LaPlant, Betsy

Abstract Background: CLL is a disease of the elderly and at least half of the patients requiring therapy are over age 70. While chemoimmunotherapy (CIT) has dramatically improved response rates in patients with CLL, some CIT regimens are not well tolerated by elderly patients. The MD Anderson group has reported that the fludarabine, cyclophosphamide, rituximab (FCR) regimen is not well tolerated in individuals ≥age 70 (Ferrajoli Leuk Lymph 46:S86). The German CLL Study Group has postulated that physiologic health is more important than chronologic age and have conducted a trial of FCR that permits enrollment of patients ≥age 70 provided they have a creatinine clearance (CrCl) ≥70 and good performance status (PS). While this approach expands the number of individuals who can receive CIT, it still excludes large percentages of CLL patients in need of treatment. Here, we examine how age, CrCl, and PS relate to the efficacy and tolerability of the pentostatin, cyclophosphamide, and rituximab (PCR) regimen. Methods: We treated 64 previously untreated CLL patients meeting NCI 96 criteria for treatment with pentostatin (2mg/m2), cyclophosphamide (600 mg/m2) and rituximab (375mg/m2) (Kay ASH 2006). All medications were administered on day 1 of every 3 week cycle with the intent of administering 6 cycles. We measured ECOG PS at study entry and used age, weight, and baseline creatinine to calculate the CrCl of all patients at study entry using the Cockroft-Gault equation. Results: Eighteen of 64 patients (28%) were ≥age 70. Although individuals ≥age 70 were more likely to have a dose delay of >1 week at some point during the trial (7% vs. 28%; p=0.03), there was no difference in the average number of cycles administered, the number of patients requiring dose reductions, or the number of patients with grade 3/4 hematologic toxicity, infectious complications, or other non-hematologic toxicity. No difference in OR (93% vs 83%; p=0.34) or CR (41% vs. 39%; p=0.86) was observed between patients <age 70 compared to those ≥70. We next evaluated whether CrCl related to the efficacy and tolerability of PCR. 25 patients (39%) had a CrCl<70, including 15 (23%) with a CrCl<60 and 5 (8%) with CrCl<50. Although individuals with CrCl<70 were more likely to have a dose reduction (5% vs. 24%; p=0.05), there was no difference in the average number of cycles administered, the number of patients requiring a dose delay, or the number of patients with grade 3/4 hematologic toxicity, infectious complications, or other non-hematologic toxicity. No difference in OR (89% vs 92%; p=1.0) or CR (45% vs. 36%; p=0.60) was observed between patients with CrCl≥70 and those with CrCl<70. We next evaluated how PS related to the efficacy and tolerability. 34 patients (53%) were PS 0 and 30 (47%) were PS≥1. This analysis suggested PCR was well tolerated among those with PS≥1. Again no difference in the OR or CR was observed between patients with PS 0 and those with PS≥1. Conclusions: In this phase II clinical trial, the PCR regimen was well tolerated by patients ≥age70, those with higher PS, and the 25 individuals with CrCl≤70 (range 34–67). The efficacy of PCR was also not significantly affected by age, renal function, or performance status. These findings suggest the PCR regimen may be superior to the FCR regimen for elderly patients and those with decreased renal function.

Abstract Background: The prognosis of patients with early Rai and Binet stage CLL is variable. Recently developed prognostic tests (mutation status, ZAP-70, chromosome evaluation by FISH) require significant technologic expertise and are not available worldwide to most patients with CLL. Smudge cells are ruptured CLL cells appearing on a blood smear. Using a proteomic approach, we recently discovered that the cytoskeletal protein vimentin is expressed at higher levels in CLL cells with unmutated IgVH and that vimentin expression is a marker of poor prognosis in early stage CLL (Blood, 2005;106:707). Hypothesis: Since vimentin plays an important role in the cytoskeleton and lymphocyte rigidity, we hypothesized that smudge cell formation is inversely correlated with vimentin expression and that the percentage of smudge cells may predict prognosis in CLL. Methods: We blindly reviewed the blood smears archived at the time of diagnosis of patients with untreated, early stage CLL. A total of 200 lymphocytes and smudge cells were counted per slide and results reported as percentage of total lymphocytes (intact and smudged). The percentage of smudge cells was correlated with vimentin expression measured by flow cytometry, IgVH mutation status, time to treatment (TTT), and survival. Results: Blood smears of 75 patients were reviewed. The median percentage of smudge cells was 27% (range, 4–72%). The percentage of smudge cells did not correlate with lymphocytosis (r=0.04, p=0.73) and did not change overtime for serial evaluations for individual patients (p=0.61). The percentage of smudge cells appeared to correlate inversely with vimentin expression (r = − 0.627; p = 0.0017). The percentage of smudge cells was higher in patients with mutated IgVH than in patients with unmutated IgVH (median 31% vs. median 13%, p=0.02). The percentage of smudge cells as a continuous variable correlated with both a prolonged TTT (p=0.0023) and overall survival (p=0.04). Patients with less than 30% smudge cells had a median TTT of 72.7 months. The median TTT in patients with ≥30% smudge cells was not reached (p=0.0011), Figure 1. Conclusion: A lower percentage of smudge cells is associated with unmutated IgVH status and with worse clinical outcome in early stage CLL. The percentage of smudge cells does not vary based on the magnitude of the lymphocytosis, but is patient specific and remains constant over time. Evaluation of the percentage of smudge cells on blood smears could be a universally available prognostic test for patients with early stage CLL. Figure Figure

