Citations

Abstract Chronic lymphocytic leukemia (CLL) represents one of the most common hematological malignancies and is characterized by the expansion of a clonal B cell population. Commonly, CLL is defined as a disease of failed apoptosis of the leukemic B cells, and it is this feature that makes them refractory to common chemotherapeutic agents designed to kill CLL cells. The mechanism controlling apoptosis in CLL is complex and influenced by numerous factors, including NFkB-mediated expression of antiapoptotic proteins, such as Bcl-2 and XIAP. We recently demonstrated that glycogen synthase kinase-3 (GSK-3) b positively regulates NFkB-mediated gene transcription and cell survival in pancreatic cancer cells (Cancer Research 2005. 65:2076). Similar to pancreatic cancer, we have found that pharmacological inhibition of GSK-3 results in decreased expression of NFkB target genes Bcl-2, Mcl-1 and XIAP in CLL B cells. In addition we noted a dose dependent increase in apoptosis levels for both the MEC1 cell line and primary CLL B cell patient samples. Using CLL blood B cells, we have found that both GSK-3b and NFkB accumulate in the nucleus of CLL cells, but not normal blood B cells. In addition, we observed that inhibition of GSK-3 leads to a decrease in NFkB-mediated gene transcription, without affecting the nuclear accumulation of NFkB. However, using chromatin immunoprecipitation, we found that NFkB binding to its target gene promoters (XIAP, Bcl-2) is significantly affected in CLL B cells treated with a GSK-3 inhibitor. These results suggest that GSK-3 regulates the nuclear activity of NFkB in CLL cells by affecting the binding of p65/p50 to the promoters of a subset of its target genes. Our results establish that inhibition of GSK-3 induces apoptosis of CLL cells and suggest GSK-3b as a potential therapeutic target in the treatment of CLL.

Abstract Chronic Lymphocytic Leukemia (CLL) is primarily characterized by the presence of leukemic B lymphocytes resistant to the process of apoptosis. Causes for this resistance include aberrant expression of multiple anti-apoptotic proteins, perhaps including Tcl-1 (1). Tcl-1 is expressed during normal development of both B and T cells and activates Akt to provide a survival signal through phosphorylation and inactivation of apoptotic pathway components. Overexpression of Tcl-1 in the B cells of transgenic mice results in a B-cell leukemia phenotype typical of human CLL, suggesting a primary role for Tcl-1 in CLL tumorigenesis. A recent report showed that Tcl-1 protein expression in CLL cells correlated with other biological parameters, but no data were available as to its clinical relevance (2). We therefore examined Tcl-1 expression in relation to clinical outcome using 51 peripheral blood mononuclear cell samples from a Phase II clinical trial testing the combination of pentostatin, cyclophosphamide, and rituximab in previously untreated CLL patients (Kay et al., ASH 2006). Tcl-1 protein expression was measured by immunoblot using GAPDH as a normalization control across lanes and lysate from a single Tcl-1 transgenic mouse spleen as a normalization control across immunoblots. All samples were run at least in duplicate and digital quantitation was performed using a ChemiDoc instrument (BioRad). Tcl-1 expression in patient cells was calculated in comparison to Tcl-1 expression in the mouse lysate, arbitrarily set to 1.0. Data were analyzed as a continuous measure as well as by specific cutoffs. Higher Tcl-1 expression was associated with failure to achieve a minimal residual disease-negative state after treatment. Specifically, Tcl-1 expression (measured as a continuous variable) was associated with residual disease measured by post-treatment CD5+/CD19+ cell percentages (continuous variable as well as dichotomized by cutpoint of 1.0% for CD5+/CD19+; p=0.03 for both comparisons). For the dichotomized Tcl-1 expression with the cutpoint of 0.275 (second tertile), this variable was marginally significantly associated with whether or not post-treatment CD5+/CD19+ was less than 1.0%. Using this same cutoff, there was also a suggestion that patients with reduced Tcl-1 were more likely to achieve a complete response. Finally, progression-free survival was shorter in patients with increased Tcl-1 expression, although these data did not reach statistical significance in this sample set. Tcl-1 < 0.275 Tcl-1≥ 0.275 p value CD5/CD19≥ 1% 15 10 0.046 CD5/CD19 < 1% 16 2 CR 17 3 0.064 No CR 18 13 Median PFS (mos.) 36.5 17.1 0.137 Statistically significant associations with other parameters including Rai stage, IgVH mutation status, ZAP-70 expression, CD38 expression, and interphase cytogenetics categories were not detected in this sample set. These data further support the clinical relevance of the Tcl-1 mouse model to human CLL, and provide preliminary evidence that Tcl-1 protein expression correlates with clinical outcome of CLL patients treated with chemoimmunotherapy. If validated in larger studies, Tcl-1 expression may serve as a novel prognostic factor.

