Weiner, George J.

Abstract Background: There are a number of ongoing clinical trials assessing next-generation immunochemotherapy (IC) regimens (i.e. RX-CHOP) in DLBCL. In addition to standard clinical trial workup, some trials require central pathology review and/or molecular phenotyping before treatment assignment and/or initiation of therapy. There is concern that these studies may be biasing patient selection due to missing patients with aggressive disease who require immediate therapy and cannot delay their treatment to enroll on a study. Here we examine clinical characteristics and outcome stratified by the time from diagnosis to initiation of therapy from a large observational cohort of patients with DLBCL from the R-CHOP era. Methods: Patients were prospectively enrolled in the University of Iowa / Mayo Clinic SPORE Molecular Epidemiology Resource (MER) within 9 months of diagnosis and followed for relapse, retreatment, and death. Clinical management at diagnosis and subsequent therapies were per treating physician. This analysis includes patients with stage II-IV DLBCL or primary mediastinal B-cell lymphoma (PMBCL) who underwent front-line anthracycline based IC; patients with primary CNS lymphoma, PTLD, or a component of low-grade lymphoma were excluded. Time from diagnosis to treatment was defined as the time from date of first lymphoma-containing biopsy to the initiation of IC therapy; delayed therapy was defined as initiating therapy more than 14 days after diagnosis. Event-free survival was defined as time from diagnosis until progression, retreatment, or death due to any cause. EFS24 was defined as progression free status 24 months from diagnosis. Results: 720 patients with stage II-IV newly diagnosed DLBCL or PMBCL and treated with IC were enrolled in the MER from 2002-2012. Median age at diagnosis was 62 years (range 18-92) and 399 patients (55%) were male. 541 patients (75%) had stage III/IV disease and IPI at diagnosis was 0-1 in 166 patients (23%), 2 in 221 patients (31%), 3 in 222 patients (31%) and 4-5 in 111 patients (15%). 233 of 395 patients (59%) were GCB per Hans. At a median follow-up of 73 months, (range 0-163), 349 (49%) patients had an event and 267 patients died (37%); 37% of patients failed to achieve EFS24. Median time from initial lymphoma diagnosis to initiation of IC was 14 days (range 0-79, IQR=8-23). Patients with delay in therapy (>14 days from diagnosis) were more frequently female (50%, p=0.0051) and older than patients who initiated therapy within 14 days from diagnosis (median age at diagnosis of 63 years vs. 60 years, p=0.0008). Patients with delay in treatment initiation had universally less aggressive disease characteristics, including earlier stage, non-elevated LDH, 0-1 extranodal sites, absence of B-symptoms, lower ECOG PS, and lower IPI (see table). In addition, patients with delayed therapy were enriched for GCB subtype per Hans algorithm (p=0.056). Patients with initiation of therapy within 14 day of diagnosis had significantly worse outcome (EFS24 failure=44%) compared to patients with delayed time to initiation of therapy (EFS24 failure=28%, p<0.0001, figure), which remained significant after adjusting for either IPI or aaIPI (both p<0.005). The association between delayed time to initiation of therapy and EFS24 was observed in both GCB (EFS24 failure = 42% vs. 27%, p=0.019) and non-GCB (EFS24 failure = 46% vs. 27%, p=0.014) subsets by Hans. The lower event rate in delayed therapy patients results in an approximately 10% loss of power if the study was powered based on all patients regardless of timing from diagnosis to therapy. Conclusions: Patients with delayed therapy from diagnosis have less aggressive clinical characteristics compared to patients who initiate treatment within 14 days from diagnosis. Studies with a lengthy trial work-up including central pathology review period may be selecting patients with less aggressive disease based on the patient's ability to delay treatment to complete study enrollment requirements. Furthermore, selection of patients with less aggressive disease may result in underpowered studies due to a lower event rate (fewer events) than expected. This retrospective analysis would suggest that trials in DLBCL should consider streamlined enrollment and therapy initiation to avoid potential selection bias and loss of power. Further assessment of implications on trial design and outcomes by cell of origin in this setting is ongoing. Table Table. Figure Figure. Disclosures Maurer: Kite Pharma: Research Funding; Celgene: Research Funding. Ansell:BMS, Seattle Genetics, Merck, Celldex and Affimed: Research Funding. Nowakowski:Morphosys: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Research Funding.

