Citations

Abstract Herein, we present the long-term follow-up of the randomized E1912 trial comparing the long-term efficacy of ibrutinib–rituximab (IR) therapy to fludarabine, cyclophosphamide, and rituximab (FCR) and describe the tolerability of continuous ibrutinib. The E1912 trial enrolled 529 treatment-naïve patients aged ≤70 years with chronic lymphocytic leukemia (CLL). Patients were randomly assigned (2:1 ratio) to receive IR or 6 cycles of FCR. With a median follow-up of 5.8 years, median progression-free survival (PFS) is superior for IR (hazard ratio [HR], 0.37; P < .001). IR improved PFS relative to FCR in patients with both immunoglobulin heavy chain variable region (IGHV) gene mutated CLL (HR: 0.27; P < .001) and IGHV unmutated CLL (HR: 0.27; P < .001). Among the 354 patients randomized to IR, 214 (60.5%) currently remain on ibrutinib. Among the 138 IR-treated patients who discontinued treatment, 37 (10.5% of patients who started IR) discontinued therapy due to disease progression or death, 77 (21.9% of patients who started IR) discontinued therapy for adverse events (AEs)/complications, and 24 (6.8% of patients who started IR) withdrew for other reasons. Progression was uncommon among patients able to remain on ibrutinib. The median time from ibrutinib discontinuation to disease progression or death among those who discontinued treatment for a reason other than progression was 25 months. Sustained improvement in overall survival (OS) was observed for patients in the IR arm (HR, 0.47; P = .018). In conclusion, IR therapy offers superior PFS relative to FCR in patients with IGHV mutated or unmutated CLL, as well as superior OS. Continuous ibrutinib therapy is tolerated beyond 5 years in the majority of CLL patients. This trial was registered at www.clinicaltrials.gov as #NCT02048813.

Abstract Background: The ECOG-ACRIN randomized phase 3 clinical trial E1912 established ibrutinib-rituximab (IR) as the standard of care for CLL patients <= 70 years in the frontline setting by improving the progression free (PFS) and overall survival (OS) compared to previous standard chemo-immunotherapy with fludarabine, cyclophosphamide and rituximab (FCR) (Shanafelt et al. NEJM 2019). Quality of life (QOL) was an important secondary endpoint on this trial comparing continuous (IR) vs time-limited (FCR) therapy due to the differing profile of treatment-related toxicities over the short and long-term. E1912 patient-reported outcomes (PROs) results are presented here. Methods: Patients enrolled on E1912 completed the Functional Assessment of Cancer Therapy-General (FACT-G) and Leukemia subscale at randomization (baseline), 3, 6, and 12 months post-randomization, and every 6 months for 2 years regardless of disease status. The primary outcome was the 31-item FACT-Leukemia Trial Outcome Index (FACT-Leu TOI), calculated by summing items from the FACT-G physical wellbeing (PWB), functional well-being (FWB), and leukemia subscales (score range: 0-124). The primary endpoint was defined as the difference in FACT-Leu TOI change scores from randomization to 12 months (at response evaluation) between patients treated with continuous therapy Arm A (IR) vs time-limited therapy Arm B (FCR). Mean change scores from baseline to each time point were calculated using all cases with data at baseline and the corresponding time point. Comparisons between treatment arms were performed using two-sample t tests. Linear mixed effects models were used to estimate the trajectories of PRO scores. Results: PRO data was extracted on 3/8/2021. PRO data was provided at baseline and 12 months for 233/354 (65.8%) patients on the IR arm and 118/175 (67.4%) patients on the FCR arm. At enrollment, there were no significant differences in the baseline FACT-Leu TOI scores (mean ± SE) between the two arms: IR (93.27 ± 1.03) vs FCR (92.68 ± 1.38; p=0.73). The FACT-Leu TOI score