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Acalabrutinib, a next-generation Bruton’s tyrosine kinase inhibitor (BTKi), associates with dramatic efficacy against B-cell malignancies. Recently, unexplained ventricular arrhythmias (VAs) with next-generation BTKi-therapy have been reported. Yet, whether acalabrutinib associates with VAs in long-term follow-up is unknown. Leveraging a large-cohort of 290 consecutive B-cell malignancy patients treated with acalabrutinib from 2014 to 2020, we assessed the incidence of VAs. The primary-endpoint was incident VA development (ventricular fibrillation, ventricular tachycardia, and symptomatic premature ventricular contractions). Probability-scores were assessed to determine likelihood of acalabrutinib-association. Incident rates as function of time-on-therapy were calculated. Weighted average observed incidence rates were compared with expected population rates using relative-risks. Absolute excess risk (AER) for acalabrutinib-associated VAs was estimated. Over 1063 person-years of follow-up, there were 8 cases of incident-VAs, including 6 in those without coronary disease (CAD) or heart failure (HF) and 1 sudden-death; median time-to-event 14.9 months. Among those without prior ibrutinib-use, CAD, or HF, the weighted average incidence was 394 per 100 000 person years compared with a reported incidence of 48.1 among similar-aged non–BTKi-treated subjects (relative risk, 8.2; P

Complex karyotype, defined as ≥3 cytogenetic abnormalities, is prognostic of survival in patients treated with ibrutinib or venetoclax in relapsed/refractory (RR) chronic lymphocytic leukemia (CLL). Recent studies re-evaluating this dichotomous variable have shown that higher numbers of cytogenetic abnormalities (ie, ≥5) have a worse overall survival in patients treated with chemoimmunotherapy. We sought to determine if increasing karyotypic complexity, treated as a continuous variable, was prognostic of survival for patients treated with ibrutinib for CLL. We conducted a retrospective analysis of all patients with CLL treated with single-agent ibrutinib or in combination with an anti–CD20 antibody at our institution. We included 456 patients with both treatment-naive and RR disease. Median number of prior therapies was 2 (range, 0-13), 30% of patients had presence of del(17p), and 75% expressed unmutated IGHV. Fifty percent had ≥3 cytogenetic abnormalities, including 30% with ≥5. In a multivariable analysis, increasing karyotypic complexity was an independent predictor of shorter progression-free survival (hazard ratio, 1.07; 95% confidence interval, 1.04-1.10; P < .0001) and overall survival (hazard ratio, 1.09; 95% confidence interval, 1.05-1.12; P < .0001). Furthermore, we found that presence of clonal evolution determined by cytogenetic analysis at progression was prognostic of subsequent survival (P = .02). This solidifies karyotypic complexity as an important prognostic factor for patients with CLL treated with ibrutinib. Further research should consider sequential karyotypic analysis as a determination of risk of progression and death in patients with CLL.

Bruton tyrosine kinase inhibitors (BTKi) have significantly changed the treatment landscape for patients with B-cell malignancies, including chronic lymphocytic leukemia, Waldenstrom macroglobulinemia, mantle cell lymphoma, and marginal zone lymphoma. Unfortunately, patients with BTKi-resistant disease have shortened survival. Clinical and molecular risk factors, such as number of prior therapies and presence of TP53 mutations, can be used to predict patients at the highest risk of developing BTKi resistance. Many mechanisms of BTKi resistance have been reported with mutations in BTK and phospholipase C γ2 supported with the most data. The introduction of venetoclax has lengthened the survival of patients with BTKi-resistant disease. Ongoing clinical trials with promising treatment modalities, such as next-generation BTKi and chimeric antigen receptor T-cell therapy, have reported promising efficacy in patients with BTKi-resistant disease. Continued research focusing on resistance mechanisms and methods of how to circumvent resistance is needed to further prolong the survival of patients with BTKi-resistant B-cell malignancies.

Background:The Eμ-TCL1 syngeneic model is the most widely used mouse model of chronic lymphocytic leukemia and has been extensively used to understand the pathogenesis of select genes, the effect of the immune microenvironment and for pre-clinical drug development studies. Recently there has been an increasing awareness of the impact of age and sex differences on not only the development of cancers but also the efficacy and toxicity of specific cancer therapies. However, despite the predominance of older males in CLL patient demographics, the Eμ-TCL1 adoptive transfer studies have used almost exclusively young female recipient mice. Methods:In this study we performed primary and secondary adoptive transfer experiments in order to understand the impact of recipient age and sex on the development of disease as assessed by flow cytometry and survival in the Eμ-TCL1 adaptive transfer model. Results:We found that young female recipients had pro-longed survival in a primary adoptive transfer, however sex differences were not observed in a subsequent secondary adoptive transfer experiment. Furthermore, while recipient age did not have a significant effect on the rate of disease establishment or survival in female mice, aged male mice had a significantly decreased rate of Eμ-TCL1 tumor engraftment. Conclusions:These findings suggest that age and sex differences must be considered in the experimental design of studies using the Eμ-TCL1 adaptive transfer model of CLL.

Acalabrutinib has demonstrated significant efficacy and safety in relapsed chronic lymphocytic leukemia (CLL). Efficacy and safety of acalabrutinib monotherapy were evaluated in a treatment-naive CLL cohort of a single-arm phase 1/2 trial (ACE-CL-001). Adults were eligible for enrollment if chemotherapy was declined or deemed inappropriate due to comorbidities (N = 99). Patients had a median age of 64 years and 47% had Rai stage III/IV disease. Acalabrutinib was administered orally 200 mg once daily, or 100 mg twice daily until progression or intolerance. A total of 99 patients were treated; 57 (62%) had unmutated immunoglobulin heavy-chain variable gene, and 12 (18%) had TP53 aberrations. After median follow-up of 53 months, 85 patients remain on treatment; 14 discontinued treatment, mostly because of adverse events (AEs) (n = 6) or disease progression (n = 3). Overall response rate was 97% (90% partial response; 7% complete response), with similar outcomes among all prognostic subgroups. Because of improved trough BTK occupancy with twice-daily dosing, all patients were transitioned to 100 mg twice daily. Median duration of response (DOR) was not reached; 48-month DOR rate was 97% (95% confidence interval, 90-99). Serious AEs were reported in 38 patients (38%). AEs required discontinuation in 6 patients (6%) because of second primary cancers (n = 4) and infection (n = 2). Grade ≥3 events of special interest included infection (15%), hypertension (11%), bleeding events (3%), and atrial fibrillation (2%). Durable efficacy and long-term safety of acalabrutinib in this trial support its use in clinical management of symptomatic, untreated patients with CLL.

