Chaffee, Kari G.

Abstract Introduction: Ibrutinib has shown remarkable safety and efficacy in CLL. Due to CYP3A4 (3A4) metabolism, the concurrent use of 3A4 inhibitors/inducers with ibrutinib should be avoided. Ibrutinib is also associated with bleeding complications, in part due to effects on collagen-mediated platelet aggregation, thus caution is advised with the simultaneous use of anticoagulant (AC) and antiplatelet agents. It is unknown what proportion of CLL patients starting ibrutinib therapy in routine practice are on these medications. We conducted a retrospective study to evaluate these aspects in a large cohort of CLL pts treated with ibrutinib outside the context of clinical trials. Methods: Following IRB approval, consecutive CLL pts who initiated ibrutinib off-protocol at Mayo Clinic, Rochester, MN from November 2013 through July 2015 were evaluated. A medication review for drug-drug interactions was performed by a pharmacist on all pts. Baseline characteristics, concomitant medications, and toxicity were recorded. Time to toxicity and ibrutinib discontinuation were analyzed by Kaplan Meier and cumulative incidence methods accounting for competing risk of death, respectively. Results: Ninety-six CLL pts started ibrutinib. Median age was 66 years and 64 (67%) were male. Ibrutinib indications included: relapsed/refractory CLL (n=84), treatment-naïve CLL with del17p (n=8), and CLL with Richter's transformation (n=4). Approximately 80% had unmutated IGHV and 45% had del17p or del11q on FISH. Upon initial pharmacy consult prior to ibrutinib, the median number of concomitant medications was 9 (range, 1-31). Sixty (63%) pts were taking concurrent medications increasing their risk of ibrutinib toxicity and 4 (4%) pts were on drugs potentially reducing ibrutinib efficacy. At ibrutinib initiation, 16 (17%) pts were on concomitant 3A4 inhibitors. This included 9 (9%) on moderate 3A4 inhibitors (fluconazole, diltiazem, imatinib, cyclosporine) and 7 (7%) on strong 3A4 inhibitors (voriconazole, posaconazole, clarithromycin, itraconazole). In 4 pts, the 3A4 inhibitor was switched to another agent or discontinued to allow standard 420 mg daily dosing. Ibrutinib was initiated at 140 mg daily in 7 pts on moderate 3A4 inhibitors and at 140 mg every 48 hours in 5 pts on strong 3A4 inhibitors. Four (4%) pts were on strong 3A4 inducers (carbamazepine, rifampin, rifabutin) at the initiation of ibrutinib. The 3A4 inducer was discontinued prior to ibrutinib start in 3 pts, while the initial ibrutinib dose was decreased to 140 mg every 48 hours in the remaining patient (also on 2 strong 3A4 inhibitors). During the course of ibrutinib, an additional 8 (8%) pts were started on 3A4 inhibitors/inducers which necessitated dose modifications. Upon commencing ibrutinib, 9 (9%) pts were on concomitant AC (6 warfarin, 3 enoxaparin). Due to significant bleeding risk, warfarin was switched to enoxaparin in 2 pts, to aspirin (ASA) in 1 and warfarin was discontinued in 1. In 2 pts, an alternative AC could not be used so ibrutinib was begun at 140 mg daily and titrated upward. Twenty-nine (30%) pts were on ASA (3 [3%] also on clopidogrel) at ibrutinib initiation. Nineteen (20%) pts were on selective serotonin release inhibitors (SSRIs), and 9 (9%) were on NSAIDs. Thirteen (13%) pts were on fish oil and 24 (25%) were on herbal medications; all of which were discontinued prior to starting ibrutinib. Ten (10%) pts had clinically significant bleeding on ibrutinib including 4 (4%) requiring hospitalization (1 subdural hematoma). Of these 4 pts, 1 was on enoxaparin, 2 were on a SSRI and 1 a NSAID. Six pts had minor bleeding necessitating a dose reduction of ibrutinib to 140-280 mg daily. After 16 months follow-up, the risk of bleeding was 21% (95% CI: 1-37%, Figure). After a median follow-up of 7.6 months, 73 (76%) pts remain on ibrutinib. There was no difference in rates of discontinuation of ibrutinib between patients who were on 3A4 inhibitors/inducers versus those who were not. Conclusion: In the "real-world" setting, 2 out of 3 CLL patients commencing ibrutinib therapy is on a concomitant medication with a potentially clinically significant drug-drug interaction with ibrutinib. These findings have implications for the practicing hematologist who must maintain a high degree of vigilance when prescribing ibrutinib to CLL pts. We highly recommend a formal medication review by a clinical pharmacist in all patients initiating ibrutinib. Figure 1. Figure 1. Disclosures Ding: Merck: Research Funding. Kay:Hospira: Research Funding; Tolero Pharma: Research Funding; Genentech: Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding. Shanafelt:Glaxo-Smith_Kline: Research Funding; Pharmactckucs: Research Funding; Celgene: Research Funding; Genentech: Research Funding; Cephalon: Research Funding; Janssen: Research Funding; Hospira: Research Funding; Polyphenon E Int'l: Research Funding.

