Bowen, Deborah A.

Abstract Background: Chronic lymphocytic leukemia (CLL) can have a profound effect on the quality of life (QOL) of patients living with the illness. To our knowledge, no studies to date have evaluated the influence of the doctor-patient relationship on patient’s emotional distress or QOL. Methods: We conducted an international, web-based survey of patients with CLL using standardized instruments to evaluate QOL. Additional questions on the survey explored how often patients thought about their disease and evaluated their satisfaction with specific aspects of their relationship with the physician caring for them. Patients were also asked to indicate what phrases their physicians had used to describe/characterize CLL. Results: Between June and October 2006, 1482 patients responded to the survey. The diagnosis of CLL was validated in a randomly selected subset of patients. Over half (55.9%; n=822) of patients reported they thought about their CLL diagnosis daily. Although the proportion of patients who thought about CLL daily decreased with time, two or more years after diagnosis over 50% of patients still thought about their disease every day. When asked to indicate their satisfaction with various aspects of the physician caring for their CLL, more than 90% (n=1340) of patients felt their doctor had a good understanding of how their disease was progressing (i.e., the stage, blood counts, lymph nodes) but only 69% (n=1024) felt their physician had a good understanding of how CLL affected their QOL (anxiety, worry, fatigue, etc.). Similarly, while 90% (n=1324) of patients felt comfortable talking to their doctor about treatment and management of CLL, only 77% (n=1134) felt comfortable talking to their doctor about how CLL affected QOL. Reported satisfaction with their physician in these areas strongly related to patients’ measured emotional and overall QOL on standardized instruments (all p<0.001). This effect on QOL remained (p<0.002) after adjustment for age, extent of co-morbid health conditions, measured fatigue, and treatment status in a regression analysis. Finally, patients were asked to indicate whether the physician caring for them had used specific phrases to describe CLL. Thirty-three percent of patients had been told “CLL is the ‘good’ leukemia,” 24% had been told “don’t worry about your CLL,” and 35% had been told “if you could pick what cancer to have, this is what you would choose.” Overall, 52% of patients had received one or more of these characterizations of CLL by their physician. The emotional and overall QOL were worse among patients who reported their physician had used these phrases to describe CLL (all p≤0.001). This effect on QOL remained after regression analysis (p<0.002). Patients whose physician had used one of these phrases to describe CLL were also less likely to feel their physician understood how CLL was effecting their QOL and to feel comfortable discussing the effects of CLL on their QOL with their physician (all p<0.001). Conclusions: Physicians play an important role helping patients adjust to the physical, intellectual, and emotional challenges of CLL. The effectiveness with which physicians accomplish these tasks appears to impact the QOL of patients with CLL. Additional studies exploring how physicians can best support patients with CLL are needed.

Abstract Background: CLL is still an incurable lymphoid malignancy. The current standard of care is to treat only patients with obvious clinical progression as defined by the National Cancer Institute Working Group in 1996 (NCI–WG 1996). High risk CLL can be identified at diagnosis by a variety of tests including fluorescence in situ hybridization (FISH), immunoglobulin heavy-chain variable region (IgVH) analysis, and expression of ZAP-70 or CD38. With this information we can identify patients with high risk, early stage disease who are candidates for novel low toxicity therapies that could alter the natural course of their disease. Our hypothesis was that combination monoclonal antibody (MoAb) therapy using alemtuzumab and rituximab would significantly reduce the high risk clone in early stage CLL. Methods: This phase II trial was conducted with IRB approval and accrued the planned 30 patients between January 2005 and July 2007 at Mayo Clinic Rochester. The study enrolled consenting patients with Rai stage 0–II CLL without NCI–WG 1996 criteria for treatment who had high risk CLL as defined as one or more of the following 17p13–, 11q22–, unmutated (UM) IgVH (< 2%) and expression of ZAP–70 (≥ 30%) and/or CD38 (≥20%). Treatment was one 30 day cycle (alemtuzumab 3 mg, 10 mg, 30 mg days 1–3 then 30 mg 3 × week × 4 weeks with all doses subcutaneously and rituximab at 375 mg/m2/week IV × 4 doses from day 8). Patients received 7 days of allopurinol and antimicrobial prophylaxis against PCP and herpes virus infections for 7 months. CMV testing by PCR was done weekly during treatment, then monthly × 6. Results: All 30 patients have completed therapy and 27 have been evaluated for response. The median age of these 27 patients was 62 yr (range 29–77) with 8 patients > 70 years. There was a male predominance (67%) with median time from diagnosis to treatment of 0.7 yr (range 0.1 – 6.1). Stage (Rai) at the start of therapy was 0 in 7 (26%), I in 19 (70%), and II in 1. High risk markers were 17p13– in 9 (33%), 11q22– in 7 (26%), UM IgV and expression of either ZAP–70 or CD38 in 11 (41%). All 27 patients completed therapy without interruption. Non hematological grade 3–4 toxicity occurred in 3 patients (2 drug reactions caused by SMX/TMP, 1 CMV reactivation responsive to IV therapy). Response evaluation at 2 months after completion of therapy using NCI–WG 1996 criteria showed an ORR of 93% with 12 (44%) CR, 8 (30%) nPR, and 5 (19%) PR. Two (7%) patients had disease progression. Median duration of follow up was 14.1 months (range 1.9 – 27.2). Median time to disease progression in the 25 responding patients was 14.4 months (95% CI 5.9 – 22.4). Seven (26%) patients have received subsequent treatment for CLL (median 5.2 months, range 2.4 – 20.1). A minimal residual disease assay using 3-color flow cytometry on peripheral blood was negative in 6 of the 7 patients with CR who had no evidence of residual CLL on immunohistochemical examination of the bone marrow. These 6 patients all remain in sustained CR (median follow up 15 months, range 2 – 27.2). Conclusion: Alemtuzumab and rituximab is an effective and tolerable therapy in patients with high risk early stage CLL. A randomized controlled trial is now required to test if this intervention is better than the standard observation approach. In addition, this combination MoAb regimen could be used as a platform to develop even more effective combination treatments for patients with CLL.