Abstract Background: Bruton’s tyrosine kinase (BTK) is an essential component of the B-cell receptor signaling pathway, a pathway critical to the survival and proliferation of malignant B cells. Ibrutinib, a small molecule inhibitor of BTK, has shown significant activity in several B-cell malignancies and is currently FDA approved for the treatment of patients (pts) with CLL or mantle cell lymphoma who have received at least one prior treatment.In a Phase 1 dose-escalation study, ibrutinib induced a response in 6 (38%) of 16 patients (pts) with relapsed/refractory FL and 6/11 (54%) of pts treated at doses ≥ 2.5 mg/kg (Advani JCO 2013, Fowler ASH abstr 156:2012). 560 mg daily was identified as a well-tolerated dose in lymphoma resulting in full-target occupancy. On the basis of these results, the Mayo Clinic and Princess Margaret P2Cs conducted a CTEP-sponsored Phase 2 trial of single-agent ibrutinib in relapsed/refractory FL (NCI 9271). Methods: Eligible pts had relapsed or refractory FL (Gr 1, 2, or 3a) that had progressed during or after 1 or more prior chemotherapy regimens. Therapy consisted of ibrutinib, 560 mg daily, until progression or unacceptable toxicity. Response was assessed by CT at 8 weeks and then every 12 weeks. All pts were required to have an on-study biopsy and a second biopsy at progression after response with fresh tissue collected for correlative studies. The primary endpoint was overall response rate (ORR) and secondary endpoints were safety and tolerability, overall survival, time to response, time to treatment failure, duration of response, and progression-free survival (PFS). Planned exploratory correlative studies included C1D8 and C3D1 FDG-PET response evaluation in a subset of 20 patients, and whole-transcriptome sequencing for correlation of mutations with response and resistance. Results: 40 patients (38 evaluable for response) were accrued from April 2013 to April 2014. Median age was 64 years (range 46-82), 70% were men, 55% had FLIPI ≥ 3, median number of prior regimens was 3 (range 1-11), 20% had a prior stem cell transplant, 45% were rituximab refractory, and 36% were refractory to their most recent treatment. At a median follow-up of 6.5 months (mo) (range 1.8-14.6+), the ORR for the 40 intention-to-treat pts is 30% (95% CI: 17-47%) with 1 CR and 11 PRs by CT criteria (4/12 responders had a negative restaging PET/CT). 26 (65%) patients have exhibited tumor size reduction. Only 2/18 (11%) pts with rituximab-refractory disease responded, compared to 8/19 (42%) pts with rituximab-sensitive disease (P=0.06) and 2/3 who were rituximab-naïve. There was no correlation between response and number of prior regimens. Median time to response was 2.4 mo (range 1.8-12.9 mo). Median PFS is 9.9 mo (95% CI: 6 mo, not reached). One of 12 responders has progressed after 9.9 mo on treatment. Median treatment duration was 5 mo (range 1-15+ mo). Dose delays (2 pts) and reductions were infrequent (4 pts). 17 pts have discontinued treatment due to PD (12), refusal (2), AEs (2), and death (1). Gr 3-4 AEs occurred in 30% of pts, including the following AEs in more than 1 pt: anemia (2), neutropenia (3), and infection (2). 3 pts have died (1 PD, 1 pneumonia, 1 gastric hemorrhage). Of the 20 pts with C1D8 PET scans, 19 also had C3D1 PET scans and were evaluable for response. Six of these 19 pts had objective responses by CT criteria at week 8 or beyond. Of the 6 responders, C1D8 PET/CT showed qualitative (visual) improvement in 3 pts, no visual change in 1 pt, and qualitative worsening in 2 pts. On the C3D1 PET/CT, 4 of 6 had qualitative improvement and 2 had no change. Evaluation of quantitative PET data including SUVs and total lesion glycolysis is ongoing and will be presented. Conclusions: Single agent ibrutinib is well tolerated with a modest ORR in relapsed/refractory FL at this early assessment. Continued follow-up is warranted to capture late responders and to establish response duration. Ibrutinib appears less active in FL than in MCL and CLL. Early PET scans (C1D8) do not reliably predict for response. Support by N01-CM-2011-00099 Disclosures Bartlett: Gilead: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Astra Zeneca: Research Funding; Janssen: Research Funding; ImaginAb: Research Funding; Genentech: Research Funding; Millennium: Research Funding; Pfizer: Research Funding; Pharmacyclics: Research Funding; Novartis: Research Funding; Medimmune: Research Funding; Celgene: Research Funding. Off Label Use: PF-05082566 for B-NHL. Kuruvilla:Janssen: Honoraria. Reeder:Millennium, Celgene, Novartis: Research Funding.

