Abstract: Postoperative acute kidney injury (AKI) is a common complication of major gastrointestinal surgery with an impact on short- and long-term survival. No validated system for risk stratification exists for this patient group. This study aimed to validate externally a prognostic model for AKI after major gastrointestinal surgery in two multicentre cohort studies. Methods The Outcomes After Kidney injury in Surgery (OAKS) prognostic model was developed to predict risk of AKI in the 7 days after surgery using six routine datapoints (age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker). Validation was performed within two independent cohorts: a prospective multicentre, international study (‘IMAGINE’) of patients undergoing elective colorectal surgery (2018); and a retrospective regional cohort study (‘Tayside’) in major abdominal surgery (2011–2015). Multivariable logistic regression was used to predict risk of AKI, with multiple imputation used to account for data missing at random. Prognostic accuracy was assessed for patients at high risk (greater than 20 per cent) of postoperative AKI. Results In the validation cohorts, 12.9 per cent of patients (661 of 5106) in IMAGINE and 14.7 per cent (106 of 719 patients) in Tayside developed 7-day postoperative AKI. Using the OAKS model, 558 patients (9.6 per cent) were classified as high risk. Less than 10 per cent of patients classified as low-risk developed AKI in either cohort (negative predictive value greater than 0.9). Upon external validation, the OAKS model retained an area under the receiver operating characteristic (AUC) curve of range 0.655–0.681 (Tayside 95 per cent c.i. 0.596 to 0.714; IMAGINE 95 per cent c.i. 0.659 to 0.703), sensitivity values range 0.323–0.352 (IMAGINE 95 per cent c.i. 0.281 to 0.368; Tayside 95 per cent c.i. 0.253 to 0.461), and specificity range 0.881–0.890 (Tayside 95 per cent c.i. 0.853 to 0.905; IMAGINE 95 per cent c.i. 0.881 to 0.899). Conclusion The OAKS prognostic model can identify patients who are not at high risk of postoperative AKI after gastrointestinal surgery with high specificity. Presented to Association of Surgeons in Training (ASiT) International Conference 2018 (Edinburgh, UK), European Society of Coloproctology (ESCP) International Conference 2018 (Nice, France), SARS (Society of Academic and Research Surgery) 2020 (Virtual, UK).

Abstract: The intermediate-term impact of acute kidney injury (AKI) in patients after major gastrointestinal and liver surgery has not been well characterized. This study aimed to evaluate the 1-year mortality rate and renal outcomes associated with postoperative AKI in a national prospective cohort. Methods This prospective multicentre, observational cohort with 1-year postoperative follow-up included adults undergoing major gastrointestinal and liver surgery across the UK and Ireland between 23 September and 18 November 2015. AKI was defined according to Kidney Disease Improving Global Outcomes (KDIGO) criteria. The primary outcome was death at 1-year after surgery, and the secondary outcome was Major Adverse Kidney Events (MAKE-365). Cox proportionate and multilevel logistic regression were used to account for case mix. Results Of 5745 patients across 173 centres, 1-year follow-up data was completed for 3504 patients (62.2 per cent, 126 centres), with attrition largely explained by centre non-participation (63.1 per cent). Some 13.6 per cent (475 of 3504) patients developed AKI by 7 days after surgery (stage 1: 9.2 per cent; stage 2/3: 4.3 per cent). At 1 year, 10.8 per cent (378 patients) experienced a MAKE-365 endpoint (303 patients had died, 61 had renal replacement therapy and 78 had renal dysfunction). Patients who experienced AKI by 7 days after surgery had a higher hazard of death at 1 year for KDIGO stage 1 (hazard ratio 1.50 (95 per cent c.i. 1.08 to 2.08), P = 0.016) and KDIGO stage 2/3 (hazard ratio 2.96 (95 per cent c.i. 2.02 to 4.33), P & lt; 0.001). Both KDIGO stage 1 (odds ratio 2.09 (95 per cent c.i. 1.50 to 2.92), P & lt; 0.001) and stage 2/3 (odds ratio 9.26 (95 per cent c.i. 6.31 to 13.59), P & lt; 0.001) AKI were independently associated with MAKE-365. Conclusion AKI events within 7 days after gastrointestinal or liver surgery are associated with significantly worse survival and renal outcomes at 1 year.

