Leis, José F.

Abstract Background: Donor cell chimerisms are tested at frequent intervals after allogeneic hematopoietic stem cell transplantation (alloHSCT). However, the predictive value of this testing in patients with myelofibrosis (MF) is not well-defined. In this study, our primary objective is to evaluate the correlation of day 30 and day 100 donor cell chimerism and overall survival (OS) in patients (pts) who undergo alloHSCT for MF. Methods: Charts were reviewed for pts who underwent alloHSCT for MF at Mayo Clinic in Arizona, Minnesota and Florida between January 2005 and December 2015. Patients who died within 30 days of alloHSCT were excluded. Chimerism studies were evaluated in the peripheral blood for CD3 and CD33 fractions at day +30 (D30) and day +100 (D100). Cut-off value of 100% and less than 100% was used because of limited variability below 100%. Standard statistical methods were used to compare continuous and categorical variables. The Kaplan-Meier method was used to provide survival curves. Results: Baseline characteristics: Sixty three consecutive patients who underwent alloHSCT for MF since January 2005 until December 2015, and had D30 and/or D100 chimerism studies available were included in the study. Of these, 24 (38%) were female. Median age at diagnosis was 56 years (range, 19 - 73 years) and median age at AHSCT was 58 years (range, 19 - 73 years). Dynamic International Prognostic Scoring System-Plus (DIPSS-Plus) risk category at the time of alloHSCT was high in 31 (49%), intermediate-2 in 30 (48%) and intermediate-1 in 2 (3%) pts. JAK2 V617F mutation status was available in 61 pts and was positive in 35 (57%) pts. Nineteen (30%) pts had been treated with a JAK2 inhibitor prior to alloHSCT. Fifty-two (83%) pts had at least grade-2 fibrosis in bone marrow at the time of HCT. Transplantation: Median time from diagnosis to AHSCT was 12.9 months (range, 2.3 - 248.2 months). Fifty-five (87%) received a reduced intensity conditioning (RIC) regimen while 8 (13%) received myeloablative conditioning regimen. Of these 55 pts, RIC regimens used were busulfan fludarabine based regimen in 15 (27%), fludarabine melphalan based regimen in 18 (33%) and fludarabine melphalan carmustine in 22 (40%) pts. Donor source was matched related in 30 (48 %), matched unrelated in 28 (44%), single-antigen mismatched related in 4 (6%) and mismatched unrelated in 1 (2%). Peripheral blood stem cells were used in all AHSCTs. Outcomes: Median follow-up was 24.4 months (range, 1.5 - 83.6 months). Amongst pts who had <100% donor chimerism at D30 in CD33 fraction, 2 had 90%, 1 had 80% and 2 had zero% donor chimerism. At D100, 1 pt had 95%, 1 had 90%, 1 had 60%, 2 had 5% and 1 had zero% donor chimerism. Eighteen out of 57 (32%) pts who had 100% donor chimerism in CD33 fraction at D30 had died at the time of analysis compared to 4 out of 5 (80%) patients with less than 100% (p=0.03). Eight out of 38 pts (21%) who had 100% donor chimerism in CD33 fraction at D100 died versus 3 out of 6 (50%) with less than 100% (p=0.12). There was no significant survival effect of CD3 chimerism (p values=0.68, 0.59). Of the 23 deaths that had occurred at the time of analysis, cause of death was disease progression or relapse in 8 (35%), graft versus host disease in 6 (26%), transplant related (sepsis / engraftment failure) in 5 (22%) and unrelated causes in 4 (17%). Survival analysis: As depicted in the Kaplan Meier curve (figure 1), median overall survival (OS) for pts with 100% donor chimerism in CD33 fraction at day 30 was not reached while for <100% donor chimerism was 16 months (p=0.04). Survival at 3 years for patients with 100% CD33 donor chimerism at D30 was 65% while it was 40% for pts with less than 100%. Also, survival at 3 years for patients with 100% CD33 donor chimerism at day 100 was 75% compared to 50% for patients with less than 100%. Conclusions: In our study, 100% donor chimerism in CD33 fraction is associated with improved survival after alloHSCT for MF compared to pts with less than 100%. Further understanding regarding the reason for this relationship is critical. Larger studies to replicate these results would be imperative to validate these findings. Disclosures Mesa: Incyte: Research Funding; Ariad: Consultancy; Promedior: Research Funding; Novartis: Consultancy; Celgene: Research Funding; Gilead: Research Funding; CTI Biopharma: Research Funding; Galena: Consultancy.

