Davids, Matthew S.

Abstract Introduction: Rituximab (R) improves survival in CLL when added to intensive chemotherapy (such as fludarabine and cyclophosphamide [FCR]), and has been shown to improve progression-free survival when given as maintenance therapy following first- or second-line chemoimmunotherapy. However, early phase 2 studies demonstrated only modest activity of R monotherapy (R mono), particularly at standard dose, and its use as a single agent for pts with CLL has remained controversial. Here we describe the characteristics and outcomes of pts with CLL receiving R mono in a real-world setting. Methods: The Connect CLL registry (NCT01081015), a multicenter, prospective observational cohort study, enrolled 1,494 pts with CLL between 2010-2014 from 179 community, 17 academic, and 3 government sites throughout the USA. Pts were ≥ 18 years and were enrolled ≤ 2 months after initiating any line of therapy (LOT). Pts were treated according to individual physician/patient decision making, and adherence to IWCLL standards cannot be determined. Bone marrow biopsy and CT scans were at the physician's discretion; responses were physician assessed and not centrally reviewed. For this analysis, pts were stratified by first (LOT1) or subsequent LOT (LOT≥2), and by treatment with R mono or other treatments (Tx). Kaplan-Meier methods were used to estimate event-free survival (EFS; event defined as death, progression/relapse, or transformation). A log-rank test was used to evaluate differences in EFS. A multivariate analysis of EFS in LOT1 pts was performed using the Cox regression model. Results: Of the pts enrolled, 105 (11.8%) pts in LOT1 and 81 (13.4%) pts in LOT≥2 received R mono. Of the pts receiving other Tx, 620/784 pts (79%) in LOT1 and 333/524 pts (64%) in LOT≥2 received R in combination. In LOT1, pts receiving R mono were older than pts receiving other Tx (74 vs 67 years; P < 0.0001); in LOT≥2 median ages were comparable (71 vs 70 years). Pts receiving R mono were more likely to have Rai stage 0-1 CLL than pts receiving other Tx, both in LOT1 (63.9% vs 51.8%; P = 0.05) and LOT≥2 (70.4% vs 49.9%; P = 0.005). The proportion of pts receiving R mono vs other Tx with a CCI score of ≥ 4 was similar in LOT1 (25.7% vs 22.8%) and LOT≥2 (32.1% vs 28.4%). Median absolute lymphocyte count at enrollment was lower in pts on R mono vs other Tx in LOT1 (27.7 vs 46.1 x 109/L) but similar in LOT≥2 (35.6 vs 30.2 x 109/L). A lower proportion of pts receiving R mono had FISH/cytogenetics performed at enrollment than pts receiving other Tx in LOT1 (48.6% vs 67.0%; P = 0.0002) and LOT≥2 (30.9% vs 49.6%; P = 0.002). The most common Tx regimens in LOT1 were FCR (25.9%), bendamustine plus R ([BR] 21.0%), R mono (11.8%), fludarabine plus R ([FR] 6.3%), and chlorambucil (4.6%); and in LOT≥2, BR (27.6%), R mono (13.4%), FCR (8.6%), bendamustine (7.4%), FR (4.1%), and ofatumumab (4.0%). The most common reason to initiate treatment in any LOT was bone marrow failure (LOT1, 44.8% vs 39.3%; LOT≥2, 37.0% vs 31.5%; R mono vs other Tx). Duration of therapy was shorter for pts receiving R mono vs other Tx in LOT1 (1.4 vs 4.1 months) and LOT≥2 (1.6 vs 3.3 months). In LOT1, responses were lower in pts on R mono vs other Tx: overall response rate (ORR) was 38.1% vs 64.2% (complete response [CR], 16.2% vs 41.2%; P < 0.0001). In LOT≥2, ORR was 25.9% vs 24.6% for pts on R mono vs other Tx (CR, 9.9% vs 11.5%; P = 0.68). Partial response did not differ significantly between pts receiving R mono vs other Tx in LOT1 and LOT≥2. Pts receiving R mono in LOT1 had inferior median EFS vs other Tx (34 vs 50 months; log-rank P = 0.04); however, after adjusting for factors such as ECOG status and del(17p) status, there was no difference in EFS (HR 0.932; P = 0.79). In pts in LOT≥2, median EFS was similar for R mono and other Tx (15 months for both groups; P = 0.93). Conclusions: Pts receiving R mono as frontline CLL therapy were older than pts receiving other Tx. They also had lower stage disease and lower lymphocyte counts, a shorter duration of treatment, and inferior response rates. Pts receiving R mono in relapsed CLL, more closely approximated pts receiving other Tx in terms of age. Despite the shorter duration of therapy for pts receiving R mono in LOT1 and LOT≥2, both groups had similar ORR and EFS in LOT≥2. These data reinforce the idea that R mono is inadequate as frontline therapy in progressive CLL, and demonstrate the opportunity for improvement in relapsed/refractory disease with novel agents relative to traditional chemoimmunotherapy approaches. Disclosures Sharman: Celgene: Research Funding; Gilead: Research Funding; Pharmacyclics: Research Funding; Acerta: Research Funding; TG Therapeutics: Research Funding; Seattle Genetics: Research Funding. Davids:Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Infinity: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie, Janssen, Gilead: Consultancy; Celgene Corporation: Consultancy. Farber:Seattle Genetics: Research Funding. Grinblatt:Celgene Corporation: Consultancy, Speakers Bureau. Lamanna:Gilead: Research Funding; AbbVie: Research Funding; Genentech: Research Funding; Infinity: Research Funding; Pronai: Research Funding; Celgene Corporation: Research Funding. Mato:TG Therapeutics: Consultancy; Abbvie: Research Funding; Acerta Pharma: Research Funding; Gilead Sciences: Research Funding; ProNAi: Research Funding; TG Therapeutics: Research Funding; Theradex: Research Funding; Pharmacyclics: Consultancy; Gilead Sciences: Consultancy; Abbvie: Consultancy. Nabhan:Astellas: Research Funding; Seattle Genetics: Research Funding; Cardinal Health: Consultancy; Infinity: Consultancy; Abbvie: Consultancy; Genentech: Consultancy, Research Funding; Celgene Corporation: Consultancy, Research Funding. Sullivan:Celgene Corporation: Employment, Equity Ownership. Flick:Celgene Corporation: Employment, Equity Ownership. Kiselev:Celgene Corporation: Employment, Equity Ownership. Bhushan:Celgene Corporation: Employment, Equity Ownership. Swern:Celgene: Employment, Equity Ownership. Flowers:Seattle Genetics: Research Funding; Optum Rx, Seattle Genetics, Genentech/Roche: Consultancy; Celgene Corporation: Consultancy, Honoraria; Spectrum, Janssen, Infinity, AbbVie, Acerta, Pharmacyclics, TG Therapeutics: Research Funding; Millennium: Consultancy, Research Funding; Gilead: Consultancy, Research Funding.

Abstract Introduction: Given the availability of several active treatment (tx) options for CLL, providers frequently make tx recommendations based on their interpretation of objective data from consensus criteria and clinical trials. There are limited data describing patient (pt) experience, values, and insights when encountering multiple tx choices. The CLL Society, a pt-driven, physician-curated nonprofit organization focused on the unmet needs of the CLL community, sought to explore how CLL pts make tx decisions. Methods: A 64 question survey was distributed online and in paper to CLL pts from Oct-Dec 2017. The survey was developed by CLL experts. The research was IRB-approved. Chi square was used for statistical comparison; all other analyses are descriptive in nature. Results: 1147 pts from 48 states completed the survey. Median age was 65 (range 28-86), 46% male, 96% Caucasian. Who Influences Tx: Of the 79% of pts who have seen a CLL expert, defined as a provider focused on CLL at an academic/research center, 95% rated their provider as very/extremely influential. 83% of pts rated their own opinions as influential, and 59% rated the opinion of a general hematologist/oncologist (gen heme/onc), a provider who sees a variety of cancer types, as influential. Only 27% let their provider unilaterally decide on tx. Of these pts, 19% trusted their provider to select the best tx and 5% didn't have enough understanding to be involved in the decision. 64% were influenced by outside sources of information, such as family members, live CLL support groups, or online sources including pt experts and forums. Factors in Deciding Tx: Of the 67% pts surveyed who have been treated, 73% were offered > 1 tx choice by their provider. In deciding on a specific tx, 94% of respondents stated that it was very/extremely important to know there were tx options beyond their current regimen. The most important factors in selecting tx were response rate (91%), overall survival (88%), progression-free survival (86%), long-term side effects (82%), ability to achieve undetectable MRD (80%), cost/insurance coverage (66%), and location of tx (50%) with significant differences between subgroups (Table 1). Tx was impacted by cost or insurance issues for 16% (n=104). Of these 104 pts, cost/insurance issues resulted in tx delay for 34 and change in tx plan for 24 pts. 16 pts reported that an appeal led to coverage and 16 pts received financial assistance. Pts' willingness to accept potentially curable but high-risk tx was heavily influenced by availability of alternate options. For example, 18% of pts would be willing to consider cytotoxic chemotherapy if alternate options were available vs. 72% if no options were available. Similar patterns were seen with CAR-T tx (28% vs. 79%) and bone marrow transplantation (BMT) (15% vs. 66%) with significant differences between subgroups (Table 2). 