Citations

611 Background: Regorafenib is an oral multikinase inhibitor with survival benefit in refractory mCRC patients (pts). Toxicities such as Palmar-plantar erythrodysesthesia syndrome (PPES), fatigue and hypertension (HTN) have limited its use. Despite absence of supportive data, various dosing or interval scheduling have been implemented into clinical practice. Methods: A randomized phase II study of regorafenib dose-escalation (Arm A: 80 mg/day, weekly dose escalation if no significant drug-related toxicities, up to 160 mg/day) vs. standard dose (Arm B: 160 mg/day) in pts with mCRC for 21 days of a 28-day cycle. Pts were randomized 1:1:1:1 to arms A1 and B1 (Pre-emptive Clobetasol for PPES); A2 and B2 (Reactive Clobetasol). The primary endpoint was the proportion of patients who completed 2 cycles of treatment and initiated the 3rd in Arm A (Pooled A1 + A2) vs. Arm B (Pooled B1 + B2). Superiority for Arm A was to be declared if the one-sided p-value calculated using Fisher’s exact method was less than 0.2. Results: From June 2015 to June 2017, 123 pts were randomized with 116 (A = 54, B = 62) evaluable for the primary endpoint. Demographic data were well balanced with overall median age of 61yrs (range: 29-81), M/F (61/39%) and ECOG PS 0/1 (37/63%) and KRAS MT/WT/UNK (47/44/9%).The study met its primary endpoint with 43% of pts on Arm A initiating the 3rd vs. only 25% of pts Arm B [one-sided p-value 0.028]. Median Overall Survival (OS) was improved in Arm A vs. Arm B (9.0 mos vs. 5.9 mos; p = 0.094). Median Progression Free Survival (PFS) was 2.5 mos for Arm A vs. 2.0 mos for Arm B (p=0.553). Overall rates of grade 3/4 toxicity were more favorable for Arm A vs. Arm B (% PPES 15 vs. 16, HTN 7 vs. 15 and fatigue 13 vs. 18, respectively). Multiple QOL parameters were improved in A vs. B primarily at week 2 of the first cycle. Conclusion: A strategy with weekly dose escalation of regorafenib from 80 mg to 160 mg/day was found to be superior to a starting dose of 160 mg/day. These results establish a new standard for optimizing regorafenib dosing. Further data on outcomes of preemptive vs. reactive clobetasol strategies are undergoing analysis and will be presented later. Clinical trial information: NCT02368886.

When vertebrates face acute stressors, their bodies rapidly undergo a repertoire of physiological and behavioral adaptations, which is termed the stress response. Rapid changes in heart rate and blood glucose levels occur via the interaction of glucocorticoids and their cognate receptors following hypothalamic‐pituitary‐adrenal axis activation. These physiological changes are observed within minutes of encountering a stressor and the rapid time domain rules out genomic responses that require gene expression changes. Although behavioral changes corresponding to physiological changes are commonly observed, it is not clearly understood to what extent hypothalamic‐pituitary‐adrenal axis activation dictates adaptive behavior. We hypothesized that rapid locomotor response to acute stressors in zebrafish requires hypothalamic‐pituitary‐interrenal (HPI) axis activation. In teleost fish, interrenal cells are functionally homologous to the adrenocortical layer. We derived eight frameshift mutants in genes involved in HPI axis function: two mutants in exon 2 ofmc2r(adrenocorticotropic hormone receptor), five in exon 2 or 5 ofnr3c1(glucocorticoid receptor [GR]) and two in exon 2 ofnr3c2(mineralocorticoid receptor [MR]). Exposing larval zebrafish to mild environmental stressors, acute changes in salinity or light illumination, results in a rapid locomotor response. We show that this locomotor response requires a functioning HPI axis via the action ofmc2rand the canonical GR encoded bynr3c1gene, but not MR (nr3c2). Our rapid behavioral assay paradigm based on HPI axis biology can be used to screen for genetic and environmental modifiers of the hypothalamic‐pituitary‐adrenal axis and to investigate the effects of corticosteroids and their cognate receptor interactions on behavior.

