Citations

The gene encoding SAP97 ( DLG1) joins a growing list of genes encoding ion channel interacting proteins (ChIPs) identified as potential channelopathy-susceptibility genes because of their ability to regulate the trafficking, targeting, and modulation of ion channels that are critical for the generation and propagation of the cardiac electrical impulse. In this study we provide the first data supporting DLG1-encoded SAP97’s candidacy as a minor Brugada syndrome susceptibility gene.

Abstract Background Echinococcus multilocularis is one of the most severe and lethal parasitic diseases of humans, most often reported in Europe and Asia. Only 1 previous case has been documented in the contiguous United States from Minnesota in 1977. European haplotypes have been identified in carnivores and domestic dogs as well as recently in patients in western and central Canada. Methods We used immunohistochemical testing with the monoclonal antibody Em2G11 and a species-specific enzyme-linked immunosorbent assay affinity-purified antigen Em2, as well as COX1 gene sequencing. Results Using pathology, immunohistochemical staining, specific immunodiagnostic testing, and COX1 gene sequencing, we were able to definitively identify E. multilocularis as the causative agent of our patient’s liver and lung lesions, which clustered most closely with the European haplotype. Conclusions We have identified the first case of a European haplotype E. multilocularis in the United States and the first case of this parasitic infection east of the Mississippi River. Given the identification of this haplotype in Canada, this appears to be an emerging infectious disease in North America.

20023 Background: EGFR is a transmembrane receptor tyrosine kinase belonging to the ErbB family of proteins. Anti-EGFR antibodies have shown efficacy as monotherapy and can enhance cytotoxic chemotherapy in patients with advanced colorectal cancers. We studied EGFR expression in primary colon cancers and its association with, microsatellite instability (MSI), clinicopathological variables and patient survival rates. Methods: Archival colon carcinomas were studied from patients with high risk Dukes’ stage B2 (n = 78) and C (n = 230) patients enrolled in a prior adjuvant trial of 5-fluorouracil, leucovorin plus standard dose or high-dose levamisole (NCCTG 91–46–53). EGFR expression (anti-EGFR H11 antibody, DAKO) was analyzed by immunohistochemistry (IHC) and intensity (0–3+), extent and their product (weighted score) were determined. MSI was analyzed using BAT26 and expression of hMLH1, hMSH2 and hMSH6 proteins by IHC. Patients were censored at 5 years after randomization for DFS and censored at 8 years post study randomization for overall survival (OS) data. Results: EGFR protein expression was detected in 216 of 308 (70%) of Dukes’ B2 and C primary colon carcinomas from patients and localized to the plasma membrane. EGFR expression variables (intensity, extent, weighted score) were increased in poor/undifferentiated compared to moderate/well differentiated tumors (p ≤ 0.036). Similar EGFR expression levels were found in MSI-H (n = 27) versus MSS (n = 203) colon cancers and for other clinicopathological variables. EGFR intensity was more likely moderate (2+) or strong (3+) in Dukes’ C versus B2 tumors (p = 0.088). In addition, higher EGFR intensity (2+, 3+) showed a trend toward worse disease-free survival (5 yr DFS %: 62.2 vs. 71.7; p = 0.095), but not overall survival (p = 0.14). Conclusions: EGFR overexpression is associated with increased tumor aggressiveness as indicated by poor tumor cell differentiation and reduced DFS in colon cancer patients receiving adjuvant 5-FU and levamisole. These findings indicate that EGFR may be an important therapeutic target in the adjuvant setting. [Table: see text]

10529 Background: BAX mutations are associated with defective DNA mismatch repair (MMR) in human colon cancers. However, the impact of BAX inactivation upon tumor cell apoptosis and proliferation in vivo remain unknown. We analyzed and compared caspase-3 and Ki-67 expression in tumors with and without BAX mutations. Methods: TNM stage II and III (n= 377) colon carcinomas were studied from participants in a 5-FU-based adjuvant therapy trial. Archival tumors were analyzed for instability at the BAT26 mononucleotide locus using polymerase chain reaction and hMLH1, hMSH2 and hMSH6 by immunohistochemistry (IHC). Frameshift mutations in a tract of eight deoxyguanosines within BAX were analyzed. Expression of caspase-3 and Ki-67 proteins were analyzed by IHC. Results: Thirty-nine of 377 (10%) tumors showed defective MMR defined as instability at BAT26 and loss of either hMLH1, hMSH2 and/or hMSH6 proteins. BAX mutations were found in 20 of 37 (54%) MMR deficient tumors and in 1 of 50 (2%) tumors with intact MMR. Mean and median number of caspase-3-positive cells were increased in tumors with defective MMR (p= 0.04), but did not differ based upon BAX status [ Table ]. However, tumors with BAX mutations showed higher Ki-67 labeling indices compared to those with wild type BAX (p= 0.01)[ Table ]. Neither BAX mutations nor caspase-3- positive cells were prognostic in a univariate analysis. Tumors with lower Ki-67 extent had improved overall survival (p=0.06), but not DFS (p=0.24). Defective MMR (vs intact) was associated with better DFS in a multivariate analysis (p= 0.03). Conclusion: MMR deficient colon cancers show frequent BAX inactivation, yet have increased apoptotic rates as indicated by increased caspase-3 expressing tumor cells. BAX mutation was associated with hyperproliferation suggesting a growth advantage compared to wild type tumors. [Table: see text] No significant financial relationships to disclose.