improved from baseline to 12 months in both arms (Table 1 and Figure 1). The change scores from baseline to 12 months, the primary outcome, were not significantly different between IR (7.59 ± 1.09) vs FCR (8.22 ± 1.44; p=0.73). Change in FACT-Leu TOI from baseline to 3 months was 5.77 ± 0.77 and 4.06 ± 1.18 (p=0.22); and from baseline to 6 months was 6.87 ± 0.87 and 8.01 ± 1.44 (p=0.50) in the IR and FCR arms, respectively. After the first 6 months of treatment, the improvement in FACT-Leu TOI scores was maintained in both treatment arms. There was no significant difference in total FACT-Leu TOI score in the continuous therapy (IR) vs time-limited therapy (FCR) arms over the first 36 months post registration. Analysis of FACT subscales showed PWB improved in the IR arm (0.37 ± 0.22) and declined in the FCR arm (-0.92 ± 0.39) from baseline to 3 months (p=0.004 for difference in PWB change between arms) but there was no significant difference between the two arms for change in PWB scores from baseline to 6 and 12 months. There were no significant differences between the two arms for change in FWB and FACT-Leu subscales from baseline to 3, 6 and 12 months. Conclusions: QOL improves in CLL patients age 70 and younger when treated in the frontline setting with IR or FCR. The improvement in QOL is maintained during continuous therapy with ibrutinib and there is no significant decline in QOL over time. Given the improvement in PFS and OS with IR over FCR seen in E1912, the results of this QOL analysis support the use of frontline ibrutinib in previously untreated younger CLL patients. Acknowledgement: This study was conducted by the ECOG-ACRIN Cancer Research Group (Peter J. O'Dwyer, MD and Mitchell D. Schnall, MD, PhD, Group Co-Chairs) and supported by the National Cancer Institute of the National Institutes of Health under award numbers: U10CA180794, U10CA180820, UG1CA189863, UG1CA190140, UG1CA232760, UG1CA233180, UG1CA233230, UG1CA233253, UG1CA233277, UG1CA233290, UG1CA233339, UG1CA189859, UG1CA233332. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Figure 1 Figure 1. Disclosures Kay: Oncotracker: Membership on an entity's Board of Directors or advisory committees; CytomX Therapeutics: 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; Tolero Pharmaceuticals: Research Funding; Acerta Pharma: Research Funding; Behring: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; Rigel: Membership on an entity's Board of Directors or advisory committees; Dava Oncology: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Targeted Oncology: Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Research Funding; Sunesis: Research Funding; Genentech: Research Funding; Bristol Meyer Squib: Membership on an entity's Board of Directors or advisory committees, Research Funding. O'Brien: Amgen, Astellas, Celgene, GlaxoSmithKline, Janssen Oncology, Aptose Biosciences Inc., Vaniam Group LLC, AbbVie, Alexion, Verastem, Juno Therapeutics, Vida Ventures, Autolus, Johnson and Johnson, Merck, Bristol Myers Squibb, NOVA Research Company, Eli Lill: Consultancy; Kite, Regeneron, Acerta, Caribou, Gilead, Pharmacyclics, TG Therapeutics, Pfizer, Sunesis: Research Funding. Coutre: Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Honoraria, 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, Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Beigene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Data Safety Monitoring Committee, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; Acerta: Other: Data Safety Monitoring Committee, Research Funding. Barr: AstraZeneca: Consultancy; Gilead: Consultancy; Janssen: Consultancy; Genentech: Consultancy; Beigene: Consultancy; Bristol Meyers Squibb: Consultancy; Seattle Genetics: Consultancy; TG Therapeutics: Consultancy; Morphosys: Consultancy; Abbvie/Pharmacyclics: Consultancy. Cashen: Secura Bio, ADC Therapeutics: Consultancy. Mato: Adaptive Biotechnologies: Consultancy, Research Funding; DTRM BioPharma: Consultancy, Research Funding; Johnson and Johnson: Consultancy, Research Funding; Acerta/AstraZeneca: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding; AstraZeneca: Consultancy; BeiGene: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; LOXO: Consultancy, Research Funding; MSKCC: Current Employment; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; TG Therapeutics: Consultancy, Other: DSMB, Research Funding; Nurix: Research Funding; Janssen: Consultancy, Research Funding; Genmab: Research Funding. Erba: AbbVie Inc; Agios Pharmaceuticals Inc; Astellas; Bristol Myers Squibb; Celgene, a Bristol Myers Squibb company; Daiichi Sankyo Inc; Genentech, a member of the Roche Group; GlycoMimetics Inc; Incyte Corporation; Jazz Pharmaceuticals Inc; Kura Oncology; Nov: Other: Advisory Committee; AbbVie Inc: Other: Independent review committee; AbbVie Inc; Agios Pharmaceuticals Inc; ALX Oncology; Amgen Inc; Daiichi Sankyo Inc; FORMA Therapeutics; Forty Seven Inc; Gilead Sciences Inc; GlycoMimetics Inc; ImmunoGen Inc; Jazz Pharmaceuticals Inc; MacroGenics Inc; Novartis; PTC Therapeutics: Research Funding; AbbVie Inc; Agios Pharmaceuticals Inc; Bristol Myers Squibb; Celgene, a Bristol Myers Squibb company; Incyte Corporation; Jazz Pharmaceuticals Inc; Novartis: Speakers Bureau. Stone: Onconova: Consultancy; AbbVie: Consultancy; Boston Pharmaceuticals: Consultancy; Bristol Myers Squibb: Consultancy; Gemoab: Membership on an entity's Board of Directors or advisory committees; Elevate Bio: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Research Funding; Jazz: Consultancy; Syros: Membership on an entity's Board of Directors or advisory committees; Syndax: Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy, Research Funding; Takeda: 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; Foghorn Therapeutics: Consultancy; Innate: Consultancy; Janssen: Consultancy; GlaxoSmithKline: Consultancy; Amgen: Membership on an entity's Board of Directors or advisory committees; Arog: Consultancy, Research Funding; Actinium: Membership on an entity's Board of Directors or advisory committees; Syntrix/ACI: Membership on an entity's Board of Directors or advisory committees; Aprea: Consultancy; Celgene: Consultancy; Macrogenics: Consultancy. Litzow: Actinium: Research Funding; Amgen: Research Funding; AbbVie: Research Funding; Pluristem: Research Funding; Jazz: Other: Advisory Board; Omeros: Other: Advisory Board; Astellas: Research Funding; Biosight: Other: Data monitoring committee. Tallman: NYU Grand Rounds: Honoraria; Kura: Membership on an entity's Board of Directors or advisory committees; Syros: Membership on an entity's Board of Directors or advisory committees; Innate Pharma: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Biosight: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Jazz Pharma: Membership on an entity's Board of Directors or advisory committees; Oncolyze: Membership on an entity's Board of Directors or advisory committees; KAHR: Membership on an entity's Board of Directors or advisory committees; Orsenix: Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Rafael Pharmaceuticals: Research Funding; Glycomimetics: Research Funding; Biosight: Research Funding; Orsenix: Research Funding; Abbvie: Research Funding; Mayo Clinic: Honoraria; UC DAVIS: Honoraria; Northwell Grand Rounds: Honoraria; NYU Grand Rounds: Honoraria; Danbury Hospital Tumor Board: Honoraria; Acute Leukemia Forum: Honoraria; Miami Leukemia Symposium: Honoraria; New Orleans Cancer Symposium: Honoraria; ASH: Honoraria; NCCN: Honoraria. Shanafelt: Genentech, Pharmacyclics: Research Funding. Wagner: Eli Lilly, Johnson & Johnson: Other: Spouse, previously held individual stocks;; Celgene-BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Athenex Inc: Consultancy.