Background: ENA is an oral, selective inhibitor of IDH2 approved for the treatment (Tx) of patients (pts) with relapsed/refractory IDH2 mutated (IDH2m) AML. Here we report the results of a Phase 2 expansion and Phase 1b of the Beat AML Master Trial Phase 2/1b sub-study to assess the efficacy of Tx of newly diagnosed (ND) IDH2m AML pts ≥ 60 years of age with ENA monotherapy (ENAm) and subsequent response-driven addition of AZA Tx. (ClinicalTrials.gov NCT03013998). Methods: The study initiated with a 3-outcome, 2-stage Phase 2 design, which enrolled patients on ENAm for up to 5 cycles. Pts without CR/CRi after 5 cycles of ENAm, or progression/intolerance prior to this time, were transferred to Phase 1b to receive ENA + AZA (Figure 1). Key eligibility included ND IDH2m AML pts with age ≥ 60 years and ECOG performance status 0-2. Pts received ENAm 100 mg/day in continuous 28-day cycles and ENA + AZA (75 mg/m2 days 1-7 every 28 days) for Phase 1b. Response was assessed using 2017 ELN AML criteria. The primary endpoint was CR/CRi rate. The 2-stage design required 24 pts and tested the null hypothesis (H0) that CR/CRi rate equaled 20% vs 50% and then expanded to test a revised H0 of 30% vs 50% in 60 pts (conditional alpha=0.025, power=77%). Expansion also allowed further assessment of safety of this treatment regimen. Results: At data cut off (06/18/2020), 60 pts enrolled, received ENAm, and were evaluable for the primary endpoint. Median age was 75 years and 52% were female (Table 1). Median time on ENAm was 4.7 months (mos). At data cut off, 12 pts were still on ENAm Tx. Most common reasons for discontinuing ENAm were Tx failure (defined as no response to treatment) (23 or 38%), disease progression (loss of response to treatment) (7 or 12%) and adverse events (AEs; 6 or 10%). Five pts (8%) went to transplant. CR/CRi was achieved in 28 pts (47%; adjusted 95% CI 28-59, unadjusted exact 95% CI 34-60) (Table 2). Responses were higher (p=0.04) among the 44 pts with IDH2 R140 (55%) as compared to the 16 with IDH2 R172 mutation (25%) further supporting distinct biology between these subsets. After a median follow up of 14.6 mos, the median overall survival (mOS) was 24.4 mos (95% CI 10.6-not reached). The median duration of response was not reached with 12 mos estimation of 57% (95% CI 34-75). Overall, 20 ENA-related serious adverse events (SAEs) occurred in 15 pts, the most common was differentiation syndrome (12 or 20%) and 1 had ENA-related SAE of tumor lysis syndrome (1.7%). One pt had ENA-related Grade 5 AE (renal failure/death). Most common AEs of any grade (in ≥20%) were nausea, anemia, and low potassium (Table 3). The 7-day/30-day/60-day deaths observed with ENAm were 2%/5%/11%, respectively. Phase 1b: Seventeen pts had inadequate response to ENAm and transferred to Phase 1b to receive ENA + AZA. Median time on Tx (including ENAm) was 6.2 mos and median time on Tx after pts started ENA + AZA was 2.1 mos (Table 2). Most common reasons for discontinuing ENA + AZA included Tx failure (5 or 29%), disease progression (2 or 12%), transplant, death and AEs (each 2 or 12%). CR/CRi was 41% (exact 95% CI 18-67). After a median follow up of 12.7 mos, the mOS from start of ENA + AZA combination Tx was 8.9 mos. Four ENA-related SAEs occurred in 3 pts on ENA + AZA Tx and the most common was differentiation syndrome (2 or 12.5%). One dose-limiting toxicity (Grade 3 nausea) related to both Txs was observed. Most common AEs (≥20%) of any grade were anemia, low albumin and vomiting (Table 3). One death occurred at day 13 of ENA + AZA. Conclusions: In newly diagnosed pts ≥60 years old with IDH2m AML, ENA had a low early death rate, high CR/CRi rate (47%, adjusted 95% CI 28-59), and yielded durable remissions. The most common unique toxicity with ENA was differentiation syndrome that occurred in 20% of patients. In pts who did not achieve CR/CRi with ENAm, a subset of patients achieved CR/CRi with addition of AZA. This combined approach of serial therapy with ENA monotherapy followed by AZA addition in pts with sub-optimal response resulted in a mOS exceeding 2 years for pts enrolled on study. Further focus on improving response among patients with IDH2 R172 mutations, identifying subsets of pts not responding to ENA monotherapy, and integrating new targeted agents into this treatment regimen are warranted. Figure 1 Disclosures Stein: Syndax: Consultancy, Research Funding; Celgene Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy; Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy; Biotheryx: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; PTC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Syros: Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy. Borate:Genentech: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz Pharmaceuticals: Research Funding; AbbVie: Other: Investigator in AbbVie-funded clinical trials; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding. Baer:Takeda: Other: Institutional research funding; AbbVie: Other: Institutional research funding; Astellas: Other: Institutional research funding; Forma: Other: Institutional research funding; Kite: Other: Institutional research funding; Oscotec: Other: Institutional research funding; Incyte: Other: Institutional research funding. Kovacsovics:Agios: Honoraria; Astella: Honoraria; Pfizer: Research Funding; Novartis: Research Funding; AbbVie: Research Funding; Jazz: Honoraria. Schiller:Astellas Pharma: Honoraria, Research Funding; Celator: Research Funding; Constellation: Research Funding; Abbvie: Research Funding; Actinium: Research Funding; Ariad: Research Funding; Stemline: Speakers Bureau; Cyclacel: Research Funding; Daiichi Sankyo: Research Funding; Deciphera: Research Funding; DeltaFly: Research Funding; Bristol-Myers Squibb: Current equity holder in publicly-traded company, Research Funding; Forma: Research Funding; FujiFilm: Research Funding; Gamida: Research Funding; Genentech-Roche: Research Funding; Geron: Research Funding; Jazz Pharmaceuticals: Research Funding; Karyopharm: Research Funding; Kite Pharma: Research Funding; Mateon: Research Funding; MedImmune: Research Funding; Onconova: Research Funding; Pfizer: Current equity holder in publicly-traded company, Research Funding; Regimmune: Research Funding; Samus: Research Funding; Sangamo: Research Funding; Tolero: Research Funding; Trovagene: Research Funding; Kaiser Permanente: Consultancy; Johnson & Johnson: Current equity holder in publicly-traded company; Agios: Consultancy, Research Funding, Speakers Bureau; Amgen: Consultancy, Current equity holder in publicly-traded company, Research Funding, Speakers Bureau; AstraZeneca: Consultancy; Incyte: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Research Funding; Ono Pharma: Consultancy; Celgene: Research Funding, Speakers Bureau; Sanofi: Speakers Bureau; Gilead: Speakers Bureau. Olin:Astellas: Other: Site PI; Genentech: Other: Site PI; Pfizer: Other: Site PI; Daiichi Sankyo: Other: Site PI; Genentech: Consultancy; Amgen: Consultancy. Foran:Trillium: Research Funding; Xencor: Research Funding; H3Biosciences: Research Funding; Agios: Honoraria, Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Abbvie: Research Funding; Boehringer Ingelheim: Research Funding; Actinium: Research Funding; Aprea: Research Funding; Aptose: Research Funding; Kura Oncology: Research Funding; Takeda: Research Funding; Revolution Medicine: Consultancy; Novartis: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees. Lin:Trovagene: Research Funding; Tolero Pharmaceuticals: Research Funding; Seattle Genetics: Research Funding; Prescient Therapeutics: Research Funding; Abbvie: Research Funding; Bio-Path Holdings: Research Funding; Astellas Pharma: Research Funding; Aptevo: Research Funding; Incyte: Research Funding; Pfizer: Research Funding; Mateon Therapeutics: Research Funding; Ono Pharmaceutical: Research Funding; Jazz: Research Funding; Gilead Sciences: Research Funding; Genetech-Roche: Research Funding; Celyad: Research Funding; Celgene: Research Funding. Patel:DAVA Pharmaceuticals: Honoraria; Celgene: Consultancy, Speakers Bureau; Agios: Consultancy; France Foundation: Honoraria. Foster:Daiichi Sankyo: Consultancy; Bellicum Pharmaceuticals: Research Funding; Macrogenics: Consultancy, Research Funding. Druker:Leukemia & Lymphoma Society: Research Funding; Henry Stewart Talks: Patents & Royalties; Iterion Therapeutics (formerly Beta Cat Pharmaceuticals): Membership on an entity's Board of Directors or advisory committees; Vivid Biosciences: Membership on an entity's Board of Directors or advisory committees; GRAIL: Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Patient True Talks: Consultancy; The RUNX1 Research Program: Membership on an entity's Board of Directors or advisory committees; Third Coast Therapeutics: Membership on an entity's Board of Directors or advisory committees; VB Therapeutics: Membership on an entity's Board of Directors or advisory committees; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millipore (formerly Upstate Biotechnology): Patents & Royalties; MolecularMD (acquired by ICON): Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; McGraw Hill: Patents & Royalties; Merck & Co: Patents & Royalties; Cepheid: Consultancy, Membership on an entity's Board of Directors or advisory committees; Dana-Farber Cancer Institute: Patents & Royalties; EnLiven: Consultancy, Research Funding; Aptose Therapeutics Inc. (formerly Lorus): Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; ARIAD: Research Funding; Blueprint Medicines: Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; ALLCRON: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Research Funding; Aileron Therapeutics: Membership on an entity's Board of Directors or advisory committees; Pfizer: Research Funding; Oregon Health & Science University: Patents & Royalties. Byrd:Acerta Pharma: Research Funding; Syndax: Research Funding; Vincera: Research Funding; Pharmacyclics LLC, an AbbVie Company, Janssen, Novartis, Gilead, TG Therapeutics: Other; Pharmacyclics LLC, an AbbVie Company, Gilead, TG Therapeutics, Novartis, Janssen: Speakers Bureau; Novartis: Research Funding; Kartos Therapeutics: Research Funding; Trillium: Research Funding; Leukemia and Lymphoma Society: Other; Janssen: Consultancy; Pharmacyclics LLC, an AbbVie Company, Gilead, TG Therapeutics, BeiGene: Research Funding. Levine:Loxo: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; C4 Therapeutics: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Imago: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Research Funding; Qiagen: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Prelude Therapeutics: Research Funding; Amgen: Honoraria; Astellas: Consultancy; Morphosys: Consultancy; Novartis: Consultancy; Isoplexis: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; Lilly: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Research Funding; Gilead: Honoraria. Mims:Abbvie: Membership on an entity's Board of Directors or advisory committees; Kura Oncology: Membership on an entity's Board of Directors or advisory committees; Leukemia and Lymphoma Society: Other: Senior Medical Director for Beat AML Study; Jazz Pharmaceuticals: Other: Data Safety Monitoring Board; Syndax Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy; Novartis: Speakers Bureau. OffLabel Disclosure: Enasidenib is not approved for the treatment of newly diagnosed AML.