Abstract Background: Current drugs in myelofibrosis (MF), including JAK inhibitors, do not induce complete or partial remissions. Imetelstat is a 13-mer lipid-conjugated oligonucleotide that targets the RNA template of human telomerase reverse transcriptase. A phase-2 study in essential thrombocythemia showed platelet-lowering activity of imetelstat accompanied by reduction in JAK2V617F allele burden, thus providing the main rationale for conducting the current study. Methods: The current study (NCT01731951) is investigator-driven and IRB approved. Drug and research funding were provided by Geron Corporation (Menlo Park, CA, USA). The objective was to obtain preliminary information on therapeutic activity and safety of imetelstat in DIPSS-plus high or intermediate-2 risk MF. Adverse events (AEs) were monitored by Common Terminology Criteria for Adverse Events (Version 4.03) and responses by the International Working Group criteria (Blood2013). Laboratory correlative studies included measurement of plasma cytokines and analysis of mutations. Results : 33 patients were accrued and met eligibility criteria (median age 67 years; 67% males); type of MF was primary 55% and post-PV/ET 45%; risk distribution was high 48% and intermediate-2 52%. Karyotype was abnormal in 16 (48.5%) patients. 79% of patients had received prior therapy including JAK inhibitors in 33%. Protocol treatment : Imetelstat was administered by a 2-hour intravenous infusion (9.4 mg/kg) every three weeks (cohort A; n=19) or weekly x 3 followed by every three weeks (cohort B; n=16). As of 7/24/2014, 11 (33.3%) patients remain on active treatment (median number of cycles completed for all patients = 7; range 1-21). Three patients have died post-registration: intracranial hemorrhage (related), upper gastrointestinal hemorrhage (unrelated) and disease progression. Median follow-up for living patients was 11.0 months (range, 3.6 – 18.4). 22 (66%) patients have discontinued treatment, mainly because of suboptimal response (n=15) or disease progression (n=3). Toxicity : Treatment-related grade 4 neutropenia was seen in 6 (18%) patients and grade 4 thrombocytopenia in 7 (21%). Grade 3 anemia was seen in 9 (27%) patients. Two patients experienced grade 4+ non-hematologic AE: grade 5 intracranial hemorrhage (related), grade 5 upper gastrointestinal hemorrhage (not related); other grade 3+ non-hematologic AEs were seen in only one patient. Regardless of attribution, treatment-emergent grade 1 or 2 liver function test abnormalities affected bilirubin 46%, ALP 52%, AST 55% and ALT 24%. There were 3 instances of grade 3 ALP and one of bilirubin elevations. Efficacy : There were 7 (21.2%) complete (CR; n=4) or partial (PR; n=3) remissions, occurring at a median of 5 cycles of treatment (range 1-9). All 4 CR patients experienced reversal of BM fibrosis and 3 of them a complete molecular response. Six of the 7 CR/PR patients remain in remission (median 9.9 months, range 4.8-14.7). Other responses included anemia response in 4 (31%) of 13 transfusion-dependent patients, >50% reduction in palpable spleen size in 9 (39%) of 23 evaluable patients, ≥50% reduction in leukocyte count in 8 (80%) of 10 patients with marked leukocytosis (WBC >25 x 10(9)/L), resolution of leukoerythroblastosis in the majority of patients, and normalization of platelet count in 9 (75%) of 12 patients with thrombocytosis. Laboratory correlative studies : Mutational frequencies were 79% for JAK2, 18% for CALR, 3% for MPL, 33% for ASXL1, 9% for IDH1/2 and 33% for spliceosome component mutations. CR/PR rates were 27% in JAK2-mutated vs 0% unmutated (p=0.3) and 32% in ASXL1-unmutated vs 0% mutated (p=0.07). CR rate was 38% in SF3B1/U2AF1-mutated vs 4% unmutated (p=0.036). Grade 3+ neutropenia or thrombocytopenia was more likely to occur in JAK2-unmutated (p=0.02) and ASXL1-mutated cases (p=0.049). Multi-cytokine panel screening showed significant differences between baseline and post-treatment samples involving several cytokines, including IL-1b, IL-5, IL-7, IL-17, VEGF, IL-8 and TNF-α (p<0.001 for all). CR/PR did not correlate with baseline cytokine levels. Conclusions : The current study identifies imetelstat as an active drug in patients with MF, but also reveals its potential to cause significant myelosuppression. The association between CR/PR and specific mutations suggests potential targeted activity that might be exploited for patient and disease selection. Disclosures No relevant conflicts of interest to declare.