Abstract Abstract 1790 CLL is incurable with conventional therapies and prognosis is poor in patients with relapsed or treatment refractory disease. Patients with purine analogue refractory disease and defective TP53 function have limited therapeutic options. Based on: 1) The ability of purine analogues to decrease tumor burden; 2) Higher response rates in patients treated with alemtuzumab and rituximab vs. alemtuzumab alone; and 3) Data showing that more frequent lower doses of rituximab could be more effective than standard therapy, we hypothesized that combination therapy with pentostatin, alemtuzumab and low dose rituximab (PAR) would be effective and tolerable therapy for patients with relapsed/refractory CLL and those with previously untreated progressive CLL who had 17p13-. This two stage phase II University of Iowa/Mayo Clinic Lymphoma SPORE clinical trial (NCT00669318) was approved by Mayo Clinic and the University of Iowa IRBs according to the principles of the Declaration of Helsinki. The aims are to assess: 1) Complete (CR) and overall responses; and 2) Progression-free survival (PFS), duration of response, and time to next treatment (TTT). Patients with progressive CLL (including the SLL variant) defined by standard criteria are eligible for this study if they had either previously treated CLL or previously untreated CLL with 17p13-. Cycle 1 of therapy is 5 weeks with rituximab 20 mg/m2/d IV Mon-Wed-Fri starting day 1, subQ alemtuzumab beginning days 3–5 with a dose escalation (3 mg–10 mg– 30 mg/d) and then 30 mg/d Mon-Wed-Fri, and pentostatin 2mg/m2/dose/IV days 8 & 22. Cycles 2–3 are each of 4 weeks duration and are the same as weeks 2–5 of cycle 1. Patients who achieve CR after cycle 2 with a negative CT scan and bone marrow study with no evidence of residual CLL cells after immunohistochemical staining, do not receive cycle 3 of therapy. All patients receive granulocyte growth factor support after pentostatin therapy as well as PCP and herpes virus prophylaxis. Patients are tested for CMV reactivation by PCR weekly during therapy and treated with valganciclovir if reactivation is detected. We report the results of the planned interim analysis performed after completion of therapy for the first 19 patients (July 2008 - October 2010). The median patient age was 63 years (range 47–78) with 74% males. Two patients with 17p13- were previously untreated. Of the 17 previously treated patients (median 2 prior regimens, range 1–6), 8 (47%) had purine analogue refractory CLL (disease progression < 6 months of treatment). Nine (47%) patients had advanced clinical stage (Rai III-IV). Adverse molecular prognostic factors were 17p13- (n=8, 42%, 2 also had 11q22-), 11q22- (n=1), unmutated IGHV (12/17, 71%), ZAP70+ (≥20%, 12/17, 71%) and CD38+ (≥30%, 6/18, 33%). The median beta-2-microglobulin level was 4.3 (range 2.4 – 12.6). Grade 3–4 treatment related toxicities were 9 non-hematological and 20 hematological events. Grade 3–4 infections occurred in 3 patients including one patient requiring hospitalization for CMV re-activation. Fourteen (74%) patients responded to treatment with 6 (32%) CR (includes 2 CRi) and 8 (42%) partial responses (PR). Five (26%) patients had stable disease (SD). Eleven (58%) patients completed 3 cycles of therapy. One patient achieved a CR with no residual disease after 2 cycles of therapy and received no further treatment per protocol. Median duration of response is 7 months (95% CI: 4–not reached (NR)). Among the 8 patients with 17p13- there were 3 CR/CRi, 4 PR, and 1 SD. Four patients proceeded to allogeneic transplant with reduced intensity conditioning (RIC) and were censored for TTT at the initiation of transplant related therapy. With a median of 16 (range 6 – 35) months of follow up, median PFS is 7 months (95% CI: 5–NR), median TTT is 27 months (95% CI: 5-NR) and the calculated median overall survival is 23 months (95% CI: 14–NR). We report that PAR is effective and tolerable therapy in this population of relapsed refractory patients with high to very-high risk CLL. In addition, the responses in patients with 17p13- were similar to that of the patients who did not have 17p13-. The treatment regimen was useful for disease control in 3 patients who proceeded to reduced intensity conditioning allogeneic transplantation. This study shows that PAR could play an important role in the treatment of recurrent and high risk CLL. Supported by the University of Iowa/Mayo Clinic Lymphoma SPORE CA097274 Disclosures: Zent: GlaxoSmithKline: Research Funding; Genentech: Research Funding; Genzyme: Research Funding.