TLRs, a family of membrane-bound pattern recognition receptors found on innate immune cells, have been well studied in the context of cancer therapy. Activation of these receptors has been shown to induce inflammatory anticancer events, including differentiation and apoptosis, across a wide variety of malignancies. In contrast, intracellular pattern recognition receptors such as NOD-like receptors have been minimally studied. NOD2 is a member of the NOD-like receptor family that initiates inflammatory signaling in response to the bacterial motif muramyl dipeptide. In this study, we examined the influence of NOD2 in human acute myeloid leukemia (AML) cells, demonstrating that IFN-γ treatment upregulated the expression of NOD2 signaling pathway members SLC15A3 and SLC15A4, downstream signaling kinase RIPK2, and the NOD2 receptor itself. This priming allowed for effective induction of caspase-1–dependent cell death upon treatment with muramyl tripeptide phosphatidylethanolamine (MTP-PE), a synthetic ligand for NOD2. Furthermore, the combination of MTP-PE and IFN-γ on AML blasts generated an inflammatory cytokine profile and activated NK cells. In a murine model of AML, dual treatment with MTP-PE and IFN-γ led to a significant increase in mature CD27− CD11b+ NK cells as well as a significant reduction in disease burden and extended survival. These results suggest that NOD2 activation, primed by IFN-γ, may provide a novel therapeutic option for AML.

Background: Acalabrutinib (A) is a next-generation, highly selective, covalent Bruton tyrosine kinase (BTK) inhibitor approved for marketing by the US FDA in patients (pts) with chronic lymphocytic leukemia (CLL). While responses to A monotherapy are durable in CLL, response depth may be enhanced with combination therapy and potentially allow treatment discontinuation. The safety and efficacy of A plus a CD20 antibody (obinutuzumab [O] or rituximab [R]) and the BCL-2 inhibitor venetoclax (V) were examined in a phase 1b study (CL-003; NCT02296918) in relapsed/refractory (R/R) or treatment-naïve (TN) CLL pts. Methods: Pts were aged ≥18 years with intermediate or high-risk CLL (R/R or TN) and an Eastern Cooperative Oncology Group performance status (ECOG PS) ≤2. Prior BTK inhibitor treatment was allowed for R/R pts if discontinuation was not due to CLL progression. R/R CLL pts received oral (PO) A 100 mg twice daily (BID) until progression, plus intravenous (IV) R 375 mg/m2 for 9 infusions (cycles 2-7), plus V PO daily per standard dosing (cycles 3-15). TN CLL pts received PO A and V (as above) plus IV O per standard dosing (cycles 2-7). The primary endpoint was safety. Secondary endpoints included investigator-assessed overall response rate (ORR, partial response [PR] or better) at cycle 16, complete response (CR) rate, undetectable minimal residual disease (uMRD) rate, duration of response (DOR), progression-free survival (PFS), overall survival (OS), and pharmacokinetics (PK). Results: Twelve pts were included in each cohort (R/R: male, n=9 [75%], median [range] age: 66 [55-72] y; TN: male, n=9 [75%], median [range] age: 61 [42-73] y). All pts had ECOG PS ≤1; 6/8 (75%) R/R and 8/10 (80%) TN pts had unmutated IGHV ( At a median follow-up of 23.2 mo (range: 19.8-25.3) in R/R pts and 22.0 mo (range: 19.5-24.4) in TN pts, 11 (92%) and 10 (83%) pts remained on treatment, respectively. Reasons for treatment discontinuation were adverse events (AEs) in 1 pt (8%) in each cohort (R/R: grade 1 purpura; TN: grade 2 head discomfort), and withdrawal by 1 pt (8%) in the TN cohort. The median number of treatment cycles in R/R pts was 23 (range: 14.9-27.5) for A, 6 (6-6) for R, and 13 (10.0-13.7) for V, and in TN pts was 23 (18.0-24.8) for A, 6 (6-6) for O, and 13 (13.0-13.5) for V. Reported AEs were similar to the individual agents' toxicity profiles (Table 1). Among AEs of interest, 7 R/R pts (58%) and 4 TN pts (33%) had cardiac AEs; grade ≥3 cardiac AEs were reported in 1 pt (8%). Atrial fibrillation was reported in 1 pt (grade 3; R/R pt with prior atrial fibrillation history). No ventricular arrhythmias were reported. Three R/R pts (25%) and 7 TN pts (58%) had hypertension AEs; none were grade ≥3. The most frequent infections (≥40%) were upper respiratory tract infection (URTI; 50%) in R/R pts and URTI (67%), sinusitis (42%), and nasopharyngitis (42%) in TN pts. Grade ≥3 infections occurred in 3 TN pts (lung infection, n=2 [17%]; prostate infection, staphylococcal bacteremia, staphylococcal sepsis, n=1 [8%] each) and no R/R pts. Six R/R pts (50%) and 3 TN pts (25%) had infusion-related reactions; none were grade ≥3. One R/R pt (8%) and 6 TN pts (50%) had decreased neutrophil counts; all were grade ≥3. No tumor lysis syndrome AEs, Richter transformations, or deaths were reported. After 16 cycles, ORR was 92% (95% CI: 62-100) in R/R pts and 100% (95% CI: 74-100) in TN pts. At the time of data cutoff, 50% of pts in each cohort had achieved CR or CR with incomplete marrow recovery (CRi). All pts with CR or CRi achieved uMRD (10-4) in peripheral blood (PB) at the time of CR/CRi or earlier. Overall, 8 (67%) R/R and 9 (75%) TN pts achieved uMRD (10-4) in PB at cycle 10 (Table 2). Median DOR, PFS, and OS were not reached in either group. Estimated 18-mo PFS and OS rates were 100% (95% CI: not estimable) in both cohorts. The PK of A and its active metabolite, ACP-5862, were consistent when given as monotherapy or with V, R, or O. The PK of V remained within the range observed with monotherapy (Salem et al. J Clin Pharmacol. 2017;57:484-492) when given with A. Conclusions: Combination therapy with A plus an anti-CD20 antibody and BCL-2 inhibitor leads to a tolerable safety profile with high CR and uMRD rates in both R/R and TN CLL pts, with minimal to no drug-drug interactions. Disclosures Woyach: Pharmacyclics, Janssen, Morphosys, Karyopharm, Verastem, Abbvie, Lox: Research Funding; Pharmacyclics LLC, an AbbVie Company, AbbVie, Janssen, AstraZeneca, ArQule: Honoraria; Janssen, Pharmacyclics, AstraZeneca, Abbvie, Arqule: Consultancy. Blachly:AbbVie, AstraZeneca, KITE Pharma: Consultancy. Rogers:Janssen: Research Funding; AstraZeneca: Consultancy, Other: Travel Funding; Pharmacyclics: Consultancy; AbbVie: Consultancy, Research Funding; Genentech: Research Funding; Acerta Pharma: Consultancy. Lozanski:Genentech, Novartis, Beckman Coulter: Research Funding. Andersen:Ohio State University: Current Employment, Research Funding. Patel:AstraZeneca: Current Employment, Current equity holder in publicly-traded company. Munugalavadla:Acerta Pharma/AstraZeneca: Current Employment, Current equity holder in publicly-traded company; Gilead Sciences: Current equity holder in publicly-traded company, Other: Family Association. Butturini:Puma Biotechnology: Divested equity in a private or publicly-traded company in the past 24 months; Dynavax, Puma Biotechnology: Ended employment in the past 24 months; Roche/Genentech, Pfeizer, AstraZeneca, Amgen: Current equity holder in publicly-traded company; Acerta Pharma: Current Employment. Xu:Acerta Pharma: Current Employment, Research Funding; AstraZeneca: Research Funding. Wang:Acerta Pharma: Current Employment. Byrd:Acerta Pharma: Research Funding; Syndax: Research Funding; Novartis: Research Funding; Kartos Therapeutics: Research Funding; Trillium: Research Funding; Leukemia and Lymphoma Society: Other; Janssen: Consultancy; Pharmacyclics LLC, an AbbVie Company, Gilead, TG Therapeutics, BeiGene: Research Funding; Pharmacyclics LLC, an AbbVie Company, Gilead, TG Therapeutics, Novartis, Janssen: Speakers Bureau; Pharmacyclics LLC, an AbbVie Company, Janssen, Novartis, Gilead, TG Therapeutics: Other; Vincera: Research Funding.