Abstract Background: Individuals with clinically ascertained monoclonal B-cell lymphocytosis (c-MBL) having the phenotype of the chronic lymphocytic leukemia (CLL) have a 1-4% per year risk of progression to CLL requiring therapy. The risk factors for progression and the outcomes of individuals with c-MBL are not well defined. Methods: Using the Mayo Clinic CLL Database, we identified individuals with c-MBL (absolute B-cell count of <5x109/L, in the absence of symptoms, organomegaly, splenomegaly and cytopenias) who were seen at Mayo Clinic, Rochester, MN between 01/1995 - 5/2016. Patients in whom an absolute B-cell count was not available were included in the analysis if the absolute lymphocyte count was <5x109/L. Baseline clinical characteristics and prognostic test results (including IGHV mutation status, genetic abnormalities detected by FISH, and expression of ZAP-70, CD38 and CD49d) were recorded. Time to first therapy (TFT) was analyzed using cumulative incidence methods accounting for competing risk of death. Multivariable Cox proportional hazards regression analysis was used to identify factors that predicted TFT. Because of missing data for some prognostic parameters, multiple models were run, introducing one novel prognostic factor at a time to the base model (which consisted of age and sex). Overall survival (OS) of these individuals was compared to age- and sex-matched population of the state of Minnesota. Results: Eight hundred and fifty-one individuals with c-MBL were identified and included in this analysis. Median age was 69 years (range, 38-95 years), and 527 (62%) were males. The median absolute B-cell count at the time of diagnosis was 2.6 x 109/L (range, 0.1-5.0 x 109/L). The median serum beta-2 microglobulin (β2M) was 2.2 mg/dL (range, 1.0 - 21.5 mg/dL). One hundred and nine (30%) individuals had unmutated IGHV genes, and 38 (7%) had high-risk FISH (defined as either del17p13 or del11q23). The CD38 (≥30%), ZAP-70 (≥20%), and CD49d (≥30%) status was positive in 19%, 23% and 34% individuals, respectively. After a median follow-up of 6.8 years, 99 individuals required therapy for progressive disease (at a rate of 2.1% per year, Figure 1). On multivariable analysis, the following factors were associated with a higher risk of progression to CLL requiring therapy: a) unmutated IGHV status (hazard ratio [HR]:3.8, 95%CI 2.1 - 7.0, p<0.0001); b) positive CD49d status (HR: 3.1, 95%CI 1.6 - 5.9, p=0.0006); and c) positive CD38 status (HR: 2.8, 95% CI 1.7 - 4.8, p<0.0001). Although the HR for high-risk FISH was 2.0 (95% CI 0.9 - 4.4), it was not significantly associated with TFT (p=0.11), likely due to small sample size. Age, sex, serum β2M, and ZAP-70 expression were not predictive of TFT. Among these individuals with B-cell counts <5x109/L, further stratification of the absolute B-cell count at diagnosis showed no association with TFT (Figure 2). The median OS of individuals with c-MBL was 11.8 years. Although the OS among individuals with c-MBL and the age- and sex-matched general population of Minnesota appeared similar for the first 10 years of follow-up, OS was significantly shorter in the c-MBL group during the full follow-up interval (p=0.004, Figure 3). Conclusion: In this large cohort of individuals with clinically ascertained MBL, the risk of progression to CLL requiring therapy was 2.1% per year. Biological characteristics of the B-cell clone including IGHV mutation status, and CD49d and CD38 status predicted time to first CLL therapy. On extended follow-up, the OS of individuals with c-MBL was significantly shorter relative to age- and sex-matched general population. These findings have important implications for counselling individuals with clinically ascertained MBL. Disclosures Parikh: Pharmacyclics: Honoraria, Research Funding. Ding:Merck: Research Funding. Kenderian:Novartis: Patents & Royalties, Research Funding. Shanafelt:Pharmacyclics: Research Funding; GlaxoSmithkKine: Research Funding; Janssen: Research Funding; Genentech: Research Funding; Celgene: Research Funding; Cephalon: Research Funding; Hospira: Research Funding.