Abstract Background: Aberrant B-cell receptor (BCR) and MYD88 signaling cooperatively drive Waldenstrom macroglobulinemia (WM) tumor cell survival. To sustain BCR-driven growth and maintain optimal cellular homeostasis, WM cells upregulate proteasome function. We have recently described the role of two distinct 19S proteasome-associated deubiquitinating enzymes (DUBs), USP14 and UCHL5, in maintaining WM-cell viability. Pharmacologic inhibition with b-AP15 (commercial compound) results in WM-cell death and accumulation of high molecular weight ubiquitinated protein conjugates; an event that is phenocopied by siRNA knockdown of USP14 and UCHL5. VLX1570 is a lead-optimized clinical grade analog of b-AP15 with enhanced solubility, stability and target residence time. We investigated the effect of VLX1570 on BCR components, WM cell survival proteins and its in vivo activity in a human xenograft model of WM. Materials: VLX1570 was obtained from Vivolux AB and bortezomib from Sellekchem. Human WM cell lines (BCWM.1, MWCL-1 and RPCI-WM1) and their drug-resistant derivatives were used (total n=12). Bone marrow aspirates from WM-patients and from healthy donors were obtained from the Mayo Clinic biospecimens core. PBMCs from healthy donors were used as comparators where needed. NOD/SCID mice were obtained from Taconic Labs and used for profiling the in vivo properties of VLX1570. Results: We first examined for USP14/UCHL5 protein expression by immunohistochemical analysis in primary tumor tissue from WM patients and compared it to healthy donor cells. WM patient-derived cells exhibited greater staining intensity of both DUBs. Preferential binding of VLX1570 to USP14 and UCHL5 in WM cells was probed in a WM cell using an enzyme-based competition assay (HA-Ub-Vs), which demonstrated time-dependent decrease in labeled USP14 and UCHL5 after treatment with VLX1570. In drug-resistant (bortezomib or ibrutinib-resistant) WM cells, VLX1570 induced >50% tumor-specific apoptosis and displayed synergistic activity with ibrutinib (median CI: 0.5). In addition to ER stress markers, we had previously observed that gene expression of BCR-signalosome components were reduced in VLX1570-treated WM cells (NanoString platform) and this was substantiated at the protein level where p-SYK, SYK and BTK decreased in a time-dependent manner. BCR end-effectors were probed in response to VLX1570 and a decrease in nuclear translocation of NFkB (p65) was noted. USP14 has been shown to control the availability of the chemokine receptor CXCR4, which regulates homing of WM cells to bone marrow. After VLX1570 treatment, we noted a significant decrease in CXCR4 surface receptor expression in all WM cell lines tested and primary WM cells. Lastly, to determine the in vivo anti-WM effects of VLX1570, we injected NOD/SCID mice (xenotransplanted with RPCI-WM1-Luc cells) with VLX1570 (I.P. route, 4.4mg/kg every other day) and measured tumor burden along with pharmacodynamic indicators. VLX1570-treated mice (n=7) demonstrated significantly lower tumor volumes by caliper measurement and bioluminescent signal (p=0.01 - 0.003) as well as reduced serum human-IgM, compared to vehicle-treated mice (n=7). Importantly, mice treated with VLX1570 survived longer vs. vehicle-treated mice (median survival, 62 vs. 44 days, respectively, p=0.0008). No unforeseen toxicities were noted and weight of the mice in vehicle vs. VLX1570-treated mice did not significantly change. IHC analysis in mice tumor tissues demonstrated reduced CXCR4, human-IgM, Ki67 and increased cleaved caspase-3 and ubiquitinated (k48-linked) protein level, the latter serving as a more specific indicator of USP14/UCHL5 inhibition. Conclusions: We provide substantial in vitro and in vivo evidence on the anti-WM effects of a novel first-in-class clinical grade USP14/UCHL5 inhibitor, VLX1570. In addition to anticipated induction of ER stress machinery, we describe for the first time VLX1570-mediated modulation of BCR components and WM cell survival proteins as well as demonstrate its robust activity in an aggressive human xenograft model of WM. These data provide the rationale for a clinical trial of single agent VLX1570 in patients with symptomatic WM. Disclosures Martin: Janssen: Consultancy, Honoraria; Acerta: Consultancy; Gilead: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Bayer: Consultancy. Gullbo:Vivolux AB: Other: Shareholder. Linder:Vivolux AB: Other: Shareholder.