Abstract BACKGROUND: The diagnosis of monoclonal B-cell lymphocytosis (MBL) is used to characterize patients who have a circulating population of clonal B-cells, a total B-cell count of <5 x 109/L, and no other features of another B-cell lymphoproliferative disorder. In most patients the immunophenotype is similar to that of chronic lymphocytic leukemia with co-expression of CD19 and CD5. The natural history of CLL-phenotype MBL is unclear. We used the Mayo Clinic hematopathology database to identify patients with CLL-phenotype MBL and abstracted clinical information on natural history and prognostic parameters from clinical and research records. METHODS: Using hematopathology records, we identified a cohort of 1820 patients seen at Mayo Clinic between August 1998 and May 2006 who underwent investigation using peripheral blood flow cytometry and who were found to have a clonal B-cell population of CLL phenotype. After elimination of patients with advanced stage (Rai I-IV), previously treated CLL, and individuals with an established diagnosis of CLL/MBL >1 year prior to flow, 636 unique patients with isolated lymphocytosis were identified. Based on our prior analysis (Leukemia Research 32:1458) demonstrating that nearly all patients with an ALC >10x109/L have a B-cell count >5x109/L, we focused the remaining analysis on the 405/636 patients who had an ALC <10x109/L and the necessary raw data from flow cytometry analysis to determine the B-cell count. RESULTS: Among the 405 individuals with an ALC <10x109/L, 306 (76%) had a B-cell count <5x109/L at the time of flow and met the current criteria for the diagnosis of MBL (BJH 130:325). Median age at the time of MBL diagnosis was 70 years (range 34 – 93). A slight male preponderance was observed (59% male). B-cell counts ranged from 0.02 to 4.99x109/L and ALC ranged from 0.3–9.6 x109/L. CD38 status was available for 268 (88%) MBL patients of whom 20% were CD38 positive using the 30% threshold. Cytogenetic analysis by fluorescent in situ hybridization (FISH) was available in 130 (42%) MBL patients. Using the hierarchical classification system of Dohner and colleagues, 57 (44%) were 13q-, 23 (18%) were trisomy 12, 5 (4%) were 11q-, 4 (3%) were 17p-, and 39 (30%) had no defect detected. ZAP-70 status was available for 77 (25%) patients of whom 13% were ZAP-70+ positive. Patients underwent sequential monitoring with a median follow-up of 1.7 yrs (range 0–8.1 yrs). Time from diagnosis to treatment for patients meeting criteria for MBL (n=306) as compared to Rai stage 0 CLL patients with B-cell counts between 5.0 and 10.0 x109/L (n=99) was not significantly different and is shown in Figure 1 (p=0.87). For individuals with MBL, survival free of treatment was 98% (95%CI: 96–100%) at 1 year, 93% (95%CI: 89–98%) at 2 years, and 77% (95%CI: 67–89%) at 5 years. While gender (p=0.10), and B-cell count as a continuous variable (p=0.15) were not found to be associated with time to treatment (TTT) among MBL patients, age (p=0.02, HR=0.94, 95% CI: 0.89–0.99) and CD38 status (p<0.02, HR: 3.3, 95% CI: 1.2–9.2) did show a relationship with TTT. CONCLUSIONS: Although we observed a low rate of progression among individuals meeting criteria for MBL, TFS was similar to individuals meeting current criteria for Rai stage 0 CLL who had B-cell counts between 5.0 – 10.0 x109/L . Among individuals meeting criteria for MBL, younger patients and those who were CD38 positive had a shorter time to treatment. Additional studies are needed to determine what B-cell count or other characteristics should be used to distinguish between MBL and Rai stage 0 CLL. FIGURE: FIGURE:.