Abstract Background: Isolated brain parenchyma relapse as initial site of relapse is a rare complication of NHL and carries a poor prognosis. Few large series focus on treatment characteristics and outcomes of isolated brain parenchyma relapse of NHL. Methods: The IPCG conducted a retrospective review of patient and treatment characteristics and outcomes of this complication. Following initial diagnosis and treatment of NHL (1980–2004), cases with brain parenchyma relapse as initial relapse site, with no evidence of lymphoma elsewhere in the body at the time of brain relapse, were eligible. Cases with brain, spine or leptomeningeal involvement at NHL diagnosis were not eligible. Results: 113 cases were assembled from 13 investigators in 8 countries. Preliminary data summaries are: 94 (83%) cases had diffuse large B-cell NHL, 5 (4%) follicular lymphoma, 3 (3%) Burkitt’s lymphoma, other NHL subtypes (11) . Median age at NHL diagnosis was 61yrs (16–85 yrs). 55% were male. Median ECOG at NHL diagnosis was 1. Median time from NHL diagnosis to isolated brain relapse was 1.8 yrs (3 months–15.9 yrs). 76 (67%) relapsed in brain less than 3 yrs after NHL diagnosis. Symptoms at brain relapse included mental status changes in 37%, gait/balance disturbance (27%), motor/sensory symptoms (23%). Median ECOG at brain relapse was 2. Parenchyma relapse was documented by brain imaging plus biopsy in 54 (48%), or imaging without biopsy in 58 (52%); not reported (1). 53 (48%) cases had one brain lesion; 56 (50%) had two or more lesions; not reported (4). Site of relapse was cerebral hemispheres in 53 (48%) cases, deep brain structures (brain stem/cerebellum) in 30 (27%), cerebral hemispheres and deep brain structures in 23 (21%); not reported (7). At brain relapse, CSF was positive in 11 (10%) cases, negative in 56 (50%); not reported (46[40%]). Treatment for brain relapse was chemotherapy alone in 52 (46%) cases, WBRT alone in 34 (30%), chemotherapy followed by RT in 26 (23%), and brain surgery alone (1). 78 (69%) cases are deceased. Median survival from brain parenchyma relapse to death was 1.6 yrs (95% CI: 11 months–2.6 yrs). Effect of treatment type at brain relapse on survival, will be reported. Brain lymphoma was the cause of death in 49 (63%) cases; CNS toxicity was the cause in 6 (8%) cases. Conclusion: Though a rare relapse site, prospective studies are needed to improve understanding and outcomes of isolated brain parenchyma relapse of NHL.

Abstract BACKGROUND: B-Chronic Lymphocytic Leukemia (CLL) is still uncurable but very powerful new tools are available with the use of chemoimmunotherapy (CIT). Purine nucleoside-based regimens that incorporate rituximab have generated very high levels of overall responses (OR) with significant percentage of those complete responses (CR) in previously untreated CLL. Here we report and update our experience with a phase 2 pentostatin-based CIT regimen for previously untreated CLL as conducted at 2 medical centers. We also studied the association of outcome based on risk stratification parameters and achievement of minimal residual disease. METHODS: Building on prior work of pentostatin in CLL by us (Kay ASH, 2004) and others, we initiated a trial of combined pentostatin (P)(2 mg/m2), cyclophosphamide (C)(600 mg/m2) and rituximab (R)(375 mg/m2) for symptomatic, previously untreated patients (n=65). This PCR regimen is given on a 21-day, 6-cycle schedule. However, the initial cycle of treatment uses thrice weekly rituximab as described by us earlier. In brief, this was rituximab at 100 mg/m2 on day 1, 375 mg/m2 on days 3 and 5 of the first week only. Prophylactic Sulfamethoxazole/Trimethoprim and Acyclovir were given to all patients for 1 year starting on the first cycle of therapy with PCR. All patients were risk stratified using CD38, ZAP-70, immunoglobulin heavy chain variable region gene (IgVH) and FISH panel assessments at entry. RESULTS: These patients were characterized as mostly in high-risk categories. Of 64 evaluable patients, 34 (53%) were high Rai risk (stage 3–4), 71% were non mutated for the IgVH gene, 34% were CD38+ and 34% were ZAP-70+. Thirty patients (52%) had one FISH anomaly, and 21 (36%) had complex FISH defects. Thirty-eight patients (58%) had grade 3+ hematologic toxicity but minimal transfusion needs, and