Abstract Abstract 3585 Relapsed/refractory CLL is often resistant to antibody-based therapy. Understanding the dynamics of interaction between complement and cell-based antibody-antigen complexes that promote complement dependent cytotoxicity (CDC) of targeted cells could lead to improved therapies. We are conducting a clinical trial of chemoimmunotherapy for relapsed/refractory CLL using pentostatin, alemtuzumab (ALEM), and low-dose rituximab (RTX). Correlative studies were designed to determine if circulating CLL cells developed resistance to CDC. Peripheral blood CLL cells were obtained from 12 patients (median age 66 years, 11 male, 17p13- in 4) including 7 (58%) who responded (4 CR, 3 PR) to treatment. Blood samples were obtained before initiating therapy (day 1), 48 hr after the 1st RTX dose (20 mg/m2 IV MWF), one hour after the 2nd dose of RTX and 1st dose of ALEM (3 mg SC) (day 3), and 72 hr after the 3rd doses of RTX (cumulative dose 60 mg/m2) and ALEM (cumulative dose 43 mg) (day 8). All blood samples were taken prior to the 1st dose of pentostatin. B cells were examined for expression of several markers including complement control proteins (CCP), CD20 and CD52. By treatment day 8, ALC decreased by 70 % or more for 7 patients. The other 5 patients had ALC that were 50 – 100% of pre-treatment levels. In agreement with previous studies from our laboratories, low-dose RTX rapidly decreased CD20 levels on circulating CLL cells; on day 3 after the 2nd RTX dose (and 1st ALEM dose), CD20 was reduced by > 75% in 10 subjects. CD20 levels recovered by day 8 in 6 of these subjects. One hour after completion of mAb infusions on day 3, fragments of complement breakdown product C3dg were demonstrable on circulating CLL cells in 7 subjects, suggesting that infusion of RTX had promoted complement activation on circulating cells. After the RTX and ALEM infusions on day 3, circulating CLL cells with bound C3dg fragments had considerably reduced levels of CD20 but were not cleared from the circulation, suggesting that RTX had bound to the cells, activated complement and promoted shaving (CD20 loss) without inducing bloodstream clearance of these cells. CD52 levels on circulating CLL cells showed modest decreases by day 8 (~ 50% of pre-treatment values) in 4 subjects. To study CDC in vitro, washed blood samples were reconstituted with ABO-matched normal human serum, ALEM was added and complement activation (C3 fragment deposition) and CDC of targeted CLL cells were measured by flow cytometry. Alternatively, mononuclear cells were isolated by ficoll-hypaque centrifugation and subjected to the same analyses, with very similar results. ALEM-mediated in vitro CDC of CLL cells varied from 10 to 90 % for pre-treatment blood samples. Measures of ALEM-mediated CDC and C3b fragment deposition in vitro correlated with the density of CD52 on CLL cells (P<0.001). The initial burden of circulating cells was not predictive of a drop in ALC, and pre-therapy levels of CDC were not correlated with cell clearance after therapy. On day 8, ALEM-mediated in vitro CDC of circulating CLL cells had decreased to <50% of the values measured on pre-treatment samples in 6 subjects, suggesting that cells of these patients might be developing resistance to ALEM-mediated CDC. This decrease in CDC was not correlated with decreases in levels of CD52 expression on patients’ CLL cells or with increases in expression of CCP (CD35, CD46, CD55, CD59). Our findings demonstrate that even after treatment with both RTX and ALEM, CLL cells can persist in the bloodstream in a subset of patients, suggesting that some patients have circulating CLL cells that are resistant to mAb-mediated clearance and CDC due to mechanism(s) that may include loss of antigen and possibly intrinsic resistance. Disclosures: Zent: Genzyme: Research Funding; Genentech: Research Funding; Novartis: Research Funding; G.S.K.: Research Funding. Weiner:Genentech: Consultancy.

Abstract Background: The clinical impact of ibrutinib is irrefutable and has been hailed as a revolutionary treatment for several cancers, including mantle cell lymphoma (MCL). Despite high response rates noted with ibrutinib therapy in MCL (ORR, 68%), complete responses are low and durability of remission is suboptimal in MCL vs. CLL or Waldenstrom macroglobulinemia (WM) patients (Cheah et al Ann Oncol 2015). This relative lack of efficacy may be due to MCL cells having a higher proliferation rate and being less indolent in nature than CLL or WM cells. Tumor cells with a high proliferation index rely on optimally functioning protein metabolism/homeostasis systems. In MCL, this observation has been fortuitously exploited with the use of bortezomib, a 20S proteasome inhibitor. Indeed the ubiquitin proteasome system is a validated target and consists of several individual components whose function in MCL has yet to be mapped out. We have recently reported that inhibition of the 19S proteasomal