Abstract BACKGROUND: The diagnosis of CLL among asymptomatic patients without lymphadenopathy or cytopenias has historically been based on documenting a characteristic lymphocyte clone and the presence of lymphocytosis. Currently, there are no data regarding what lymphocyte type (absolute lymphocyte count [ALC] or B-cell count) or threshold should be used for this diagnosis. We analyzed the relationship of these lymphocyte counts to clinical outcome in a cohort of 459 patients to determine whether the CLL diagnosis: should be based on ALC or B-cell count what lymphocyte threshold should be used for diagnosis whether any lymphocyte counts has independent prognostic value after accounting for molecular prognostic markers. METHODS: We used the Mayo Clinic CLL database to identify all Rai stage 0 patients diagnosed with CLL between 1/1/00 and 12/31/07 who were evaluated and had flow cytometry at Mayo within 12 months of diagnosis. All patients had lymphocytosis (ALC ≥5 x 109/L) and fulfilled the 1996 criteria for CLL. Raw data from the peripheral blood flow analysis was used in conjunction with blood counts to determine ALC and absolute B-cell count at diagnosis. Estimates of survival were calculated using the Kaplan-Meier method. RESULTS: To assess whether B-cell count or ALC more strongly related to clinical outcome, we evaluated the relationship of these variables with treatment free survival (TFS) and overall survival (OS; n=459). When treated as continuous variables (i.e. measuring risk of each 1.0 x 109/L increase in cell count), both ALC and B-cell count were related to TFS (hazard ratio [HR] ALC=1.02; p<0.0001; HR B-cell count=1.02; p<0.0001) and OS (HR ALC=1.02; p=0.04; HR B-cell count=1.02; p=0.02). Because B-cell count and ALC related to TFS and OS as a continuous variables, we next evaluated what threshold (nearest 1.0 x109/L) at diagnosis best related to an individual’s risk of requiring chemotherapeutic treatment and/or dying of CLL using the HR (log rank statistic) and c-statistic [c=1 indicates perfect discrimination between poor survivors and good survivors; c=0.5 equivalent to chance]. The B-cell threshold that best predicted OS was 11 x 109/L (HR=2.36, p=0.01; c=0.60). This threshold also predicted TFS (HR=3.02; p<0.0001; c=0.64). With respect to ALC, a threshold of 12 x 109/L was able to predict TFS (HR=2.28, p=0.003; c=0.62) but not OS (HR=1.62, p=0.12; c=0.56). The B-cell threshold used in the current diagnostic criteria (5 x 109/L) was able to predict TFS (HR=3.24, p<0.0001; c=0.63), but not OS (HR=1.64, p=0.13; c=0.55) Finally, we evaluated the ability of B-cell count to predict TFS independent of IGHV mutation status, ZAP-70 status, CD38 status, and FISH. Since not all patients had all prognostic tests performed, the predictive value of B-cell count (< or ≥11 x 109) independent of the other prognostic variable was assessed for each variable independently. B-cell count retained prognostic value independent of IGHV mutation status, ZAP-70 status, CD38 status, and FISH (all p≤0.001) [Table]. CONCLUSIONS: Although B-cell count and ALC have similar ability to predict TFS and OS as continuous variables, B-cell count may be a better predictor of TFS and OS when a defined lymphocyte threshold is used. These findings provide evidence to justify the recent proposal by Hallek et al (Blood 111:5446) to base the diagnosis of CLL on B-cell count rather than ALC. The results also provide justification for retaining the size of the B-cell count as part of the diagnostic criteria even in the era of molecular/biologic prognostic markers, but imply a threshold of 11 x 109 is the B-cell count that best predicts patient’s TFS and risk of death. Differentiating between CLL and MBL based on a patient’s likelihood of developing clinical symptoms and dying of disease could minimize unnecessary psychologic distress caused by labeling asymptomatic individuals at low risk for adverse clinical consequences as having leukemia. TABLE: TREATMENT FREE SURVIVAL HR p-value CD38 + 3.20 0.0002 B-cell ≥11 3.10 0.0001 ZAP + 8.33 < 0.0001 B-cell ≥11 6.86 < 0.0001 Unmutated 5.26 < 0.0001 B-cell ≥11 3.06 0.001 FISH (17p- or 11q-) 3.97 0.01 B-cell ≥11 3.67 < 0.0001