Abstract: Current genome-wide association studies of ischemic stroke have focused primarily on late-onset disease. As a complement to these studies, we sought to identify the contribution of common genetic variants to risk of early-onset ischemic stroke. Methods We performed a meta-analysis of genome-wide association studies of early-onset stroke (EOS), ages 18–59 years, using individual-level data or summary statistics in 16,730 cases and 599,237 nonstroke controls obtained across 48 different studies. We further compared effect sizes at associated loci between EOS and late-onset stroke (LOS) and compared polygenic risk scores (PRS) for venous thromboembolism (VTE) between EOS and LOS. Results We observed genome-wide significant associations of EOS with 2 variants in ABO , a known stroke locus. These variants tag blood subgroups O1 and A1, and the effect sizes of both variants were significantly larger in EOS compared with LOS. The odds ratio (OR) for rs529565, tagging O1, was 0.88 (95% confidence interval [CI]: 0.85–0.91) in EOS vs 0.96 (95% CI: 0.92–1.00) in LOS, and the OR for rs635634, tagging A1, was 1.16 (1.11–1.21) for EOS vs 1.05 (0.99–1.11) in LOS; p -values for interaction = 0.001 and 0.005, respectively. Using PRSs, we observed that greater genetic risk for VTE, another prothrombotic condition, was more strongly associated with EOS compared with LOS ( p = 0.008). Discussion The ABO locus, genetically predicted blood group A, and higher genetic propensity for venous thrombosis are more strongly associated with EOS than with LOS, supporting a stronger role of prothrombotic factors in EOS.

Abstract: Background: Umbralisib is an oral, once-daily, dual inhibitor of phosphatidylinositol-3-kinase-delta (PI3Kδ) and casein kinase-1ε (CK1ε) that exhibits improved selectivity for the delta isoform of PI3K. The UNITY-NHL trial (NCT02793583) is a multicenter, open-label, registration directed Phase 2 study designed to evaluate the safety and efficacy of umbralisib in previously treated NHL patients (pts). Previously reported results in pts with relapsed/refractory (R/R) marginal zone lymphoma (MZL) demonstrated that umbralisib was active with a manageable safety profile. In contrast with other PI3K inhibitors, there was a low incidence of immune-mediated toxicities with umbralisib, possibly attributable to enhanced selectivity for the PI3Kδ isoform as well as inhibition of CK1ε. Herein, we present results from the final analysis of the iNHL population treated with single agent umbralisib. Methods: Eligible pts had histologically confirmed iNHL: MZL (splenic, nodal, extranodal), follicular lymphoma (FL; Gr 1, 2, 3a), or small lymphocytic lymphoma (SLL). MZL pts were R/R to ≥1 prior lines of treatment, which must have included an anti-CD20, while FL and SLL pts were R/R to ≥2 prior lines, which had to include an anti-CD20 and an alkylating agent. Umbralisib was administered orally at 800 mg once-daily in 28-day treatment cycles until disease progression or unacceptable tolerability. The primary endpoint of the study was overall response rate (ORR) as assessed by an independent review committee (IRC), according to the revised IWG criteria (Cheson 2007). Secondary endpoints included duration of response (DoR), progression-free survival (PFS), time to response (TTR), and safety. Pneumocystis jiroveci pneumonia (PCP) and anti-viral prophylaxis were mandated for all pts. Results: 208 iNHL pts received at least 1 dose of umbralisib, including 69 MZL, 117 FL, and 22 SLL pts. The median duration of exposure was 8.4 mos (range 0.2 - 27.0), median age was 66, and 56.7% were male. Pts had received a median of 2 prior regimens (range 1 - 10) with 46.1% having received ≥ 3 regimens. FL patients had a median of 3 prior regimens. With a median follow up of 27.8 mos, MZL pts had an ORR of 49.3% (95% CI 37.0% - 61.6%) with 15.9% achieving a complete response (CR), and a Disease Control Rate (DCR: CR+PR+SD) of 82.6%. ORR was consistent amongst MZL subtypes. The median TTR was 2.8 months (95% CI 2.7 - 2.9). The median profession-free survival (PFS) was not reached (95% CI 12.1 mos - not evaluable [NE] ) with an