Abstract E1912 was a randomized phase 3 trial comparing indefinite ibrutinib plus 6 cycles of rituximab (IR) to 6 cycles of fludarabine, cyclophosphamide, and rituximab (FCR) in untreated younger patients with CLL. We describe measurable residual disease (MRD) levels in E1912 over time and correlate them with clinical outcome. Undetectable MRD rates (<1 CLL cell per 104 leukocytes) were 29.1%, 30.3%, 23.4%, and 8.6% at 3, 12, 24, and 36 months for FCR, and significantly lower at 7.9%, 4.2%, and 3.7% at 12, 24, and 36 months for IR, respectively. Undetectable MRD at 3, 12, 24, and 36 months was associated with longer progression-free survival (PFS) in the FCR arm, with hazard ratios (MRD detectable/MRD undetectable) of 4.29 (95% confidence interval [CI], 1.89-9.71), 3.91 (95% CI, 1.39-11.03), 14.12 (95% CI, 1.78-111.73), and not estimable (no events among those with undetectable MRD), respectively. In the IR arm, patients with detectable MRD did not have significantly worse PFS compared with those in whom MRD was undetectable; however, PFS was longer in those with MRD levels <10−1 than in those with MRD levels above this threshold. Our observations provide additional support for the use of MRD as a surrogate end point for PFS in patients receiving FCR. In patients on indefinite ibrutinib-based therapy, PFS did not differ significantly by undetectable MRD status, whereas those with MRD <10−1 tended to have longer PFS, although continuation of ibrutinib would very likely be necessary to maintain treatment efficacy.

Abstract Lineage-ambiguous leukemias are high-risk malignancies of poorly understood genetic basis. Here, we describe a distinct subgroup of acute leukemia with expression of myeloid, T lymphoid, and stem cell markers driven by aberrant allele-specific deregulation of BCL11B, a master transcription factor responsible for thymic T-lineage commitment and specification. Mechanistically, this deregulation was driven by chromosomal rearrangements that juxtapose BCL11B to superenhancers active in hematopoietic progenitors, or focal amplifications that generate a superenhancer from a noncoding element distal to BCL11B. Chromatin conformation analyses demonstrated long-range interactions of rearranged enhancers with the expressed BCL11B allele and association of BCL11B with activated hematopoietic progenitor cell cis-regulatory elements, suggesting BCL11B is aberrantly co-opted into a gene regulatory network that drives transformation by maintaining a progenitor state. These data support a role for ectopic BCL11B expression in primitive hematopoietic cells mediated by enhancer hijacking as an oncogenic driver of human lineage-ambiguous leukemia. Significance: Lineage-ambiguous leukemias pose significant diagnostic and therapeutic challenges due to a poorly understood molecular and cellular basis. We identify oncogenic deregulation of BCL11B driven by diverse structural alterations, including de novo superenhancer generation, as the driving feature of a subset of lineage-ambiguous leukemias that transcend current diagnostic boundaries. This article is highlighted in the In This Issue feature, p. 2659

Abstract Genomic classification has improved risk assignment of pediatric, but not adult B-lineage acute lymphoblastic leukemia (B-ALL). The international UKALLXII/ECOG-ACRIN E2993 (#NCT00002514) trial accrued 1229 adolescent/adult patients with BCR-ABL1− B-ALL (aged 14 to 65 years). Although 93% of patients achieved remission, 41% relapsed at a median of 13 months (range, 28 days to 12 years). Five-year overall survival (OS) was 42% (95% confidence interval, 39, 44). Transcriptome sequencing, gene expression profiling, cytogenetics, and fusion polymerase chain reaction enabled genomic subtyping of 282 patient samples, of which 264 were eligible for trial, accounting for 64.5% of E2993 patients. Among patients with outcome data, 29.5% with favorable outcomes (5-year OS 65% to 80%) were deemed standard risk (DUX4-rearranged [9.2%], ETV6-RUNX1/-like [2.3%], TCF3-PBX1 [6.9%], PAX5 P80R [4.1%], high-hyperdiploid [6.9%]); 50.2% had high-risk genotypes with 5-year OS of 0% to 27% (Ph-like [21.2%], KMT2A-AFF1 [12%], low-hypodiploid/near-haploid [14.3%], BCL2/MYC-rearranged [2.8%]); 20.3% had intermediate-risk genotypes with 5-year OS of 33% to 45% (PAX5alt [12.4%], ZNF384/-like [5.1%], MEF2D-rearranged [2.8%]). IKZF1 alterations occurred in 86% of Ph-like, and TP53 mutations in patients who were low-hypodiploid (54%) and BCL2/MYC-rearranged (33%) but were not independently associated with outcome. Of patients considered high risk based on presenting age and white blood cell count, 40% harbored subtype-defining genetic alterations associated with standard- or intermediate-risk outcomes. We identified distinct immunophenotypic features for DUX4-rearranged, PAX5 P80R, ZNF384-R/-like, and Ph-like genotypes. These data in a large adult B-ALL cohort treated with a non–risk-adapted approach on a single trial show the prognostic importance of genomic analyses, which may translate into future therapeutic benefits.