Abstract Introduction: The use of B-cell receptor (BCR) signal inhibitors-based therapies (e.g., Ibrutinib) for B-chronic lymphocytic leukemia (CLL) was initiated just a few years ago but has rapidly escalated due to their clinical efficacy and relative ease of use. However newer therapeutic approaches are needed due to multiple issues including the continued need to improve complete responses and reduce toxicity profiles. To that end our group has discovered a novel membrane target in the ubiquitous presence of Axl receptor tyrosine kinase (Axl RTK) on CLL B-cells and has reported that the Axl RTK inhibitor TP-0903 is able to induce apoptosis of CLL B-cells at nanomolar doses (Sinha, Clin Cancer Res, 2015). Given this we assessed if TP-0903 would be effective in the induction of apoptosis of leukemic B-cells from CLL patients who are currently on Ibrutinib therapy or whom have relapsed while on Ibrutinib treatment. Methods: Relapsed/refractory CLL patients (n=22) who were placed on Ibrutinib for progressive disease provided blood samples at a median of 3.2 months after Ibrutinib therapy initiation for these studies. We also obtained sequential samples on 8 patients from initial start of ibrutinib therapy and then over a 6 month follow-up period. CLL B-cells from these blood samples were subject to Ficoll separation, purified by using a Rosette Sep B-cell enrichment kit and then studied by flow cytometry to determine Axl RTK expression levels by flow cytometric analysis. Purified CLL B-cells (CD19+/CD5+) were cultured with TP-0903 in vitroat increasing doses (0.01µM - 0.50µM) for 24 hours and the LD50 dose was determined. In addition, 3 CLL patients who had been on Ibrutinib therapy and had a documented relapse were studied in similar fashion using TP-0903. LD50-sensitivity was measured. "LD50-sensitivity" was defined as an LD50 ≤0.50µM and "insensitive" was defined as an LD50 dose >0.50µM. CLL prognostic factors (e.g., FISH, IGHV mutation status, Rai stage, CD38, and CD49d) were evaluated at the time of ibrutinib treatment. Differences in factors between sensitive and insensitive cases were computed using the Kruskal-Wallis test for continuous variables and Chi-square test for categorical variables. Results: Twenty-two CLL patients (5 female, 17 male) were included in the analysis. Fourteen (64%) patients were found to be TP-0903 LD50-sensitive. Axl expression on CLL B-cells for this cohort was heterogeneous with a median of CD19+/CD5+ cells positive for Axl at 69.9% (range of 2.7-91.3%). The sensitive subjects tended to be younger with a median age at Ibrutinib treatment initiation of 62 vs 75.5 years (p=0.004). There were no significant differences in gender, FISH, IGHV mutation status, CD38, CD49d, or Rai stage between the sensitive and insensitive LD50 groups. There were no significant differences in relation to median Axl expression on CLL B-cells (sensitive: 72.6%, range: 2.7-91.3%; insensitive: 41.5%, range: 16.5-83.1%; p=0.35). The median number of treatments prior to initiation of ibrutinib did not differ between sensitivity groups (sensitive: 2.53, range: 8-10; insensitive: 43.5, range 12-20; p=0.2833). Association for ZAP70+ CLL B-cells tended to have more apoptosis induction by TP-0903 (sensitive: 84.6% ZAP70+; insensitive: 42.9% ZAP70+; p=0.052). In 8 CLL patients that were studied sequentially while on Ibrutinib continued to express Axl or increased their Axl expression (n=2) over a 3-6 month follow-up period. Three CLL patients who had relapsed on Ibrutinib were sensitive to TP-0903 with LD50 values of ≤0.50µM. Summary: Here we find that CLL B-cells from over 60% of relapsed CLL patients on Ibrutinib therapy were highly sensitive to the high-affinity Axl inhibitor TP-0903 with induction of apoptosis at nanomolar doses (≤0.50µM). The sensitivity of CLL B-cells to TP-0903 appears to be independent of Axl expression levels and of the known CLL prognostic factors but more evident for younger patients and for ZAP70+ expression status. Given this level of activity for apoptosis induction of CLL B-cells by TP-0903 encourages the further testing of this drug in clinical trials for CLL patients. Disclosures Parikh: Pharmacyclics: Honoraria, Research Funding. Shanafelt:Pharmacyclics: Research Funding; Janssen: Research Funding; Genentech: Research Funding; GlaxoSmithKline: Research Funding; Celgene: Research Funding; Cephalon: Research Funding; Hospira: Research Funding. Warner:Tolero Pharmaceuticals: Employment, Equity Ownership, Patents & Royalties. Bearss:Tolero Pharmaceuticals: Employment, Equity Ownership, Patents & Royalties. Kay:Pharmacyclics: Research Funding; Tolero Pharmaceuticals: Research Funding; Acerta: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Morpho-Sys: Membership on an entity's Board of Directors or advisory committees; Infinity Pharm: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees.