estimated 12-month PFS rate of 64.2%. The median DoR was not reached (95% CI 10.3 mos - NE), and no pts who achieved CR have experienced disease progression to date. With a median follow up of 27.5 mos, FL pts had an ORR of 45.3% (95% CI 36.1% - 54.8%) with 5.1% achieving a CR, and a DCR of 79.5%. The median TTR was 4.6 mos (95% CI 3.0 - 5.6). The median PFS was 10.6 mos (95% CI 7.2 - 13.7) with an estimated 12-month PFS rate of 45.9%. The median DoR was 11.1 mos (95% CI 8.3 - 15.6). With a median follow up of 29.3 mos, SLL pts had an ORR of 50.0% (95% CI 28.2 - 71.8) with 4.5% achieving a CR, and a DCR of 86.4%. The median TTR was 2.7 mos (95% CI 2.4 - 2.8). The median PFS was 20.9 mos (95% CI 7.4 - 24.1) with an estimated 12-month PFS rate of 62.6%. The median DoR was 18.3 mos (95% CI 2.4 - NE). Best % change in target lesions form baseline for pts with at least one post-baseline assessment is shown in the figure. At the data cut-off, 60 pts (26 MZL, 27 FL, 7 SLL) remained on treatment. The most common ≥G3 AEs were neutropenia (11.5%), diarrhea (10.1%) and increased ALT/AST (7.2%). Other AEs of interest included pneumonitis (All G 1.4%; ≥G3 1.0%), and colitis (All G 1.4%; ≥G3 0.5%). Serious AEs were reported in 28.1% of pts, with 24.6% ≥G3. One patient with SLL had a fatal myocardial infarction (unrelated to umbralisib); there were no other G5 AEs. A total of 31 pts (14.9%) discontinued due a treatment-related adverse event (AE). Treatment-related AEs leading to dose reductions occurred in 20 (9.6%) pts. Conclusions: In the Phase 2 UNITY-NHL study, umbralisib achieved meaningful clinical activity in a heavily pretreated iNHL population. The safety profile was manageable, with a relatively low incidence of immune-mediated toxicities and AE-related discontinuations. These results suggest umbralisib has a favorable benefit-risk profile in this patient population and further development is ongoing. Figure Disclosures Zinzani: Kirin Kyowa: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Consultancy, Speakers Bureau; MSD: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ADC Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Eusapharma: Consultancy, Speakers Bureau; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics, Inc.: Honoraria, Speakers Bureau; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; EUSA Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Jurczak:Sandoz-Novartis: Consultancy; Afimed: Research Funding; Acerta: Consultancy, Research Funding; Pharmacyclics: Research Funding; Bayer: Research Funding; Maria Sklodowska-Curie National Research Institute of Oncology, Krakow, Poland: Current Employment; TG Therapeutics, Inc.: Research Funding; Celgene: Research Funding; Servier: Research Funding; Takeda: Research Funding; Roche: Research Funding; Merck: Research Funding; MEI Pharma: Research Funding; Janssen China R & D: Consultancy, Research Funding; BeiGene: Consultancy, Research Funding; AstraZeneca: Consultancy; European Medicines Agency,: Consultancy; Jagiellonian University, Krakow, Poland: Ended employment in the past 24 months; Epizyme: Consultancy; Gilead Sciences: Research Funding; MorphoSys: Research Funding; Nordic Nanovector: Research Funding. Ghosh:Kite/Gilead: Consultancy, Speakers Bureau; Juno/Celgene/Bristol-Myers Squibb: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding, Speakers Bureau; SGN: Consultancy, Research Funding, Speakers Bureau; TG Therapeutics: Consultancy, Research Funding; Roche/Genentech: Research Funding; Karyopharm: Consultancy; Genmab: Consultancy, Speakers Bureau; AbbVie: Speakers Bureau; AstraZeneca: Speakers Bureau; Celgene/Bristol-Myers Squibb: Speakers Bureau; Forty Seven Inc: Consultancy, Other: Research Bureau, Research Funding; Janssen: Consultancy, Research Funding, Speakers Bureau. Derenzini:TG Therapeutics, Inc.: Research Funding. Cheah:Celgene, F. Hoffmann-La Roche, MSD, Janssen, Gilead, Ascentage Pharma, Acerta, Loxo Oncology, TG therapeutics: Honoraria; Celgene, F. Hoffmann-La Roche, Abbvie, MSD: Research Funding. Phillips:Karyopharm: Consultancy; Beigene: Consultancy; Seattle Genetics: Consultancy; BMS: Consultancy; Abbvie: Consultancy, Research Funding; AstraZeneca: Consultancy; Incyte: Consultancy, Other: travel expenses; Cardinal Health: Consultancy; Bayer: Consultancy, Research Funding; Pharmacyclics: Consultancy. Lech-Marańda:Roche, Amgen, Gilead: Speakers Bureau; Roche, Novartis, Takeda, Janssen-Cilag, Amgen, Gilead, AbbVie, Sanofi: Consultancy. Cheson:Abbvie: Consultancy, Research Funding; Kite: Consultancy; TG Therapeutics: Speakers Bureau; Morphosys: Consultancy; Symbio: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Research Funding; Jannsen: Consultancy; Parexel: Consultancy; Trillium: Research Funding; GSK: Membership on an entity's Board of Directors or advisory committees. Caimi:Verastem: Other: Advisory Board; Celgene: Speakers Bureau; Amgen: Other: Advisory Board; Bayer: Other: Advisory Board; Kite Pharma: Other: Advisory Board; ADC Therapeutics: Other: Advisory Board, Research Funding. Leslie:BeiGene: Honoraria, Speakers Bureau; KitePharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Speakers Bureau; Celgene: Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics: 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; ADC therapeutics: 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; Karyopharm: Honoraria, Speakers Bureau; Epizyme: Honoraria, Speakers Bureau; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Chavez:Karyopharm: Consultancy; BeiGene: Speakers Bureau; Bayer: Consultancy; Merck: Research Funding; AbbVie: Consultancy; Genentech: Speakers Bureau; Epizyme: Speakers Bureau; Gilead: Consultancy; Novartis: Consultancy; Kite, a Gilead Company: Consultancy, Speakers Bureau; Celgene: Consultancy; Morphosys: Consultancy, Speakers Bureau; AstraZeneca: Speakers Bureau; Verastem: Consultancy; Pfizer: Consultancy. Fonseca:Bristol-Myers Squibb Company: Speakers Bureau. Babu:Merck: Research Funding; Syndax: Research Funding; AbbVie: Research Funding; Janssen Oncology: Research Funding; TG Therapeutics: Research Funding; Amgen: Research Funding; Sanofi: Research Funding; Lutheran Hospital: Other; Argenx: Consultancy, Research Funding; Nektar: Research Funding; Novartis: Research Funding; Bayer: Honoraria; Lilly: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Alexion Pharmaceuticals: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Fort Wayne Medical Oncology & Hematology: Current Employment, Current equity holder in publicly-traded company; AstraZeneca/MedImmune: Research Funding; AstraZeneca: Consultancy, Honoraria; Genentech, Inc./ F. Hoffmann-La Roche: Research Funding; Boehringer Ingelheim: Consultancy. Hodson:Gilead Sciences: Research Funding. Burke:Bristol Myers Squibb: Consultancy; Verastem: Consultancy; Bayer: Consultancy; Astra Zeneca: Consultancy; Gilead: Consultancy; Seattle Genetics: Speakers Bureau; AbbVie: Consultancy; Morphosys: Consultancy; Adaptive: Consultancy; Epizyme: Consultancy; Kura: Consultancy; Celgene: Consultancy; Adaptive Biotechnologies: Consultancy; Roche: Consultancy. Sharman:TG Therapeutics: Consultancy, Research Funding; Bristol Meyers Squibb: Consultancy, Research Funding; BeiGene: Research Funding; Genentech: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Acerta: Consultancy, Research Funding; Roche: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. O'Connor:Kymera Therapeutics: Current equity holder in private company, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Other: Data Safety Monitoring Committee, Research Funding; TG Therapeutics: Current Employment, Current equity holder in publicly-traded company; Servier: Consultancy; Mundipharma: Other: Consulting; Nomocan: Membership on an entity's Board of Directors or advisory committees; Merck: Research Funding; Astex Pharmaceuticals: Honoraria, Research Funding. Miskin:TG Therapeutics, Inc.: Current Employment, Current equity holder in publicly-traded company. Sportelli:TG Therapeutics, Inc.: Current Employment, Current equity holder in publicly-traded company. Weiss:TG Therapeutics, Inc.: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Fowler:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; TG 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, Research Funding.