Abstract Background There is a critical need to identify patient characteristics associated with long-term ovarian cancer survival. Methods Quality of life (QOL), measured by the Functional Assessment of Cancer Therapy-Ovarian-Trial Outcome Index (FACT-O-TOI), including physical, functional, and ovarian-specific subscales, was compared between long-term survivors (LTS) (8+ years) and short-term survivors (STS) (<5 years) of GOG 218 at baseline; before cycles 4, 7, 13, 21; and 6 months post-treatment using linear and longitudinal mixed models adjusted for covariates. Adverse events (AEs) were compared between survivor groups at each assessment using generalized linear models. All P values are 2-sided. Results QOL differed statistically significantly between STS (N = 1115) and LTS (N = 260) (P < .001). Baseline FACT-O-TOI and FACT-O-TOI change were independently associated with long-term survival (odds ratio = 1.05, 95% confidence interval = 1.03 to 1.06 and odds ratio = 1.06, 95% confidence interval = 1.05 to 1.07, respectively). A 7-point increase in baseline QOL was associated with a 38.0% increase in probability of LTS, and a 9-point increase in QOL change was associated with a 67.0% increase in odds for LTS. QOL decreased statistically significantly with increasing AE quartiles (cycle 4 quartiles: 0-5 vs 6-8 vs 9-11 vs ≥12 AEs, P = .01; cycle 21 quartiles: 0-2 vs 3 vs 4-5 vs ≥6 AEs, P = .001). Further, LTS reported statistically significantly better QOL compared with STS (P = .03 and P = .01, cycles 4 and 21, respectively), with similar findings across higher AE grades. Conclusions Baseline and longitudinal QOL change scores distinguished LTS vs STS and are robust prognosticators for long-term survival. Results have trial design and supportive care implications, providing meaningful prognostic value in this understudied population.