Abstract BACKGROUND: Consistent with the advanced age at diagnosis (median age ~70 years), most patients with CLL have co-existent health problems. These co-morbidities influence the ability of many CLL patients to tolerate aggressive chemotherapy-based treatment and can also contribute to treatment-related side effects. The recent development of novel signaling inhibitors, particularly the Bruton's tyrosine kinase inhibitor ibrutinib, has been a major treatment advance for patients with CLL. While these agents generally have favorable toxicity profiles relative to standard chemotherapy-based treatments, they are chronic therapies which patients typically stay on for an extended period. Preliminary data suggests ibrutinib may be associated with an increased risk of atrial fibrillation (Afib). In one randomized trial comparing ibrutinib to ofatumumab in patient with relapsed CLL, incident grade 3+ Afib occurred in 3% of ibrutinib treated patients compared to 0% of ofatumumab treated patients (NEJM 371:213). Despite these observations, the baseline frequency of Afib in patients with CLL is not well described - particularly incident atrial fibrillation acquired during the course of the disease. METHODS: We used the Mayo Clinic CLL database to evaluate the prevalence of Afib at the time of CLL diagnosis as well as the incidence of Afib during follow-up. All patients with a new diagnosis of CLL after January 1995 who were seen at Mayo within 12 months of diagnosis were included in the analysis. Afib was identified by chart review and by billing search using ICD9 codes. Data on co-morbid conditions associated with risk of Afib was also abstracted (e.g. hypertension, coronary artery disease [CAD], valvular heart disease, cardiomyopathy, diabetes mellitus, pulmonary disease). RESULTS: A total of 2444 patients with newly diagnosed and previously untreated CLL were seen at Mayo Clinic within 12 months of diagnosis between 1/1995 and 4/2015.Median age at diagnosis was 65 years and 1626 (66.5%) patients were men. A history of Afib was present at the time of CLL diagnosis in 148 (6.1%) patients. Four additional patients had Afib documented in the record but the precise date of onset (e.g. prior to or after CLL diagnosis date) could not be determined. Age, male sex and history of CAD, valvular heart disease, cardiomyopathy, hypertension, and diabetes were associated with a greater likelihood of having a history of Afib at the time of CLL diagnosis (all p<0.01). Among the 2292 patients without a history of Afib at CLL diagnosis, 139 (6.1%) had incident Afib during the course of follow-up for their CLL. The incidence of Afib among patients without a history of Afib at diagnosis was approximately 1%/year (Figure 1A). Considering both Afib present at the time of CLL diagnosis or acquired during the course of the disease, 291 (11.9%) of the 2444 patients in this cohort experienced Afib (median follow-up: 59 months). Among patients without Afib at the time of CLL diagnosis, the following characteristics at the time of CLL diagnosis were associated with an increased risk of incident Afib on multivariate analysis: older age (age 65-74 HR=2.4, p<0.001; age ≥75 HR=3.6, p<0.001), male sex (HR=1.8, p=0.004); valvular heart disease (HR=2.4, p=0.007), and hypertension (HR=1.5; p=0.02). A predictive model for acquired Afib was subsequently constructed based on the independent factors in the Cox regression model. An individual weighted risk score was assigned to each independent factor based on the regression coefficients of the HRs. The Afib risk score (range 0-7) was defined as the sum of the scores of these independent factors. The risk of incident Afib among patients with risk scores of 0-1, 2-3, 4, and 5+ is shown in Figure 1B. Rates for these 4 groups were significantly different (p<0.001), with