Abstract INTRODUCTION: The prevalence of liver dysfunction in patients with previously untreated chronic lymphocytic leukemia (CLL) is unknown; knowledge of which may provide important context for emerging therapeutic options with possible hepatotoxicity. The impact of liver dysfunction on outcomes of CLL patients is not well described. METHODS: Between 09/1993 and 04/2016, previously untreated CLL patients seen in the Division of Hematology at Mayo Clinic at diagnosis (<12 months) and who had baseline assessment of at least one of the following liver function tests (LFTs): alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), or total bilirubin were included in this analysis. Baseline lab values were defined as the closest value to CLL diagnosis for each lab within 12 months prior to diagnosis up through 6 months after CLL diagnosis. Patients with at least one abnormal LFT (defined as greater than 1.5 x the upper limit of normal) were classified as having liver dysfunction at diagnosis. Analysis for factors related to baseline liver function was performed using age- and sex-adjusted logistic regression models. Kaplan-Meier methods and multivariable Cox regression analysis was used to evaluate time to first treatment (TTFT) and overall survival (OS). RESULTS: Of 2336 previously untreated CLL patients who met the inclusion criteria, 123 (5%) patients had at least one abnormal LFT value at time of diagnosis. Thirty five patients had abnormal AST (median value 106 U/L, range 72-745 U/L, reference range 8-48 U/L), 25 patients had abnormal ALT (median 112 U/L, range 82-313 U/L, reference 7-55 U/L), and 54 patients had abnormal total bilirubin (median 2.10 mg/dL, range 1.8-26.5 mg/dL, reference range ≤ 1.2 mg/dL). Forty five patients had abnormal alkaline phosphatase; 35 patients in the year 2003 or later (median 198 U/L, range 172-2269 U/L, reference range 45-115 U/L) and 10 patients in 2002 or earlier (median 471.5 U/L, range 394-706 U/L, reference range 98-260 U/L). Abnormal LFTs were more common among those with advanced Rai stage disease (Rai 0-II=4.7% vs. Rai III-IV=13.4%; p<0.001) and among patients with lower hemoglobin (median 13.1 g/dL vs. 13.9 g/dL; p<0.001) at diagnosis. No difference in the rate of abnormal LFTs was observed based on cytogenetic abnormalities detected by FISH or CD38, CD49d, ZAP-70 or IGHV gene mutation status. There was no significant difference in prior alcohol abuse history between patients with liver dysfunction at diagnosis (6%) and those without (5%) (p=0.63). Similarly, there was no significant difference in body mass index between groups (median 27.8 vs. 27.8; p=0.12). After 12 years of follow-up, an estimated 69% of the cases with abnormal LFTs were treated. The most common type of treatments included anti-CD20 monoclonal antibody therapy only, followed by purine nucleoside based chemoimmunotherapy, and an alkylating agent with a monoclonal antibody. The median time to treatment was 4.3 years for cases with abnormal LFTs compared to 6.3 years for cases without abnormal LFTs (p=0.02). However, after adjusting for age, sex and Rai stage, there was no difference in TTFT among patients with abnormal LFTs at baseline compared to those with normal LFTs (hazard ratio [HR] = 1.2 (95% CI, 0.9-1.6); p=0.23). The median survival of CLL patients with abnormal LFTs at diagnosis was significantly shorter than those with normal LFTs (8.6 vs. 11.6 years, p<0.001, Figure 1). After adjusting for age, sex and Rai stage, multivariable cox regression analysis showed that abnormal LFTs retained independent prognostic significance for OS with a HR of 1.4 (95% CI, 1.1-1.8; p=0.012). CONCLUSION: At the time of CLL diagnosis, ~1 out of every 20 patients with previously untreated CLL has abnormal LFTs. These data provide context to the recent reports of hepatotoxicity with the use of signal inhibitors in untreated CLL. Although the presence of liver dysfunction at diagnosis does not seem to predict a shorter TTFT, the OS of these patients is significantly shorter compared to patients who have normal LFTs. Figure 1 Figure 1. Disclosures Ding: Merck: Research Funding. Kenderian:Novartis: Patents & Royalties, Research Funding. Kay:Pharmacyclics: Research Funding; Tolero Pharmaceuticals: Research Funding; Acerta: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Morpho-Sys: Membership on an entity's Board of Directors or advisory committees; Infinity Pharm: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Shanafelt:Janssen: Research Funding; Pharmacyclics: Research Funding; GlaxoSmithkKine: Research Funding; Genentech: Research Funding; Cephalon: Research Funding; Celgene: Research Funding; Hospira: Research Funding. Parikh:Pharmacyclics: Honoraria, Research Funding.

Abstract Background Although hypogammaglobulinemia is a well-recognized complication in patients with chronic lymphocytic leukemia (CLL), its prevalence at the time of CLL diagnosis and association with novel prognostic markers and clinical outcomes are not well understood. Methods All patients seen at Mayo Clinic between 1/1995 - 4/2013 with newly diagnosed CLL (<12 months diagnosis) and who had baseline assessment of serum immunoglobulin G (IgG) were included in this analysis. Baseline demographic and clinical characteristics as well as serum IgG levels measured by either immunoassay or serum protein electrophoresis analysis were recorded. Based on the normal range for IgG at our laboratory, patients with serum IgG<757 mg/dL were classified as having hypogammaglobulinemia. Patients with IgG<757 were also further stratified by terciles (lower tercile: IgG<585 mg/dL; middle tercile: IgG 585-687 mg/dL, upper tercile: IgG 688-756 mg/dL). The relationship between hypogammaglobulinemia at diagnosis and prognostic parameters including immunoglobulin heavy chain (IGHV) gene mutation status, genetic abnormalities detected by fluorescence in-situ hybridization (FISH), and ZAP-70, CD38 and CD49d expression was assessed. Associations of hypogammaglobulinemia with time to first treatment (TTT) and overall survival (OS) was also evaluated. Results Of 