deubiquitinating enzymes (DUBs), USP14 and UCHL5; with the small molecule inhibitor b-AP15 is lethal to drug-resistant WM tumor cells. This intriguing observation, prompted us to define the role of USP14/UCHL5 and their inhibition in a diverse panel of B-cell lymphoma cell lines, including MCL models as well as ibrutinib-resistant MCL cells. Materials: b-AP15 (and its clinical grade analog, VLX1570) was obtained from Vivolux AB and bortezomib from Sellekchem. Human NHL (DLBCL, MCL, Burkitt), Hodgkin lymphoma (HL), multiple myeloma (MM) cell lines as well as established drug-resistant subclones were used in drug-sensitivity screening experiments (total n=25). Results: USP14 and UCHL5 mRNA expression was queried in the CCLE database (Broad-Novartis) and showed highest expression in plasma cell and B-lymphoid tumor cell types. This was also observed at the protein level, wherein analysis of The Human Protein Atlas database revealed moderate to high intensity staining for USP14 and UCHL5 localizing to the cytoplasmic/membranous and nuclear compartments in high-grade NHL tissues. Next, we examined B-lymphoid tumor cell sensitivity to pharmacologic inhibition of USP14/UCHL5 with either b-AP15 or VLX1570 (72hr fluorescein diacetate hydrolysis assay or CellTiter Glo). We observed that MCL cells, including those resistant to ibrutinib (Jeko/IR cell line) were highly sensitive to VLX1570 (median IC50 12 - 25nM). In contrast, MM cells were not as sensitive (IC50's ranging between 58 - 90nM). Nine DLBCL cell lines exposed to equivalent time/concentrations of b-AP15 showed a median IC50 of 311nM (range, 70 - 910nM) and 3 HL models exhibited an IC50 of 531nM (range, 420 - 783nM). No difference in sensitivity to VLX1570 was noted between ABC-type vs. GCB-type DLBCL models. These functional results aligned with prior genomic inquiry where USP14 and UCHL5 gene expression was noted to be higher in MCL cell lines compared to DLBCL and non-hematologic cancer models analyzed (FDR=0.0019, p=0.001), suggesting their more central role in maintaining MCL tumor viability. Indeed MCL tumor survival (particularly ibrutinib-resistant cells) appears linked to USP14/UCHL5 function as treatment of Jeko/IR cells with VLX1570 (250nM, 12hrs) caused marked apoptosis (71.8% annexin-V+ staining) and cleavage of PARP-1. Moreover, the combination of ibrutinib and VLX1570 synergistically induced MCL cell death (median CI: 0.3). Mechanistic studies demonstrated that VLX1570 modulates several proteins critical for MCL survival including cyclin-D1, Myc and CXCR4/CD184. Reduction in cyclin-D1 was also noted to coincide with cell cycle arrest of VLX1570-treated MCL cells. Altogether, these findings suggest that VLX1570 modulates critical cellular signaling pathways utilized by MCL tumor cells, particularly those that are involved in resistance to ibrutinib. Conclusions: MCL remains a challenging malignancy to treat with no effective treatments for ibrutinib-relapsed disease. Our data supports the role of the proteasome-associated DUBs, USP14 and UCHL5, as critical factors involved in ibrutinib-resistant MCL tumor survival. VLX1570 is a potentially effective agent for the treatment of ibrutinib-resistant MCL. Disclosures Gullbo: Vivolux AB: Other: Shareholder. Linder:Vivolux AB: Other: Shareholder.

Abstract Abstract 287 Purpose: Farnesyltransferases are key cellular enzymes involved in the prenylation of proteins. Prenylated proteins are important for malignant cell growth. The purpose of this phase II study (NCT00082888) was to assess tumor response and toxicity associated with the oral farnesyltransferase inhibitor tipifarnib (R115777, Johnson and Johnson) in patients with relapsed aggressive, indolent, or uncommon lymphoma. The uncommon group included low incidence lymphoma types such as Hodgkin lymphoma (HL) and T-cell non-Hodgkin lymphoma- cutaneous T-cell lymphoma (CTCL) and peripheral T-cell lymphoma (PTCL). Patients and Methods: Patients with relapsed or refractory non-Hodgkin (NHL) or Hodgkin (HL) were eligible if they had measurable disease, performance status ≤2, platelet count ≥75,000 × 10(6)/L, an absolute neutrophil count ≥1000 × 10(6)/L and a creatinine ≤2 × upper limit of normal. Patients initially received tipifarnib 300 mg twice daily, days 1–21 every 28 days. The trial was conducted by the University of Iowa/Mayo Clinic Lymphoma SPORE. Results: Ninety-three patients with lymphoma (42 aggressive, 15 indolent, and 36 uncommon) enrolled in the trial between March 2004 and November 2008. The median age was 62 years (range, 18–91). The median number of prior therapies was 5 (range, 1–17). The overall response rate (ORR) was 20% (19/93) with 6% (6/93) complete responses (CR) and 14% (13/93) partial responses (PR). The ORR was 17%, 7%, and 31% for the aggressive, indolent, and uncommon groups, respectively (Table). Among the 19 responders were 7 diffuse large B-cell lymphoma (DLBCL), 7 T-cell NHL, 1 follicular