Background: Chronic myeloid leukemia (CML) is driven by the activity of the oncogenic BCR-ABL tyrosine kinase, which can be effectively inhibited by tyrosine kinase inhibitors (TKIs) leading to prolonged overall and disease-free survival. Despite their effectiveness, disease can progress on TKI therapy, and lifelong treatment with TKI can have substantial negative effects on quality of life and financial health. Studies assessing the safety of TKI discontinuation in CML patients in molecular remission showed that TKIs can be discontinued in up to 45% of patients without disease recurrence. Programmed death receptor-1 (PD-1) is an inhibitory immune checkpoint receptor expressed by T-cells that can be inhibited by the anti-PD-1 monoclonal antibody pembrolizumab. Preclinical data have shown that PD-1 is highly expressed on CML-specific cytotoxic T-cells and PD-1 ligand (PD-L1) is present on CML cells. In murine CML models, the administration of anti-PD-L1 antibodies prolonged survival. As these studies suggest that disease relapse might be due to PD-1/PD-L1 mediated immune escape by CML cells, we designed the BLAST MRD CML 1 trial to study whether adding pembrolizumab to TKI is safe, increases the rate of conversion to undetectable minimal residual disease (UMRD) and allows a higher rate of TKI discontinuation. Methods: The primary endpoint of this ongoing national, ECOG-sponsored, single-arm pilot phase II clinical trial is to assess the proportion of CML patients on stable-dose TKI who convert to UMRD during or within 2 years of initiating pembrolizumab therapy (NCT#03516279). Secondary endpoints are (I) the proportion of CML patients who maintain UMRD for 6 months and 12 months, (II) the proportion of CML patients who discontinue TKI after achieving UMRD, (III) the proportion of patients who maintain UMRD off TKI at 2 years after first determined UMRD, and (IV) the incidence of grade 3 or 4 immune related adverse events related to pembrolizumab treatment during the first 2 years after registration. UMRD state is defined as an undetectable BCR-ABL using the central RQ-PCR assay with a sensitivity of 4.5 [MR4.5] on 2 consecutive occasions separated by at least 4 weeks with the date of achievement of UMRD constituting the date of first test. Immune related and other adverse events will be assessed according to CTCAE v 5.0 terminology and grading. Adult (≥18 years) patients with pathologically-confirmed CML and who have achieved major molecular response (MR3) but not UMRD at time of screening are eligible. Eligibility was recently expanded to allow third line TKI. Therefore, currently eligible patients must have been on first, second, or third line TKI therapy with either dasatinib, imatinib, nilotinib, or bosutinib for at least 2 years prior to enrolment. Patients with accelerated or blast phase CML or who have received prior allogeneic hematopoietic stem cell transplant or anti-PD-1/PD-L1 therapy are excluded. Patients will continue a standard dose of TKI therapy and receive pembrolizumab at 200 mg IV every 21 days (Figure 1). MRD status will be assessed centrally every 4 cycles. Patients who achieve UMRD at or prior to cycle 17 will discontinue TKI and pembrolizumab. If MRD remains positive prior to cycle 17, TKI and pembrolizumab will be continued for an additional 18 cycles. If MRD is still detectable after the second year of combined therapy, patients will come off study. If patients are in an UMRD state by the end of year 1 or 2 of pembrolizumab therapy, pembrolizumab will be discontinued. Patients who remain in UMRD status for one year after the first UMRD result will discontinue TKI therapy. Once TKI is discontinued, BCR-ABL will monitored q4 weeks for the first six months post TKI discontinuation, then q8 weeks for the subsequent six months, then q12 weeks for another year. Assuming that the addition of pembrolizumab to TKI will increase the conversion rate to UMRD from 20% to 40%, enrollment of 36 patients (40 patients to allow for 10% drop-out) would give this trial 91% power with a one-sided type-I error of 0.089. The combination therapy will be considered promising if 11 or more patients meet the criteria for TKI discontinuation. Toxicity will be monitored and reviewed every six months. Disclosures Zeidan: Incyte: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Cardinal Health: Consultancy, Honoraria; Leukemia and Lymphoma Society: Other; Epizyme: Consultancy, Honoraria; Ionis: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; Celgene / BMS: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Otsuka: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria, Research Funding; Agios: Consultancy, Honoraria; Boehringer-Ingelheim: Consultancy, Honoraria, Research Funding; Cardiff Oncology: Consultancy, Honoraria, Other; Taiho: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Astellas: Consultancy, Honoraria; Daiichi Sankyo: Consultancy, Honoraria; Acceleron: Consultancy, Honoraria; CCITLA: Other; Astex: Research Funding; MedImmune/Astrazeneca: Research Funding; Trovagene: Consultancy, Honoraria, Research Funding; Aprea: Research Funding; Seattle Genetics: Consultancy, Honoraria; BeyondSpring: Consultancy, Honoraria; ADC Therapeutics: Research Funding. Radich:Amgen: Consultancy; Bristol-Myers Squibb: Consultancy; Jazz: Consultancy; Novartis Pharmaceuticals Corporation: Consultancy, Research Funding. Bhatt:Incyte: Consultancy, Research Funding; Takeda: Consultancy; Omeros: Consultancy; Agios: Consultancy; Rigel: Consultancy; Tolero: Research Funding; Abbvie: Consultancy, Research Funding; Pfizer: Research Funding; Partnership for health analytic research: Consultancy; Jazz: Research Funding; National Marrow Donor Program: Research Funding; Oncoceutics: Other. Gore:Abbvie: Consultancy, Honoraria, Research Funding. Luger:Daiichi-Sankyo: Honoraria; Pfizer: Honoraria; Bristol-Myers Squibb: Honoraria; Acceleron: Honoraria; Agios: Honoraria; Loxo Oncology: Honoraria; Onconova: Research Funding; Kura: Research Funding; Hoffman La Roche: Research Funding; Ariad: Research Funding; Biosight: Research Funding.