1485 patients who met the eligibility criteria, 382 (26%) had hypogammaglobulinemia (median IgG=624 mg/dL) at the time of CLL diagnosis while the remaining 1103 (74%) had normal serum IgG levels (median IgG=1040 mg/dL). Baseline demographic and clinical characteristics of patients with and without hypogammaglobulinemia are shown in Table 1. When patients with hypogammaglobulinemia (IgG<757 mg/dL) were further stratified into terciles, patients in the lower tercile (n=127) were more likely to have advanced Rai stage (III-IV) at diagnosis (15% vs. 6% vs. 4%, p=0.008), be CD49d positive (56% vs. 43% vs. 32%, p=0.01), and have trisomy 12 on FISH testing (29% vs. 24% vs. 9%, p=0.005) compared to patients in the middle (n=127) and upper (n=128) terciles. After median follow-up of 4.2 years, 479 (32%) patients had received treatment for CLL, and 328 (22%) patients had died. The median TTT for patients with hypogammaglobulinemia was 3.8 years compared to 7.4 years for patients with a normal IgG (p-value<0.001). Among patients with hypogammaglobulinemia, the median TTT for patients in the lower, middle, and upper terciles were 1.7, 2.9, and 6.3 years respectively (p-value<0.001, Figure 1). On multivariable analysis that included age, gender, Rai stage, IGHV mutation status, FISH risk category and hypogammaglobulinemia, the following were independently associated with a shorter TTT: advanced (III-IV) Rai stage (hazard ratio [HR] =15.3, p<0.0001); intermediate (I-II) Rai stage (HR=3.0, p<0.0001); unmutated IGHV (HR=2.6, p=<0.0001); and hypogammaglobulinemia (HR=1.5, p=0.02). Conclusion In this large cohort study, approximately one-quarter of CLL patients had a low serum IgG level at the time of diagnosis. High-risk features, including advanced Rai stage and expression of CD49d, were associated with greater risk of hypogammaglobulinemia at the time of diagnosis. Patients with hypogammaglobulinemia at diagnosis had shorter TTT, a finding that persisted after adjusting for other prognostic factors. Evaluation of acquired hypogammaglobulinemia during the course of follow-up among patients who initially had normal IgG levels is ongoing. Disclosures: Shanafelt: Genentech: Research Funding; Glaxo-Smith-Kline: Research Funding; Cephalon: Research Funding; Hospira: Research Funding; Celgene: Research Funding; Polyphenon E International: Research Funding.

Abstract Introduction Outcomes have improved in treating lymphoid malignancies but relapse remains an ongoing issue. The mTOR inhibitor, everolimus (RAD) and lenalidomide (LEN) have both shown clinically significant activity as single agents in patients with relapsed and refractory (R/R) Hodgkin (HL) and non-Hodgkin (NHL) lymphomas. The low toxicity and differing mechanisms of action were explored further by combining these active agents. A phase I/II clinical trial of the mTOR inhibitor everolimus (RAD) and lenalidomide (LEN) was designed to explore the tolerability, toxicity and to determine the MTD of this combination for Phase II study. The phase I data is reported here. Methods This Phase I/II trial for patients with R/R lymphoid malignancy opened at Mayo Clinic between January 2011 and May 2013 and utilized a standard cohort of 3+3 design to determine the MTD of the combination. Eligibility required age≥18, biopsy proven relapsed or refractory NHL or HL, ECOG PS 0, 1 or 2, measurable disease, Hb >9g/dl, ANC ≥1200/uL, platelet ≥ 50,000/uL, creatinine ≤1.5xULN and willingness to sign informed consent. Women of child bearing potential had pregnancy testing and all patients followed recommendations for contraception. Dose limiting toxicity was defined in cycle 1 as Gr 4 neutropenia ≥7days or platelets ≤ 25,000 ≥7days, grade 4 infection or grade ≥3 non-Heme toxicity at least possibly related to treatment per CTCAE v4.0. The starting dose (level 0) was RAD 5mg daily + LEN 10 mg/d X 21d in a 28-day cycle. Results Twenty-five patients were enrolled on the phase I portion and 23 are evaluable for analysis. The median age was 63 years (23-82) and 18 (78%) were male. Sixty-five percent had stage IV disease and 43% had 4 or more prior treatments (1- ≥5) including stem cell transplantation in 39%. Histologies included HL (n=3) and NHL (n=20)(DLBCL = 11, FL-III = 2, LPL = 3, MCL = 1, MF = 1, and other = 2). Two DLTs (rash, Gr4 neutropenia) were reported at the starting dose (level 0) and the protocol was amended for DLT definition change. At dose level -1 (RAD 5mg daily + LEN 5mg/d X 21d) a DLT (Gr4 neutropenia) was seen in only 1 of 6 patients so the study was re-opened to dose level 0 and 3 additional patients were treated without developing a DLT. At dose level +1 (RAD 5 mg daily + LEN 15mg/d X 21d) 1 Gr3 rash occurred and 2 patients experienced Gr4 neutropenia. Therefore the MTD was determined to be RAD 5mgdaily + LEN 10 mg/d X 21d. At least 1 Gr≥3 adverse event was seen in 91% of patients. The most common Gr≥3 toxicities were neutropenia (57%), leucopenia (52%), thrombocytopenia (39%), fatigue (22%), and anemia (13%). Eight of 23 patients (35%) had Gr≥3 infection. Five patients discontinued study due to adverse events. One death on study occurred due to disease progression. Three patients continue on therapy. Responses have been seen in 4 patients and 10 patients have stable disease, encouraging signs in this heavily pretreated population. Conclusions This phase I/II trial of everolimus and lenalidomide in malignant lymphoma shows the combination to be tolerable with neutropenia as the main dose limiting toxicity. The MTD of this combination is RAD 5mg daily and LEN 10 mg/d X 21 d. Encouraging responses were seen. The phase II study has opened with 2 patients accrued to date. Updated results will be presented. This trial is sponsored by Novartis and Celgene Disclosures: Reeder: Celgene: Research Funding; Novartis: Research Funding; Millenium: Research Funding. Off Label Use: lenalidomide and everolimus are not approved for treatment of lymphoma. Nowakowski:Celgene: Membership on an entity’s Board of Directors or advisory committees, Research Funding. Witzig:Celgene: Research Funding.