no major infections. NCI Working Group Criteria Responses occurred in 58 (91%) with 26 (41%) complete responses (CR), 14 (22%) nodular partial responses (nodular PR), and 18 (28%) partial responses (PR) patients. Outcome for all 64 patients demonstrates a median progression-free survival of 32.6 months. Importantly, no high risk factor (i.e., age, FISH, IgVH status, CD38+, ZAP-70+) except for del (17p) defect (n=3) precluded attaining a CR or NPR. In contrast, we found this regimen was equally effective in young vs. elderly (>70 yrs) patients and in del(11)(q22.3) vs. other favorable prognostic FISH factors. Examination of outcome among CR and nodular PR patients for PFS by flow cytometry status (negative vs. positive, i.e., ≤ 1 % CD5+/CD19+ vs. ≥ 1 % CD5+/CD19+) demonstrated improvement in progression free survival for patients who attained flow cytometry negativity (p = 0.009). Conclusion: This novel regimen of pentostatin, cyclophosphamide and rituximab for previously untreated CLL demonstrated significant clinical activity despite poor risk-based prognoses with minimal toxicity in terms of bone marrow suppression and/or infections. The additional feature of this approach is the ability to have durable responses for all age groups and even CLL patients with a del(11)(q22.3).

Abstract Abstract 1731 Background: Symptom burden in primary, post-ET and post-PV myelofibrosis (MF) is frequently severe and correlates with a poor prognosis. However, symptom manifestations are heterogeneous with variable presence of specific symptoms, splenomegaly and cytopenias. We sought to identify the spectrum and features of MF symptomatic phenotypes by cluster analysis of prospectively gathered information on MF symptoms and disease features. Methods: Data was collected among an international cohort of subjects with MF. Data included demographics, disease features and completion of the Brief Fatigue Inventory (BFI) and Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN-SAF TSS) (Blood 2011; 118:401–408). Surveyed symptoms addressed key disease features on a 0 (absent) to 10 (worst-imaginable) scale. Cluster development was based on consideration of r-squared in hierarchical clustering using Ward's linkage. Final cluster assignment was based on the nonhierarchical k-means method. Comparisons between symptom clusters were based on ANOVA and chi-squared tests. Results: Subject Demographic and Disease Characteristics: Data from 329 prospectively enrolled persons with MF was collected (Chinese 102, French 54, German 19, Italian 22, Dutch 45, English 51, Spanish 29, Swedish 7) including 223 PMF, 67 post-ET MF and 39 post-PV MF patients. Participants were of typical age (mean 59) and gender (47% F). Among all participants, four natural symptom clusters were identified (Figure 1). Among clusters, disease features including leukopenia, thrombocytopenia, and enlarged spleen varied significantly between clusters (P<0.05). Cluster 1: The “Fatigue Dominant with Few Lab Abnormalities” Profile (n=150 (46%; 69% PMF, 20% post-ET MF, 11% post-PV MF)). Cluster 1, the largest, is characterized by fatigue-dominant complaints in the setting of the lowest overall MPN-SAF TSS and highest proportion of males (59%). Individuals among this group have the lowest prevalence of laboratory abnormalities (65% total; anemia, 67%; thrombocytopenia, 20%) or clinical deficiencies including enlarged spleen (average 6.0 cm below costal margin), prior thrombosis (9%), prior hemorrhage (5%) or prior RBC-transfusions (20.4%). Interestingly, individuals in this group are most likely to have had prior splenectomy (5.8%). Cluster 2: The “Cognitive Complaints with Enlarged Spleen” Cluster (n=105 (32%; 65% PMF, 20% post-ET MF, 15% post-PV MF)). Cluster 2 is the 2nd largest cluster. Subjects have relatively few abnormal lab values (67% vs 65%–77%) but have high severity of fatigue, sexual difficulties, insomnia, inactivity and reduced QOL. These individuals have the largest spleen size (8.7cm below costal margin). Cluster 3: The “Nighttime and Cognitive Complaints” Group (n=53 (16%; 64% PMF, 25% post-ET MF, 11% post-PV MF)). Cluster 3 is the smallest cluster. Subjects have many cognitive and nighttime-related complaints including sexual difficulties, night sweats, insomnia, and concentration problems. Subjects