Citations

Abstract The metabolic signatures of cancer cells are often associated with elevated glycolysis which promotes alteration in cellular bioenergetics. 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), a critical control point in the glycolytic pathway has emerged as a potential anti-cancer target associated with many aspects of neoplastic progression. Pharmacological (PFK158 treatment) and genetic inhibition of PFKFB3 activity, decreases glucose uptake, ATP production, and lactate dehydrogenase activity and inhibits cell proliferation in vitro by arresting the cells in the G0/G1 phase induced cell death in malignant pleural mesothelioma (MPM). It induces an early response of increased macropinocytosis and drastic endosomal vacuolization to overcome the nutrient stress both in sarcomatoid (H28) and epithelioid (EMMeso) MPM cells. Inhibition of PFKFB3 leads to the activation of the endocytic Rac1-Rab5-Rab7 pathway resulting in a unique form of cell death called “methuosis”. Transmission Electron Microscopy analysis showed that pharmacological and genetic inhibition of PFKFB3 activity leads to the formation of nascent macropinocytotic vesicles, which rapidly coalesced to form large vacuoles with compromised lysosomal function. Confocal microscopy revealed F-actin and α-tubulin disassembly leading to the disruption of cell structure integrity. In parallel, PFKFB3 expression inversely modulates endoplasmic reticulum (ER) stress in MPM. Pharmacological and genetic inhibition of PFKFB3 led to an escalation in ER activity and aggravated ER stress mostly by upregulating BiP and GADD153 expression levels. However, EHT1864, a Rac1 inhibitor, could not rescue MPM cells from ER stress, suggesting that the activation of macropinocytosis and ER stress are a result of two independent PFKFB3 modulated adaptive responses. Both immunofluorescence microscopy and co-immunoprecipitation analyses revealed that the two crucial biomolecules of each pathway, Rac1 and Calnexin, interact with each other only at the later stages of PFKFB3 inhibition. Finally, PFK158, in a combination of with CBPt, demonstrated a significant reduction in tumor weight in mesothelin overexpressed EMMeso xenograft model. Since most cancer cells exhibit an increased glycolytic rate, these results provide evidence for PFK158, in combination with standard chemotherapy, may have a potential in the treatment of MPM. Citation Format: Sayantani Sarkar Bhattacharya, Ling Jin, Debarshi Roy, Deokbeom Jung, Prabhu Thirusangu, Yinan Xiao, Julie Staub, Julian Molina, Viji Shridhar. PFKFB3 inhibition reprograms malignant pleural mesothelioma to glycolytic stress-induced macropinocytosis and ER stress as independent binary adaptive responses [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2658.

Objective The hypertrophic cardiomyopathy (HCM) risk-sudden cardiac death (SCD) calculator endorsed by the 2014 European Society of Cardiology has not been independently validated in the Asians. We aimed to investigate whether the HCM Risk-SCD calculator effectively predicts SCD in Korean HCM population. Methods An observational, longitudinal cohort study was performed in 730 patients with HCM from 2007 to 2017. The primary endpoint was a composite of SCD and appropriate implantable cardioverter-defibrillator (ICD) therapy. Results During a follow-up period of 4288 person-years, 16 (2.2%) patients reached the primary endpoint. This validation study revealed a calibration slope of 0.892 and C-statistics of 0.718. The primary endpoint occurred in 1.1% (7/615), 4.6% (3/65) and 12.0% (6/50) of low-risk, intermediate-risk and high-risk groups, respectively. Although most patients (85.2%) without the primary endpoint were classified into the low-risk group, 7 of 11 SCD (63.6%) occurred in the low-risk group. In univariable and multivariable analysis, sex (woman) was significantly associated with the primary endpoint and emerged as independent predictor. The addition of sex to the HCM Risk-SCD calculator significantly improved the predictive value of the primary endpoint (net reclassification improvement 0.557, p=0.015). Conclusions In the Korean HCM population, the HCM Risk-SCD calculator had a high negative predictive value and accuracy for predicting SCD or appropriate ICD therapy, but misclassified a few patients experiencing the primary endpoint as low-risk or intermediate-risk groups.