Abstract Introduction Approximately 2-8% chronic lymphocytic leukemia (CLL) patients develop diffuse large B-cell lymphoma (DLBCL, so-called Richter syndrome [RS]) over long-term follow-up. The outcomes of patients with RS are variable and poorly understood. Methods CLL patients seen at Mayo Clinic from January 1995 to April 2013 who developed biopsy-proven DLBCL during follow-up were included in this analysis. Clinical characteristics, therapy and overall survival (OS) of all patients with RS were analyzed. Results One hundred and twenty patients with biopsy-proven RS were identified in the Mayo Clinic database. The median age at diagnosis of RS was 67 years (range, 29-88 years), 87 (73%) were male, and 83 (69%) had received prior CLL therapy. The median duration between diagnosis of CLL and development of RS was 3.8 years (range, 0-34.5 years). Stereotyped B-cell receptors were found in 9/30 (30%) RS patients compared to 219/1294 (17%) non-RS patients (OR=2.1, p=0.07). IGHV4-39 gene usage was present in 2/26 (8%) RS patients compared to 57/1354 (4%) non-RS patients (p=0.3). Of the 30 RS biopsy samples in which Epstein Barr virus (EBV) in-situ hybridization studies were performed, EBV was detected in 7 (23%) patients. After a median follow-up of 5.2 years, 86 (72%) patients have died. Causes of death were as follows: progressive DLBCL (n=46, 53%), progressive CLL (n=2, 2%), infection (n=8, 9%), unknown (n=20, 23%) and other (n=10, 12%). The median OS of the entire cohort was 0.9 years (95% CI, 0.5-1.3 years). Tsimberidou and colleagues proposed a prognosis score (RS score) based on the following variables at the time of RS diagnosis: Eastern Co-operative Group performance status of 2-4, lactate dehydrogenase >1.5 x normal, platelets<100 x 109/L, tumour size >5 cm and >1 prior therapy for CLL. Each parameter was assigned one point, and patients were then assigned to one of four risk groups based on their calculated RS score: 0 or 1, low risk; 2, low-intermediate risk; 3, high-intermediate risk; 4 or 5, high risk. The OS according to the RS score for our group of patients is shown in Figure 1. Median survival in the low, intermediate-1, intermediate-2 and high-risk groups were 2.4 years, 0.7 years, 0.3 years and 0.2 years, respectively (p<0.001). Fifteen (12%) patients received cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) as initial therapy for RS, and 68 (57%) received rituximab in addition to CHOP (R-CHOP). There was no difference in survival among patients who received CHOP compared to R-CHOP (median, 1.8 years. vs. 1.2 years, p=0.5). Twenty-four patients (20%) received non-CHOP-based chemotherapy, and treatment was unknown in 4 (3%) patients. Nine patients (7%) died before definitive therapy could be instituted. Thirteen (11%) patients were able to proceed to stem cell transplantation (SCT): 10 (8%) autologous SCT, 2 (2%) allogeneic SCT and 1 (1%) autologous SCT followed by an allogeneic SCT. Although RS patients who underwent SCT were younger compared to those who did not undergo SCT (median, 59 years. vs. 69 years, p=0.001), no differences in prior CLL therapy or receipt of R-CHOP therapy for DLBCL was noted between the two groups. The median survival of patients who proceeded to SCT was superior compared to those who did not (5.2 years vs. 0.7 years; p=0.005). Conclusion Stereotyped B-cell receptors but not VH4-39 had a suggested evidence of an increased risk of RS in our cohort. Although 90% RS patients received intensive chemotherapy, only 11% patients were able to proceed to SCT. Median survival of RS patients remains dismal at 1 year, and newer therapies are needed to improve outcomes. Disclosures: Shanafelt: Genentech: Research Funding; Glaxo-Smith-Kline: Research Funding; Cephalon: Research Funding; Hospira: Research Funding; Celgene: Research Funding; Polyphenon E International: Research Funding.