grade II, and 4 HL. The overall median response duration for the 19 responders was 7.5 months (mean, 12.8; range, 1.8 – 48.1 months). The median response duration was 11.3 months (mean, 10.1; range, 1.8 – 18.5 months), 2 months, and 7.5 months (mean, 15.5; range, 1.9 – 48.1 months) for the aggressive (7), indolent (1), and uncommon (11) groups, respectively. Five patients in the uncommon group are still receiving treatment with a range of treatment duration between 25 – 60+ months. Among the 5 still receiving treatment 4 responded and 1 is stable. The range of response duration is 15.4, 17.7, 43.1, and 48.1 months. These five patients (2 with HL, 1 anaplastic large cell cutaneous, and 2 PTCL) are currently receiving doses of 400 (1), 200 (2), and 100 (2) mg twice daily. The median time to progression for all patients was 3.6 months (95% CI: 2.1 – 4.5 months). The grade 3,4 toxicities observed were primarily fatigue (10%) and reversible myelosuppression with 11% anemia, 37% neutropenia, and 32% thrombocytopenia. Correlative studies demonstrated tipifarnib-induced upregulation of Bim, a marker of tipifarnib action in lymphoma cell lines, in 7 of 9 paired lymphoma biopsies. Conclusions: Tipifarnib has activity in lymphoma, with responses in patients with heavily pretreated DLBCL, HL and T-cell types, but little activity in follicular NHL. This agent has an excellent toxicity profile and targets a novel pathway. Further studies in combination with other agents are warranted for patients with DLBCL, HL or T-cell NHL. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 2408 Purpose: Vitamin D insufficiency is common globally and in the United States. Approximately 25–50% of patients seen in routine clinical practice have vitamin D levels below the optimal range with low levels linked to higher cancer incidence. Although vitamin D insufficiency is also related to inferior prognosis in some cancers, no data exists for chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL). Patients and Methods: To test the hypothesis that vitamin D levels predict outcome in patients with CLL, we evaluated the relationship of 25 (OH)D serum levels with time-to-treatment (TTT) and overall survival (OS) in 390 newly diagnosed CLL patients participating in a prospective cohort study (discovery cohort) and separate cohort of 153 previously untreated patients participating in an observational study (confirmation cohort). 25 (OH)D levels were measured by liquid chromatography-tandem mass spectrometry. Intra- and inter-assay coefficients of variation were all <7% (data not shown). All vitamin D assays were performed on stored research samples; results were not included in the clinical record and were not known to the treating physicians in either study. Vitamin D insufficiency was defined as a serum 25 (OH)D level <25 ng/mL (62.5 nmol/L), an accepted level3 for the establishment of hypovitaminosis D and the threshold used in routine clinical practice to identify individuals with 25 (OH)D insufficiency by our laboratory in routine clinical practice (http://www.mayomedicallaboratories.com). Results: We evaluated the relationship of 25 (OH)D serum levels with time-to-treatment (TTT) and overall survival (OS) in newly diagnosed CLL patients participating in a prospective cohort study (discovery cohort) and a separate cohort of previously untreated patients participating in an observational study (confirmation cohort). Of 390 CLL patients in the discovery cohort, 119 (30.5%) were 25 (OH)D insufficient. 25 (OH)D insufficiency had no relationship with CD38, ZAP-70, CD49d or IGHV mutation status and had no relationship with FISH risk category as classified using the Dohner system. After median follow-up of 3 years, TTT (hazard ratio [HR]=1.66; p=0.005) and OS (HR=2.39; p=0.01) were shorter for 25 (OH)D insufficient patients (figure). We next attempted to validate these findings in an independent group of previously untreated CLL patients. In the validation cohort, 61 of 153 patients (39.9%) were 25 (OH)D insufficient. After median follow-up of 9.9 years, TTT (HR=1.59; p=0.05) and OS (HR 1.63; p=0.06) were again shorter for 25 (OH)D insufficient patients. On pooled multivariable analysis of patients in both cohorts adjusting for age, sex, stage, CD38, ZAP-70, IGHV, CD49d, and FISH, 25 (OH)D insufficiency remained an independent predictor of TTT (HR=1.47; p=0.008). On multivariable analysis for OS, the HR for death associated with 25 (OH)D insufficiency was similar to univariate findings although the p value did not reach the threshold of statistical significance (HR=1.47; 95% CI=0.97–2.23; p=0.07). Conclusion: 25 (OH)D insufficiency is associated with inferior TTT and OS in CLL patients. Whether normalizing vitamin D levels in deficient CLL patients would improve outcome merits clinical testing. Disclosures: Zent: Genzyme: Research Funding; Genentech: Research Funding; Novartis: Research Funding; G.S.K.: Research Funding.