Background and Purpose— Hypertrophic cardiomyopathy patients with atrial fibrillation are at increased risk of stroke, and anticoagulation is strongly recommended. However, limited data are available regarding the safety and effectiveness of non–vitamin K antagonist oral anticoagulants (NOACs) for primary prevention of stroke. Methods— Using the Korean Health Insurance Review and Assessment Service database, we identified 2397 patients with hypertrophic cardiomyopathy and nonvalvular atrial fibrillation on oral anticoagulation from 2013 to 2016 without history of ischemic stroke, intracranial hemorrhage (ICH), or gastrointestinal bleeding (992 on warfarin and 1405 on NOACs). Inverse probability of treatment weighting with propensity scores was used to balance covariates between treatment groups. Risk for ischemic stroke, ICH, gastrointestinal bleeding, death, and their composite outcome associated with NOAC use was assessed with warfarin use as the reference. Results— During a mean follow-up of 1.6 years, the incidence rates of ischemic stroke, ICH, gastrointestinal bleeding, death, and composite outcome were all significantly lower in the NOAC than in the warfarin group (stroke, 2.8 versus 5.0; ICH, 0.5 versus 1.3; gastrointestinal bleeding, 2.3 versus 3.0; death, 3.0 versus 5.1; composite, 7.5 versus 12.5 events per 100 person-years). NOACs were associated with significantly lower risks of ischemic stroke (hazard ratio [HR], 0.47; 95% CI, 0.32–0.68), ICH (HR, 0.31; 95% CI, 0.14–0.69), gastrointestinal bleeding (HR, 0.62; 95% CI, 0.40–0.96), death (HR, 0.45; 95% CI, 0.31–0.65), and the composite outcome (HR, 0.48; 95% CI, 0.38–0.61) than warfarin. The same trend was observed regardless of the NOAC dose and across various high-risk subgroups. In analysis of individual NOACs, all NOACs were associated with lower risks of ischemic stroke and composite outcome. Conclusions— NOACs showed superior effectiveness and safety versus warfarin in the primary prevention of stroke versus warfarin in real-world Asian hypertrophic cardiomyopathy with atrial fibrillation.

Background:Hereditary transthyretin amyloidosis (hATTR) is a rare protein misfolding disorder that causes progressive and debilitating polyneuropathy. A randomized, controlled phase 3 trial (NEURO‐TTR; NCT01737398) demonstrated efficacy and safety of inotersen in patients with hATTR polyneuropathy (Benson 2018 NEJM).Aims:To provide an update on the long‐term efficacy and safety of inotersen, an antisense oligonucleotide inhibitor of transthyretin protein production, in patients with hereditary transthyretin amyloidosis (hATTR) with polyneuropathy.Methods:Patients who completed NEURO‐TTR were eligible to enroll in an ongoing open‐label extension (OLE) study (NCT02175004). We report an update on the long‐term efficacy and safety of inotersen in patients with hATTR polyneuropathy after 24 months in the OLE. Assessments included modified Neuropathy Impairment Score +7 neurophysiologic tests composite score (mNIS+7), Norfolk Quality of Life–Diabetic Neuropathy questionnaire total score (Norfolk QoL‐DN), Short Form 36 Health Survey version 2 (SF‐36v2) physical component summary (PCS), and safety monitoring.Results:Of 139 patients who completed NEURO‐TTR, 135 (97.1%) enrolled in the OLE. As of 5/31/2018, some patients were ongoing but had not yet completed 24 months in the OLE, and longest inotersen exposure in both studies was 5.2 years. Patients who switched from placebo to inotersen in the OLE demonstrated slowing of neurologic disease progression by mNIS+7 and Norfolk QoL‐DN as early as 6 months after starting inotersen (mean change from OLE baseline to month 6/year 2: 6.22/5.08 for mNIS+7 and 0.54/2.26 for Norfolk QoL‐DN). Patients who received inotersen for 39 months (15 months NEURO‐TTR + 24 months OLE) continued to show benefit (mean change from OLE baseline to year 2: 11.18 for mNIS+7 and 5.22 for Norfolk QoL‐DN). Patients who continued inotersen also showed stabilization of health‐related quality of life measured by SF‐36v2 PCS. No evidence of increased risk for grade 4 thrombocytopenia or severe renal events has been observed with increased exposure duration; no new safety concerns have been identified.Summary/Conclusion:In the OLE, inotersen improved, halted, or slowed progression of hATTR polyneuropathy, with greater stabilization observed in patients who initiated inotersen earlier.