Abstract Background: Monoclonal B-cell lymphocytosis (MBL) is characterized by the presence of a circulating population of clonal B-cells where the total B-cell count is <5 × 109/L and criteria for the diagnosis of other lymphoproliferative disorders are not present. In most patients the immunophenotype is similar to that of chronic lymphocytic leukemia with co-expression of CD19 and CD5. The natural history of MBL is unclear. We used the Mayo Clinic hematopathology database to identify patients with MBL and abstracted clinical information on natural history and prognostic parameters from clinical and research records. Methods: After IRB review and approval, we reviewed the hematopathology records of 2292 patients seen at Mayo Clinic between August 1998 and May 2006 who had a clonal B-cell population on flow cytometry phenotypically consistent with CLL and fewer than <5 × 109/L B-cells. Clinical records were then reviewed to identify patients who fulfilled the criteria for MBL (no evidence of other lymphoproliferative disorders, no adenopathy on exam). Patient characteristics, prognostic parameters, and clinical outcomes were abstracted from the clinical and research records of these patients. Cox regression analysis was used to evaluate association between prognostic markers and time to treatment. Results: A total of 118 patients meeting the criteria for MBL were identified. Median age at the time of MBL diagnosis was 69.4 years (range 39.0 – 91.4). A slight male preponderance was observed (54% male). CD38 status was available for 106 (90%) patients of whom 20% were CD38 positive using the 30% threshold to classify CD38. Cytogenetic analysis by fluorescent in situ hybridization (FISH) was available in 58 (49%) patients. Using the hierarchical classification system of Dohner and colleagues, 26 (44.8%) were 13q-, 10 (17.2%) were trisomy 12, 2 (3.4%) were 11q-, 1 (1.7%) was 17p-, and 19 were (32.8%) no defect was detected. ZAP-70 status was available for 32 patients of whom 22% were ZAP-70+ positive. IgVH gene mutation status was only available for 15 (12.7%) patients of whom 40% were unmutated. Time from MBL diagnosis to treatment is shown in Figure 1. Survival free of treatment was 92.7% (95%CI: 86.8–99.1%) at 1 year, 90.9% (95%CI: 84.2–98.2%) at 2 years, and 87.5% (95% CI: 78.7–97.4%) at 5 years. While age (p=0.68) and gender (p=0.14) were not found to be associated with time to treatment (TTT), CD38 status showed a strong relationship with TTT (p<0.001, HR: 22.7, 95% CI: 3.4–239.6). Conclusion: The distribution of prognostic parameters (e.g. CD38, FISH) in patients with MBL appears similar to that of patients with early stage CLL. We observed a low rate of progression, with 5 year survival free of treatment greater than 87%. TTT among newly diagnosed MBL patients was associated with the CD38 status of clonal B-cells. Figure Figure

Abstract Backgrounds B cell receptor (BCR) signals and microenvironment protection have been recognized to have key influences on CLL survival and activation. Akt activation is down-stream of the BCR signaling cascade and is critical in the mediation of the bi-directional interactions between CLL B-cells and bone marrow stroma. MK2206 is an allosteric Akt inhibitor previously tested for safety in solid tumor patients. Our preclinical data has demonstrated the synergy of MK2206 with bendamustine (B) to induce CLL apoptosis in vitro. MK2206 also abolished the signal activation and cytokine production induced by BCR ligation in CLL leukemic cells (Ding, ASH 2012). Therefore, we conducted a phase 1 trial testing the safety and efficacy of MK2206 in combination with bendamustine and rituximab (BR) for patients with relapsed/refractory CLL. Methods A phase 1 dose-escalation study was designed to define the maximum tolerated dose (MTD) as well as the safety and efficacy of 3 dose levels (90 mg or 135 mg or 200 mg weekly) of the oral Akt inhibitor MK2206 in combination with bendamustine (70 mg/m2 daily for 2 days in each cycle) and rituximab (cycle 1: 375 mg/m2, cycle 2-6: 500 mg/m2) therapy in relapse/refractory CLL patients. To test the targeting efficacy of MK2206 on Akt and downstream signals, we designed a one-week “run-in” of single agent MK2206 before the initiation of BR during cycle 1. MK2206 was then given along with BR on day 1 of cycles 2-6. Tumor response was evaluated 2 months after the 6th/last cycle of therapy based on IWCLL 2008 criteria. Correlative laboratory studies included assessment of Akt signaling and the plasma cytokine levels (multiplex beads assay (Invitrogen)) at baseline and after one week of first dose of single agent MK2206. Results Nine patients (median age 68) were enrolled in the phase I portion of this trial. All 9 patients had unmutated immunoglobulin heavy chain variable region genes (IGHV) and 4 had del(11q). Six had received prior chemoimmunotherapy (CIT: FCR or PCR or PCO) and 5 had high risk disease defined as early progression within 26 months of the last CIT. Three had received alemtuzumab containing regimen. We have observed potent lymphocyte mobilization in all evaluated patients (n=7) after one-dose of MK2206 during week 1 (mean increase ALC: 35%) as well as reductions of plasma CCL3, CCL4 and CCL2 in the majority of the patients. A single dose-limiting toxicity (DLT) (febrile neutropenia and hemolytic anemia) was observed at dose