the 10-year Afib rates (95% C.I.) for those with a score of 0-1, 2-3, 4, and 5+: 4% (2-6%), 9% (6-13%), 17% (11-23%), and 33% (20-43%), respectively. CONCLUSIONS: A history of Afib is present in approximately 1 out of every 16 patients with newly diagnosed CLL. Among patients without Afib at diagnosis, the incidence rate of Afib is ~1%/year. The risk of incident Afib in newly diagnosed CLL patients can be predicted based on age, sex, and co-morbid health conditions present at diagnosis. These data provide context to help interpret data on the frequency of Afib in CLL patients treated with ibrutinib and other novel agents. Disclosures Shanafelt: Janssen: Research Funding; Polyphenon E Int'l: Research Funding; Glaxo-Smith_Kline: Research Funding; Cephalon: Research Funding; Genentech: Research Funding; Hospira: Research Funding; Celgene: Research Funding; Pharmactckucs: Research Funding. Ding:Merek: Research Funding. Kay:Tolero Pharm: Research Funding; Hospira: Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract INTRODUCTION. Although uncommon, involvement of the central nervous system (CNS) is the most common extramedullary manifestation of Chronic Lymphocytic Leukemia (CLL). Nonetheless, a broad array of conditions can lead to neurologic symptoms in CLL patients and distinguishing between clinically significant CLL involvement of the CNS and other etiologies can be challenging. The actual prevalence of CNS involvement by CLL is unknown, the only available data being case reports and small case series. METHODS. Between 01/1995 and 11/2014, 186 of the 4317 (4%) patients with CLL followed at our center underwent an MRI of the CNS (e.g. brain, spine) and/or a lumbar puncture (LP) with cerebral spinal fluid (CSF) analysis to evaluate neurologic symptoms. As the mere presence of CLL cells in the CSF is not diagnostic of clinically significant CNS disease, a final diagnosis of clinically significant CNS involvement by CLL was established by the collaborative review of the pathologist, neurologist and treating hematologist based on comprehensive work-up and multi-disciplinary evaluation. RESULTS. After evaluation, the etiology of neurologic symptoms was clinically significant involvement of the CNS by CLL in 19 (10%) patients, CNS Richter Syndrome (RS) in 15 (8%), infection in 42 (23%), autoimmune conditions in 31 (17%), other cancer in 9 (5%), and another etiology in 70 (37%). The sensitivity of LP to detect clinically significant CNS involvement by CLL was 89%, however its specificity was only 42% where CLL cells were also frequently observed in the CSF in concomitance with inflammatory processes, such as infections and autoimmune disease. Factors associated with clinically significant CNS involvement by CLL/RS were mutated IGHV (p=0.04), low CSF glucose (p=0.02), elevated CSF total nucleated cells (TNC)(p=0.004), lymphocytes (p=0.02) and CLL cells, both as absolute count (p=0.05) and percentage of TNC (p=0.02). Median OS among patients with clinically significant CNS involvement by CLL or RS were 21 and 11 months, respectively. Median OS for patients with neurological symptoms secondary to infection was 6 months, to autoimmune process was 63 months, to other cancers was 19 months, and to other non-CLL related etiologies was 37 months. CONCLUSIONS. Clinically significant CNS involvement by CLL and RS are rare conditions. Neurologic symptoms in patients with CLL are attributable to non-CLL-related etiologies in the majority of cases, even when CLL B-cells are present in the CSF. Analysis of the CSF has high sensitivity but limited specificity to distinguish clinically significant CNS involvement by CLL from other etiologies. Comprehensive evaluation is required before attributing neurologic symptoms to CLL. Disclosures No relevant conflicts of interest to declare.