BackgroundExtracorporeal photopheresis (ECP) is an immunomodulatory cellular therapy which has been shown to induce a tolerogenic state in patients with acute and chronic graft‐vs‐host disease. ECOG‐ACRIN explored the activity of ECP as a part of a reduced intensity conditioning regimen in two multicenter trials in patients with MDS (E1902) and lymphomas (E1402). While both studies closed before completing accrual, we report results in 23 patients (17 MDS and 6 lymphoma).Study Design and MethodsPatients received 2 days of ECP followed by pentostatin 4 mg/m2 /day for two consecutive days, followed by 600 cGy of total body irradiation prior to stem cell infusion. Immunosuppression for aGVHD was infusional cyclosporine A or tacrolimus and methotrexate on day +1, +3, with mycophenolate mofetil starting on day 100 for chronic GVHD prophylaxis.ResultsAll patients engrafted, with median time to neutrophil and platelet engraftment of 15‐18 days and 10‐18 days respectively. Grade 3 or 4 aGVHD occurred in 13% and chronic extensive GVHD in 30%.ConclusionsThese studies demonstrate that ECP/pentostatin/TBI is well tolerated and associated with adequate engraftment of neutrophils and platelets in patients with lymphomas and MDS.

149 Background: Patients with metastatic hormone-sensitive prostate cancer (mHSPC) have a variable response to ADT and some benefit from the addition of docetaxel or an androgen signaling pathway inhibitor. We found that loss of the epigenetic regulator KDM5D is associated with more aggressive prostate cancer (PC). We sought to determine whether MYBL2 which is regulated by KDM5D mediates this effect. MYBL2 is a transcription factor which controls key genes (e.g. FOXM1) and increases cell cycle progression and survival. Methods: AR expressing hormone-sensitive cell lines, LNCaP and LAPC4 were used. Motif analysis and CHiPseq of LNCaP with and without siKDM5D was performed and impact of modulation of KDM5D and MYBL2 in both cells on cell survival was assessed. Gene expression profiling (GEP) data assessed MYBL2’s association with KDM5D levels in localized disease (publicly available data) and mHSPC (Decipher whole Affymetrix platform on CHAARTED samples). Results: Silencing KDM5D increased H3K4me3 and increased MYBL2 expression. GEP showed a strong negative correlation between KDM5D and MYBL2 in patients with localized PC (-0.66; TCGA) but not from primary prostate cancer tissue with mHSPC (-0.03; CHAARTED). Cells with low KDM5D and high MYBL2 were androgen independent and more resistant to docetaxel. In TCGA, patients with high MYBL2 had a higher rate of relapse from localized disease. In patients with metastatic disease (CHAARTED) low MYBL2 was associated with a better overall survival (OS) on multivariable analysis when treated with ADT or ADT + docetaxel. Conclusions: Low MYBL2 is associated with a longer OS with ADT alone and ADT and docetaxel independent of clinical variables. Patients with high MYBL2 expression had better OS with ADT plus docetaxel compared with patients with high MYBL2 treated with ADT alone.[Table: see text]