level 1 (90 mg weekly) among 6 patients treated at this dose. Two patients with dose-limiting toxicities at dose level 2 (135 mg weekly) were observed where one patient had a rash and one patient had dehydration and febrile neutropenia among three patients treated at this dose. Accordingly, the 90 mg once weekly dose was determined to be the MTD for phase 2 trial testing. The most frequent grade 3 or 4 adverse events observed to date were neutropenia (44%) including febrile neutropenia (22%), rash (22%), diarrhea (22%), nausea and vomiting (11%), dehydration (11%), hemolytic anemia (11%) and thrombocytopenia (11%). The frequency of cytopenias was similar to the published German experience with BR (50% grade 3 or 4 hematological toxicities compared to 44% in N1087) in relapsed CLL patients (Fischer, JCO 2011). The median number of cycles received was 6 (range 1-6). Using an intent to treat analysis, two patients achieved complete response (CR, n= 2, 22%), one patient achieved nodular partial response (nPR, n=1, 11%) and five patients achieved a partial response (PR, n=5, 56%). The overall response rate (ORR) is 89%. Conclusion The Akt inhibitor MK2206 in combination with BR is well tolerated in patients with relapsed/refractory CLL. Single dose of MK2206 inhibits Akt phosphorylation, mobilizes leukemic cells and decreases plasma cytokines involved in BCR signals. The preliminary efficacy of this combination demonstrated promising results with a 89% ORR and 22% CR albeit in the small phase 1 cohort. These results compare favorably to BR alone (9% CR and 59% ORR) in relapsed/refractory CLL patients. Phase 2 testing of this combination is now underway. Acknowledgment This work was supported by the funding from NCI grant K23CA160345 (WD), NCI grant CA95241 (NEK) and Alliance for Clinical Trials in Oncology (CA025224 and CA33601). Disclosures: Off Label Use: MK2206, used in a phase 1 trial of relapsed CLL disease. Shanafelt:Genentech: Research Funding; Glaxo-Smith-Kline: Research Funding; Cephalon: Research Funding; Hospira: Research Funding; Celgene: Research Funding; Polyphenon E International: Research Funding. Zent:Novartis: Research Funding; GlaxSmithKline: Research Funding; Biothera: Research Funding; Genzyme: Research Funding; Genentech : Research Funding. Reeder:Celgene: Research Funding; Novartis: Research Funding; Millenium: Research Funding.

Abstract Abstract 4152 BACKGROUND: Patients with biologically aggressive chronic lymphocytic leukemia (CLL) characterized by being refractory to purine nucleoside analogues and/or possessing the cytogenetic abnormality del (17p13) have poor clinical outcomes with a median survival of <3 years. Several groups have reported that nonmyeloablative allogeneic stem cell transplant (alloSCT) provides long-term disease control in a subset of high-risk CLL patients. The Seattle group also recently reported that alemtuzumab use prior to alloSCT may increase the risk of early relapse/progression (Sorror, ASH 2010). This is a potentially critical observation since alemtuzumab is one of the few active agents in patients with del(17p13) and is frequently used for pre-transplant debulking in patients with this genetic defect. METHODS: We performed retrospective analysis of 38 CLL patients who underwent nonmyeloablative alloSCT for CLL at the Mayo Clinic between 2003 and 2011. The relationship between transplant outcome and debulking regimen used immediately prior to alloSCT, disease status at the time of alloSCT, post transplant engraftment, GVHD development was explored. The degree of marrow involvement prior to alloSCT was assessed using the leukemia index calculated by multiplying the % involvement by CLL cells and the % cellularity. RESULTS: Median age at the time of alloSCT was 55.5 (range, 29–69) and 13 patients (34%) were female. The median duration from CLL diagnosis to alloSCT was 4.7 years. Thirty-two patients (84%) had received more than 3 prior therapies prior to alloSCT. Thirty-seven patients (97%) had received purine analog-based therapies, 18 (47%) patients had received alkylating agents and 25 (66%) had received alemtuzumab. 33 (87%) patients were purine analog refractory. On cytogenetic evaluation by FISH, 17 (45%) patients had del(17p13), 10 (26%) had del(11q23) and 1 (3%) had del(6q23). Nine patients were in complete remission (CR) by IWCLL 2008 criteria at the time of alloSCT and 7 patients were in complete remission with incomplete marrow recovery (CRi). Of the remaining 22 patients, 20 had either a partial remission or stable disease at the time of alloSCT and 2 had progressive disease. Two (5%) patients had bulky lymphadenopathy (≥ 5cm by CT imaging), 11 (29%) patients had splenomegaly, and 8 (21%) patients had more than 30% CLL involvement by the leukemia index. Fludarabine (F) and 200cGy total body irradiation (TBI) was used as the conditioning regimen for 35 patients (92%). 