with post-ET MF are predominant. This cluster also has the 2ndsmallest spleen size (7 cm) or history of prior thrombosis (9.6%), hemorrhage (7.8%) or requirement for transfusions (21.2%). Cluster 4: The “Severe Fatigue with Few End-organ Complaints” Cluster (n=21 (6%; 81% PMF, 14% post-ET MF, 5% post-PV MF)). Cluster 4 is the most symptomatic cohort with the highest proportion of subjects with PM. There is a lower frequency of end-organ complaints including abdominal pain, cough, and headaches. Symptoms including sexual difficulties, sad mood and insomnia are predominant. No subjects had prior splenectomy. Subjects also have the highest prevalence of prior thrombosis (29%), hemorrhage (14%), and transfusions (43%). Additionally, this cohort has the largest prevalence of lab abnormalities (77%) with thrombocytopenia (71%), leukopenia (41%) and anemia (41%). Conclusion: This analysis will allow us to examine a new framework for evaluating persons with MF using symptom profiles and is the 1st cluster evaluation of MF. Lab and physical findings contrast significantly between symptom clusters indicating these phenotypic symptoms likely result from etiological factors present in specific disease phenotypes. Future studies should evaluate whether there is a correlation between cluster profiles, prognosis and genotype. Disclosures: Kiladjian: Celgene: Research Funding; Novartis: Honoraria, Research Funding; Shire: Honoraria. Roy:Novartis, BMS: Speakers Bureau. Harrison:Novartis: Honoraria, Research Funding, Speakers Bureau; YM Bioscience: Consultancy, Honoraria; Sanofi Aventis: Honoraria; Shire: Honoraria, Research Funding. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees. Passamonti:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees. Mesa:Incyte: Research Funding; Lilly: Research Funding; Sanofi: Research Funding; NS Pharma: Research Funding; YM Bioscience: Research Funding.

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 Abstract 2852 Background: The 18-item Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF, Scherber et al Blood 2011) given in conjunction with the 9-item Brief Fatigue Inventory (BFI, Mendoza et al Cancer 1999) is a patient-completed questionnaire for assessing symptoms in persons with MPNs. The MPN-SAF has been translated and validated in 9 languages to date. The Total Symptom Score (TSS) is computed from 10 of the most pertinent MPN-SAF items to assess symptom burden in MPN patients and to evaluate response to therapy. Psychometric properties of the TSS have been previously reported (Emanuel et al Blood 2012). The purpose of this analysis is to compare MPN-SAF symptoms and psychometric properties of the TSS across 9 languages in an international sample. Methods: Data were collected in an international cohort of subjects with MPNs. Surveyed symptoms included fatigue, early satiety, abdominal pain and discomfort, inactivity, headaches, concentration, dizziness, extremity tingling, insomnia, sexual problems, mood changes, cough, night sweats, pruritus, bone pain and fever on a 0 (absent) to 10 (worst imaginable) scale. TSS was computed using the published scoring algorithm on a 0 (all symptoms absent) to 100 (all symptoms worst imaginable) scale. Demographic and disease-related data including disease type, gender, and age had to be present to be included in analysis. Demographics were compared across languages groups using ANOVA and chi-squared tests. Symptoms and TSS were compared across language groups using a general linear model adjusting for disease type, age, and gender with post-hoc Tukey pairwise comparisons. Internal consistency and factor structure of the TSS were investigated overall and within language groups using Cronbach's alpha and principal-axis factoring analysis. Results: Subject Demographics and Disease Type: 1,851 subjects with polycythemia vera (PV N=655), essential thrombocythemia (ET N=769) and myelofibrosis (MF N=427; 286 primary MF, 61 PV-MF, 80 ET-MF) were prospectively enrolled and administered the MPN-SAF and BFI in 1 of 9 languages: English [UK] 55, English [US] 102, Italian 186, Swedish 114, German 112, French 457, Spanish 192, Dutch 236, and Chinese 397. Age (median 61, range, 15–94) and gender (55% F) were typical. Disease type and age varied across language groups (both p <0.001). MPN-SAF Symptoms and TSS: Symptom frequencies ranged from 19% (fever) to 88% (fatigue) overall with mean severities ranging from 0.4 (SD=1.3, fever) to 4.3 (SD=2.3, fatigue). Fatigue had the highest mean severity among all symptoms within each language group. Overall, mean TSS was 21.5 (SD=16.7) with the Swedish (mean=18.1, SD=15.2) and Dutch (mean=27.6, SD=17.1) cohorts reporting the lowest and highest unadjusted TSS means, respectively. When comparing symptom items across languages (adjusting for disease type, age, and gender), concentration and sexual problems had the most statistically significant pairwise differences (11 and 10, respectively, out of a possible 36) followed by dizziness and overall quality of life (9 each, out of a possible 36). No statistically significant pairwise differences were observed for abdominal discomfort, headache, extremity tingling, or insomnia. For the TSS, the Dutch cohort appeared to statistically significantly differ (all p <0.05) with all other languages except the English cohorts. All other TSS pairwise comparisons were not statistically significant. TSS Internal Consistency and Factor Structure: The TSS had excellent internal consistency overall (Cronbach's alpha 0.83) as well as within language groups (Cronbach's alpha 0.81–0.86). Overall factor analysis identified a single underlying construct among the 10 TSS items. Factor loadings ranged from 0.41 for fever to 0.73 for inactivity. A single factor solution was appropriate for each language group with factor loadings ranging from 0.18 to 0.85. Conclusion: This analysis suggests that the available translations of the MPN-SAF are generally acceptable for use in a broad context. The TSS demonstrated acceptable internal consistency and similar factor structure across all language groups. Most symptom and TSS comparisons between languages were not statistically significant, but for the few which differed, further studies are needed to evaluate whether these variances are due to disease-related factors or due to linguistic or cultural influences present in the cohorts. Disclosures: Kiladjian: Novartis: Honoraria, Research Funding; Celgene: Research Funding; Shire: Honoraria. Griesshammer:Shire: Honoraria. Roy:Novartis, BMS: Speakers Bureau. Harrison:Novartis: Honoraria, Research Funding, Speakers Bureau; YM Bioscience: Consultancy, Honoraria; Sanofi Aventis: Honoraria; Shire: Honoraria, Research Funding. Passamonti:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees. Mesa:Incyte: Research Funding; Lilly: Research Funding; Sanofi: Research Funding; NS Pharma: Research Funding; YM Bioscience: Research Funding.

Abstract Abstract 1726 Background: We previously reported that symptom burden among persons with ET and PV can be severe and adversely affect QOL. The presence of severe symptoms is linked to poor prognosis. There is considerable inter-subject heterogeneity regarding which symptoms are present in which subjects. No studies have empirically evaluated whether disease characteristics can be grouped in related symptom clusters. Using our previously validated 18 item Myeloproliferative Neoplasm Assessment Form (MPN-SAF) (Blood 2011;118:401–408) given in conjunction with the 9 item Brief Fatigue Inventory (BFI) (Cancer 1999;85:1186–1196), we sought to evaluate symptom burden by means of cluster analysis. Methods: Data was collected from an international cohort of subjects with MPNs including demographics, disease features and the completed BFI and MPN-SAF instruments. Surveyed symptoms included fatigue, early satiety, abdominal pain and discomfort, inactivity, headaches, concentration, dizziness, extremity tingling, insomnia, sexual difficulties, mood changes, cough, night sweats, pruritus, bone pain and fever on a 0 (absent) to 10 (worst-imaginable) scale. Development of symptom clusters was based on consideration of r-squared in hierarchical clustering using Ward linkage. Final cluster assignment was based on the nonhierarchical k-means method. Comparisons between symptom clusters were based on ANOVA and chi-squared tests. Results: Subject Demographic and Disease Characteristics: Data from 1,141 subjects with PV (N=519) and ET (N=622) was prospectively collected (Chinese 236, French 305, German 45, Italian 114, Dutch 191, English 56, Spanish 