82% were willing to take a life-long tx for long-term control without potential for cure. Willingness to accept long-term tx was significantly higher in treated vs. untreated pts (84% vs. 77%, p=.006) and men vs. women (84% vs. 78%, p=.008). Clinical Trial Education: Of those treated by a gen heme/onc, 31% received no education on clinical trials. Only 15% reported good understanding of trial opportunities vs. 52% treated by a CLL expert (p<.001). 9% of pts treated by gen heme/onc were offered clinical trial participation vs. 47% treated by a CLL expert (p<0.001). Pts who declined or would have declined participation cited reasons including preference for "proven" tx (38%), distance from trial site (29%), fear (20%), frequent imaging (20%), overall lack of understanding about trials (15%), and lack of information (14%). Summary: Most respondents want to be and are involved in tx decisions. While providers are influential in decision making, CLL pts also rely on outside sources. Gender, age, and tx status influence which factors drive decision making. Pts select tx based on response rate, survival, side effects, and ability to achieve deep response and want a plan in place for sequencing tx. The majority are willing to consider long-term tx without cure. Few want chemotherapy, CAR-T, or BMT unless they have no other options. A significant opportunity for improvement in education on clinical trial opportunities was identified. This description of pt experience, values, and preferences enriches the informed consent process and may lead to more tailored and patient-centered care. Disclosures Kennard: AbbVie, Gilead, Verastem: Consultancy. Furman:TG Therapeutics: Consultancy; Loxo Oncology: Consultancy; Sunesis: Consultancy; Verastem: Consultancy; Incyte: Consultancy, Other: DSMB; Genentech: Consultancy; Acerta: Consultancy, Research Funding; Gilead: Consultancy; Janssen: Consultancy; Pharmacyclics LLC, an AbbVie Company: Consultancy; AbbVie: Consultancy. Pagel:Pharmacyclics, an AbbVie Company: Consultancy; Gilead: Consultancy. Davids:Sunesis: Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; MEI Pharma: Consultancy, Research Funding; Surface Oncology: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Merck: Consultancy; Merck: Consultancy; MEI Pharma: Consultancy, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; MEI Pharma: Consultancy, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Sunesis: Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, 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; Verastem: Consultancy, Research Funding; Surface Oncology: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Roche: Consultancy; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Research Funding; Verastem: Consultancy, Research Funding; BMS: Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Surface Oncology: Research Funding; Verastem: Consultancy, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sunesis: Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy; Roche: Consultancy. Nabhan:Cardinal Health: Employment, Equity Ownership. Kay:Acerta: Research Funding; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Infinity Pharm: Membership on an entity's Board of Directors or advisory committees; Cytomx Therapeutics: Membership on an entity's Board of Directors or advisory committees. Siddiqi:Juno Therapeutics: Other: Steering committee. Brander:Genentech: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Pharmacyclics, an AbbVie Company: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Teva: Consultancy, Honoraria; Novartis: Consultancy, Other: DSMB; TG Therapeutics: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; BeiGene: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Acerta: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; DTRM: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding. Wierda:AbbVie, Inc: Research Funding; Genentech: Research Funding. Hill:Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees. Cheson:AbbVie, Roche/Genentech, Pharmacyclics, Acerta, TG Therapeutics: Consultancy. Choi:Pharmacyclics: Consultancy, Research Funding, Speakers Bureau; Gilead: Speakers Bureau; Rigel: Consultancy; Genentech: Speakers Bureau; AbbVie, Inc: Consultancy, Speakers Bureau. Mato:AstraZeneca: Consultancy; Prime Oncology: Honoraria; Portola: Research Funding; Johnson & Johnson: Consultancy; Medscape: Honoraria; Celgene: Consultancy; TG Therapeutics: Consultancy, Research Funding; Acerta: Research Funding; Pharmacyclics, an AbbVie Company: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Regeneron: Research Funding.