4017 Background: Published reports suggest that CC pts of A descent have inferior survival compared to W pts. Whether these differences are explained by clinical factors at diagnosis, socioeconomic factors impacting access to care, or intrinsic differences in the biology of the tumors or the response to therapy is unclear. Pts in clinical trials have data collected for important baseline clinical factors and should receive comparable oncologic care regardless of socioeconomic factors. Methods: We analyzed data from 13,435 individual pts on 11 phase III adjuvant CC trials accrued from 1977 to 2002. Analysis was restricted to stage II and III pts, with race reported as black or white. Endpoints were overall survival (OS - time to death), recurrence-free survival (RFS - time to recurrence or death), and recurrence-free interval (RFI - time to recurrence censoring for death). Cox models stratified by study controlled for gender, stage, age, and treatment type (rx) to determine the effect of race. Kaplan-Meier estimates (KM) were adjusted (adj) by the Xie-Liu method for study, gender, stage, age, and rx. Results: A pts (n=1134, 8.4%) were younger than W (median 58 vs 61, p<0.001) and more likely female (55 vs 45%, p<0.001). A pts had poorer OS than W pts ( table ). OS results were consistent in subsets defined by gender, stage, and age. RFS results were attenuated compared to OS, but still favored improved RFS in W pts ( table ). RFI results were further attenuated and not significantly different by race ( table ). Conclusions: Even with identical rx for CC in controlled clinical trials, A pts have poorer OS and RFS than W pts. The OS deficit was consistent across subgroups, and neither deficit was explained by differences in gender, stage, age, or rx. RFI was similar for both races, suggesting that the OS and RFS differences may be largely due to deaths unrelated to CC. [Table: see text] [Table: see text]

4006 Background: Lymph node (LN) metastasis is associated with decreased survival in rectal cancer. It has been suggested that at least 14 LN be evaluated for adequate staging. However, a large percentage of patients have fewer than the recommended number of LN examined. We hypothesized that LN ratio would be predictive of overall survival in rectal cancer. Methods: Data was analyzed from Intergroup 0114, a mature trial of postoperative adjuvant chemotherapy and radiation in T3/4 and/or LN positive rectal cancer. Survival was the same for all arms allowing the entire group to be considered as one. The primary endpoint evaluated was overall survival. A proportional hazards model was used to determine the relative prognostic impact of LN ratio compared to number of LN examined, number of positive LN, number of negative LN and AJCC nodal stage. LN ratio was defined as the number of positive LN divided by the total number of LN examined. Four groups were analyzed based on proportion of positive LN: =0.25, >0.25–0.50, >0.50–0.75 and >0.75. Results: 1,648 patients were evaluable. There were 251 T1/2, 1,251 T3 and 146 T4 tumors. 513 patients were N0, 743 N1 and 392 N2. Median number of LN was 9. LN ratio was predictive of 5-year overall survival with rates of 0.71, 0.56, 0.50 and 0.43 respectively when analyzed by quartile (p<0.0001). LN ratio remained significant when overall survival was analyzed by number of LN examined and grouped into <10, <15 and >15 nodes evaluated (p<0.0001 for all). LN ratio also predicted overall survival in N1 (p=0.04) and N2 (p=0.0002) disease. When comparing LN ratio (χ2=79.5, p<0.0001) to number of LN examined (χ2=4.7, p=0.03), number of positive LN (χ2=38, p<0.0001), number of negative LN (χ2=32, p<0.0001) and AJCC nodal stage (χ2=55.5, p<0.0001), LN ratio appears to be the strongest predictor of overall survival. Conclusion: LN ratio predicts overall survival in patients with resected rectal cancer. Importantly, this is true in patients who have had a small number of LN evaluated, in addition to those with a large number of LN examined. LN ratio also appears to be a stronger predictor of overall survival than other described LN prognostic factors. LN ratio may be a useful variable to stratify outcome in patients with node-positive rectal cancer. No significant financial relationships to disclose.