22 patients received unrelated donor grafts (15 matched, 7 mismatched), and 16 received related donor grafts (all matched). Patients received mycophenolate (MMF) and either tacrolimus (unrelated grafts) or cyclosporin (related grafts) for graft versus host disease (GVHD) prophylaxis. 31 out of 37 evaluable patients (84%) achieved initial 100% donor chimerism (22 within 100 days) and 24 (63%) developed ≥grade 2 GVHD. After median follow-up of 1 year (range = 0–5.4 years), 26 of 38 patients (68%) are alive, and the median overall survival is 47 months. To date, 13 (34%) have experienced CLL progression/relapse requiring accelerated taper of GVHD prophylaxis (n = 2), donor lymphocyte infusion (n = 5), or chemo/immunotherapies (n= 6). For the 12 deceased patients, causes of death was CLL relapse/progression (n = 5), GVHD (n = 2) and infectious or other complications without CLL relapse/progression (n = 5). Pre-transplant use of alemtuzumab (A) within 3 months of transplant was the only pre-transplant characteristics associated with overall survival (OS). Median OS of patients receiving A within 3 months of alloSCT was 1 year compared to not reached for those who did not receive A within 3 months of alloSCT (p = 0.011; Figure 1a). A trend was also observed between alemtuzumab use within 12 months of alloSCT; however, it did not reach statistical significance (p=0.069; Figure 1b). No statistically significant associations between residual marrow involvement at time of alloSCT (p = 0.93), type of graft (p = 0.65), or presence of del (17p13) (p = 0.13), number of prior treatments (p = 0.45), patient age (p = 0.80) or disease status at time of alloSCT (p = 0.21) were observed. CONCLUSION: In this cohort of patients with high risk CLL, alemtuzumab use prior to transplant was the greatest predictor of OS after nonmyeloablative alloSCT. Non-alemtuzumab based debulking strategies need to be developed for patients with del (17p13). Disclosures: No relevant conflicts of interest to declare.

Abstract Background: Patients with CLL have a variable clinical course. Current novel prognostic indicators (ZAP-70, CD38, IgVH gene mutation status, FISH) are able to identify early-stage CLL patients at high risk of rapid disease progression. These prognostic factors focus on characteristics of the malignant B cell clone and are not currently changeable factors. Identification of modifiable characteristics of the host unrelated to the leukemic B-cell but that relate to CLL-specific survival may provide opportunities for therapeutic intervention. Since the immune system is likely to modulate disease progression in CLL patients, we evaluated critical features of that system in relation to the size of the circulating clonal B-cell population in a CLL cohort. Methods: 186 consecutive patients with CLL who were evaluated at Mayo Clinic within 2 months of diagnosis between 2000 and 2002 were identified. The primary end-point of the study was to assess if host immunity affected time to treatment (TTT). Baseline flow cytometry analysis was available for 166 patients (88%) and was used to calculate the absolute number of T-cell and natural kill (NK)-cells present at diagnosis. The size of the T-cell/NK-cell compartment relative to the size of the malignant monoclonal B-cell (MBC) compartment was then evaluated by calculating the NK:MBC ratio and T:MBC ratio. Relationships with other prognostic parameters and with TTT were evaluated. Results: Patients exhibited substantial variation in the absolute number of T-cells and NK cells as well as T:MBC and NK:MBC ratios at the time of diagnosis. Higher T:MBC and NK:MBC ratios were observed among patients with early Rai stage and mutated IgVH genes (all P≤0.0002). As continuous variables, both the T:MBC ratio (p value=0.03) and NK:MBC ratio (p value=0.02) were associated with TTT. Since they correlated with TTT as continuous variables, thresholds to classify MBC, T:MBC ratio, and NK:MBC were identified using the method of Contal and O’Quigly. On multivariate Cox modeling including stage, CD38, absolute MBC count, T:MB ratio, and NK:MB ratio, the independent predictors of TTT were disease stage, T:MB ratio, and NK:MB ratio (Table 1). Conclusion: Measurable characteristics of the host immune system appear to relate to the rate of disease progression in patients with newly diagnosed CLL. These characteristics can be modified and continued evaluation of immunomodulatory drugs, vaccination strategies, and cellular therapies to delay/prevent disease progression are warranted. Additional studies exploring how interactions between the host immune system and the leukemic clone influence clinical outcomes are needed.