Abstract Introduction Transformation of chronic lymphocytic leukemia (CLL) into Hodgkin lymphoma (HL) is a rare, but recognized complication of CLL. The prognosis of CLL with HL Transformation (HT) appears significantly worse than de novo HL, but most series are small and there are limited published data. These reports have prompted several groups to recommend aggressive therapy with stem cell transplantation (SCT) in first complete remission (CR1). We describe the largest reported series of HT patients (pts) with analyses of the clinicobiologic characteristics, treatment patterns, and clinical outcomes based upon our multi-institutional clinical experience. Methods Pts diagnosed with HT from 01/2000 - 01/2018 were retrospectively identified in 13 tertiary cancer centers. Clinicobiologic characteristics, treatment type, and survival outcomes for each pt were analyzed. Overall survival (OS) was measured from the time of HT diagnosis until time of death. OS estimates were calculated using the Kaplan-Meier method. The log-rank test was used to calculate differences in survival. Results Ninety-four pts with HT were identified. Median age at HT was 67 years (yrs; range, 38-85) and 81% of the pts were male. Median time from CLL diagnosis to HT was 5.5 yrs (range, 0-20.2; 7 pts with simultaneous diagnosis of CLL and HL). At initial CLL diagnosis, 31%, 34%, 21%, 10%, and 4% were Rai Stage 0, 1, 2, 3, and 4, respectively. At CLL diagnosis, 67% (25/37) had an un-mutated IgVH gene, 36% (21/59) had del(13q), 32% (14/44) had trisomy 12, 24% (14/59) had del(11q), and 15% (9/61) had del(17p). Prior to HT diagnosis, pts had a median of 2 (range, 0-12) therapies for CLL. Seventeen (18%) had no prior CLL treatments. Forty-three (46%) and 25 (27%) patients had received purine analogue- and ibrutinib-based therapy prior to HT, respectively. Baseline characteristics at HT are described in Table 1. As initial therapy for HL, the majority of pts (61%, n = 62) received ABVD-based regimens (adriamycin, bleomycin, vinblastine, and dacarbazine) at full (n = 48) or reduced (n = 14) doses. Of these, CD20 monoclonal antibody was added in 6 and Bruton-tyrosine kinase inhibitor was added in 2. Ten (11%) received a brentuximab-based regimen. Seven (7%) received an RCHOP-based regimen (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone). Six patients (6%) received no therapy for HT due to frailty. Subsequent therapy included autologous SCT and allogeneic SCT in 7 (7%) and 11 (12%) of patients, respectively. Two (2%) and 5 (5%) pts received their autologous and allogeneic SCT while in CR1, respectively. The median number of treatments for HT per pt was 1 (range, 0-5) with 59 (61%) pts only receiving one line of therapy. After HT diagnosis, pts had a median follow-up of 1.6 yrs (range, 0.0 - 15.1). Two-yr OS after HT diagnosis was 72% (95%CI 62 - 83%). The pts who received any CLL directed therapy (n = 80) prior to HT had a significantly lower estimated 2-yr OS of 69% (95%CI 58 - 82%) compared with pts who did not receive any prior CLL-directed therapy (n = 17; 93%; 95%CI 82-100%; p 0.02; Figure 1). Pts who received purine-analogue-based therapy for their CLL prior to HT had a significantly lower estimated 2-yr OS of 60% (95%CI 46 - 79%) compared with pts who did not receive purine-analogue-based CLL-directed therapy prior to HT (n = 51; 83%; 95%CI 73 - 96%; p 0.009; Figure 2). Although limited by small sample size, the pts who underwent SCT for HT in CR1 had a similar 2-yr OS (n = 7; 67%; 95%CI 38-100%) to pts who did not undergo SCT for HT in CR1 (n = 87; 72%; 95%CI 63 - 84%; p 0.46; Figure 3). Conclusions In this retrospective analysis, we describe the largest reported series of pts with HT from CLL. Two-yr survival in pts with HT was shorter than what is historically expected in patients with de novo HL, but longer than what is expected in CLL pts who transform to diffuse large B-cell lymphoma. Pts