Abstract Background Severe cytopenias in CLL are typically associated with bone marrow failure due to massive infiltration of the bone marrow by leukemic cells and negatively impact patient morbidity/mortality. Although near complete marrow replacement by CLL is typically observed in patients whose degree of cytopenia meet criteria for advanced Rai stage disease (Hg<11g/dL; platelet <100 x10^9/L), profound variability in the degree of cytopenia and the extent of marrow infiltration exists, and the relationship between these dimensions is not well characterized. Methods We used the Mayo Clinic CLL database to identify all previously untreated CLL/SLL patients who underwent bone marrow biopsies. CLL patients known to have autoimmune-based cytopenias were excluded from this study. Hemoglobin, platelets, absolute neutrophil count (ANC), absolute lymphocyte count (ALC), and absolute monocyte (AMC) at the time of bone marrow biopsy were collected. Characteristics from bone marrow biopsy including marrow cellularity, % CLL involvement, CLL leukemic index (calculated as % cellularity times % CLL), and non-CLL leukemic index (calculated as % cellularity times (1-% CLL)) were also collected. Bone marrow cellularity and % CLL involvement were recorded in the Mayo Clinic CLL database based on clinical estimates made by Mayo hematopathologists. Clinical characteristics and CLL prognostic factors (e.g., Rai stage, CLL FISH, IGHV, ZAP-70, CD38 and CD49d) were also obtained from the database. Age- and sex-adjusted Pearson correlations between the bone marrow measurements and hemoglobin and platelet levels were computed, and scatterplots were created. Results A total of 695 untreated CLL patients diagnosed between 1972 and 2015 who had a CBC test at the time of bone marrow biopsy performed at Mayo Clinic were identified. Median age at diagnosis was 61 years, and 487 (70%) patients were men. Mean time from CLL diagnosis to bone marrow biopsy was 2.2 years. At the time bone marrow biopsy was performed, 20% of patients had advanced stage disease (Rai III/IV) disease, while 44% and 36% had intermediate (Rai I/II) and early stage (Rai 0), respectively. With respect to prognostic parameters, 53% had unmutated IGHV and 20% had high risk CLL FISH (11q- and 17p-). The distribution of other prognostic factors included 43% CD49d+, 35% CD38+, and 42% ZAP-70+ CLL diseases. Median peripheral blood counts were: hemoglobin 13g/dL, platelet 167,000/mL, ALC 26,600/mL, ANC 4100/mL, AMC 700/mL. The median bone marrow cellularity and percent CLL involvement were 70% and 70%, respectively. The median CLL leukemic index was 42%, and median non-CLL leukemic index was 21%. Pearson correlation analysis of bone marrow measurements with peripheral blood hemoglobin found the strongest correlation with the CLL leukemic index (r= -0.49, p<0.001) (Figure), followed by the % marrow CLL involvement (r= -0.45, p<0.001), cellularity (r= -0.40, p<0.001), and non-CLL leukemic index (r= 0.37, p<0.001). Pearson correlation analysis of the bone marrow measurements with platelet count also found the strongest correlation with the CLL leukemic index (r= -0.39, p<0.001), followed by % marrow CLL involvement (r= -0.38, p<0.001), non-CLL leukemic index (r= 0.35, p<0.001), and cellularity (r= -0.28, p<0.001). The peripheral blood ANC levels did not correlate with the four bone marrow measurements. Age- and sex-adjusted Pearson correlations between the bone marrow measurements and hemoglobin and platelet levels were similar to the above unadjusted results. Conclusion To our knowledge, this is the first study to examine the relationship between peripheral blood counts and the extent of bone marrow infiltration in patients with CLL. Although the bone marrow leukemic index had the strongest correlation with peripheral blood Hg and platelet counts, the correlation was modest with an r value of -0.49. These findings suggest that the extent of infiltration of the bone marrow by CLL cells only partially explains of the anemia and thrombocytopenia observed in CLL, indicating other biologic interactions between CLL B-cells and hematopoietic cells contribute to anemia and thrombocytopenia in these patients. More research is needed to determine the nature of these interactions. Disclosures Ding: Merek: Research Funding. Kay:Genentech: Research Funding; Pharmacyclics: Research Funding; Hospira: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tolero Pharm: Research Funding. Shanafelt:genentech: Research Funding; Glaxo-Smith-knine: Research Funding; Celgene: Research Funding; Cephalon: Research Funding; Pharmacyclics: Research Funding; Janssen: Research Funding; Hospira: Research Funding; Polyphenon E Int'l: Research Funding.