Abstract BACKGROUND: Although chemoimmunotherapy (CIT) has 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. Interactions with nurturing environments can enhance CLL B-cell resistance to apoptosis. These interactions include cytokine mediated prosurvival signals by angiogenic molecules, such as VEGF and bFGF that nurture CLL B-cells in an autocrine fashion and promote CLL cell survival partly through up regulation of anti-apoptotic proteins. These findings provide a strong rationale for testing anti-VEGF therapy in combination with a purine nucleoside analogue CIT regimen for upfront treatment. We conducted a randomized phase 2 CIT trial using pentostatin, cyclophosphamide, and rituximab with (PCR-B) or without (PCR) bevacizumab (B), an anti-VEGF monoclonal anti-body. METHODS: Eligible patients were previously untreated and had CLL in need of treatment by NCI-WG criteria (Blood 111:5446). Patients were randomized using a dynamic allocation procedure stratifying for stage (0-II vs. III-IV) and FISH (17p or 11q deletion vs. other) to receive either 6 cycles of rituximab (100 mg on day 1 of cycle 1; 375 mg/m2on day 2 of cycle 1 and day 1 of cycles 2-6) followed by pentostatin (2 mg/m2) and cyclophosphamide (600 mg/m2) (PCR) administered every 21 days. Patients in the PCR-B cohort also received bevacizumab 15mg/kg on day 1 of cycles 1-5 and days 1, 22, & 43 of cycle 6. All patients underwent complete response evaluation 3 months after day 1 of cycle 6 (or last cycle of treatment for those completing < 6 cycles). MRD was assessed using 6-color flow cytometry (Leukemia 21:956) at the completion of treatment. RESULTS: 68 patients were enrolled through the Mayo Clinic Cancer Research Consortium between 1/2009 and 1/2013. Three patients were excluded from analysis: 1 patient canceled prior to treatment, 1 was dosed incorrectly, and 1 was ineligible due to immunophenotyping inconsistent with CLL. Median age of eligible patients was 63 years (range 43-81) and 43 (66%) were men. With respect to disease stage, 3 (5%), 38 (58%), and 24 (37%) had low, intermediate and high Rai stage disease. Eleven (17%) patients had deletion 17p or 11q & 29 (45%) had unmutated IGHV. No statistically significant differences were observed in these variables by treatment arm. All 65 evaluable patients have completed active treatment, with 54 (83.1%) completing the intended 6 cycles (PCR group 27/32 [84.4%] and PCR-B 27/33 [81.8%]). Hematologic grade 3+ adverse events deemed at least possibly related to treatment were observed in 10 (31.3%) patients on PCR and 12 (36.4%) on PCR-B (p=0.79). Non-hematologic grade 3+ adverse events deemed at least possibly related to treatment were observed in 9 (28.1%) patients on PCR and 18 (54.4%) on PCR-B (p=0.04). The most common such events were hypertension (PCR: 3.1% vs. PCR-B: 21.2%), proteinuria (0% vs. 6.1%) and creatinine increase (3.1% vs. 6.1%). Across both arms, 64/65 (98.5%) patients achieved a response including 31/32 (96.9%) treated with PCR and 33/33 (100%) treated with PCR-B (p=0.49). CR/CRi was achieved in 10/32 (31.3%) patients treated with PCR & 18/33 (54.5%) treated with PCR-B (p=0.08). Of the 28 who achieved a CR/CRi, MRD analysis was completed on 26, of whom 12 (46%) were MRD negative. With respect to treatment arm, 5/32 (16%) patients on PCR and 7/33 (21%) on PCR-B achieved an MRD negative CR. Median time to retreatment for all 65 patients was 44.8 (95% CI: 34.6 – NA) months. Median overall survival has not yet been reached. With current follow-up no differences between treatment-free survival (p=0.38), progression-free survival (p=0.23), or overall survival (p=0.45) are observed by treatment arm. Plasma levels of angiogenic cytokines VEGF, bFGF, thrombospondin (TSP) and the chemokines CCL3 and CCL4 were measured prior to treatment and at the time of the post treatment response evaluation. Correlations of these cytokines with clinical outcome will be presented. CONCLUSION: The addition of bevacizumab to purine analogue-based CIT was generally well-tolerated and may increase complete remission rates in patients with CLL. No clear improvement in treatment free survival has been observed to date. Disclosures Shanafelt: Hospiria: Research Funding; Pharmacyclics/Jannsen: Research Funding; Cephalon: Research Funding; Celgene: Research Funding; glaxoSmithKline: Research Funding; Genetech: Research Funding; Polyphenon E Int'l: Research Funding. Off Label Use: Off label use of pentostatin for treatment of CLL. Off label use of bevacizumab for treatment of CLL. . Kay:Genetech: Research Funding; Pharmacyclics: Research Funding; Hospira: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees.