Abstract Abstract 1952 Poster Board I-975 Background: Vitamin D is a naturally occurring steroid hormone. In addition to its well-established role in maintaining serum calcium homeostasis, vitamin D has effects on cellular differentiation, proliferation, apoptosis, and angiogenesis. Vitamin D3 is naturally produced in skin in response ultraviolet-B (UVB) radiation from the sun. Several recent studies, however, have shown that a high proportion of community-dwelling subjects in both tropical and temperate climates are deficient in vitamin D, and that subjects in northern latitudes often require dietary supplementation to maintain vitamin D sufficiency. Further, several reports now suggest that vitamin D sufficiency is protective against the development of several cancers, including non-Hodgkin lymphoma (NHL). However, it is not known whether vitamin D impacts prognosis in diffuse large B-cell lymphoma (DLBCL), the most common NHL subtype. Methods: We evaluated serum vitamin D concentrations in two cohorts of DLBCL patients. The first cohort consisted of 374 patients newly diagnosed from September 2002-February 2008 who were prospectively enrolled in the University of Iowa/Mayo Clinic Lymphoma SPORE Molecular Epidemiology Resource, an observational study in which neither therapeutic nor diagnostic management is prescribed. All serum was obtained within 120 days of diagnosis, and was prior to treatment in 221 (59%). In the second study, 62 patients newly diagnosed from February 2006-August 2007 were enrolled on NCCTG clinical trial N0489, and all serum was obtained before the first course of therapy. Central pathology review was performed on all patients to confirm the diagnosis of DLBCL. Serum 25-hydroxyvitamin (25-OH-VitD) levels were measured by the gold standard method for vitamin D determination: liquid chromatography tandem mass spectroscopy (LC-MS/MS). Vitamin D deficiency was defined as total serum 25-OH-VitD < 25 ng/mL (62.5 nmol/L). SPORE patients were followed per a standard protocol for event-free (progression, retreatment, or death due to any cause) and overall survival (EFS and OS, respectively); N0489 patients were followed in a similar way per the clinical trial protocol. We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CI). Results: SPORE patients were primarily treated with immunochemotherapy (83%); all N0489 patients were treated with epratuzumab + R-CHOP21. The median age at diagnosis was 62 years (range, 19-93) for SPORE patients and 61 years (range, 21-82) for N0489 patients. Median follow-up for SPORE patients was 36 months (range, 1-77) with 95 deaths and 131 events; median follow-up for N0489 patients was 24 months (range, 7-39) with 13 deaths and 18 events. Vitamin D deficiency was identified in 188 SPORE patients (50%) and 15 N0489 patients (24%). There were no differences in the prevalence of vitamin D deficiency by age, IPI, or whether serum was obtained prior to starting treatment (all p > 0.28). Vitamin D deficiency was associated with inferior overall (HR=2.33, 95% CI 1.53-3.57, logrank p = 0.0001) and event-free survival (HR=1.71, 95% CI 1.20-2.44, logrank p = 0.003) in the SPORE cohort. These associations remained significant after adjusting for IPI and treatment: OS HR=1.97, 95% CI 1.27-3.07; EFS HR=1.47, 95% CI 1.02-2.21. These results were similar for the subset of SPORE patients who were treated with R-CHOP. The HRs for vitamin D deficiency and event-free survival were consistent in the N0489 patients (HR=1.63, 95% CI 0.61-4.35, IPI adjusted HR=1.43, 95% CI 0.53-3.85), although these results lacked precision due to a smaller sample size. We were unable to evaluate OS in N0489 due to the small number of deaths. Conclusions: Approximately 50% of all DLBCL patients in this northern US latitude population are vitamin D deficient at the time of diagnosis and treatment. Vitamin D deficient patients have an inferior event-free and overall survival compared to patients with vitamin D levels within the normal range. Vitamin D supplementation during treatment of DLBCL patients with vitamin D deficiency should be evaluated in a clinical trial setting. Disclosures: No relevant conflicts of interest to declare.

Abstract Patients with very-high risk (purine analogue refractory and TP53 defective) CLL have limited treatment options. In these patients alemtuzumab can be effective against CLL cells in the circulation and bone marrow, and in combination therapy with fludarabine can be active in patients with bulky disease, but these regimens have a high risk of serious infections. Addition of rituximab to alemtuzumab can also improve efficacy but has limited activity against bulky disease. We conducted a phase II clinical trial to determine the efficacy and toxicity of therapy with pentostatin, alemtuzumab, and low dose higher frequency rituximab (PAR) in patients with relapsed/refractory or progressive CLL with 17p13 deletion. The rituximab schedule was designed to decrease the loss of CD20 expression by circulating CLL cells. Methods This two-stage phase II trial study (NCT00669318) conducted at the Mayo Clinic Rochester and University of Iowa with IRB approval had an accrual goal of 38 evaluable patients. Eligibility required a diagnosis of progressive CLL by standard criteria and either previous treatment for CLL (<4 purine analogue regimens) or 17p13 deletion (17p13-). Exclusion criteria were organ failure, poor performance status (ECOG >3), infection with HIV, hepatitis B, hepatitis C, active autoimmune cytopenia, or alemtuzumab therapy within the past 2 months. Rituximab 20 mg/m2 IV M-W-F started on day 1, alemtuzumab started on day 3 with an escalation of 3-10-30 mg/d SQ and then 30 mg M-W-F from day 8, and