Abstract INTRODUCTION: Among patients (pts) with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), the indications for liver biopsy are not known. Additionally, the histopathologic findings of CLL infiltration in the liver along with its clinical implications have not been thoroughly described in the literature. METHODS: We identified all pts with a diagnosis of CLL/SLL from the CLL Clinical Database at Mayo Clinic, Rochester, MN who underwent a liver biopsy. We also cross referenced the Mayo Clinic Hematopathology Database for all pts who underwent a liver biopsy. The indications for biopsy, description of the pathologic findings in the liver biopsy, CLL therapy and outcomes were abstracted from the clinical records. Retrospective pathology review was performed on cases with CLL involvement in which slides were available for review. RESULTS: Fifty-two CLL/SLL pts who underwent a liver biopsy were identified. The indications for liver biopsy were as follows: liver lesion identified on radiographic imaging in 21 (41%) pts, abnormal liver function tests (LFTs) in 17 (33%) pts, hepatosplenomegaly in 11 (21%) pts, and unknown in 3 (6%) pts. Among all 52 pts, there was concern for Richter transformation at time of biopsy in 7 (13%) pts. Types of biopsy were as follows: percutaneous in 20 (39%) pts, intraoperative in 17 (33%) pts, transjugular in 3 (6%) pts, and unknown in 12 (23%) pts. CLL/SLL involvement was identified in 38/52 (73%) pts undergoing liver biopsy. Among these, the diagnosis of CLL/SLL was made on liver biopsy in 8 pts, and 7 pts had additional findings on their liver biopsy including metastatic colon cancer (n=3), hemochromatosis (n=2), steatohepatitis (n=1), and cirrhosis (n=1). Liver biopsy revealed Richter transformation in 4 (8%) pts (3 pts with diffuse large B cell lymphoma (DLBCL) and 1 patient with Hodgkin lymphoma), other malignancy in the absence of CLL in 7 (15%) pts (2 metastatic colorectal, 2 metastatic esophageal, 1 hepatocellular carcinoma, 1 metastatic lung, and 1 neuroendocrine), and 1 patient with steatohepatitis. Two (4%) pts had normal findings on liver biopsy. Among the 38 pts with liver involvement by CLL, 27 had slides available for retrospective pathology review. CLL involvement ranged from 2-100% of the liver parenchyma. Seven pts (26%) underwent excisional biopsies or resections and 20 (74%) underwent core biopsies. The portal tracts were the most common region of the liver involved (22/26 pts, 85%). Of these, 8/22 (36%) pts had extension into the lobules or sinusoids, as well. Of the 4 cases without portal involvement, 2 showed extensive involvement such that it effaced the liver parenchyma in the region of involvement. One patient (4%) had a predominantly sinusoidal involvement. One patient (4%) showed small nodular infiltrates that were difficult to localize due to their size. Proliferation centers were noted in only 3 pts (11%). Most pts (29/38; 76%) whose liver biopsy demonstrated involvement by CLL did not receive immediate CLL-specific treatment. Nine of the 38 pts (24%) with CLL involvement on liver biopsy received therapy (Table): purine analog based therapy (n=4), rituximab and steroids (n=2), steroids only (n=1), alkylator and rituximab (n=1), and ibrutinib (n=1). Pts with extensive involvement of the liver by CLL were more likely to receive purine nucleoside analog based therapy compared to pts with portal infiltration by CLL (2/2 pts [100%] vs. 1/6 pts [17%]). The remaining pts were offered no therapy due to incidental finding of CLL in the liver biopsy (n=11), chemotherapy for other cancer (n=5), palliative care (n=3), or unknown (n=10). Pts with Richter's transformation received R-CHOP (n=2) and CHOP (n=1) for DLBCL, and ABVD (n=1) for Hodgkin lymphoma. Pts with other cancers without CLL received appropriate therapy for their underlying malignancy. CONCLUSION: Abnormal LFTs and radiographic abnormalities were the most common indications for a biopsy in this large cohort of CLL pts. Infiltration of the portal tracts by CLL/SLL was the most common histopathological finding. Proliferation centers were not commonly seen, which may make the diagnosis challenging for the pathologist if there is not a prior history of CLL/SLL. The mere presence of CLL/SLL infiltration did not mandate treatment and many pts were able to continue observation. Table Table. Disclosures Ding: Merck: Research Funding. Kenderian:Novartis: Patents & Royalties, Research Funding. Shanafelt:GlaxoSmithkKine: Research Funding; Celgene: Research Funding; Cephalon: Research Funding; Genentech: Research Funding; Janssen: Research Funding; Pharmacyclics: Research Funding; Hospira: Research Funding. Parikh:Pharmacyclics: Honoraria, Research Funding.