Abstract Background: CLL patients (pts) treated with novel targeted therapies continue to experience disease progression. Approximately 7-15% of relapsed CLL treated with ibrutinib or venetoclax developed Richter's syndrome (RS), an aggressive high grade lymphoma transformation. Standard chemotherapy has limited efficacy in RS. We hypothesized that checkpoint blockade would re-establish anti-tumor immune response in progressive CLL/RS and here we aim to update the clinical data and correlative analysis of MC1485: a phase 2 study of PD-1 blocking antibody pembrolizumab in relapsed/refractory CLL and RS. Methods: Relapsed/refractory CLL including RS enrolled in the CLL arm of MC1485 trial was reported here. The primary end point of this study is overall response rate (ORR). Pts with prior allogeneic stem cell transplant were excluded. Pembrolizumab 200 mg was administered intravenously every 3 weeks. NCI CTCAE v4.0 and IWCLL 2008 criteria were used for non-hematological adverse events (AE) and for CLL grade hematological AE. Tumor expression of PD-1 and PD-L1 were assessed with standard immunohistochemical (IHC) staining. Percentage expressions of individual antigens were analyzed with whole-slide scanning followed by image analysis with Image-Pro software (Media Cybernetics). Fluorescence in situ hybridization (FISH) was performed on available CLL/RS tissue sections to assess copy number of chromosome 9p region that contains PD-L1 and PD-L2. Results: 25 pts including 16 CLL and 9 RS (biopsy-proven large cell lymphoma) were enrolled in CLL arm. The median age was 69 years (46-81). Twelve (48%) pts had del(17p) or monosomy 17 or TP53 mutation. The median number of prior therapies was 4 (1-10). 96%, 72% or 48% of pts had received alkylator and anti-CD20 antibody, purine analog or anthracycline. Fifteen (60%) pts had prior ibrutinib and 12 (48%) progressed clinically while receiving ibrutinib, including 6 who progressed to RS and 6 who developed progressive CLL. The median number of pembrolizumab doses that pts received was 3 (1 to 21), administered over a median treatment duration of 11 weeks (1 to 56). Drug-related AE occurred in 21 pts (88%) with the most common ones being neutropenia in 9 (37%), cough in 7 (29%) and dyspnea in 6 (25%) pts. Drug-related grade 3 or above AE occurred in 9 (38%) pts with most common ones being thrombocytopenia (5, 21%), dyspnea (2, 8%), and fatigue (2, 8%). The most common immune-related AE was liver enzyme elevation (12%, 8% G3) and was reversible with therapy interruption or steroid therapy. Based on investigator assessment using the Revised Response Criteria for Lymphomas and IWCLL 2008 criteria, one RS pt had complete response (CR, 4%), 3 RS had partial responses (PR, 12%). Among 9 RS pts, 1 CR (11%), 3 PR (33%), 3 SD (33%) and 2 PD (22%) were observed. Thus the ORR in RS was 44%. No CLL pts achieved a CR/PR, 3 had SD and 9 had progressive disease (PD). The ORR of all pts was 16%. Of the 4 RS who had CR/PR, responses occurred early after 2 cycles of therapy and median duration of therapy for CR/PR pts was 8.3 months with data cut-off by June 30th 2016 (Figure 1A). The causes for therapy discontinuation in RS were PD (3, 33%), alternate therapy (2, 22%), and thrombocytopenia due to increased marrow CLL (1, 11%). Increased marrow CLL was observed in 2 RS pts with PR to RS phase of disease assessed by PET, thus the protocol was amended to allow addition of idelalisib/ibrutinib to control the underlying marrow CLL. For RS pts who had a CR/PR or SD, variable nodal responses were observed (Figure 1B). In particular, 6 RS who had prior ibrutinib experienced CR or PR or SD with nodal responses. After a median follow-up of 10.2 (1.9 to 16.1) months, the median overall survival (OS) for all pts was 10.7 months (95% confidence interval [CI], 5.4 to not reached). The 6 month OS rate for RS and CLL pts were 73% and 59%, respectively. Biomarker assessment using IHC analysis on 10 pts with available tumor/nodal tissues (6 RS and 4 CLL) showed an increased expression of PD-L1 (p = 0.02) and a trend for an increased expression of PD-1 (p = 0.1) in the group of pts with CR/ PR versus pts in the group with no clinical response. One out of 10 tested showed polysomic for chromosome 9p. Conclusion: Pembrolizumab had an acceptable safety profile in CLL and RS patients. We confirmed that pembrolizumab has substantial therapeutic activity in RS. Single-agent pembrolizumab does not appear to have clear activity in CLL. Disclosures Ding: Merck: Research Funding. Parikh:Pharmacyclics: Honoraria, Research Funding. Shanafelt:GlaxoSmithKline: Research Funding; Genentech: Research Funding; Janssen: Research Funding; Pharmacyclics: Research Funding; Celgene: Research Funding; Cephalon: Research Funding; Hospira: Research Funding.