Abstract Abstract 3898 Background: Although chemoimmunotherapy (CIT) has substantially improved response rates, treatment free survival, and overall survival in patients with chronic lymphocytic leukemia (CLL), only 4050 of patients achieve a complete remission and the majority have residual disease when evaluated using sensitive assays. There remains interest in identifying new approaches to improve the effectiveness of CIT. Ofatumumab is a humanized anti-CD20 monoclonal antibody that is approved for patients with relapsed CLL refractory to fludarabine and alemtuzumab. The single agent activity of ofatumumab in patients with refractory CLL suggests it may have greater efficacy than rituximab in patients with CLL. To explore the efficacy of ofatumumab based CIT, we initiated a clinical trial studying the effect of ofatumumab in combination with pentostatin and cyclophosphamide (PCO) for patients with previously untreated CLL. METHODS: Eligible patients were previously untreated and had CLL in need of treatment according to the NCI-WG criteria (Blood 111:5446). The treatment schema included 6 cycles of ofatumuamb (300 mg on day 1 of cycle 1;1000 mg on day 2 of cycle 1 and day 1 of cycles 26) followed by pentostatin (2 mg/m2) and cyclophosphamide (600 mg/m2) administered every 21 days. All patients underwent complete response evaluation including evaluation for MRD using sensitive flow cytometry (Leukemia 21:956) at the completion of treatment. RESULTS: 33 patients were enrolled at Mayo Clinic and Duke University between 3/2010 and 9/2010. All patients were eligible for treatment and have completed active treatment. Clinical characteristics included: 76 male, median age 63 (range: 5083); intermediate Rai risk 27; and high Rai risk 73. On prognostic testing 33 were CD38, 48 Zap-70 , 58 IGHV unmutated, and 6 had high risk FISH (del 17p13; del 11q22). 26 of 33 eligible patients (79) completed all 6 cycles of PCO induction. Seven patients went off treatment early (toxicity: n5; refusal: n1; progression: n1). Adverse events deemed at least possibly related to PCO induction included 8 (24) patients with grade 3 hematologic toxicity and 5 (15) with grade 3 non-hematologic toxicity. The overall response rate to PCO induction was 94 (31/33) with 15 (45) CR/CRi, 5 (15) CCR, 9 (27) nPR, and 2 (6) PR. 2/10 (20) patients with CR's tested for MRD were also MRD negative by 6 color flow cytometry analysis. Finally, we compared this cohort of patients treated with ofatumuamb-based CIT to our prior 108 patient cohort of patients treated with rituximab-based CIT both of which used an identical chemotherapy backbone (pentostatin and cyclophosphamide). Although the age, gender, ALC, and prognostic profile (CD38, ZAP-70, and IGHV mutation status) of treated patients were similar (all p0.3), the ofatumumab cohort included more advanced stage patients (Rai stage III/IV: 73 vs. 41 p0.002). Ofatumumab-based CIT appeared to be better tolerated than our previous experience with rituximab-based CIT (grade 3 hematologic toxicity ofatumumab-CIT 24 \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\scriptstyle \raisebox{1ex}{8$}\!\left/ \!\raisebox{-1ex}{$33$}\right.}\]\) \end{document} vs. rituximab-CIT51 \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\scriptstyle \raisebox{1ex}{55$}\!\left/ \!\raisebox{-1ex}{$108$}\right.}\]\) \end{document}, p0.009; grade 3 non-hematologic toxicity ofatumumab-CIT 15 \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\scriptstyle \raisebox{1ex}{5$}\!\left/ \!\raisebox{-1ex}{$33$}\right.}\]\) \end{document} vs. rituximab-CIT 24 \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\scriptstyle \raisebox{1ex}{26$}\!\left/ \!\raisebox{-1ex}{$108$}\right.}\]\) \end{document}, p0.34). Despite a higher proportion of Rai Stage III/IV patients in the ofatumumab cohort, the efficacy of ofatumumab-based CIT also compared favorably to our previous experience with rituximab based CIT (Table). CONCLUSION: Front-line ofatumumab-based CIT appears to be well-tolerated in patients with CLL. Compared to our historic experience with rituximab based CIT, ofatumumab-based CIT appeared to have less hematologic toxicity and improved efficacy. This trial has been expanded to provide a larger experience with ofatumumab-based CIT. Disclosures: Shanafelt: Hospira: Research Funding; Glaxo-Smith-Kine: Research Funding; Genentech: Research Funding. Off Label Use: Off label use of pentostatin and Ofatumumab. Lanasa:GlaxoSmithKline: Consultancy, Speakers Bureau. Zent:GlaxoSmithKline: Research Funding; Genentech: Research Funding; Genzyme: Research Funding. Tun:Celgene: Research Funding. Kay:Biothera: Research Funding; Clegene: Research Funding; Cephalon: Research Funding; Genentech: Research Funding; Glaxo Smith Kline: Research Funding; Hospira: Research Funding; Novartis: Research Funding; Supergen: Research Funding; Calistoga: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Emergent Biosolutions (Formerly Trubion): Membership on an entity's Board of Directors or advisory committees.