Background: Bruton tyrosine kinase (BTK) inhibitors are effective treatments for B-cell malignancies, but an increased incidence of cardiovascular (CV) toxicities has been observed with ibrutinib. Acalabrutinib (acala) is a next-generation, potent, highly selective, covalent BTK inhibitor approved for chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma and mantle cell lymphoma. The objective of this analysis was to characterize CV adverse events (AEs) in patients (pts) with CLL who received acala monotherapy. Methods: Data from pts with CLL in 4 studies (ACE-CL-001 [NCT02029443]; ACE-CL-007 [ELEVATE-TN, NCT02475681]; ACE-CL-309 [ASCEND, NCT02970318]; 15-H-0016 [NCT02337829]) were pooled. Cutoff dates ranged from December 2018 to February 2019. Pts who received ≥1 dose of acala monotherapy were included. For pts who crossed over from control arms to acala, only AEs recorded after crossover were included. Acala was given orally at total daily doses of 100 mg to 400 mg, later switched to 100 mg twice daily, and continued until disease progression (PD) or toxicity. Cardiac AEs and hypertension (htn) were examined. Results: 762 pts were included (treatment-naïve: n=352 [46%]; relapsed/refractory: n=410 [54%]; median age: 67 years [range: 32-89]; Eastern Cooperative Oncology Group performance status ≤1: 93%; median acala exposure: 24.9 mo [range: 0-58.5]; median follow-up: 25.9 mo [range: 0-58.5]). A total of 199 cardiac AEs of any grade (irrespective of treatment relationship) were reported in 129 pts (17%). Cardiac AEs led to treatment discontinuation in 7 pts (0.9%). The most frequent cardiac AEs reported in ≥2% of pts were atrial fibrillation (afib: n=34; 4%; afib/flutter: n=38; 5%), palpitations (n=23; 3%), and tachycardia (n=17; 2%). The median time to afib/flutter onset was 521 days (range: 8-1280). Overall, 91% (117/129) of pts with vs 79% (503/633) without cardiac AEs had ≥1 CV risk factor before acala initiation. The most prevalent CV risk factors (≥20%) among the 129 pts with cardiac AEs were htn (n=86; 67%), hyperlipidemia (n=38; 29%), and arrhythmias (n=29; 22% [afib: n=16; 12%]). Htn AEs were reported in 9% (67/762) of pts, among whom 46 (69%) had pre-existing htn and 18 (27%) had htn risk factors. The median time to htn onset was 197 days (range: 2-1345). Thirty-seven pts (4%) had 51 grade ≥3 cardiac AEs (grade 3: n=37; grade 4: n=12; grade 5: n=2). Grade ≥3 cardiac AEs of interest included afib (n=10; 1.3%), complete atrioventricular (AV) block (n=2; 0.3%), acute coronary syndrome (n=1; 0.1%), atrial flutter (n=1; 0.1%), second degree AV block (n=1; 0.1%), and ventricular fibrillation (n=1; 0.1%). Two patients experienced grade 5 AEs (cardiac failure congestive [n=1], acute myocardial infarction [n=1]). Among the 37 pts with grade ≥3 AEs, 18 (49%) were continuing acala at data cutoff; 6 (16%) had discontinued due to the grade ≥3 cardiac AEs, 4 (11%) to other AEs, 5 (14%) to PD, 3 (8%) to death, and 1 (3%) to other reasons. Among the 51 grade ≥3 cardiac AEs, 16 (31%) led to dose delay and 36 (71%) were managed with concomitant medications. Most events (43/51 [84%]) resolved (dose delay: n=15; drug withdrawal: n=4; no dose change: n=24). Cardiac AEs occurring in the first 6 mo on acala were assessed based on a predominance of AEs (afib) during this time period with ibrutinib (Brown JR, et al, Haematologica. 2017;102:1796). Overall, 48% of pts with any-grade cardiac AEs experienced them in the first 6 mo on acala. Thirteen grade ≥3 cardiac AEs (25% of total) were observed in 9 pts in the first 6 mo (Table); all but 1 AE (grade 4 cardiac tamponade resulting in hospitalization) were managed with concomitant medications. Two of the 13 AEs resulted in treatment discontinuation (Table). Conclusions: At a median exposure of 24.9 mo, cardiac AEs occurred infrequently in pts with CLL treated with acala monotherapy; only 0.9% discontinued treatment due to cardiac AEs. Among grade ≥3 cardiac AEs, 25% were reported during the first 6 mo on treatment. Most pts with cardiac AEs had pre-existing risk factors that may have contributed to their development. The incidence of afib with acala (4%) was comparable to that of the general CLL population (6.1%; Shanafelt TD, et al. Leuk Lymphoma. 2017;58:1630). These data suggest a low risk of cardiac AEs with acala treatment in pts with CLL. The safety of acala vs ibrutinib in pts with high-risk CLL will be investigated in the phase 3, randomized ACE-CL-006 trial (NCT02477696). Disclosures Brown: Janssen, Teva: Speakers Bureau; Abbvie, Acerta, AstraZeneca, Beigene, Invectys, Juno/Celgene, Kite, Morphosys, Novartis, Octapharma, Pharmacyclics, Sunesis, TG Therapeutics, Verastem: Consultancy; Gilead, Loxo, Sun, Verastem: Research Funding. Byrd:Acerta Pharma: Research Funding; Syndax: Research Funding; Leukemia and Lymphoma Society: Other; Trillium: Research Funding; Kartos Therapeutics: Research Funding; Vincera: Research Funding; Novartis: Research Funding; Janssen: Consultancy; Pharmacyclics LLC, an AbbVie Company, Gilead, TG Therapeutics, BeiGene: Research Funding; Pharmacyclics LLC, an AbbVie Company, Gilead, TG Therapeutics, Novartis, Janssen: Speakers Bureau; Pharmacyclics LLC, an AbbVie Company, Janssen, Novartis, Gilead, TG Therapeutics: Other. Ghia:Adaptive, Dynamo: Consultancy, Honoraria; Novartis: Research Funding; Acerta/AstraZeneca: Consultancy, Honoraria; ArQule: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Research Funding; BeiGene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Celgene/Juno: Consultancy, Honoraria; Lilly: Consultancy, Honoraria; MEI: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding. Sharman:TG Therapeutics: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Acerta: Consultancy, Research Funding; Roche: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Bristol Meyers Squibb: Consultancy, Research Funding; BeiGene: Research Funding. Hillmen:F. Hoffmann-La Roche: Honoraria, Research Funding; Astra Zeneca: Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding, Speakers Bureau; Pharmacyclics: Research Funding; Gilead: Research Funding. Stephens:MingSight: Research Funding; Acerta: Research Funding; Karyopharm: Consultancy, Research Funding; Gilead: Research Funding; Arqule: Research Funding; Pharmacyclics: Consultancy; Verastem: Research Funding; Beigene: Consultancy; Juno: Research Funding; Innate: Consultancy; Janssen: Consultancy. Sun:VERASTEM, GENMAB: Research Funding. Jurczak:Janssen, MeiPharma, Merck, Pharmacyclics, Roche, Tekeda, TG Therapeutics: Research Funding; Maria Sklodowska-Curie National Research Institute of Oncology: Consultancy, Current Employment; Jagiellonian University: Ended employment in the past 24 months, Research Funding. Patel:AstraZeneca: Current Employment, Current equity holder in publicly-traded company. Baek:Acerta Pharma: Current Employment. Lezhava:Astra Zeneca: Current Employment; Melinta Therapeutics Inc: Ended employment in the past 24 months. Kuptsova-Clarkson:AstraZeneca: Current Employment. Moslehi:AstraZeneca, Janssen, BMS, Boston Biomedical, Immunocure, Myovant, Boston Biomedical, Deciphera: Consultancy. Furman:Acerta: Consultancy; Abbvie: Consultancy; Verastem: Consultancy; Sunesis: Consultancy; Pharmacyclics: Consultancy; Oncotarget: Consultancy; Loxo Oncology: Consultancy; Janssen: Consultancy, Speakers Bureau; Incyte: Consultancy; TG Therapeutics: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Beigene: Consultancy; Genentech: Consultancy.