BackgroundThis multicenter, randomized phase 2 trial evaluated complete responses (CRs), efficacy, and safety with ofatumumab and bendamustine and with ofatumumab, bendamustine, and bortezomib in patients with untreated, high‐risk follicular lymphoma (FL).MethodsPatients with grade 1 to 3a FL and either a Follicular Lymphoma International Prognostic Index (FLIPI) score of 2 with 1 lymph node >6 cm or an FLIPI score of 3 to 5 were randomized to arm A (ofatumumab, bendamustine, and maintenance ofatumumab) or to arm B (ofatumumab, bendamustine, bortezomib, and maintenance ofatumumab and bortezomib).ResultsOne hundred twenty‐eight patients (66 in arm A and 62 in arm B) received treatment. The median age was 61 years, and 61% had disease >6 cm; 29% had an FLIPI score of 2, and 71% had an FLIPI score of 3 to 5. In arm A, 86% completed induction, and 64% completed maintenance. In arm B, 66% and 52% completed induction and maintenance, respectively. Dose modifications were required in 65% and 89% in arms A and B, respectively. Clinically significant grade 3 to 4 toxicities included neutropenia (A, 36%; B, 31%), nausea/vomiting (A, 0%; B, 8%), diarrhea (A, 5%; B, 11%), and sensory neuropathy (A, 0%; B, 5%). The estimated CR rates were 62% (95% confidence interval [CI], 50%‐74%) and 60% (95% CI, 47%‐72%) in arms A and B, respectively (P = .68). With a median follow‐up of 3.3 years, the estimated 2‐year progression‐free survival (PFS) and overall survival (OS) rates were 80% and 97%, respectively, for arm A and 76% and 91%, respectively, for arm B.ConclusionsThe CR rates, PFS, and OS were not improved with the addition of bortezomib to ofatumumab and bendamustine in patients with high‐risk FL. Although grade 3 to 4 toxicities were similar, more patients treated with bortezomib required dose modifications and early discontinuation.

1030 Background: Previous studies have shown that 44-71% of trastuzumab (T)-treated pts develop HER2-specific immunity (Clin Cancer Res 2007, 13:5133; Cancer Res 2016, 76:3702; Breast Cancer Res 2018, 20:52). M is an Fc-engineered mAb that shares similar HER2 binding and antiproliferative activity as T. The Fc region of M has been engineered for increased affinity to the activating FcγRIIIA (CD16A) and lower binding to the inhibitory FcγRIIB (CD32B), attributes that may enhance the mAb’s immune function, such as antigen presentation. Methods: HER2+ cancer pts who progressed on prior therapy received M (0.1-6 mg/kg QW for 3 of every 4 weeks [N = 34]; or 10-18 mg/kg Q3W [N = 32]) in phase 1 trial NCT01148849. PBMC and plasma were collected pre-dose and 50 days post-dose for 46 pts and > 4 years for 3 pts on long-term treatment. Response to HER2 or control antigens (Ag) was assessed by IFNγ ELISpot and antibody (Ab) ELISA. In 14 pts, T-cell antigen receptor (TCR) repertoire was assessed by immunosequencing. Results: Following M treatment, mean frequencies of IFNγ-producing T cells specific for intra- or extracellular fragments of HER2 increased by 2.5 to 6-fold (p < 0.0027, paired t test). Most (95%) of subjects responded to ≥2 of 6 (median = 5) HER2 Ag. Mean HER2-specific Ab concentration increased by 19-54% (p < 0.0001), with all subjects responding to ≥2 (median = 5) of the 6 Ag. A small 1.6-fold increase in IFNγ response to control CMV/EBV/Flu (but not tetanus or cyclin D1) peptides was observed; no increase in Ab response to control Ag was noted. Subsets of HER2-specific T-cell and Ab responses persisted during long-term treatment. Median TCR clonality increased by 54% (p = 0.003), with an average of 125 unique clones expanding, while overall TCR diversity remained unchanged (p = 0.19). Conclusions: Treatment of HER2+ cancer with M was associated with enhanced HER2-specific T-cell and Ab responses together with increased TCR clonality, indicative of a more focused T-cell repertoire. The high frequency of HER2-specific immunity in M-treated patients ( > 95%) is consistent with its enhanced Fc region contributing to linkage of innate and adaptive immune responses.