Introduction: Hypomethylating agents (HMAs) such as decitabine (DEC) or azacitidine (AZA) are FDA approved therapies for patients with different myeloid malignancies as single agent or in combination with venetoclax. Both DEC and AZA require IV infusion for 1 hour or subcutaneous (SC) injections daily for 5-7 days of every 28-day treatment cycle. They both have limited oral bioavailability due to rapid degradation by cytidine deaminase (CDA) in the gut and liver. An orally bioavailable HMA option could reduce clinic visit frequency and reduce infusions/injections related adverse events and burden. ASTX727 is an oral tablet comprised of a fixed-dose combination (FDC) of CDA inhibitor cedazuridine (C) at 100 mg with DEC at 35 mg. In a phase 2 study, C-DEC (ASTX727) demonstrated pharmacokinetic (PK) AUC exposure similar to IV-DEC at 20mg/m2 with comparable clinical activity and safety (Garcia-Manero, et al, 15th Int'l MDS Symposium, 2019). We describe here the results of a phase 3 study designed to demonstrate exposure bioequivalence of oral C-DEC and IV-DEC and generate clinical data using C-DEC in a larger population (ASCERTAIN study). Methods: The study used a randomized cross over design where patients were randomized 1:1 to either Sequence A: C-DEC (100 mg/35 mg respectively) in Cycle 1 followed by IV-DEC at 20 mg/m2 in Cycle 2, or Sequence B receiving IV-DEC in Cycle 1 followed by C-DEC on Cycle 2 to compare PK (primary endpoint AUC equivalence over 5 days of dosing) and pharmacodynamic (PD) of DNA demethylation using LINE-1 assay. All patients received C-DEC in all subsequent cycles from Cycle 3 onwards until treatment discontinuation to study clinical efficacy and safety of C-DEC. Patients were eligible as per the FDA-approved label (MDS IPSS Intermediate [Int]-1,-2 or high risk[HR] and CMML patients). Clinical responses were assessed by an independent expert panel according to International Working Group (IWG) 2006 response criteria. Adverse events (AEs) were graded by Common Terminology Criteria for Adverse Events (CTCAE) v 4.03. Results: 138 patients were randomized, of whom 133 were treated with median age of 71.0 years (range 44-88), median weight was 83.1 kg (range 45-158), and median BSA was 1.99 m2 (range 1.4-2.9 m2). The IPSS status of the patients were Int-1 in 44%, Int-2 in 20%, and HR in 16%, and 12% of pts had CMML. Patients in the two arms were well balanced regarding cytogenetic risk, baseline hemoglobin, neutrophils, platelets, or red blood cell or platelet transfusion dependence. For the primary end point, the decitabine AUC0-24 (h*ng/mL) 5-Day geometric mean estimate was 856 from the C-DEC and 865 from IV-DEC resulting in an oral/IV AUC ratio of 98.9% (90% CI of 92.7-105.6%). All sensitivity and secondary exposure analyses confirmed the primary results. Comparison of hypomethylating activity as measured by LINE-1 demethylation showed difference between oral C-DEC and IV-DEC demethylation of &lt;1% and the 95% CI of the difference included zero. Safety findings were consistent with those anticipated for IV-DEC (related Grade ≥ 3 AEs in more than 5% were thrombocytopenia, neutropenia, anemia, febrile neutropenia, and leukopenia). As of the data cutoff, median follow up was 5.2 months ( IQR 3.5-8.0) with 101 patients evaluable for response . Preliminary response analysis of all evaluable patients showed best responses of complete response (CR) in 12 patients (11.9%), marrow (m)CR in 46 (45.5%) including 14 patients (13.9%) with mCR + hematological improvement (HI), hematologic improvement (HI) in 7 (6.9%) resulting in an objective response rate (CR+mCR+ HI) in 65 patients (64%). In addition, of all 133 treated patients, 16 patients (12%) underwent hematopoietic cell transplant. Updated response data will be presented at the meeting. Summary/Conclusions: This randomized phase 3 study demonstrates that C-DEC, the oral FDC of cedazuridine/decitabine (100 mg/35 mg) resulted in an equivalent DEC exposure to IV-DEC at 20 mg/m2 over 5 days. Safety findings are consistent with those anticipated with IV-DEC with no clinically significant GI toxicity. Preliminary clinical activity is also consistent with published data from IV-DEC. C-DEC is an oral HMA alternative to IV-DEC. Combination studies with other oral agents are being planned. Disclosures Garcia-Manero: Amphivena: Consultancy, Research