Abstract Introduction Non-Hodgkin lymphoma responds to single agents such as cyclophosphamide, combination therapy such as CVP and immunotherapy with monoclonal antibodies such as rituximab. There is no consensus on the optimal treatment for relapsed low grade or mantle cell lymphoma. Based on the success and tolerability of combining alkylating agents with proteasome inhibitors in multiple myeloma, a phase II clinical trial of rituximab, cyclophosphamide, bortezomib, and dexamethasone (R-CyBor-D) was designed to explore the efficacy and safety of this combination in relapsed low grade and mantle cell lymphoma (MCL). Methods This trial enrolled relapsed patients at Mayo Clinic from October 2008 to March 2014. Eligibility required age≥18; biopsy proven follicular grades 1 or 2 lymphoma (FL), MCL, small lymphocytic lymphoma/chronic lymphocytic leukemia, marginal zone B-cell lymphoma, or Waldenström’s macroglobulinemia (WM); life expectancy >3 months; ECOG PS 0, 1 or 2; measurable disease; Hb ≥8g/dl, ANC ≥1200/uL, platelet ≥75,000/uL, creatinine ≤1.5xULN, total bilirubin ≤1.5xULN, alkaline phosphatase ≤3xULN, AST ≤3xULN; and willingness to sign informed consent. Women of child bearing potential had pregnancy testing and all patients followed recommendations for contraception. Treatment included rituximab 375 mg/m2 IV on day 1 and oral cyclophosphamide 300 mg/m2, IV bortezomib 1.3 mg/m2, and oral dexamethasone 40 mg on days 1, 8, 15, and 22 in a 28-day cycle. Treatment was continued two cycles beyond best response or a maximum of 12 cycles. Allopurinol 300 mg on days 0-14 for the first cycle was strongly recommended. Results 21 patients were enrolled prior to study closure due to slow accrual. Bortezomib was initially given on days 1, 4, 8, and 11 in the first 16 patients, but was subsequently modified to days 1, 8, 15, and 22 due to significant peripheral neuropathy (PN). Median age was 69 years (range 51-80) and 13 (62%) were male. 62% had stage IV disease and 17 (81%) had 2 or more prior treatments with 3 (14%) having prior autologous stem cell transplantation. Histologies included FL-I (n=6), FL-II (n=2), MCL (n=8), and WM (n=5). Patients completed a median of 4 cycles of treatment (range 1-12), discontinuing due to 9 (43%) completion per protocol, 4 (19%) progression, 5 (24%) adverse events, 1 (5%) patient refusal, and 2 (10%) other reasons. Median follow-up is 32.8 months (0.9-54.8). CR or PR as best response was observed in 13 (62%, 95% CI 38-82%; 4 CR [19%], 9 PR [43%]) patients. By histology, CR or PR was observed in 7 (88%) FL patients (4 CR, 3 PR); 2 (25%) MCL patients (both PR), and 4 (80%) WM patients (all PR). CR or PR was observed in 10/16 (62%; 4 CR, 6 PR) before and 3/5 (60%; all PR) after the change in bortezomib schedule. Among 13 patients with CR or PR, median duration of response was 25.9 months (95% CI 8.0-not reached). Median PFS and OS were 11.6 months (95% CI 3.8-not reached) and 54.8 months (95% CI 24.6-54.8), respectively. At least one Gr≥3 adverse event at least possible related was observed in 14 (67%) patients, the most common being leucopenia (7, 33%), neutropenia (7, 33%), thrombocytopenia (6, 29%), anemia (5, 24%), PN (5, 24%), and fatigue (3, 14%). Peripheral sensory neuropathy at least possibly related was Gr1, Gr2, and Gr3 in 5 (24%) patients each, with a lower rate observed for patients after the change in bortezomib schedule (before 13/16 [81%] Gr≥1, after 2/5 [40%] Gr≥1). Among 14 patients who completed a baseline and at least one post-baseline FACT/GOG-NTX additional concerns questionnaire, 10 (71%) reported clinically meaningful (≥3-point) worsening in patient-reported neurotoxicity (8/11 [73%] before and 2/3 [67%] after the change in bortezomib schedule). Conclusions Our results suggest R-CyBor-D is a safe and effective combination in patients with relapsed low grade and mantle cell lymphomas. High response rates were seen in FL and WM. The majority of significant AE’s were hematologic. However, sensory neuropathy was common with twice weekly dosing of bortezomib and lessened with weekly dosing. Determination of optimal treatment regimens in this population remains an unmet need. Additional clinical trials including larger patient numbers are necessary to confirm these observations. This trial was sponsored by Millennium Disclosures Off Label Use: bortezomib was used in combination therapy to treat relapsed low grade lymphomas and Waldenstrom's macroglobulinemia. Bergsagel:Novartis: Research Funding; Constellation Pharmaceutical: Research Funding; OncoEthix: Research Funding; MundiPharma: Research Funding. Tiedemann:Janssen: Honoraria. Reeder:Millennium, Celgene, Novartis: 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.