Abstract Background: There have been few studies of sufficient size to address the relationship between glioma risk and the use of aspirin or NSAIDs, and results have been conflicting. The purpose of this study was to examine the associations between glioma and aspirin/NSAID use, and to aggregate these findings with prior published studies using meta-analysis. Methods: The Glioma International Case-Control Study (GICC) consists of 4,533 glioma cases and 4,171 controls recruited from 2010 to 2013. Interviews were conducted using a standardized questionnaire to obtain information on aspirin/NSAID use. We examined history of regular use for ≥6 months and duration-response. Restricted maximum likelihood meta-regression models were used to aggregate site-specific estimates, and to combine GICC estimates with previously published studies. Results: A history of daily aspirin use for ≥6 months was associated with a 38% lower glioma risk, compared with not having a history of daily use [adjusted meta-OR = 0.62; 95% confidence interval (CI), 0.54–0.70]. There was a significant duration-response trend (P = 1.67 × 10−17), with lower ORs for increasing duration of aspirin use. Duration-response trends were not observed for NSAID use. In the meta-analysis aggregating GICC data with five previous studies, there was a marginally significant association between use of aspirin and glioma (mOR = 0.84; 95% CI, 0.70–1.02), but no association for NSAID use. Conclusions: Our study suggests that aspirin may be associated with a reduced risk of glioma. Impact: These results imply that aspirin use may be associated with decreased glioma risk. Further research examining the association between aspirin use and glioma risk is warranted.

AbstractBackgroundOvercoming β-lactam resistance in pathogens such as Pseudomonas aeruginosa is a major clinical challenge. Rapid molecular diagnostics (RMDs) have the potential to inform selection of empiric therapy in patients infected by P. aeruginosa.MethodsIn this study, we used a heterogeneous collection of 197 P. aeruginosa that included multidrug-resistant isolates to determine whether 2 representative RMDs (Acuitas Resistome test and VERIGENE gram-negative blood culture test) could identify susceptibility to 2 newer β-lactam/β-lactamase inhibitor (BL-BLI) combinations, ceftazidime/avibactam (CZA) and ceftolozane/tazobactam (TOL/TAZO).ResultsWe found that the studied RMD platforms were able to correctly identify BL-BLI susceptibility (susceptibility sensitivity, 100%; 95% confidence interval [CI], 97%, 100%) for both BLs-BLIs. However, their ability to detect resistance to these BLs-BLIs was lower (resistance sensitivity, 66%; 95% CI, 52%, 78% for TOL/TAZO and 33%; 95% CI, 20%, 49% for CZA).ConclusionsThe diagnostic platforms studied showed the most potential in scenarios where a resistance gene was detected or in scenarios where a resistance gene was not detected and the prevalence of resistance to TOL/TAZO or CZA is known to be low. Clinicians need to be mindful of the benefits and risks that result from empiric treatment decisions that are based on resistance gene detection in P. aeruginosa, acknowledging that such decisions are impacted by the prevalence of resistance, which varies temporally and geographically.

6520 Background: Breast cancer follow-up guidelines recommend imaging for distant metastases only in the presence of signs/symptoms. However, data supporting this recommendation predates the current era of improved imaging and targeted therapies based on molecular subtype. The objective was to assess the relationship between mode of distant recurrence detection and survival. Methods: A stage-stratified random sample of Stage II-III breast cancer patients diagnosed in 2006-7 was selected from NCDB records from 1,217 CoC-accredited facilities (10/hospital n = 10,853). Women were categorized by subtype: 1) ER or PR+/HER2-; 2) ER and PR-/Her2- (triple negative); 3) HER2+. Medical records abstracted for 5-years post-surgery supplemented NCDB data and assessed distant recurrence and mode of detection (prompted by signs/symptoms or surveillance imaging), imaging (chest CT, abdomen/pelvis CT/MRI, head CT/MRI, bone scan, PET/CT), death date. The relationship between mode of recurrence detection and days from initial cancer diagnosis to death was assessed using propensity-weighted multivariable Cox proportional hazards regression stratified by subtype. Propensity weights, based on receipt of surveillance systemic imaging, accounted for sociodemographic and tumor/treatment factors. Results: 5-year distant recurrence was 22.3% for triple negative, 14.8% HER2+, and 11.2% for ER or PR+/ HER2- patients. Asymptomatic imaging detected recurrence in 22.9% and signs/symptoms in 77.1%. Patients with asymptomatic as compared to sign/symptom detected recurrences had reduced risk of death in 5 years if triple negative (HR = 0.68, 95% CI = 0.50-0.93) or HER2+ (HR = 0.40, 95% CI = 0.24-0.65) with no significant association for ER or PR+/HER2- (HR = 1.2, 95% CI = 0.88-1.51). This translated to a between-group difference in weighted median survival of 5 months for triple negative and 13 months for HER2+ patients. Conclusions: This is the first nationally representative study to show a survival advantage with asymptomatic detection of distant metastases for patients, with the benefit limited to triple negative and HER2+ disease. Further research to confirm observational findings is warranted.