109, Swedish 85. Age (mean 59, range, 26–87) and gender (54% F) were typical. Five clusters were selected (Figure 1). Frequencies of prior bleeding, spleen size, anemia, presence of any lab abnormality, language, gender, and MPN type varied significantly between clusters (P<0.05). Cluster 1: The “Reduced Symptom” Profile (n=421 (37%; 60% ET, 40% PV) The largest cluster, subjects had increased complaints of sexual difficulties and fatigue. There was a slightly higher proportion of subjects with ET (60%) versus PV. There were fewer lab abnormalities (28% prevalence) and less prior bleeding (3%) compared to other clusters. Spleen size was smallest of the cluster (1 cm below costal margin). Cluster 2: The “Fatigue-dominant” Group (n=286 (25%; 56% ET, 44% PV)). Subjects in this cluster were predominantly female and had relatively few laboratory abnormalities (19%) than other cohorts. They are characterized by high severity of fatigue compared to end-organ symptoms. Symptom profiles emphasize fatigue, QOL and insomnia with some end-organ complaints. The cohor 63% of the cohort. Cluster 3: The “End-Organ Complaints” Group (n=210 (18%; 49% ET, 51% PV)). Male predominant (56%), subjects had mainly macro-vascular symptom complaints including sexual difficulties, insomnia, and overall QOL, with few microvascular related symptoms (low itching/night sweats). Cluster 4: “Cognitive Complaints” Cluster (n=110 (10%; 53% ET, 47% PV)). The smallest cluster and female predominant (64%), main complaints include fatigue, insomnia, loss of concentration, numbness, and sad mood. Cluster 5: The “Highly Symptomatic” Cluster (n=114 (10%; 44% ET, 56% PV)). Subjects had many cognitive complaints and symptoms correlated with severe micro-vascular abnormalities (pruritus) and or splenomegaly. This cluster had the largest spleen sizes (mean 3 cm), the highest prevalence of prior thrombosis (29%), and highest frequency of lab abnormalities (43%). Cognitive and end-organ complaints were rated as most severe. Conclusion: This analysis offers new means of evaluating persons with PV and ET utilizing symptom clusters. Laboratory and physical abnormalities differed significantly between symptom clusters indicating that our groupings likely result from biological alterations present in specific disease phenotypes. Future studies should investigate correlations between clusters and prognosis and genotype. Disclosures: Kiladjian: Celgene: Research Funding; Novartis: Honoraria, Research Funding; Shire: Honoraria. Roy:Novartis, BMS: Speakers Bureau. Harrison:Novartis: Honoraria, Research Funding, Speakers Bureau; YM Bioscience: Consultancy, Honoraria; Sanofi Aventis: Honoraria; Shire: Honoraria, Research Funding. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees. Passamonti:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees. Mesa:Incyte: Research Funding; Lilly: Research Funding; Sanofi: Research Funding; NS Pharma: Research Funding; YM Bioscience: Research Funding.

Abstract BACKGROUND: The presence of constitutional symptoms has been associated with increased mortality risk in myelofibrosis (MF) (Blood 2010;115(9):1703-8). New therapies exist which alleviate the severe symptom burden profile observed in MF patients but are only approved for use in those with intermediate-2 or high risk disease (N Engl J Med 2012;366:787-798). However, it has been proposed that there are patients who may benefit from symptom based treatment regardless of prognostic score (Am Soc Hematol Educ Program 2014;2014:277-286). We have recently characterized symptom score cutoffs at which patients would statistically benefit from treatment based on symptom scores alone (Scherber et. al. EHA 2016: a2250). These treatment thresholds included aMyeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN-SAF TSS or MPN-10) total score of greater than or equal to 20, a worst individual item score of greater than 5, or a combined criteria of those with both an MPN-10 total score of greater than or equal to 20 and a worst individual item score greater than 5. This abstract represents an additional analysis of our MF cohort to better characterize the profile of patients who meet criteria for symptom-based therapy. METHODS: Patient demographics, symptom burden via the MPN-10 score (JCO 2012;30(33)4098-103), and disease traits were collected from MF patients and their physicians at a single time point during therapy. Previously we identified MPN-10 cutoffs via AkaikeÕs Information Criterion (AIC) analysis (Ecology 2014;95: 631-6), which represented the optimal model among all models specified for the data at hand to determine which patients would most benefit from symptom-directed therapy. RESULTS: Demographics. 