with HT who have received prior CLL-directed therapies (specifically purine-analogue-based treatments) are estimated to have a shorter 2-yr OS, likely due to underlying immunosuppression. The majority of pts (61%) only received 1 line of HL therapy and only 20% went on to receive SCT (7% while in CR1), indicating that these patients can have prolonged OS after achieving response to first-line therapy for HT and may not require SCT in CR1. Further study of this rare population is required to determine optimum management. Disclosures Kander: AstraZeneca: Consultancy. Parikh:Gilead: Honoraria; AstraZeneca: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Janssen: Research Funding; MorphoSys: Research Funding; Pharmacyclics: Honoraria, Research Funding. Shadman:Acerta Pharma: Research Funding; Verastem: Consultancy; Celgene: Research Funding; Gilead Sciences: Research Funding; Mustang Biopharma: Research Funding; Pharmacyclics: Research Funding; AstraZeneca: Consultancy; Beigene: Research Funding; Genentech: Research Funding; Qilu Puget Sound Biotherapeutics: Consultancy; AbbVie: Consultancy; TG Therapeutics: Research Funding; Genentech: Consultancy. Pagel:Pharmacyclics, an AbbVie Company: Consultancy; Gilead: Consultancy. Mato:Portola: Research Funding; AstraZeneca: Consultancy; Acerta: Research Funding; Prime Oncology: Honoraria; Regeneron: Research Funding; Celgene: Consultancy; Pharmacyclics, an AbbVie Company: Consultancy, Research Funding; Medscape: Honoraria; TG Therapeutics: Consultancy, Research Funding; Johnson & Johnson: Consultancy; AbbVie: Consultancy, Research Funding. Hill:Amgen: Research Funding; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees. Danilov:Verastem: Consultancy, Research Funding; Aptose Biosciences: Research Funding; Takeda Oncology: Research Funding; Genentech: Consultancy, Research Funding; TG Therapeutics: Consultancy; Bayer Oncology: Consultancy, Research Funding; Astra Zeneca: Consultancy; Gilead Sciences: Consultancy, Research Funding. Phillips:Abbvie: Research Funding; Bayer: Consultancy; Gilead: Consultancy; Genentech: Consultancy; Pharmacyclics: Consultancy, Research Funding; Seattle Genetics: Consultancy. Brander:Pharmacyclics, an AbbVie Company: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Acerta: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Novartis: Consultancy, Other: DSMB; Teva: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; DTRM: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Genentech: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; BeiGene: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding. Smith:BMS: Consultancy; Portola: Honoraria. Davids:Surface Oncology: Research Funding; Roche: Consultancy; Sunesis: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Sunesis: Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Surface Oncology: Research Funding; Astra-Zeneca: Consultancy, 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; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy; MEI Pharma: Consultancy, Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Verastem: Consultancy, Research Funding; Roche: Consultancy; Sunesis: Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; BMS: Research Funding; MEI Pharma: Consultancy, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Consultancy; Merck: Consultancy; Celgene: Consultancy; Astra-Zeneca: Consultancy, 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; Gilead: Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy; Celgene: Consultancy; BMS: Research Funding; Surface Oncology: Research Funding; MEI Pharma: Consultancy, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Research Funding.

Key Points Early progression of disease within 2 years of initial therapy independently predicts inferior survival in CLL. Early progression of disease is a robust clinical end point and a useful posttreatment risk stratification tool.