Abstract Abstract 1792 High risk disease can be identified in patients with early stage chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) using biological prognostic markers. We have shown that early therapy of high risk CLL patients with alemtuzumab (ALM) and rituximab (RTX) is effective and could possibly delay first standard treatment (Cancer 2008;113:2110-8). Efficacy of unconjugated monoclonal antibody (mAb) therapy in these patients could be improved by enhancing mAb mediated cellular cytotoxicity. Preclinical studies show that yeast cell wall derived beta glucan, which increases complement receptor 3 (CR3) binding to the complement fragment iC3b on target cells, could increase mAb mediated cellular cytotoxicity. Both ALM and RTX activate complement resulting in deposition of iC3b on the cell membrane. In CLL cells that are not lysed by complement activation, these iC3b molecules are targets for the effector cells mediating cellular cytotoxicity. We hypothesized that PGG beta glucan (Imprime PPG®, Biothera, Eagan MN) an intravenous formulation of a 1,3/1,6 glucose polymer prepared from a strain of Saccharomyces cerevisiae, would improve the efficacy of therapy with ALM and RTX in patients with CLL by increasing CR3 binding to iC3b and thus enhancing macrophage, neutrophil, and NK cell mediated cytotoxicity. We report the results of a Phase I study of the combination of ALM, RTX and PPG beta glucan in patients with CLL. Methods: The primary aim of this IRB approved study (NCT01269385) was to determine the maximum tolerated dose (MTD) of PGG beta glucan that could be safely combined with ALM and RTX. The MTD was defined as the PGG beta glucan dose level below that which induced dose limiting toxicity in at least one third of patients, or the highest dose level tested if all levels were tolerated. Eligibility for the trial required a diagnosis of CLL by standard (IWCLL-NCI 2008) criteria, no prior treatment for CLL, high risk CLL based on molecular markers, absence of standard indications for initiation of therapy for CLL, and adequate performance status and organ function. High risk CLL was defined as at least one of the following: 17p13-; 11q22-; either unmutated (<2%) IGHV or use of VH3–21 as well as CD38+ and/or ZAP70+. Patients received standard premedication for mAb, antimicrobial and allopurinol prophylaxis and weekly PCR testing for CMV reactivation with treatment of viremia. The duration of treatment was 33 days. PGG beta glucan was administered IV on days 1, 5, 10, 17, 24, and 31 and the first dose was premedicated with hydrocortisone 100mg IV, oral acetaminophen 1000 mg and diphenhydramine 50 mg. The starting dose level of PGG beta glucan was 1 mg/kg, 2nd dose level was 2 mg/kg and the 3rd dose level 4 mg/kg. Subcutaneous ALM therapy started on day 3 with daily dose escalation (3 – 10 – 30 mg) and then 30 mg Mon-Wed-Friday for 4 weeks. Weekly RTX started on day 10 at 375 mg/m2 IV × 4 doses. Results: Thirteen patients were enrolled from February 2011 to April 2012. The 11 evaluable patients had a median age of 61 years (range 47 – 77), 73% were male, 3 had early stage disease (Rai 0) and 8 had intermediate stage disease (Rai I n = 7, Rai II n = 1). High-risk parameters were 17p- in 4 patients, 11q22- in 3 patients, and unmutated IGHV and expression of ZAP70 and/or CD38 in 4 patients. There were no dose limiting toxicities. One patient had grade 4 febrile neutropenia, with no grade 3–4 anemias or thrombocytopenias, and there were no grade 3–4 non-hematological toxicities. All patients responded to therapy with 7 CR, 1 CCR, 1 nPR, and 2 PR (IWCLL-NCI 2008 criteria). Median follow up was 6.9 months (2.3 – 13.2) and one patient progressed at 9.7 months. No patients have required treatment for progressive disease and there have been no patient deaths. Two patients were not evaluable: One developed neutropenia and therapy was not held per protocol, and the other developed a grade 2 skin reaction to ALM and treatment was stopped. Discussion: The combination of PGG beta glucan with ALM and RTX is well tolerated at a PGG beta glucan dose of 4 mg/kg. All patients responded to therapy with 64% achieving a CR. These data support continuation of this study in a phase II component. Acknowledgment: This study was funded by the University of Iowa/Mayo Clinic Lymphoma SPORE (CA097274) and Biothera. Disclosures: Zent: Biothera: Research Funding; Genzyme: Research Funding; Genentech: Research Funding; Novartis: Research Funding; GlaxoSmithKline: Research Funding. Off Label Use: Phase I study using PGG beta glucan in CLL.