Background: AML is a clinically and molecularly heterogeneous disease associated with poor survival. Multiple disease-related factors including cytogenetic findings and gene mutations, as well as patient-related factors, such as demographics and African American (AA) heritage, have been identified that impact on pt outcomes. However, with recent improved survival it is unknown whether racial health disparities persist. Moreover, we are not aware of a large study that assessed possible race-associated molecular differences. Thus, the goals of our study were to 1) analyze the outcomes of adult AML pts in a nationwide population study, including possible impacts of sociodemographic, financial and racial disparities and 2) characterize molecular features of AA compared with those of Caucasian AML pts. Methods: For a nationwide population analysis, the Surveillance Epidemiology End Results (SEER) Program of the National Cancer Institute was used to identify 11,190 adults aged 18-60 years (y) diagnosed with AML (excluding acute promyelocytic leukemia) between 1986 and 2015. To characterize molecular features we performed targeted sequencing of 81 genes in 1,339 AML pts treated on frontline Cancer and Leukemia Group B/Alliance for Clinical Trials in Oncology (Alliance) protocols based on standard intensity cytarabine/anthracycline induction followed by consolidation between 1986 and 2016. No Alliance pt received an allogeneic stem cell transplant in 1st complete remission (CR). Results: The associations between demographic parameters and risk of death among SEER registry AML pts are shown in Table 1. While there was a slightly higher risk of death for men (HR 1.09) and a lower risk of death for pts with a higher median household income (>79.6k vs Conclusion: Self-reported AA race is the most important pt-associated factor associated with poor survival in AML pts < 60 y of age based on SEER. Survival analyses in Alliance pts identify AA race as independent poor survival prognosticator in AML pts besides established molecular markers. . This disparity must be urgently addressed to ensure improved outcomes for AA AML pts, and larger studies to establish molecular risk profiles are needed. Support: U10CA180821, U10CA180882 U24CA196171, https://acknowledgments.alliancefound.org; Clinicaltrials.gov Identifiers: NCT00048958, NCT00899223, NCT00900224 Disclosures Bhatnagar: KaryoPharm Therapuetics: Research Funding; Cell Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; KITE: Membership on an entity's Board of Directors or advisory committees. Blachly:AbbVie, AstraZeneca, KITE Pharma: Consultancy. Mims:Novartis: Speakers Bureau; Jazz Pharmaceuticals: Other: Data Safety Monitoring Board; Syndax Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Kura Oncology: Membership on an entity's Board of Directors or advisory committees; Leukemia and Lymphoma Society: Other: Senior Medical Director for Beat AML Study; Agios: Consultancy. Walker:Vigeo Therapeutics: Consultancy; Karyopharm: Current Employment, Current equity holder in publicly-traded company. Powell:Genentech: Research Funding; Jazz Pharmaceuticals: Consultancy, Other: Advisor, Research Funding; Pfizer: Research Funding; Rafael Pharmaceuticals: Consultancy, Other: Advisor, Research Funding; Novartis: Research Funding. Kolitz:Magellan: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees. Stone:Biolinerx: Consultancy; Novartis: Consultancy, Research Funding; Celgene: Consultancy, Other; Aztra-Zeneca: Consultancy; Jazz: Consultancy; Argenix: Other; Janssen: Consultancy; Daiichi-Sankyo: Consultancy; Pfizer: Consultancy; Gemoab: Consultancy; Syndax: Consultancy, Research Funding; Takeda: Other: DSMB; Macrogenics: Consultancy; Trovagene: Consultancy; Syntrix: Other: DSMB; Abbvie: Consultancy, Research Funding; Agios: Consultancy, Research Funding; Actinium: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy; Arog: Consultancy, Research Funding; Syros: Consultancy; Stemline: Consultancy. Byrd:Trillium: Research Funding; Leukemia and Lymphoma Society: Other; Acerta Pharma: Research Funding; Syndax: Research Funding; Pharmacyclics LLC, an AbbVie Company, Janssen, Novartis, Gilead, TG Therapeutics: Other; Janssen: Consultancy; Pharmacyclics LLC, an AbbVie Company, Gilead, TG Therapeutics, BeiGene: Research Funding; Pharmacyclics LLC, an AbbVie Company, Gilead, TG Therapeutics, Novartis, Janssen: Speakers Bureau; Kartos Therapeutics: Research Funding; Vincera: Research Funding; Novartis: Research Funding. Eisfeld:Karyopharm: Current Employment, Current equity holder in publicly-traded company; Vigeo Therapeutics: Consultancy.

Ibrutinib is associated with dramatic efficacy against B-cell malignancies. Yet, ibrutinib is linked with potentially-limiting cardiotoxicity, including emerging reports of profound hypertension. However, the long-term incidence, severity, and impacts of hypertension development during ibrutinib-use are unknown. Therefore, from 562 consecutive patients treated with ibrutinib for B-cell malignancies between 2009-2016 we assessed the incidence of new/incident or worsened hypertension [systolic blood pressure (BP) cutoff of 130mmHg]. Observed incident-hypertension rates were compared to Framingham-heart predicted incident-hypertension rates. We also evaluated the relationship of hypertension on ibrutinib to the development of other major-adverse-cardiovascular-events (MACE), including arrhythmias, myocardial infarction, stroke, heart failure, and cardiovascular death. Further, we assessed the preventative and modulatory effects of antihypertensives, by medication-class, on ibrutinib-related hypertension. Overall, 78.3% of ibrutinib-users developed new or worsened hypertension [mean systolic BP increase 5.2mmHg ({plus minus}20.7)] over a median of 30months. New hypertension developed in 71.6% of ibrutinib-users (467 observed vs. 39 Framingham-predicted cases per 1,000 person-years), with a time-to-50% cumulative incidence of 4.2months. Among those without preceding hypertension, 17.7% developed high-grade (BP g160/100mmHg) hypertension. In multivariable regression containing known predictors of MACE, new or worsened hypertension was associated with increased MACE [hazard ratio (HR) 2.17, 95%CI 1.08-4.38]. No single-antihypertensive class was associated with prevention or control of ibrutinib-related hypertension. However, antihypertensive initiation was associated with a lower risk of MACE (HR 0.40, CI 0.24-0.66). Collectively, these data suggest ibrutinib is associated with substantial increase in the incidence and severity of hypertension, and that hypertension development may suggest a higher risk of subsequent cardiotoxic events.

Alterations in global DNA methylation patterns are a major hallmark of cancer and represent attractive biomarkers for personalized risk stratification. Chronic lymphocytic leukemia (CLL) risk stratification studies typically focus on time to first treatment (TTFT), time to progression (TTP) after treatment, and overall survival (OS). Whereas TTFT risk stratification remains similar over time, TTP and OS have changed dramatically with the introduction of targeted therapies, such as the Bruton tyrosine kinase inhibitor ibrutinib. We have shown that genome-wide DNA methylation patterns in CLL are strongly associated with phenotypic differentiation and patient outcomes. Here, we developed a novel assay, termed methylation-iPLEX (Me-iPLEX), for high-throughput quantification of targeted panels of single cytosine guanine dinucleotides from multiple independent loci. Me-iPLEX was used to classify CLL samples into 1 of 3 known epigenetic subtypes (epitypes). We examined the impact of epitype in 1286 CLL patients from 4 independent cohorts representing a comprehensive view of CLL disease course and therapies. We found that epitype significantly predicted TTFT and OS among newly diagnosed CLL patients. Additionally, epitype predicted TTP and OS with 2 common CLL therapies: chemoimmunotherapy and ibrutinib. Epitype retained significance after stratifying by biologically related biomarkers, immunoglobulin heavy chain mutational status, and ZAP70 expression, as well as other common prognostic markers. Furthermore, among several biological traits enriched between epitypes, we found highly biased immunogenetic features, including IGLV3-21 usage in the poorly characterized intermediate-programmed CLL epitype. In summary, Me-iPLEX is an elegant method to assess epigenetic signatures, including robust classification of CLL epitypes that independently stratify patient risk at diagnosis and time of treatment.