695 MF patients without previousruxolitinib therapy were included in this analysis. Overall, of 455 patients (65.4%) fit a cutoff of having a single worst symptom item of greater than 5/10. 401 patients (57.7%) had a MPN-10 score of equal to or greater than 20. A total of 381 (54.8%) patients fit both of these criteria. A distribution of worse MPN-10 individual scores is shown in Table 1. Mean TSS score was 26.4 (SD=17.7). Symptom Criteria Associations. Demographics and disease traits: Neither mean age or age greater than 60 was significantly associated with meeting any of the symptom score cutoff criteria. Females were significantly more likely to meet any of the symptom score cutoffs (for all criteria, p=0.0003 or less). Patients with splenomegaly, particularly spleen size of greater than 15cm below the LCM, were significantly more likely than those with a normal sized spleen to meet any of the three criteria (spleen enlargement of any size p=0.014 or less; spleen greater than 15cm p=0.0114 or less). Patients who met any of the three symptom criteria tended to have a longer MPN duration, although this trend did not meet significance. A prior history of thrombosis was not associated with achieving any cutoff criterions. Symptom burden: Individuals who met the any symptom criteria were significantly more likely to have higher DIPSS prognostic risk score (for all p=0.0002 or less). Laboratory values: For those meeting criteria for a worst symptom greater than 5, mean WBC was 11.7 vs 9.1 x 109/L (p=0.025) and platelet count was 238.7 versus 329.1 (p=0.023). For those meeting criteria for a TSS greater than or equal to 20, mean WBC was 11.8 vs 9.5 x 109/L (p=0.04). For individuals meeting both criteria, mean WBC was 11.9 vs 9.5 x 109/L (p=0.034). The presence of peripheral blasts were significantly more common in patients with an individual worst symptom score greater than 5 (p=0.0364). Hemoglobin level was not significantly associated with symptom criteria for any cutoffs. CONCLUSION: Our analysis indicates that patients who would be treated based on symptom criteria are similar to patients who would be treated based on high risk features such as high DIPSS prognostic score, concerning blood count abnormalities (i.e., leukocytosis, thrombocytopenia, presence of peripheral blasts), and splenomegaly (particularly massive splenomegaly). Thrombosis history and age were not associated with criterion cutoff assignment, and it is notable that elderly age nor history of thrombosis alone would likely alter treatment choice other than anticoagulation. This data supports that JAK2 inhibitor treatment be strongly considered in patients meeting symptom based criteria. Disclosures Dueck: Bayer: Honoraria. Kiladjian:Novartis: Honoraria, Research Funding; AOP Orphan: Membership on an entity's Board of Directors or advisory committees, Research Funding. Zweegman:Celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria, Research Funding. Schouten:Sanofi: Consultancy; Novartis: Consultancy. Etienne:ARIAD: Speakers Bureau; Pfizer: Speakers Bureau; novartis: Consultancy, Speakers Bureau; BMS: Speakers Bureau. Harrison:Shire: Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Baxaltra: Consultancy, Honoraria, Speakers Bureau; Incyte Corporation: Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Other: travel, accommodations, expenses, Research Funding, Speakers Bureau. Radia:Novartis: Honoraria; Pfizer: Honoraria. Cervantes:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Baxalta: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AOP Orphan: Membership on an entity's Board of Directors or advisory committees. Vannucchi:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Mesa:Promedior: Research Funding; Celgene: Research Funding; CTI: Research Funding; Gilead: Research Funding; Incyte: Research Funding; Galena: Consultancy; Ariad: Consultancy; Novartis: Consultancy.