pentostatin 2 mg/m2 IV every 2 weeks started on day 8. Peg-G-CSF or GM-CSF was used after each dose of pentostatin and patients received Pneumocystis and Varicella prophylaxis. CMV PCR assays were done weekly during treatment and viremia was treated with either valganciclovir or ganciclovir. Cycle 1 was 5 weeks and subsequent cycles were 4 weeks. At the end of cycle 2 patients with a clinical CR had a CT scan and a bone marrow study with immunohistochemical (IHC) staining for residual CLL cells, and therapy was stopped if there was no radiological or IHC evidence of residual CLL (stringent CR). Patients with residual disease received a 3rd cycle of therapy. Results Forty-one patients were enrolled (July 2008 - February 2013) and all 39 who started therapy were evaluable for response: Median age 61 years (range 47-78), 30 (77%) males, 36 (92%) relapsed/refractory CLL (median prior regimens = 2, range 1-10), 3 (8%) previously untreated, 23 (59%) advanced stage (Rai III-IV), 16 (41%) intermediate stage (Rai I-II). Prognostic factors: FISH (hierarchical classification) 15 (38%) 17p13-, 6 (15%) 11q22-, 5 (13%) 12+, 3 (8%) no defects, 8 (21%) 13q14-, and 2 (5%) other abnormalities, IGHV analysis (n=38) 27 (71%) unmutated (<2%), ZAP-70 (n=37) 28 (76%) positive (>20%). Thirty (77%) patients completed planned therapy (28 had 3 cycles, 2 had 2 cycles with stringent CR). Nine patients received one (n=4) or two (n=5) cycles of therapy because of disease progression or complications. Grade 3-4 hematological adverse events (n=37) at least possibly related to treatment included neutropenia (n=22), thrombocytopenia (n=11), anemia (n=2) and hemolysis (n=2). Non-hematological adverse events (n=17) included infections/neutropenic fever (n=8), fatigue (n=3), and hemorrhage (n=2). CMV reactivation was detected and treated in 14 patients (grade 1-2). No patients died during treatment or from treatment related complications. The overall response rate was 56% (95% CI 40-72) with 4 (10%) CR, 7 (18%) CRi, 11 (28%) PR, 7 (18%) SD, and 10 (26%) PD. Four patients (3 CR and 1 CRi) had IHC negative bone marrow studies. Thirteen (33%) patients have died due to progressive CLL (n = 11), sepsis (n=1), and pneumonia (n=1). Median follow up for surviving patients is 23 months (range 3-55). Seven (18%) patients proceeding to RIC allogeneic transplant were censored for time to next treatment. Twenty-one (54%) patients required therapy for progressive CLL and 7 (18%) have required no further therapy. Median progression free survival was 7 months (95% CI: 5-16), time to next treatment 9 months (95% CI: 6-27) and median overall survival has not been reached. Discussion PAR was effective and tolerable therapy for high-risk CLL. This study suggests that alemtuzumab can be used safely in combination with a purine analogue in a short-duration regimen. Disclosures: Zent: Genentech : Research Funding; Genzyme: Research Funding; Biothera: Research Funding; GlaxSmithKline: Research Funding; Novartis: Research Funding. Off Label Use: Pentostatin therapy for CLL, use of lower doses of rituximab.

Abstract Background: Patients (pts) with aggressive NHL who relapse after conventional chemotherapy or stem cell transplant have a poor prognosis. Novel agents are needed for this important subset. Tipifarnib is an orally available methylquinolone derivative that is an inhibitor of the farnesyl transferase enzyme that transfers the farnesyl group from farnesyl pyrophosphate to specific polypeptides including small GTPases of the Ras, Rho-B, and Rheb families, as well as nuclear lamins and kinetochore proteins. Tipifarnib has documented activity in acute leukemia and produces stable disease in relapsed multiple myeloma. The goal of this study was to evaluate the activity of single-agent tipifarnib in patients with relapsed aggressive NHL in the context of a phase II trial. Methods: Pts with relapsed diffuse large, follicular grade III, or mantle cell lymphoma were eligible for this study. Pts were treated with oral tipifarnib 300 mg twice daily d1–21 q 28 days until progression. Pts were restaged after 2 cycles, 6 cycles, and every 3 cycles thereafter. Tumor was sampled prior to tipifarnib and at day 8 in selected patients with accessible tumors. These paired samples were assayed for accumulation of unprocessed HDJ-2 and prelamin A, two polypeptides that require farnesylation for processing. Results: Forty-two pts were accrued between March 2004 and June 2006. Thirty-seven pts had diffuse large cell, 1 follicular grade III, and 4 had mantle cell. Of the 38 patients evaluable for response, 7 (18%) had a partial response and 8 (21%) had stable disease. The 7 responders all had diffuse large cell histology. Median progression-free survival (PFS) for all pts was 2 months (range, 0–25+). The PFS of the 7 responders was noteworthy at 4.2, 4.9+, 6.7, 9.6, 14.9+, 21.6+, and 25.1+ months, respectively. The primary toxicity was myelosuppression and 33% of pts required dose reductions. The median dose received in all pts was 300 mg twice daily (mean 275, range, 100–400). The median dose received by the 7 responders was 200 mg twice daily (range, 100–400). The dose of 300 mg twice daily resulted in accumulation of unfarnesylated forms of one or both markers in all pts studied to date. Conclusion: Oral tipifarnib has antitumor activity as a single agent with an excellent toxicity profile in pts with relapsed/refractory aggressive lymphoma. When given in this dose and schedule, tipifarnib is well-tolerated and can be taken for months without cumulative toxicity. This drug warrants further investigation in combination with conventional chemotherapy and other novel agents for the treatment of this important subset of patients.