Abstract Background. Trisomy 12 (tris12) is a recurrent cytogenetic abnormality in chronic lymphocytic leukemia (CLL), occurring in approximately 15-20% of cases, often as the unique cytogenetic alteration, that is usually considered a clonal driver lesion occurring early in CLL evolution. In the Dohner hierarchical categorization, tris12 CLL are identified as having an intermediate prognostic risk, although recent reports suggest a more complex and heterogeneous clinical behavior. Compared to CLL lacking this cytogenetic abnormality, tris12 CLL show more atypical morphology and immunophenotype, more frequent expression of the negative prognostic markers CD49d and CD38, and presence of NOTCH1 mutations and an unmutated (UM) IGHV gene status. The increased fraction of tris12 CLL carrying adverse prognostic features is in contrast to the intermediate clinical behavior associated with most tris12 CLL cases. Aim. To perform a comprehensive evaluation of the clinical impact of the major genetic, immunogenetic and immunophenotypic prognostic markers in tris12 CLL. Methods. The study was based on a multicenter series of tris12 CLL defined according to Dohner (n=283, including 73 cases also bearing del13q), and a comparison group (control) of 553 cases with either del13q (n=308) or without any cytogenetic abnormality (no del17p, del11q, tris12, del13q, n=245). Median follow-up of patients in the tris12 and control groups were 4 years (range 0-22) and 7 years (range 0-28), with 54% and 57% treated patients, and 18% and 15% deaths, respectively. Patient characterization included modified Rai stage, CD49d (CD49dhigh, ≥30% positive cells by flow cytometry), CD38 (CD38high, ≥30% positive cells by flow cytometry) and ZAP-70 (ZAP-70high, ≥20% positive cells by flow cytometry) expression, and IGHV mutational status (mutated, M, or UM according to the 2% cutoff). TP53, BIRC3, NOTCH1 andSF3B1 mutations were screened either at diagnosis or before therapy by NGS with at least 1000X coverage and 1% of sensitivity. Groups were compared by chi-square test; overall survival (OS) was computed from diagnosis to death or censored at last observation, and analyzed by Cox regression analysis. Results. Comparing the tris12 and the control groups, median age was 64 years (range 30-92) vs 66 years (range 33-92), male gender 55% vs 56% (p=0.86), the modified Rai stage was early in 52% vs 54%, intermediate in 41% vs 42% and advanced in 7% vs 4% (p=0.20). As previously reported, tris12 CLL were characterized by a higher prevalence of cases expressing CD49d (85% vs 31%) and CD38 (62% vs 17%; all p<0.0001), and of UM IGHV cases (55% vs 25%, p<0.0001). Analysis of recurrent mutations highlighted a higher prevalence of NOTCH1 mutations (26% vs 8%, p<0.0001) and of BIRC3 mutations (21% vs 1%, p<0.0001) in tris12 vs control group CLL. Conversely, no differences were found in the fraction of cases with TP53 mutations (3% vs 4%, p=0.38) or SF3B1 mutations (7% vs 7%, p=0.89), and in cases expressing ZAP-70 (62% vs 52%, p=0.09). The impact of these features on OS was tested by univariate analysis: in tris12 CLL, only the UM IGHV gene status predicted shorter OS (HR=2.37, p=0.0063), while none of the other characteristics reaching statistical significance as OS predictors (CD49d HR=1.36, p=0.36; CD38 HR=0.42, p=0.052; ZAP-70 HR=3.12, p=0.07; TP53 HR=2.33, p=0.25; NOTCH1 HR=1.40, p=0.22; SF3B1 HR=2.05, p=0.17; BIRC3 HR=1.22, p=0.61). On the other hand, in the control cohort, a significantly higher HR was found for CD49d (HR 3.11, p<0.0001) and CD38 (HR 3.45, p<0.0001) expression, TP53 (HR 2.88, p=0.0026), NOTCH1 (HR 3.57, p<0.0001), and SF3B1 (HR 2.57, p=0.0038) mutations, as well as for the UM IGHV gene status (HR=2.81, p<0.0001), but not for ZAP-70 expression and BIRC3 mutations (HR=1.74 and HR=1.91, p=0.15 and p=0.37, respectively). Conclusions. Mutational status of IGHV genes was the sole prognostic factor able to stratify OS in tris12 CLL. Despite the high frequency of NOTCH1 and BIRC3 mutations, as well as of CD49d and CD38 overexpression, these markers failed to convey a prognostic risk in tris12 CLL. The lack of a significant clinical impact for TP53 and SF3B1 mutations might be partly explained by the low number of mutated cases combined with a relative short follow up in our tris12 cohort. These findings are in keeping with the hypothesis of a different patho-biological mechanism occurring in tris12 CLL, which however remains to be fully elucidated. Disclosures D'Arena: Janssen-Cilag: Honoraria. Rossi:Gilead: Honoraria, Research Funding; Abbvie: Honoraria; Janseen: Honoraria. Gaidano:Janssen: Consultancy, Honoraria, Speakers Bureau; Gilead: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Speakers Bureau; Morphosys: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria. Shanafelt:Genentech: Research Funding; Janssen: Research Funding; Celgene: Research Funding; GlaxoSmithkKine: Research Funding; Pharmacyclics: Research Funding; Cephalon: Research Funding; Hospira: Research Funding.