Chronic lymphocytic leukemia (CLL) occurs in 2 major forms: aggressive and indolent. Low miR-29b expression in aggressive CLL is associated with poor prognosis. Indiscriminate miR-29b overexpression in the B-lineage of mice causes aberrance, thus warranting the need for selective introduction of miR-29b into B-CLL cells for therapeutic benefit. The oncofetal antigen receptor tyrosine kinase orphan receptor 1 (ROR1) is expressed on malignant B-CLL cells, but not normal B cells, encouraging us with ROR1-targeted delivery for therapeutic miRs. Here, we describe targeted delivery of miR-29b to ROR1+ CLL cells leading to downregulation of DNMT1 and DNMT3A, modulation of global DNA methylation, decreased SP1, and increased p21 expression in cell lines and primary CLL cells in vitro. Furthermore, using an Eμ-TCL1 mouse model expressing human ROR1, we report the therapeutic benefit of enhanced survival via cellular reprograming by downregulation of DNMT1 and DNMT3A in vivo. Gene expression profiling of engrafted murine leukemia identified reprogramming of cell cycle regulators with decreased SP1 and increased p21 expression after targeted miR-29b treatment. This finding was confirmed by protein modulation, leading to cell cycle arrest and survival benefit in vivo. Importantly, SP1 knockdown results in p21-dependent compensation of the miR-29b effect on cell cycle arrest. These studies form a basis for leukemic cell–targeted delivery of miR-29b as a promising therapeutic approach for CLL and other ROR1+ B-cell malignancies.

To define the efficacy of venetoclax with extended follow-up and identify clinical or biological treatment effect modifiers, updated data for previously treated patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) enrolled in 4 early-phase trials were pooled. Rates of response, complete remission (CR/CRi), and undetectable minimal residual disease (U-MRD) were analyzed for all patients (n = 436) and for those patients who were planned to receive 400 mg/day monotherapy (n = 347). Univariate and multiple regression analyses were performed to identify the pretreatment factors associated with response rates and duration of response (DoR). Objective responses were documented in 75% of all patients, including 22% CR/CRi. Overall, 27% and 16% of the patients achieved U-MRD in blood and marrow, respectively. Estimated median progression-free survival (PFS), DoR, and time to progression were 30.2, 38.4, and 36.9 months, respectively. Similar efficacy outcomes were observed within the 400 mg/day monotherapy subset. For those who achieved CR/CRi, the 3-year PFS estimate was 83%. DoR was superior for patients achieving CR/CRi or U-MRD in landmark analyses. In multiple regression analyses, bulky lymphadenopathy (≥5 cm) and refractoriness to B-cell receptor inhibitor (BCRi) therapy were significantly associated with lower CR rate and shorter DoR. Fewer prior therapies were associated with higher CR rate, but not DoR. Chromosome 17p deletion and/or TP53 mutation and NOTCH1 mutation were consistently associated with shorter DoR, but not probability of response. Thus, both pretreatment factors and depth of response correlated with DoR with venetoclax. Patients without bulky lymphadenopathy, BCRi-refractory CLL, or an adverse mutation profile had the most durable benefit.

Ibrutinib, a once-daily oral inhibitor of Bruton tyrosine kinase, has greatly improved outcomes for patients with chronic lymphocytic leukemia (CLL). The phase 3 RESONATE trial, which compared single-agent ibrutinib to ofatumumab in high-risk, relapsed patients with CLL, provided support for approval of ibrutinib in the United States and Europe. We describe long-term follow-up of patients treated in RESONATE, where continued superiority of progression-free survival (PFS) (hazard ratio [HR], 0.133; 95% confidence interval [CI], 0.099-0.178) was observed. Overall survival benefit continues (HR, 0.591; 95% CI, 0.378-0.926), although with decreased magnitude relative to that seen before crossover to ibrutinib was implemented for patients on ofatumumab (HR, 0.426; 95% CI, 0.220-0.823). Notably, overall response to ibrutinib increased over time, with 91% of patients attaining a response. The PFS benefit with ibrutinib was independent of baseline risk factors, although patients with ≥2 prior therapies had shorter PFS than those with

The clinical benefit of CTLA-4 blockade on T cells is known, yet the impact of its expression on cancer cells remains unaddressed. We define an immunosuppressive role for tumor-expressed CTLA-4 using chronic lymphocytic leukemia (CLL) as a disease model. CLL cells, among other cancer cells, are CTLA-4+. Coculture with activated human T cells induced surface CTLA-4 on primary human CLL B cells. CTLA-4 on CLL-derived human cell lines decreased CD80 expression on cocultured CD80+ cells, with restoration upon CTLA-4 blockade. Coculture of CTLA-4+ CLL cells with CD80-GFP+ cell lines revealed transfer of CD80-GFP into CLL tumor cells, similar to CTLA-4+ T cells able to trans-endocytose CD80. Coculture of T cells with CTLA-4+ CLL cells decreased IL-2 production. Using a human CTLA-4 knock-in mouse lacking FcγR function, antitumor efficacy was observed by blocking murine CTLA-4 on tumor cells in isolation of the T cell effect and Fc-mediated depletion. These data implicate tumor CTLA-4 in cancer cell–mediated immunosuppression in vitro and as having a functional role in tumor cells in vivo.

Dysregulated cellular differentiation is a hallmark of acute leukemogenesis. Phosphatases are widely suppressed in cancers but have not been traditionally associated with differentiation. In this study, we found that the silencing of protein phosphatase 2A (PP2A) directly blocks differentiation in acute myeloid leukemia (AML). Gene expression and mass cytometric profiling revealed that PP2A activation modulates cell cycle and transcriptional regulators that program terminal myeloid differentiation. Using a novel pharmacological agent, OSU-2S, in parallel with genetic approaches, we discovered that PP2A enforced c-Myc and p21 dependent terminal differentiation, proliferation arrest, and apoptosis in AML. Finally, we demonstrated that PP2A activation decreased leukemia-initiating stem cells, increased leukemic blast maturation, and improved overall survival in murine Tet2−/−Flt3ITD/WT and human cell-line derived xenograft AML models in vivo. Our findings identify the PP2A/c-Myc/p21 axis as a critical regulator of the differentiation/proliferation switch in AML that can be therapeutically targeted in malignancies with dysregulated maturation fate.

Acute myeloid leukemia (AML) is the most common diagnosed leukemia. In older adults, AML confers an adverse outcome1,2. AML originates from a dominant mutation, then acquires collaborative transformative mutations leading to myeloid transformation and clinical/biological heterogeneity. Currently, AML treatment is initiated rapidly, precluding the ability to consider the mutational profile of a patient’s leukemia for treatment decisions. Untreated patients with AML ≥ 60 years were prospectively enrolled on the ongoing Beat AML trial (ClinicalTrials.gov NCT03013998 ), which aims to provide cytogenetic and mutational data within 7 days (d) from sample receipt and before treatment selection, followed by treatment assignment to a sub-study based on the dominant clone. A total of 487 patients with suspected AML were enrolled; 395 were eligible. Median age was 72 years (range 60–92 years; 38% ≥75 years); 374 patients (94.7%) had genetic and cytogenetic analysis completed within 7 d and were centrally assigned to a Beat AML sub-study; 224 (56.7%) were enrolled on a Beat AML sub-study. The remaining 171 patients elected standard of care (SOC) (103), investigational therapy (28) or palliative care (40); 9 died before treatment assignment. Demographic, laboratory and molecular characteristics were not significantly different between patients on the Beat AML sub-studies and those receiving SOC (induction with cytarabine + daunorubicin (7 + 3 or equivalent) or hypomethylation agent). Thirty-day mortality was less frequent and overall survival was significantly longer for patients enrolled on the Beat AML sub-studies versus those who elected SOC. A precision medicine therapy strategy in AML is feasible within 7 d, allowing patients and physicians to rapidly incorporate genomic data into treatment decisions without increasing early death or adversely impacting overall survival. Preliminary results from the Beat AML umbrella trial demonstrates the feasibility and efficacy of applying prospective genomic profiling for matching newly diagnosed patients with AML with targeted therapies.

Ibrutinib positively modulates many T-cell subsets in chronic lymphocytic leukemia (CLL). To understand ibrutinib’s effects on the broader landscape of immune cell populations, we comprehensively characterized changes in circulating counts of 21 immune blood cell subsets throughout the first year of treatment in patients with relapsed/refractory (R/R) CLL (n = 55, RESONATE) and previously untreated CLL (n = 50, RESONATE-2) compared with untreated age-matched healthy donors (n = 20). Ibrutinib normalized abnormal immune cell counts to levels similar to those of age-matched healthy donors. Ibrutinib significantly decreased pathologically high circulating B cells, regulatory T cells, effector/memory CD4+ and CD8+ T cells (including exhausted and chronically activated T cells), natural killer (NK) T cells, and myeloid-derived suppressor cells; preserved naive T cells and NK cells; and increased circulating classical monocytes. T-cell function was assessed in response to T-cell receptor stimulation in patients with R/R CLL (n = 21) compared with age-matched healthy donors (n = 18). Ibrutinib significantly restored T-cell proliferative ability, degranulation, and cytokine secretion. Over the same period, ofatumumab or chlorambucil did not confer the same spectrum of normalization as ibrutinib in multiple immune subsets. These results establish that ibrutinib has a significant and likely positive impact on circulating malignant and nonmalignant immune cells and restores healthy T-cell function.