Abstract Purpose: To develop a prognostic model and cytogenetic risk classification for previously treated patients with chronic lymphocytic leukemia (CLL) undergoing reduced intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (HCT). Experimental Design: We performed a retrospective analysis of outcomes of 606 patients with CLL who underwent RIC allogeneic HCT between 2008 and 2014 reported to the Center for International Blood and Marrow Transplant Research. Results: On the basis of multivariable models, disease status, comorbidity index, lymphocyte count, and white blood cell count at HCT were selected for the development of prognostic model. Using the prognostic score, we stratified patients into low-, intermediate-, high-, and very-high-risk [4-year progression-free survival (PFS) 58%, 42%, 33%, and 25%, respectively, P &lt; 0.0001; 4-year overall survival (OS) 70%, 57%, 54%, and 38%, respectively, P &lt; 0.0001]. We also evaluated karyotypic abnormalities together with del(17p) and found that del(17p) or ≥5 abnormalities showed inferior PFS. Using a multivariable model, we classified cytogenetic risk into low, intermediate, and high (P &lt; 0.0001). When the prognostic score and cytogenetic risk were combined, patients with low prognostic score and low cytogenetic risk had prolonged PFS (61% at 4 years) and OS (75% at 4 years). Conclusions: In this large cohort of patients with previously treated CLL who underwent RIC HCT, we developed a robust prognostic scoring system of HCT outcomes and a novel cytogenetic-based risk stratification system. These prognostic models can be used for counseling patients, comparing data across studies, and providing a benchmark for future interventions. For future study, we will further validate these models for patients receiving targeted therapies prior to HCT.

7505 Background: Novel agents (NA) targeting B cell receptor kinases and Bcl-2 have substantially improved outcomes in CLL; however, the development of RS in CLL patients (pts) on NAs has been observed, and has not been systematically evaluated. Methods: We retrospectively reviewed pts at 9 academic centers diagnosed with pathologically-confirmed RS from 2011-16. Informed consent was provided through IRB-approved protocols. Descriptive statistics were utilized and overall survival (OS) was calculated from RS diagnosis (dx) to death or last follow-up by Kaplan-Meier. Results: 71 pts who developed RS on NAs for CLL were identified. Median age at CLL dx was 55 yrs (range 21-82), median of 3 therapies (range 0-12) prior to the NA. 68% pts were fludarabine-refractory, and 5 pts (7%) had relapsed post alloHCT. Median time from CLL dx to initiation of NA was 68.5 mo. (range 1.1-246.2). FISH at NA initiation: del(17p) 30/61 (49%), del(11q) 15/61 (25%), trisomy 12 15/61 (25%). Complex karyotype was present in 40/53 (75%). 46/52 (88%) were IGHV unmutated, VH1-69 10/43 (23%), VH4-39 4/43 (9%). 59 (83%) pts were on a BTK inhibitor, 6 (8%) PI3K inhibitor, 6 (8%) venetoclax. RS histology: DLBCL (87%), plasmablastic (6%), Hodgkin (4%), 3% other. RS Ki-67%: >90 (23%), 75-90 (25%), 50-75% (25%), <50% (28%). Median time from start of NA to RS dx was 9.1 mo (range 0.9-48.2), with 65% developing RS within 12 mo. of starting NA. In 56 pts, 19 different regimens were used as initial RS therapy, including: R-EPOCH (36%), R-CHOP (20%), checkpoint blockade (9%), OFAR (7%), or a different NA (7%). Of the 48 pts evaluable for response, ORR was 42% (15% CR, 27% PR). In 29 evaluable pts receiving R-EPOCH/CHOP, ORR was 48% (21% CR). With a median follow-up of 10.6 mo., median OS was only 3.3 mo. (95%CI 2.2-6.0), though none of the 7 pts who achieved CR has died. Conclusions: We report to our knowledge the largest series of CLL pts developing RS on NAs. Pts often had high risk CLL, particularly complex cytogenetics, and RS frequently developed within the first year of NA therapy. Substantial variation exists in treatment, and outcomes are poor for those who do not achieve CR. Identification of molecular drivers of RS and development of novel treatment strategies are urgently needed.