Funding; Helsinn: Research Funding; Novartis: Research Funding; AbbVie: Research Funding; Celgene: Consultancy, Research Funding; Astex: Consultancy, Research Funding; Onconova: Research Funding; H3 Biomedicine: Research Funding; Merck: Research Funding. Griffiths:New Link Genetics: Consultancy; Astex Phramaceuticals/Otsuka Pharmaceuticals: Consultancy, Research Funding; Persimmune: Consultancy; Boston Scientific: Consultancy; Genentech, Inc.: Research Funding; Genentech, Inc.: Research Funding; Novartis Inc.: Consultancy; Novartis Inc.: Consultancy; Partner Therapeutics: Consultancy; Astex Phramaceuticals/Otsuka Pharmaceuticals: Consultancy, Research Funding; Onconova Therapeutics: Other: PI on a clinical trial; Celgene, Inc: Consultancy, Research Funding; Abbvie, Inc.: Consultancy; Celgene, Inc: Consultancy, Research Funding; Persimmune: Consultancy; Partner Therapeutics: Consultancy; Boston Scientific: Consultancy; New Link Genetics: Consultancy; Onconova Therapeutics: Other: PI on a clinical trial; Abbvie, Inc.: Consultancy, PI on a clinical trial; Appelis Pharmaceuticals: Other: PI on a clinical trial; Appelis Pharmaceuticals: Other: PI on a clinical trial. Yee:Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Zeidan:Ariad: Honoraria; Acceleron Pharma: Consultancy, Honoraria, Research Funding; Celgene Corporation: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Research Funding; Otsuka: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Medimmune/AstraZeneca: Research Funding; Astellas: Honoraria; Seattle Genetics: Honoraria; Cardinal Health: Honoraria; Novartis: Honoraria; Agios: Honoraria; Daiichi Sankyo: Honoraria; BeyondSpring: Honoraria; Boehringer-Ingelheim: Consultancy, Honoraria, Research Funding; Trovagene: Consultancy, Honoraria, Research Funding; Incyte: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; ADC Therapeutics: Research Funding; Jazz: Honoraria. Al-Kali:Astex Pharmaceuticals, Inc.: Research Funding. Dao:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Patel:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Dava Oncology: Honoraria; France Foundation: Honoraria. Sabloff:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; ASTX: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi Canada: Research Funding; Actinium Pharmaceuticals, Inc: Membership on an entity's Board of Directors or advisory committees; Pfizer Canada: Honoraria, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas Pharma Canada: Honoraria, Membership on an entity's Board of Directors or advisory committees. Keating:Sanofi: Membership on an entity's Board of Directors or advisory committees; Hoffman La Roche: Membership on an entity's Board of Directors or advisory committees; Shire: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria. Fazal:Janssen: Honoraria, Speakers Bureau; Takeda: Honoraria, Speakers Bureau; Gilead: Consultancy, Honoraria, Speakers Bureau; Pfizer: Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Incyte: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Jazz: Consultancy, Honoraria, Speakers Bureau; Celgene: Speakers Bureau; Karyopharm: Honoraria, Speakers Bureau. Odenike:AbbVie: Consultancy, 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; Janssen Oncology: Research Funding; Astra Zeneca: Research Funding; Gilead Sciences: Research Funding; Agios: Research Funding; CTI/Baxalta: Research Funding; Astex Pharmaceuticals: Research Funding; Incyte: Research Funding; NS Pharma: Research Funding; Oncotherapy: Research Funding. DeZern:Astex Pharmaceuticals, Inc.: Consultancy; Celgene: Consultancy. O'Connell:Astex: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: 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; Shionogi: Membership on an entity's Board of Directors or advisory committees. Roboz:Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Orsenix: Consultancy, Membership on an entity's Board of Directors or advisory committees; Otsuka: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Trovagene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Eisai: Consultancy, Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Actinium: Consultancy, Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amphivena: Consultancy, Membership on an entity's Board of Directors or advisory committees; Argenx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astex: Consultancy, Membership on an entity's Board of Directors or advisory committees. Oganesian:Astex Pharmaceuticals, Inc.: Employment. Hao:Astex Pharmaceuticals, Inc.: Employment. Keer:Astex Pharmaceuticals, Inc.: Employment. Azab:Astex Pharmaceuticals, Inc.: Employment. Savona:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Boehringer Ingelheim: Patents & Royalties; Sunesis: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; Karyopharm Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