Background Qualitative and quantitative defects in natural killer (NK) cells have been noted in patients with acute myeloid leukemia (AML), providing rationale for infusion of donor-derived NK cells. We previously showed that decitabine enhances expression of NKG2D ligands in AML with additive cytotoxicity when NK cells and Fc (fragment crystallizable region)-engineered CD33 monoclonal antibody (CD33mAb) was used. We conducted a phase 1 study evaluating decitabine and haploidentical NK cells in relapsed AML. Using patient samples from this study, we evaluated whether ex vivo donor-derived expanded NK cells with or without CD33mAb was effective in decitabine-treated AML. Methods Bone marrow aspirates were collected from patients at pre- and post-NK cell infusion. NK cells from healthy donors were expanded for 14 days using irradiated K562 feeder cells displaying membrane-bound IL-21 (mbIL-21). Patient samples were used to test in vitro activity of mbIL-21 NK cells ± CD33m Ab-dependent cellular cytotoxicity (ADCC) and AML patient derived xenograft (PDX) mice were developed to test in vivo activity. Results Upon incubation with primary AML blasts, mbIL-21 NK cells showed variable donor-dependent intra-cellular interferon-γ production, which increased with CD33mAb-coated AML. ADCC assays revealed mbIL-21 NK cells effectively lysed primary AML blasts with higher activity on CD33mAb-coated AML. Importantly, CD33mAb-dependent enhanced cytotoxicity by mbIL-21 NK cells was maintained in AML cells from patients even 24 days post-decitabine treatment. In vivo infusion of mbIL-21 NK cells in AML PDX mice, treated with CD33mAb, reduced the tumor burden. Discussion These data show the therapeutic utility of mbIL-21 NK cells that can be further potentiated by addition of CD33mAb in AML.

Therapeutic targeting of Bruton tyrosine kinase (BTK) has dramatically improved survival outcomes for patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Acalabrutinib is an oral, highly selective BTK inhibitor that allows for twice-daily dosing due to its selectivity. In this phase 1b/2 study, 134 patients with relapsed/refractory CLL or SLL (median age, 66 years [range, 42-85 years]; median prior therapies, 2 [range, 1-13]) received acalabrutinib 100 mg twice daily for a median of 41 months (range, 0.2-58 months). Median trough BTK occupancy at steady state was 97%. Most adverse events (AEs) were mild or moderate, and were most commonly diarrhea (52%) and headache (51%). Grade ≥3 AEs (occurring in ≥5% of patients) were neutropenia (14%), pneumonia (11%), hypertension (7%), anemia (7%), and diarrhea (5%). Atrial fibrillation and major bleeding AEs (all grades) occurred in 7% and 5% of patients, respectively. Most patients (56%) remain on treatment; the primary reasons for discontinuation were progressive disease (21%) and AEs (11%). The overall response rate, including partial response with lymphocytosis, with acalabrutinib was 94%; responses were similar regardless of genomic features (presence of del(11)(q22.3), del(17)(p13.1), complex karyotype, or immunoglobulin variable region heavy chain mutation status). Median duration of response and progression-free survival (PFS) have not been reached; the estimated 45-month PFS was 62% (95% confidence interval, 51% to 71%). BTK mutation was detected in 6 of 9 patients (67%) at relapse. This updated and expanded study confirms the efficacy, durability of response, and long-term safety of acalabrutinib, justifying its further investigation in previously untreated and treated patients with CLL/SLL. This trial was registered at www.clinicaltrials.gov as #NCT02029443.

Targeted therapies including the engineered afucosylated anti-CD20 monoclonal antibody obinutuzumab, Bruton’s tyrosine kinase inhibitor ibrutinib, and B-cell lymphoma protein 2 inhibitor venetoclax have demonstrated significant clinical activity in chronic lymphocytic leukemia (CLL) and, based on their complementary mechanisms, are ideal for combination. However, combining venetoclax with other active agents raises safety concerns, as it may increase the risk for tumor lysis syndrome. To minimize this risk, we designed and implemented a fixed-duration regimen using sequentially administered obinutuzumab followed by ibrutinib (cycle 2) and venetoclax (cycle 3), for a total of fourteen 28-day cycles. This phase 1b study included 12 patients with relapsed or refractory CLL. We tested 3 dose levels of venetoclax and identified the doses of all 3 agents approved by the US Food and Drug Administration for use in the combination. Adverse events were consistent with known toxicities of the individual agents, with hematologic adverse events being most frequent. No clinically significant tumor lysis syndrome occurred. The overall response rate was 92% (95% confidence interval, 62%-100%), with 42% (5/12) achieving a complete remission or complete remission with incomplete marrow recovery. There were 6 patients with no detectable CLL in both the blood and bone marrow at the end of treatment. We found this regimen to be safe and tolerable in CLL, and capable of inducing deep responses, justifying future study in our ongoing phase 2 cohorts of relapsed or refractory and treatment-naive patients, as well as larger phase 3 trials currently in planning. This trial was registered at www.clinicaltrials.gov as #NCT02427451.

The previous edition of the consensus guidelines of the International Workshop on Chronic Lymphocytic Leukemia (iwCLL), published in 2008, has found broad acceptance by physicians and investigators caring for patients with CLL. Recent advances including the discovery of the genomic landscape of the disease, the development of genetic tests with prognostic relevance, and the detection of minimal residual disease (MRD), coupled with the increased availability of novel targeted agents with impressive efficacy, prompted an international panel to provide updated evidence- and expert opinion–based recommendations. These recommendations include a revised version of the iwCLL response criteria, an update on the use of MRD status for clinical evaluation, and recommendations regarding the assessment and prophylaxis of viral diseases during management of CLL.

We previously reported durable responses and manageable safety of ibrutinib from a 3-year follow-up of treatment-naive (TN) older patients (≥65 years of age) and relapsed/refractory (R/R) patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). We now report on long-term efficacy and safety with median follow-up of 5 years in this patient population with TN (N = 31) and R/R (N = 101) CLL/SLL. With the current 5-year follow-up, ibrutinib continues to yield a high overall response rate of 89%, with complete response rates increasing over time to 29% in TN patients and 10% in R/R patients. The median progression-free survival (PFS) was not reached in TN patients. The 5-year PFS rate was 92% in TN patients and 44% in R/R patients. Median PFS in R/R patients was 51 months; in those with del(11q), del(17p), and unmutated IGHV, it was 51, 26, and 43 months, respectively, demonstrating long-term efficacy of ibrutinib in some high-risk subgroups. Survival outcomes were less robust for R/R patients with del(17p) and those who received more prior therapies. The onset of grade ≥3 cytopenias, such as neutropenia and thrombocytopenia, decreased over time. Treatment--limiting adverse events were more frequent during the first year compared with subsequent periods. These results demonstrate sustained efficacy and acceptable tolerability of ibrutinib over an extended time, providing the longest experience for Bruton tyrosine kinase inhibitor treatment in patients with CLL/SLL. These trials were registered at www.clinicaltrials.gov as #NCT01105247 and #NCT01109069.