Abstract Background: ENESTop, an ongoing, single-arm, phase 2 study (ClinicalTrials.gov, NCT01698905), is the first trial specifically evaluating treatment-free remission (TFR; ie, stopping tyrosine kinase inhibitor [TKI] treatment without a loss of response) in patients with chronic myeloid leukemia in chronic phase (CML-CP) who achieved a sustained deep molecular response after switching from imatinib (IM) to nilotinib (NIL). Of 126 patients in ENESTop who were eligible to stop NIL, 57.9% (95% CI, 48.8%-66.7%) maintained TFR at 48 weeks. Here we present results from a subgroup analysis based on reasons for switching from IM to NIL, categorized as intolerance, resistance, and physician preference. Methods:Eligible patients were adults with CML-CP who received ≥ 3 years of total TKI therapy (> 4 weeks of IM, followed by ≥ 2 years of NIL) and achieved a sustained MR4.5 (BCR-ABL1 ≤ 0.0032% on the International Scale [BCR-ABL1IS]) on NIL therapy; patients with a documented MR4.5 at the time of switch from IM to NIL were not eligible. Enrolled patients continued NIL treatment in a 1-year consolidation phase, and those without confirmed loss of MR4.5 (ie, consecutive BCR-ABL1IS > 0.0032%) were eligible to stop NIL in the TFR phase. Patients with loss of major molecular response (MMR; ie, BCR-ABL1IS > 0.1%) or confirmed loss of MR4 (ie, consecutive BCR-ABL1IS > 0.01%) during the TFR phase reinitiated NIL treatment. The primary endpoint was the proportion of patients who maintained TFR (ie, no loss of MMR, confirmed loss of MR4, or treatment reinitiation) at 48 weeks after stopping NIL. In this post hoc analysis, rates of TFR at 48 weeks after stopping NIL and a Kaplan-Meier (KM) analysis of treatment-free survival (TFS; defined as the time from the start of TFR to the earliest occurrence of any of the following: loss of MMR, confirmed loss of MR4, reinitiation of NIL due to any cause, progression to accelerated phase/blast crisis, death due to any cause) were evaluated in subgroups of patients who switched from IM to NIL due to intolerance, resistance, or physician preference. These categories were determined by grouping the reasons for switching from IM to NIL, as reported by the investigators, based on relatedness to safety (intolerance), loss of response/treatment failure (resistance), and the physician's clinical judgment (physician preference); individual reasons included within each category are presented in the Figure. Results:A total of 125 patients who entered the TFR phase were included in this analysis; 1 patient who was found to have had atypical transcripts was excluded. Among these 125 patients, the reasons for switching to NIL were categorized as intolerance in 51 patients (40.8%), resistance in 30 patients (24.0%), and physician preference in 44 patients (35.2%). The proportion of patients who maintained TFR at 48 weeks after stopping NIL was generally similar across the 3 subgroups: 30 of 51 (58.8%; 95% CI, 44.2%-72.4%) in the intolerance subgroup, 16 of 30 (53.3%; 95% CI, 34.3%-71.7%) in the resistance subgroup, and 27 of 44 (61.4%; 95% CI, 45.5%-75.6%) in the physician preference subgroup. KM analysis of TFS showed that in all 3 subgroups, the majority of TFS events occurred within the first 24 weeks after stopping NIL (Figure). There were no notable differences in the kinetics of TFS events among subgroups. The KM-estimated median duration of TFS was not reached by the data cutoff date in all 3 subgroups. Conclusion: Primary analysis from ENESTop showed that among patients with CML-CP who achieved a sustained MR4.5after switching from IM to NIL, 57.9% of those who stopped NIL maintained TFR at 48 weeks. In the present analysis, TFR was maintained at 48 weeks after stopping NIL by > 50% of patients in the intolerance, resistance, and physician preference subgroups, with generally similar results across subgroups. These findings suggest that the rate of successful TFR following second-line NIL does not differ based on the reasons for switching from IM to NIL. Figure. Figure. Disclosures Hughes: Ariad: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Australasian Leukaemia and Lymphoma Group (ALLG): Other: Chair of the CML/MPN Disease Group. Boquimpani:Novartis: Research Funding, Speakers Bureau; BMS: Speakers Bureau. Takahashi:Novartis: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; BMS: Honoraria. Shuvaev:Pfizer: Honoraria; BMS: Honoraria; Novartis pharma: Honoraria. Ailawadhi:Pharmacyclics: Consultancy; Novartis: Consultancy; Amgen Inc: Consultancy; Takeda Oncology: Consultancy. Lipton:Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Ariad: Consultancy, Research Funding. Turkina:Pfizer: Honoraria; Novartis Pharma: Honoraria; BMS: Honoraria. Moiraghi:BMS: Speakers Bureau; NOVARTIS: Speakers Bureau. Nicolini:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria; Ariad pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees. Sacha:BMS: Consultancy, Honoraria, Speakers Bureau; Incyte: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Adamed: Consultancy, Honoraria. Kim:Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; ILYANG: Consultancy, Honoraria, Research Funding. Fellague-Chebra:Novartis: Employment. Acharya:Novartis Healthcare Pvt. Ltd.: Employment. Krunic:Novartis: Employment, Equity Ownership. Jin:Novartis: Employment, Equity Ownership. Mahon:BMS: Honoraria; PFIZER: Honoraria; NOVARTIS PHARMA: Honoraria, Research Funding; ARIAD: Honoraria.