Background: Myelofibrosis (MF) is associated with bone marrow fibrosis (BMF), splenomegaly, a high symptom burden, and poor prognosis; the JAK/STAT pathway is the central pathway implicated in its pathogenesis. Ruxolitinib, a JAK1/2 inhibitor and the only FDA-approved pharmacotherapy for treatment (Tx) of MF patients (pts), improves splenomegaly, but is unable to control all clinical manifestations of disease. Navitoclax is an orally bioavailable, novel small-molecule that targets and binds with high affinity to multiple antiapoptotic B-cell lymphoma 2 (BCL2) family proteins, including BCL-XL, BCL2, and BCL-W. Preclinical studies have demonstrated cytotoxic activity of navitoclax against myeloproliferative neoplasm-derived cell lines. Herein, the results of a phase 2 study (NCT03222609) evaluating the combination of navitoclax with ruxolitinib in pts with MF are reported. Methods: This phase 2 single-arm, multicenter, open-label study assessed the efficacy and safety of navitoclax combined with ruxolitinib in pts with MF. Eligible pts (≥18 yr, diagnosis of primary MF, post-essential thrombocythemia [PET]-MF, or post-polycythemia vera [PPV]-MF, ECOG 0-2, receiving at least 12 wk of continuous ruxolitinib therapy prior to study Tx initiation) received a starting dose of 50 mg navitoclax once-daily combined with the current stable dose of ruxolitinib (≥10 mg BID). Weekly intra-patient dose-escalation of navitoclax was allowed to a maximum daily dose of 300 mg based on tolerability and platelet count. Tx continued until the end of clinical benefit, unacceptable toxicity, or discontinuation. The primary efficacy endpoint was percentage reduction in splenic volume from baseline. Secondary endpoints included effect on total symptom score (TSS), overall response rate, rate of anemia response, improvement in BMF, and safety profile. Results: As of May 1, 2019, 34 pts (primary MF, n=16; PET-MF, n=5; PPV-MF, n=13) had received ≥1 dose of navitoclax in combination with ruxolitinib. Median age was 68 yr (range 42-86), 68% were male, and 9 pts (26%) had ≥3 prior lines of MF therapy. The median duration of prior ruxolitinib exposure was 745 days (range 134-4549). Of the 34 pts enrolled, 27 (79%) had JAK2 and 7 pts (21%) had CALR mutations. There were no pts enrolled with triple-negative MF. Of 33 pts with available baseline testing, 17 (52%) had high molecular risk, defined by mutations within ASXL1, EZH2, IDH1/2, SRSF2, or U2AF1. The mean baseline platelet count was 231 x 109/L (range 99-706); mean baseline Hgb was 10.8 g/dL; 19 (56%) pts had elevated WBC at baseline (&gt;1.5× ULN). Maximal navitoclax dose of 300 mg was achieved in 23 pts (68%). Of the 25 (74%) pts that enrolled on ruxolitinib doses &gt;10 mg BID, 22 (88%) subsequently had the dose of ruxolitinib reduced to 10 mg BID. At the time of this analysis, 24 pts were evaluable for efficacy, with 20 pts completing ≥24 wk on study and 4 pts with Tx discontinuations prior to 24 wk. At wk 24, 7 of 24 pts (29%) achieved a spleen volume reduction of ≥35% (SVR35) from baseline by MRI as determined by prespecified central review; the median TSS was 7.4 (range 0-23), a 20% improvement from baseline. A SVR35 at any time on study was achieved in 10 pts (42%). Reductions in driver mutation allelic burden of &gt;5% were observed in 10 (42%) pts; 6 pts (25%) had BMF improvement of ≥1 grade. One pt (4%) had an anemia response; the mean Hgb at wk 24 was slightly improved over baseline at 11.3 g/dL. Of the 19 pts with elevated baseline WBC, 16 (84%) reduced to within normal limits during Tx, with a median WBC reduction of 17.7 × 109/L. All pts experienced a Tx-emergent adverse event (TEAE); most common (≥20%) were thrombocytopenia (82%), diarrhea (62%), fatigue (53%), anemia (27%), nausea (27%), contusion (24%), and vomiting (21%). Grade ≥3 TEAEs occurred in 26 pts (77%); most