following planned discontinuation after clinical complete response (CR) with a 41 day overlap and toleration of venetoclax 400 mg daily; management with re‐initiation of ibrutinib was effective in regaining disease control. Of 9 pts who stopped ibrutinib, 4 pts had a slow taper over 2–8 weeks, and 2 pts also received corticosteroids at the time of ibrutinib discontinuation.Among the other 8 pts who did not discontinue ibrutinib, 6 pts remain on the combination with venetoclax (median duration 6.5 months, range 3–14 months), and 2 pts continued on ibrutinib following venetoclax discontinuation due to disease progression (both pts received further combination of ibrutinib with multi‐agent chemotherapy).The overall response rate (ORR) to combination therapy with ibrutinib and venetoclax was 81% (CR/clinical CR n = 9, partial response n = 4, stable disease n = 1, and primary refractory disease n = 2). The duration of combination therapy was <4 weeks in 2 pts, precluding response assessment. The estimated 12‐month event‐free survival was 54% (95% CI 33–87%), and the estimated 12‐month overall survival from start of combination therapy was 79% (95% CI 60–100%); see Figure 1.Summary/Conclusion:Among CLL pts who develop progression of disease on ibrutinib monotherapy, continued ibrutinib therapy with addition of venetoclax was feasible, ameliorated ibrutinib withdrawal, and was associated with high ORR.image