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

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

Abstract BACKGROUND: Infiltration of the spleen plays an important role in the disease progression of patients with chronic lymphocytic leukemia (CLL). Despite this fact, the role for splenectomy in the management of CLL is not well defined. Historically, splenectomy has primarily been used for management of select patients with auto-immune cytopenias (e.g. autoimmune hemolytic anemia [AIHA], immune thrombocytopenic purpura [ITP]). We conducted a retrospective study to evaluate the utility of splenectomy in CLL patients cared for at Mayo Clinic over the last 20 years. METHODS: We used the Mayo Clinic database to identify all CLL patients who underwent splenectomy at Mayo Clinic since 1995. Medical records were reviewed to identify the indications for splenectomy, the pathologic findings at the time of surgery, and clinical outcomes. The indications for splenectomy were categorized as: diagnostic splenectomy, AIHA, ITP, symptomatic splenomegaly, and other. Pathology reports were reviewed to identify the findings at the time of surgery with respect to involvement by CLL and/or other lymphoproliferative disorders. RESULTS: Of the 5333 CLL patients seen at Mayo Clinic between 1/1/1995 and 12/31/2015, 107 (2%) underwent splenectomy at Mayo. The rate of splenectomy in female subjects was 1.7% (31/1779), and the rate in male subjects was 2.1% (76/3554). Of the 2354 subjects with IGHV mutation status, the rate of splenectomy in IGHV mutated subjects was 2.1% (23/1085) compared to 0.7% (9/1269) in IGHV unmutated subjects (p=0.004). The indication for splenectomy in these 107 patients was diagnostic splenectomy in 14 (13.1%) patients, ITP in 22 (20.6%), hemolytic anemia in 19 (17.8%), ITP and hemolytic anemia in 3 (2.8%), symptomatic splenomegaly in 46 (43.0%), and 3 (2.8%) other lymphomas. The rate of splenectomy decreased over the interval of the study (Figure). The per year risk of requiring splenectomy for patients diagnosed with CLL prior to 1995 was 0.32%/year, compared to 0.30%/year for those diagnosed from 1995-1999, 0.24%/year for those diagnosed from 2000-2004, 0.15%/year for those diagnosed from 2005-2009, and 0.16%/year for those diagnosed from 2010-2015 (p=0.01). The indication for splenectomy also changed over the study interval (Table) Pathologic review of the spleen demonstrated normal splenic tissue in 3 (2.8%), infiltration by CLL in 99 (92.5%), involvement by diffuse large B-cell lymphoma in 2 (1.9%) and involvement by other lymphomas in 3 (2.8%; T-cell lymphoma [n=1], T-cell large granular lymphocytic leukemia [n=1], and splenic marginal zone lymphoma [n=1]). CONCLUSION: These findings describe a large experience with the use of splenectomy in patients with CLL. Splenectomy is utilized relatively rarely (2% of CLL patients). The role of splenectomy in the management of CLL also appears to be changing with both a decreased frequency of splenectomy and a change in the indication for splenectomy over the last 2 decades. The potential benefits of splenectomy must be weighed against the know risks such as a lifelong increased risk of infection, as well as a higher risk of thromboembolism and secondary cancers. Splenectomy Indication by Time Period of CLL Diagnosis Table 1 Table 1. Figure 1 Figure 1. Disclosures Parikh: Pharmacyclics: Honoraria, Research Funding. Ding:Merck: Research Funding. Shanafelt:GlaxoSmithkKine: Research Funding; Janssen: Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding; Cephalon: Research Funding; Celgene: Research Funding; Hospira: Research Funding.

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