Background: AML is a highly aggressive hematologic malignancy. Patient (pt) outcomes are affected by disease-related factors including cytogenetic findings and gene mutations, as well as pt-related factors, such as age and race. Younger pts have superior survival: ~50% of pts diagnosed as AYAs (18-39 years) may be cured of their disease. However, the impact of race on the outcome and associated disease profiles in this pt population are unknown. Methods: We compared survival and molecular profiles of 655 Non-Hispanic Black and Non-Hispanic White (hereafter referred to as Black, n=89 and White, n=566) AYA AML pts treated on frontline Cancer and Leukemia Group B/Alliance for Clinical Trials in Oncology protocols based on standard intensity cytarabine/anthracycline induction therapy between 1986 and 2016. Three hundred ten pts were analyzed molecularly via targeted sequencing of 81 genes. Additionally, we performed integrated genomic profiling (whole-exome sequencing and transcriptome sequencing) and measured residual disease (MRD) in serial samples of 4 Black pts who relapsed with their disease. Results: A comparison of clinical characteristics of AYA AML pts by race revealed almost identical age and sex distribution, and we found no significant differences between clinical features at diagnosis. With regard to genetic profiles, 42% of White pts were cytogenetically normal, whereas only 18% of Black pts had cytogenetically normal AML (CN-AML; p Black AYA AML pts had worse outcomes including a higher early death rate (ED, defined as death within 30 days of diagnosis; 11% v 2%, p To gain insights into the genetic features of Black AYA AML pts at different stages of the disease, we performed integrated genomic profiling on paired leukemic samples from diagnosis and relapse of 4 Black AYA pts. In all pts, the original dominant leukemic clone persisted and was dominant at relapse (Fig. 3). This suggests that the leukemic clone persists during treatment with conventional cytotoxic chemotherapy. This observation was further supported by MRD detection of NPM1 mutations in NPM1-mutated pts at time of morphologic CR. Conclusion: Black AYA AML pts present with distinct molecular features, including very high frequencies of CBF AML, and low frequency of NPM1. Pts aged 18-29y account for the race-associated survival disparity, especially non-CBF pts who have dramatically poor survival. On the one hand, the lower CR rates combined with persistence of dominant clones at relapse suggest reduced response to induction chemotherapy, and suggests the need for different treatment intensities and/or modalities in this pt cohort. On the other hand, high early death rates are indicative of delay in diagnosis and care, including health inequities, calling for systematic changes particularly for this population. Figure 1 Figure 1. Disclosures Blachly: KITE: Consultancy, Honoraria; INNATE: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria. Mims: Leukemia and Lymphoma Society's Beat AML clinical study: Consultancy, Research Funding; Aptevo: Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Glycomemetics: Research Funding; Kartos Pharmaceuticals: Research Funding; Xencor: Research Funding; Genentech: Consultancy; Abbvie: Consultancy; BMS: Consultancy; Kura Oncology: Consultancy; Syndax Pharmaceuticals: Consultancy; BMS: Consultancy; Jazz Pharmaceuticals: Consultancy; Aptevo: Research Funding. Walker: Karyopharm Therapeutics: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Blum: Leukemia and Lymphoma Society: Research Funding; Syndax: Honoraria; AmerisourceBergen: Honoraria; Abbvie: Honoraria; Celyad Oncology: Research Funding; Nkarta: Research Funding; Forma Therapeutics: Research Funding; Xencor: Research Funding. Larson: Rafael Pharmaceuticals: Research Funding; Epizyme: Consultancy; Astellas: Consultancy, Research Funding; Gilead: Research Funding; CVS/Caremark: Consultancy; Takeda: Research Funding; Novartis: Research Funding; Cellectis: Research Funding. Stone: Onconova: Consultancy; Boston Pharmaceuticals: Consultancy; Innate: Consultancy; Jazz: Consultancy; Novartis: Consultancy, Research Funding; AbbVie: Consultancy; GlaxoSmithKline: Consultancy; Gemoab: Membership on an entity's Board of Directors or advisory committees; Foghorn Therapeutics: Consultancy; Janssen: Consultancy; Arog: Consultancy, Research Funding; Aprea: Consultancy; Elevate Bio: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Consultancy; BerGen Bio: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Actinium: Membership on an entity's Board of Directors or advisory committees; Syndax: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Syntrix/ACI: Membership on an entity's Board of Directors or advisory committees; Syros: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy; Agios: Consultancy, Research Funding; Macrogenics: Consultancy. Paskett: Pfizer: Research Funding; Merck: Research Funding. Byrd: Vincerx Pharmaceuticals: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Newave: Membership on an entity's Board of Directors or advisory committees; Novartis, Trillium, Astellas, AstraZeneca, Pharmacyclics, Syndax: Consultancy, Honoraria. Eisfeld: Karyopharm (spouse): Current Employment.

Introduction: The development of Bruton tyrosine kinase inhibitors (BTKi) and their introduction into clinical practice represent a major advance in the treatment of chronic lymphocytic leukemia (CLL). Ibrutinib and other second generation BTKi as monotherapies generally do not produce minimal residual disease negative (MRD-) complete remissions even with extended therapy. The reason for lack of continued elimination of CLL to a MRD- status over time is unknown, and we hypothesized that biological differences in the CLL cells or immune microenvironment might make them resistant to elimination. Methods: Samples were obtained from patients on continuous ibrutinib who hadn't relapsed at time points of 3 years on treatment and 5 years on treatment; and pre-ibrutinib. Isolated CLL cells were subject to B-cell receptor (BCR) sequencing using NEBNext Immune Sequencing Kit by New England Biolabs (NEB, Inc., USA). In a separate cohort, 10X VDJ+5'-sequencing was performed on peripheral blood mononuclear cells. Flow cytometry and ELISA were used to identify alterations in immune cell subtype and identify immune profiles associated with MRD positive (MRD+) status. Results: To identify the clonal pattern in MRD+, we performed deep sequencing of the BCR repertoire on samples from 13 patients with 3 time points each. We found that dominant clones tended to remain constant, but new clones appeared in later time points (Figure 1). MiXCR (v3.0.5) was used with default parameters to identify preprocessed reads containing CDR3 regions from B-cell heavy, kappa, and lambda chains, generating a list of unique productive and nonproductive CDR3 sequences associated with their relative abundances and specific V(D)J gene usage. Two out of three patients (patients 1 and 3) showed significant change in the clone over time. In patients 1 and 2, we saw that heavy chain clones emerge at later time points. In patient 3 alone, we observed that at 5 years there are two dominant clones. Our findings suggest that each patient shows a diverse repertoire of CLL clones and that the dominant clone does not change significantly across time points. To identify cell populations based on gene expression patterns, we performed 10X VDJ+5'-seq. Based on the expression of known markers, we identified CLL cells and other immune cell subtypes. We identified differentially expressed genes (DEGs) for CLL cells in each time points. Over time, we observed upregulation of CD79a, LTB, TAGLN2, and LGALS, genes typically associated with leukemic cell survival. Suggesting differential expression of pro-survival genes contribute to continued presence of MRD over time. T cells are known to be dysfunctional in CLL and have not previously been extensively studied in the setting of long term BTKi. We performed flow cytometry to determine the repertoire and function of T cells at 3 and 5 years of ibrutinib therapy. We found that the percentage of CD3+ T cells increases at later time points in all the 8 patients (p Conclusion: Extended ibrutinib treatment yields a subset of patients who become MRD- whereas a large majority remain MRD+. Our findings suggest that BCR repertoire in CLL MRD might change in long term ibrutinib therapy and induce necessary genes for its survival in the microenvironment. Although T cells and NK cells are non-functional at later time points, better understanding of these subtypes may lead to new strategies and to improve antitumor function of these cells. Differentiating the biology of why certain patients attain MRD- status on BTK inhibitor is of high interest as it could provide rationale for therapy discontinuation or add on approaches. Figure 1 Figure 1. Disclosures Rogers: AbbVie Inc.: Consultancy, Research Funding; Acerta Pharma: Consultancy; AstraZeneca: Consultancy; Genentech: Consultancy, Research Funding; Innate Pharma: Consultancy; Pharmacyclics LLC: Consultancy; Janssen Pharmaceuticals, Inc: Research Funding; ovartis Pharmaceuticals Corporation: Research Funding. Bhat: Beigene: Consultancy; AstraZeneca: Consultancy; Aptitude Health: Honoraria; Onclive: Honoraria. Kittai: Bristol-Meyers Squibb: Consultancy; Abbvie: Consultancy; Janssen: Consultancy. Blachly: INNATE: Consultancy, Honoraria; KITE: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria. Byrd: Novartis, Trillium, Astellas, AstraZeneca, Pharmacyclics, Syndax: Consultancy, Honoraria; Vincerx Pharmaceuticals: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Newave: Membership on an entity's Board of Directors or advisory committees. Woyach: AbbVie Inc, ArQule Inc, Janssen Biotech Inc, AstraZeneca, Beigene: Other: Advisory Committee; AbbVie Inc, ArQule Inc, AstraZeneca Pharmaceuticals LP, Janssen Biotech Inc, Pharmacyclics LLC, an AbbVie Company,: Consultancy; AbbVie Inc, Loxo Oncology Inc, a wholly owned subsidiary of Eli Lilly & Company: Research Funding; Gilead Sciences Inc: Other: Data & Safety.