Abstract Results from the Phase I portion of this study in high risk chronic lymphocytic leukemia (CLL) patients (pts) (NCT01269385) showed that the combination of Imprime PGG (IPGG) at doses up to 4 mg/kg, with alemtuzumab (ALM) and rituximab (RTX), was well tolerated and associated with a 73% complete response (CR) rate (Blood 120: Abstr 1792, 2013). IPGG is a yeast-derived beta 1,3/1,6 glucan that engages innate immune cells, enhancing anti-tumor activity in combination with complement activating monoclonal antibodies (mAb) via a mechanism involving complement receptor 3 (J Immunol 177:1661, 2006). Endogenous anti-beta glucan antibodies (ABA) are required for IPGG binding to complement receptors and modulation of innate immune cell function. In pts with stage IV non-small cell lung cancer (NSCLC), correlation between serum ABA concentrations and response to an IPGG-containing frontline regimen has been observed (J Clin Oncol 32: 15S; Abstr 3045, 2014). Here we report clinical and translational results at the end of the Phase II portion of this CLL study. Methods: The primary endpoint of the Phase II study was the proportion of pts experiencing CR 3 months after completing 5 weeks of treatment with IPGG 4 mg/kg, ALM and RTX. Eligible pts (n=14) had a diagnosis of CLL by standard criteria (IWCLL-NCI 2008), no prior treatment for CLL, high risk CLL based on molecular markers (17p13-; 11q22-; unmutated [<2%] IGHV and/or use of VH3-21 AND CD38+ [³30%] and/or ZAP70+ [³20%]), no standard indication for initiation of CLL therapy, and adequate performance status and organ function. Planned enrollment was up to 39 pts but the study was terminated early due to slow accrual. Translational studies evaluated baseline serum ABA levels and in vitro binding of IPGG to immune cell subsets in whole blood. Results: The median age was 63.5 (range 47-77); 71% were male; and 6 (43%), 5 (36%) and 3 (21%) pts had Rai Stage 0, 1 and 2, respectively. CLL high-risk parameters were 17p13- in 3 (21%), 11q22- in 5 (36%), and unmutated IGHV or use of VH3-21 together with either expression of ZAP70 and/or CD38 in 6 (43%) pts. Grade 3 AEs were diarrhea (n=3) and increased transaminase levels, dehydration, gastritis, hypertension, hyponatremia, and hypertension (each n=1). Grade 4 AEs were neutropenia (n=2) and febrile neutropenia (n=1). Thirteen (93%) patients responded to therapy, with 7 CR, 2 CR with incomplete marrow recovery, 1 nodular PR and 3 PR (IWCLL-NCI 2008 criteria). Median follow-up was 12.7 mo (range 6.7 - 28.0). The overall median duration of response cannot be determined, as only 5/13 responders have progressed (median of 5.6 mo; range: 2.9 - 8.5) and the other 8 remain progression-free after a median of 8.0 mo (range 5.6 - 21.0). Four progressing pts were retreated after a median of 14.2 mo (range 12.4 - 20.5). There were no deaths during or after treatment. Translational studies demonstrated a correlation between ABA concentrations and binding of IPGG to neutrophils, monocytes and B-cells. However, there was no correlation between ABA concentrations and response to treatment. Potential functional implications of binding of IPGG to leukemic B cells, including direct and indirect enhancement of the antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis mediated by anti-tumor mAbs are under investigation. Discussion: The combination of IPGG with ALM and RTX appeared safe and well tolerated overall with an ORR of 93% and a 64% CR/CRi rate. ABA concentrations did not correlate with clinical response to an IPGG containing regimen in these CLL patients. Data on functional implications of IPGG binding to leukemic B cells will be presented. Disclosures Bose: Biothera: Corporate stock options Other, Employment, Research Funding. Zent:Biothera: Research Funding. Ottoson:Biothera: Corporate stock options Other, Employment. Leonardo:Biothera: Corporate stock options Other, Employment. Ansell:Biothera: Research Funding.