Abstract: Our group has demonstrated that combinations of epigenetic modifiers produce potent synergy in pre-clinical models of PTCL, and has confirmed this data in early phase clinical studies. We showed that the combination of romidepsin and hypomethylating agents, decitabine or azacytidine, uniquely induces the expression of genes, including cancer testis antigens, gamma interferon and endogenous retrovirus. We are conducting a phase 1 study of pembrolizumab combined with pralatrexate alone (Arm A), with pralatrexate + decitabine (Arm B), or decitabine alone (Arm C) in patients with peripheral T-cell lymphoma (PTCL) and cutaneous T-cell lymphoma. In addition, we are conducting a Phase 1/2A study of durvalumab combined with oral 5-azacitidine + romidepsin (Arm A), pralatrexate + romidepsin (Arm B), romidepsin (Arm C), or oral 5-azacitidine (Arm D) in patients with PTCL. Patient characteristics are listed in Table 1. We have treated a total of 12 patients across the 2 trials and 4 different Arms including pralatrexate plus pembrolizumab (3 patients), pralatrexate, decitabine and pembrolizumab (3 patients), decitabine and pembrolizumab (3 patients) and azacytidine, romidepsin and durvalumab (3 patients). Twelve patients out of 12 received at least one dose of drug and were evaluable for toxicity. There was a dose limiting toxicity (DLT) for each arm including prolonged grade 3 thrombocytopenia, febrile neutropenia, grade 3 hyponatremia and rash, and cytokine release syndrome, respectively. There were no treatment-related deaths. Eight patients out of 12 are evaluable for response at the time of this analysis. Three out of 8 patients achieved a complete remission, 3 out of 8 patients had a partial remission, and 2 out of 8 patients experienced progression of disease. Interestingly, all of the responses were seen in the triple combination of pralatrexate, decitabine, pembrolizumab and azacytidine, romidepsin and durvalumab. These preliminary clinical data suggest that the addition of immune-checkpoint inhibitors on an epigenetic backbone is safe and demonstrates encouraging responses in patient with PTCL and CTCL. These trials are registered at www.clinicaltrials.gov (NCT03240211, NCT03161223). Patient characteristics (n=12)Median age (range)68 (26-77)Sex, n (%) Male Female6 (50) 6 (50)Race, n (%)White/Non-Hispanic White/Hispanic Black Asian Unknown5 (42) 1 (8) 3 (25) 1 (8) 2 (17)Histology, n (%) PTCL, NOS AITL Mycosis Fungoides PTCL, NOS TFH ATLL Sezary Syndrome ALCL, ALK+2 (17) 2 (17) 2 (17) 1 (8) 1 (8) 1 (8) 1 (8)Stage at diagnosis IB II III IV Unknown1 (8) 2 (17) 3 (25) 4 (33) 2 (17)Median number of prior therapies (range) **2 unknown3 (0-5) Citation Format: Enrica Marchi, Helen Ma, Francesca Montanari, Ahmed Sawas, Jennifer K. Lue, Changchun Deng, Kareema T. Whitfield, Sandra Klein, Matthew V. Matthew, Freedy J. Loffredo, Luigi Scotto, Hyejung Lee, Hye A. Kim, Alice T. Jacobs, Aishling M. Rada, Karen A. Khan, Salvia Salvia, John Lister, Nora N. Benanni, Mark A. Francescone, Pier Luigi Zinzani, Wonseog Kim, Owen A. O'Connor. The integration of PD1 blockade with epigenetic therapy is highly active and safe in heavily treated patients with T-cell lymphoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT160.

Abstract: Mantle cell lymphoma (MCL) is an aggressive B-cell malignancy with a median survival of 3 years despite chemoimmunotherapy. Rituximab, a chimeric anti–CD20 monoclonal antibody (mAb), has shown only modest activity as single agent in MCL. The humanized mAb milatuzumab targets CD74, an integral membrane protein linked with promotion of B-cell growth and survival, and has shown preclinical activity against B-cell malignancies. Because rituximab and milatuzumab target distinct antigens and potentially signal through different pathways, we explored a preclinical combination strategy in MCL. Treatment of MCL cell lines and primary tumor cells with immobilized milatuzumab and rituximab resulted in rapid cell death, radical oxygen species generation, and loss of mitochondrial membrane potential. Cytoskeletal distrupting agents significantly reduced formation of CD20/CD74 aggregates, cell adhesion, and cell death, highlighting the importance of actin microfilaments in rituximab/milatuzumab–mediated cell death. Cell death was independent of caspase activation, Bcl-2 family proteins or modulation of autophagy. Maximal inhibition of p65 nuclear translocation was observed with combination treatment, indicating disruption of the NF-κB pathway. Significant in vivo therapeutic activity of combination rituximab and milatuzumab was demonstrated in a preclinical model of MCL. These data support clinical evaluation of combination milatuzumab and rituximab therapy in MCL.