Abstract Abstract 3903 INTRODUCTION: Monoclonal B-Cell Lymphocytosis is an asymptomatic hematologic condition characterized by the presence of small populations of clonal B-cells in the blood or bone marrow occurring in 3–5% of the general population over age 40. Although MBL is considered the precursor state to CLL and other sub-types of indolent non-Hodgkin Lymphoma, most individuals with MBL will not develop a B-cell malignancy. It is unknown, however, whether individuals with MBL may be at risk for other adverse outcomes associated with CLL, such as increased risk of infection. To explore this aspect, we evaluated the risk of hospitalization for infection among patients with clinically recognized MBL and compared this to a cohort of general medicine patients and a cohort of CLL patients. METHODS: The Mayo Clinic Rochester (MCR), a tertiary referral center in rural southeastern Minnesota, is also the primary hematology center for southeastern Minnesota, northern Iowa, and western Wisconsin. There are no metropolitan areas or hematology specialty centers within a 50 mile radius. To explore the natural history of infection in a local, community dwelling cohort of individuals with clinically identified, CLL-phenotype MBL, we used the Mayo Clinic CLL database to identify all patients with newly diagnosed MBL seen in the MCR Hematology Division between January 1999 and December 2009. Analysis was limited to MBL cases who resided within 50 miles of MCR. The comparison cohort consisted of 689 adult patients also resided within 50 miles of MCR who were seen for a general medical examination between September 2002 and December 2009 and who were enrolled as controls in a case-control study of non-Hodgkin lymphoma. Rates of infection among individuals with MBL were also compared to a cohort of 174 patients with newly diagnosed CLL diagnosed in the same time interval and who resided within 50 miles of MCR. All hospitalizations in these 3 groups were audited to document hospitalization with infection including cross-referenced with the electronic Mayo Clinic infection database, which contains all culture results obtained from hospitalized patients at MCR. Serologies and viral assays (e.g. CMV viral load) were also reviewed. Patients whose cultures were negative but who were given a clinical diagnosis of infection (e.g. pneumonia) and who were treated with a full course of antibiotics were considered to have a culture negative infection. Among the cases, only hospitalizations after CLL or MBL diagnosis were considered. RESULTS: In May 2010, there were 524 individuals in the Mayo Clinic MBL/CLL Database with the diagnosis of CLL-phenotype MBL made between January 1999 – December 2009. Of these, 154 (29%) patients resided within a 50 mile radius of Mayo Clinic and were considered a local, community-based cohort of MBL patients. Median age at MBL diagnosis for these 154 patients was 70 years (range 45–94). After median follow-up of 4.2 years (range 0.3–10.6 years), 25 (16%) individuals with MBL were hospitalized with infection as compared to 20/689 (3%) individuals in the control population (odds ratio MBL relative to control=6.5; p<0.001) and 32/174 (18%) in the cohort of patients with newly diagnosed CLL (OR MBL relative to CLL=0.9; p=0.61) (Figure 1). The 25 MBL patients hospitalized for infection were hospitalized a total of 39 times (median 1 hospitalization for infection per individual). A specific infectious organism was identified by cultures or serologies in 8/39 (21%) hospitalizations among individuals with MBL, 10/27 (37%) hospitalizations for infection among controls, and 60 (63%) of the 89 hospitalizations for infection in CLL cases. Finally we performed a pooled multivariable analysis of all patients (n=1017) adjusting for age, sex, presence of MBL, diagnosis of CLL, and whether patients with CLL or MBL received treatment for CLL during follow-up. All factors were independently associated with risk of hospitalization for infection [Age (per year, OR=1.02, p=0.02), sex (male, OR=2.6, p=0.001), presence of MBL (OR=3.3, p<0.001), diagnosis of CLL (OR=3.0, p=0.002), and treatment for CLL (OR=3.3, p<0.001)]. CONCLUSIONS: In this cohort study, patients with newly diagnosed clinical-MBL had a 6.5 fold risk of hospitalization for infection relative to the control cohort. MBL was an independent risk factor for hospitalization for infection after controlling for age, sex, and treatment. Disclosures: Zent: GlaxoSmithKline: Research Funding; Genentech: Research Funding; Genzyme: Research Funding. Kay:Biothera: Research Funding; Clegene: Research Funding; Cephalon: Research Funding; Genentech: Research Funding; Glaxo Smith Kline: Research Funding; Hospira: Research Funding; Novartis: Research Funding; Supergen: Research Funding; Calistoga: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Emergent Biosolutions (Formerly Trubion): Membership on an entity's Board of Directors or advisory committees.