Abstract Background: Autologous stem cell transplantation is an integral part of myeloma therapy for patients who are able to undergo the treatment. While high dose melphalan has remained the typical conditioning regimen for ASCT in MM, recently there have been efforts to enhance the conditioning therapy by adding newer drugs to melphalan. Addition of bortezomib as well as carfilzomib have been attempted in phase 2 trials. Previous studies have shown that the combination of melphalan and total body irradiation (TBI) is an effective conditioning regimen. Pre-clinical studies have shown that bortezomib can sensitize MM cells to radiation, and based on this finding, we designed a clinical trial to examine the feasibility of combining low dose TBI with a combination of melphalan and bortezomib. Patients and Methods: The primary goal of the phase 1 study was to determine the maximally tolerated dose (MTD) of bortezomib that can be added to high dose melphalan and low dose TBI as part of conditioning chemotherapy in patients undergoing an ASCT for MM. The secondary goals were to examine the toxicities associated with addition of bortezomib to high dose melphalan and TBI in patients with MM and to determine the progression free rate at 1 and 2 years. Patients eligible to receive full dose melphalan conditioning regimen for ASCT were included as long as they had no more than 2 prior regimens and had not received a prior transplant. An accelerated design that was later converted to a standard 3+3 cohort design was used for dose escalation. Three patients were treated at a given dose level combination and observed for at least 36 days to assess toxicity. Melphalan 80 mg/m2 was given days -4, -3, with bortezomib at increasing doses given on day -5, -2 along with TBI of 200 cGY given on the same days of bortezomib, timed after bortezomib administration. Stem cells were infused day 0. Results: Eleven patients were enrolled; 6 were males, and the median age was 60 years. Median time from diagnosis was 5.4 months (range 3.4-7.0). Four dose levels were explored with increasing doses of bortezomib (0.7 mg/m2 to 1.6 mg/m2). No dose limiting toxicities were observed. The dose levels and the best response after ASCT are as shown in the Table. The overall response rate was 100%, including 7/11 with a CR or sCR. With a median follow-up of 12.5 months, two patients have progressed; median OS was not reached. Toxicity was mostly hematologic, with other AEs being grade 3 or less and attributable to the conditioning therapy. All patients engrafted their counts adequately. Conclusion: The combination of melphalan, bortezomib, and low dose TBI is a safe conditioning regimen in patients with MM with good efficacy. The regimen should be further examined in the phase 2 setting. Table Table. Disclosures Kapoor: Celgene: Research Funding; Amgen: Research Funding; Takeda: Research Funding. Kumar:Noxxon: Consultancy, Honoraria; Celgene: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; BMS: Consultancy; AbbVie: Research Funding; Janssen: Research Funding; Skyline: Consultancy, Honoraria.

Abstract Background Follicular lymphoma (FL) is an indolent non-Hodgkin lymphoma (NHL) with heterogeneous outcomes and remains largely incurable. Immunochemotherapy (IC) continues to be the standard therapy backbone in the frontline and relapsed settings, though novel agents are increasingly used and investigated. Lenalidomide is an immunomodulatory molecule with known single-agent activity in relapsed lymphoma. It is also active in the frontline setting and has been reported to be effective and tolerated in upfront combination regimens in FL (Fowler et al, Lancet Oncol. 2014, 15(12):1311-8). Here we report our experience with frontline use of R2CHOP (lenalidomide in combination with R-CHOP) in patients with FL. Methods A phase 1/2 study of R2CHOP was conducted in NHL patients with primarily diffuse large B-cell lymphoma (DLBCL). While the phase 2 study was focused on DLBCL patients, treatment-naive patients with stage II-IV, histologically-confirmed FL (grades 1, 2, and 3a) meeting criteria for therapy were eligible for the phase 1 part of the study. Additionally, FL patients were identified in the phase 2 portion of the study after central pathology review. These patients were allowed to complete therapy and were followed accordingly. Treatment consisted of 6 cycles of R2CHOP with lenalidomide given on days 1-10 and R-CHOP given in 21-day cycles. All patients received pegfilgrastim and aspirin (if not on anticoagulation) along with other supportive measures per provider discretion. Primary objectives were safety assessment and efficacy. Results Ten patients with FL (3 had grade 1, 3 had grade 2, and 4 had grade 3a) were enrolled in the R2CHOP phase 1/2 study at Mayo Clinic. One patient was in the phase 1 arm at dose level 2 (lenalidomide 20 mg/d) and 9 patients were in the phase 2 arm (lenalidomide 25 mg/d). The mean age was 60.8 years (range: 41-82). Eight out of ten patients were male; 5/10 had ECOG performance status of 0; 5/10 had an IPI score of intermediate or higher. All patients completed 6 cycles of planned treatment. One patient required lenalidomide dose adjustment due to toxicity. There were no lenalidomide dose interruptions. The overall response rate (ORR) was 100% and the complete response (CR) rate defined by PET imaging was 90%. Eight out of ten remain progression-free and 9/10 are alive at a median follow-up of 4.6 years (range: 2.1-5.3). Estimated progression-free survival (PFS) at 5 years was 79% (95% CI: 56-100%). The main toxicity was reversible myelosuppression with 80% treatment-related hematologic grade 3 or higher adverse events (AEs) (leukopenia 80%, neutropenia 80%, thrombocytopenia 40%, anemia 20%, transaminitis 20%). Rate of nonhematologic grade 3 or higher AEs was 20% (fatigue 10%, pneumonia 10%). Conclusions Frontline therapy with R2CHOP in patients with untreated FL appears to be effective and associated with acceptable toxicity. The observed PET-based CR rate and PFS were promising in this cohort. Whether R2CHOP is superior to lenalidomide/rituximab alone or standard bendamustine/rituximab will require randomized studies. Figure Estimated PFS in FL patients treated with upfront R2CHOP. Figure. Estimated PFS in FL patients treated with upfront R2CHOP. Disclosures Reeder: Celgene: Research Funding; Novartis: Research Funding; BMS: Research Funding; Millennium: Research Funding. Foran:novartis: Honoraria; Millennium Pharmaceuticals, Inc.: Research Funding; pfizer: Honoraria; karyopharm: Honoraria; medscape: Honoraria; boehringer ingelheim: Research Funding; agios: Research Funding; Cellerant: Research Funding. Nowakowski:Bayer: Consultancy, Research Funding; Morphosys: Research Funding; Celgene: Research Funding.