Abstract: In studies of diffuse large B-cell lymphoma, positron emission tomography with [ 18 F]fluorodeoxyglucose (FDG-PET) performed after two to four cycles of chemotherapy has demonstrated prognostic significance. However, some patients treated with immunochemotherapy experience a favorable long-term outcome despite a positive interim FDG-PET scan. To clarify the significance of interim F DG-PET scans, we prospectively studied interim FDG-positive disease within a risk-adapted sequential immunochemotherapy program. Patients and Methods From March 2002 to November 2006, 98 patients at Memorial Sloan-Kettering Cancer Center received induction therapy with four cycles of accelerated R-CHOP (rituximab + cyclophosphamide, doxorubicin, vincristine, and prednisone) followed by an interim FDG-PET scan. If the FDG-PET scan was negative, patients received three cycles of ICE (ifosfamide, carboplatin, and etoposide) consolidation therapy. If residual FDG-positive disease was seen, patients underwent biopsy; if the biopsy was negative, they also received three cycles of ICE. Patients with a positive biopsy received ICE followed by autologous stem-cell transplantation. Results At a median follow-up of 44 months, overall and progression-free survival were 90% and 79%, respectively. Ninety-seven patients underwent interim FDG-PET scans; 59 had a negative scan, 51 of whom are progression free. Thirty-eight patients with FDG-PET–positive disease underwent repeat biopsy; 33 were negative, and 26 remain progression free after ICE consolidation therapy. Progression-free survival of interim FDG-PET–positive/biopsy-negative patients was identical to that in patients with a negative interim FDG-PET scan (P = .27). Conclusion Interim or post-treatment FDG-PET evaluation did not predict outcome with this dose-dense, sequential immunochemotherapy program. Outside of a clinical trial, we recommend biopsy confirmation of an abnormal interim FDG-PET scan before changing therapy.

Abstract: Vitamin C is an antioxidant vitamin that has been hypothesized to antagonize the effects of antineoplastic drugs that generate reactive oxygen species. Leukemia (K562) and lymphoma (RL) cells pre-treated with dehydroascorbic acid, the commonly transported form of vitamin C, demonstrated a dose-dependent attenuation of cytotoxicity after treatment with the widely-used antineoplastic drugs, doxorubicin, cisplatin, vincristine, methotrexate and imatinib that ranged from 30–80% as measured by trypan blue exclusion and colony formation in methylcellulose. While treatment with vitamin C alone did not appreciably alter tumor growth compared with untreated mice with xenogeneic tumors (RL) (p=0.114), mice treated with vitamin C prior to doxorubicin administration had tumors that were, on average, four times larger than tumors in mice treated with doxorubicin alone (p=0.01) at day 32 of treatment. This result indicates that vitamin C treatment can attenuate antineoplastic therapy in vivo. Pretreatment of cells with vitamin C led to a dose-dependent decrease in apoptosis with all agents tested. At the highest concentrations of intracellular vitamin C, the decrease in apoptosis ranged from 37–82% as measured by TUNEL. There was no change in P-glycoprotein expression in vitamin C-treated cells and no difference in doxorubicin concentrations in the tumors of vitamin C-treated mice suggesting that the inhibitory effects of vitamin C are not due to generalized effects of antineoplastic drug uptake or efflux. When K562 and RL cells were treated with antineoplastic agents, we found that, as has been previously reported, doxorubicin and, to a lesser extent, cisplatin, increased the intracellular levels of ROS, while other agents had little discernible effect on ROS levels. In cells treated with chemotherapeutic drugs, as well as in untreated cells, pretreatment of cells with vitamin C caused a small ( & lt;15%) reduction in intracellular levels of ROS. This modest reduction in intracellular ROS levels appeared to be minor in comparison to the reduction in cytotoxicity. While treatment with N-acetylcysteine only attenuated the cytotoxic effects of cisplatin, vitamin C pretreatment attenuated the effects of all drugs tested, suggesting a distinct mechanism of action. We found that all of the antineoplastic agents tested caused rapid mitochondrial membrane depolarization. Treatment with vitamin C prior to exposure to antineoplastic agents prevented mitochondrial membrane depolarization. Mitochondrial membrane potentials in vitamin C-treated cells 6 hr after treatment with chemotherapeutic drugs were similar to untreated control cells (p & lt;0.003). A mitochondrial site of action was further supported by the finding that vitamin C antagonizes the cytotoxic effects of actinonin, an inhibitor of peptide deformylase. These findings suggest that vitamin C supplementation during cancer treatment may detrimentally affect therapeutic response to a broad range of anti-cancer drugs and point to preserved mitochondrial membrane potential as a mechanism of action.