common were thrombocytopenia (n=15, 44%; Grade 4 n=1, 3%) and anemia (n=8, 24%; no Grade 4). Five pts (15%) experienced serious AEs that resolved including anemia, upper abdominal pain, vomiting, chest pain, increased C-reactive protein, and abnormal liver function test (3% each). There were no significant episodes of bleeding and no TEAE-related deaths. Conclusions: Navitoclax in combination with ruxolitinib was well tolerated with clinically meaningful spleen responses, allelic burden reductions, TSS improvements, and encouraging improvements in BMF in pts with MF who have received prior Tx with ruxolitinib. Disclosures Harrison: CTI: Speakers Bureau; Promedior: Honoraria; Roche: Honoraria; Celgene: Honoraria, Speakers Bureau; Gilead: Speakers Bureau; Shire: Speakers Bureau; Incyte: Speakers Bureau; Sierra Oncology: Honoraria; Janssen: Speakers Bureau. Garcia:Genentech: Research Funding; Abbvie: Research Funding. Mesa:CTI: Research Funding; Galena Biopharma: Consultancy; Samus: Research Funding; Genotech: Research Funding; AbbVie: Research Funding; NS Pharma: Research Funding; Baxalta: Consultancy; LaJolla: Consultancy; Shire: Honoraria; PharmaEssentia: Research Funding; Genentech: Consultancy; Celgene Corporation: Research Funding; AOP Orphan Pharmaceuticals: Honoraria, Other: travel, accommodations, expenses; Promedior: Research Funding; Novartis: Consultancy, Honoraria, Other: travel, accommodations, expenses; Incyte: Other: travel, accommodations, expenses, Research Funding; Gilead Sciences: Research Funding; Pfizer: Research Funding; Sierra Oncology: Consultancy. Somervaille:Novartis: Consultancy. Komrokji:pfizer: Consultancy; celgene: Consultancy; DSI: Consultancy; Incyte: Consultancy; Agios: Consultancy; JAZZ: Consultancy; Novartis: Speakers Bureau; JAZZ: Speakers Bureau. Pemmaraju:sagerstrong: Research Funding; celgene: Consultancy, Honoraria; Stemline Therapeutics: Consultancy, Honoraria, Research Funding; Daiichi-Sankyo: Research Funding; samus: Research Funding; novartis: Consultancy, Research Funding; plexxikon: Research Funding; incyte: Consultancy, Research Funding; abbvie: Consultancy, Honoraria, Research Funding; mustangbio: Consultancy, Research Funding; cellectis: Research Funding; affymetrix: Research Funding. Papadantonakis:Agios: Consultancy, Honoraria. Foran:Agios: Honoraria, Research Funding. O'Connell:Astex: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: 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; Shionogi: Membership on an entity's Board of Directors or advisory committees. Holes:AbbVie Inc: Employment, Other: Stock/stock options. Jia:AbbVie: Employment, Other: Stock/stock options. Harb:AbbVie Inc: Employment, Other: Stock/stock options. Hutti:AbbVie: Employment, Other: Stock/stock options.

With the development of modern solid-phase assays to detect anti-HLA antibodies and a more precise histological classification, the diagnosis of antibody-mediated rejection (AMR) has become more common and is a major cause of kidney graft loss. Currently, there are no approved therapies and treatment guidelines are based on low-level evidence. The number of prospective randomized trials for the treatment of AMR is small, and the lack of an accepted common standard for care has been an impediment to the development of new therapies. To help alleviate this, The Transplantation Society convened a meeting of international experts to develop a consensus as to what is appropriate treatment for active and chronic active AMR. The aim was to reach a consensus for standard of care treatment against which new therapies could be evaluated. At the meeting, the underlying biology of AMR, the criteria for diagnosis, the clinical phenotypes, and outcomes were discussed. The evidence for different treatments was reviewed, and a consensus for what is acceptable standard of care for the treatment of active and chronic active AMR was presented. While it was agreed that the aims of treatment are to preserve renal function, reduce histological injury, and reduce the titer of donor-specific antibody, there was no conclusive evidence to support any specific therapy. As a result, the treatment recommendations are largely based on expert opinion. It is acknowledged that properly conducted and powered clinical trials of biologically plausible agents are urgently needed to improve patient outcomes.