Abstract Background: Pomalidomide has demonstrated excellent activity in patients with relapsed, lenalidomide refractory, multiple myeloma (MM). Between November 2007 and March 2012, we enrolled 285 patients with relapsed MM on 5 sequential phase 2 trials; patients received pomalidomide at 2mg or 4 mg daily with weekly dexamethasone (Pom/dex). The approved dose of pomalidomide is 4 mg for 21 of 28 days. We wished to compare efficacy, tolerability and long-term outcomes between cohorts treated with 2 mg or 4mg daily continuously and 4mg daily for 21/28 days. Methods: After excluding two ineligible patients, 283 patients with lenalidomide refractory, relapsed MM from 5 sequential cohorts were analyzed. These patients were divided into 3 groups: Group1 received Pom 2mg for 28/28 day cycle (N= 69), Group 2 received Pom 4 mg for 28/28 day cycle (N= 95) and Group 3 received Pom 4mg for 21/28 day cycle (N= 119). All patients received oral dexamethasone given 40 mg daily on days 1, 8, 15, and 22. Response was assessed by the IMWG Uniform Response criteria. All patients received aspirin 325 mg daily for DVT prophylaxis or full dose anticoagulation. Results: The median age was 63 years (32-85); 35% were female. The median time from diagnosis was 53 months and the median number of prior regimens was 4. 127 (46%) had high-risk molecular markers. Prior therapies (% received) included lenalidomide (100%), thalidomide (46%), bortezomib (78%), autologous stem cell transplant (71%), and allogeneic transplant (4%). The median follow-up is 16.4 months (3.2-64.4). Forty eight percent are alive and 26% remain progression free; 15 patients are continuing to receive treatment. Frequency of AEs by groups are shown in Table 1. The most notable difference is grade 3+ neutropenia seen in 39% of group 1 and 56% and 57% of groups 2 and 3. Confirmed responses of PR or better were seen in 29% (group1), 35% (group2) and 24% (group3). Median duration of response (DOR) was 14.1 months (group1), 14.5 months (group2) and 10.2 months (group3). Median PFS was 5.5 months (group1), 6.9 months (group2) and 4.3 months (group3). Although the dose level cohorts were sequential rather than randomized, we compared OS between the dose levels in an exploratory manner. There was no significant difference in OS between dose levels (p=0.26). Median overall survival (OS) was 16.6 months (group1), 21.9 months (group2) and 16.0 months (group3). Conclusions: Pom/dex is active and well tolerated even in heavily pretreated patients Responses are durable. Response rates and overall toxicity are similar between the 2 mg and 4 mg doses. Neutropenia is more common in those receiving doses of 4mg daily or for 21/28 days compared to those receiving 2 mg daily. Table 1. All Grades Grade 3+ 2mg 28 Day 4mg 28 Day 4mg 21 Day 2mg 28 Day 4mg 28 Day 4mg 21 Day Anemia 68% 58% 74% 14% 15% 27% Lymphopenia 22% 51% 11% 16% 32% 8% Neutropenia 71% 82% 77% 39% 57% 56% Thrombocytopenia 51% 61% 63% 10% 9% 23% Leukopenia 59% 77% 72% 26% 38% 39% Pneumonia 7% 11% 12% 6% 7% 11% Fatigue 51% 65% 60% 9% 5% 8% Neuropathy 28% 32% 28% 0% 3% 0% Elevated Blood Glucose 10% 21% 8% 4% 6% 3% Pneumonitis 3% 2% 3% 3% 1% 1% VTE (Thrombosis) 3% 3% 3% 1% 3% 3% Secondary Malignancy 0% 2% 1% 0% 2% 1% Figure1. Kaplan Meier Overall Survival Curves Figure1. Kaplan Meier Overall Survival Curves Disclosures Lacy: Celgene: Research Funding. Fonseca:Medtronic, Otsuka, Celgene, Genzyme, BMS, Lilly, Onyx, Binding Site, Millennium, AMGEN: Consultancy, patent for the prognostication of MM based on genetic categorization of the disease. He also has sponsored research from Cylene and Onyx Other, Research Funding. Bergsagel:Novartis: Research Funding; Constellation Pharmaceutical: Research Funding; OncoEthix: Research Funding; MundiPharma: Research Funding. Stewart:Novartis: Consultancy; Celgene: Consultancy; Bristol Myers Squibb: Consultancy; Array BioPharma: Consultancy; Sanofi: Consultancy; Takeda Pharmaceuticals International Co.: Research Funding. Reeder:Millennium, Celgene, Novartis: Research Funding. Mikhael:Onyx: Research Funding; Celgene: Research Funding; Sanofi: Research Funding; Novartis: Research Funding.