A Phase 2a cohort expansion study to assess the safety, tolerability, and preliminary efficacy of CXD101 in patients with advanced solid-organ cancer expressing HR23B or lymphoma.

BACKGROUND: This Phase 2a dose expansion study was performed to assess the safety, tolerability and preliminary efficacy of the maximum tolerated dose of the oral histone de-acetylase (HDAC) inhibitor CXD101 in patients with relapsed / refractory lymphoma or advanced solid organ cancers and to assess HR23B protein expression by immunohistochemistry as a biomarker of HDAC inhibitor sensitivity. METHODS: Patients with advanced solid-organ cancers with high HR23B expression or lymphomas received CXD101 at the recommended phase 2 dose (RP2D). Key exclusions: corrected QT > 450 ms, neutrophils < 1.5 × 109/L, platelets < 75 × 109/L, ECOG > 1. Baseline HR23B expression was assessed by immunohistochemistry. RESULTS: Fifty-one patients enrolled between March 2014 and September 2019, 47 received CXD101 (19 solid-organ cancer, 28 lymphoma). Thirty-four patients received ≥80% RP2D. Baseline characteristics: median age 57.4 years, median prior lines 3, male sex 57%. The most common grade 3-4 adverse events were neutropenia (32%), thrombocytopenia (17%), anaemia (13%), and fatigue (9%) with no deaths on CXD101. No responses were seen in solid-organ cancers, with disease stabilisation in 36% or patients; the overall response rate in lymphoma was 17% with disease stabilisation in 52% of patients. Median progression-free survival was 1.2 months (95% confidence interval (CI) 1.2-5.4) in solid-organ cancers and 2.6 months (95%CI 1.2-5.6) in lymphomas. HR23B status did not predict response. CONCLUSIONS: CXD101 showed acceptable tolerability with efficacy seen in Hodgkin lymphoma, T-cell lymphoma and follicular lymphoma. Further studies assessing combination approaches are warranted. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01977638 . Registered 07 November 2013.

Arrhythmogenic substrate and its modification by nicorandil in a murine model of long QT type 3 syndrome.

The gain-of-function Scn5a+/DeltaKPQ mutation in the cardiac Na(+) channel causes human long QT type 3 syndrome (LQT3) associated with ventricular arrhythmogenesis. The K(ATP) channel-opener nicorandil (20muM) significantly reduced arrhythmic incidence in Langendorff-perfused Scn5a+/Delta hearts during programmed electrical stimulation; wild-types (WTs) showed a total absence of arrhythmogenicity. These observations precisely correlated with alterations in recently established criteria for re-entrant excitation reflected in: (1) shortened left-ventricular epicardial but not endocardial monophasic action potential durations at 90% repolarization (APD(90)) that (2) restored transmural repolarization gradients, DeltaAPD(90). Scn5a+/Delta hearts showed longer epicardial but not endocardial APD(90)s, giving shorter DeltaAPD(90)s than WT hearts. Nicorandil reduced epicardial APD(90) in both Scn5a+/Delta and WT hearts thereby increasing DeltaAPD(90). (3) Reduced epicardial critical intervals for re-excitation; Scn5a+/Delta hearts showed greater differences between APD(90) and ventricular effective refractory period than WT hearts that were reduced by nicorandil. (4) Reduced APD(90) alternans. Scn5a+/Delta hearts showed greater epicardial and endocardial alternans than WTs, which increased with pacing rate. Nicorandil reduced these in Scn5a+/Delta hearts to levels indistinguishable from untreated WTs. (5) Flattened restitution curves. Scn5a+/Delta hearts showed larger epicardial and endocardial critical diastolic intervals than WT hearts. Nicorandil decreased these in Scn5a+/Delta and WT hearts. The presence or absence of arrhythmogenesis in Scn5a+/Delta and WT hearts thus agreed with previously established criteria for re-entrant excitation, and alterations in these precisely correlated with the corresponding antiarrhythmic effects of nicorandil. Together these findings implicate spatial and temporal re-entrant mechanisms in arrhythmogenesis in LQT3 and their reversal by nicorandil.

Pictorial prescribing reduces fentanyl drug administration errors: a simulated controlled study.

OBJECTIVES: Transmucosal fentanyl is used to treat transient exacerbations of cancer pain. Several immediate release products are available, presented as intranasal sprays, sublingual and buccal tablets, or lozenges. These are not interchangeable, creating potential for medication errors. We compared the incidence of medication errors in a simulated scenario using handwritten drug charts and charts labelled with preprinted self-adhesive stickers with full pictorial fentanyl prescriptions. METHODS: 54 nurses were shown 5 handwritten drug charts and 5 with self-adhesive pictorial labels. Nurses indicated which preparation and dose they would administer from boxes of Instanyl, Abstral, Effentora and Actiq (Nycomed, ProStrakan, Cephalon and Teva, respectively). We measured the frequency of drug administration errors and asked them to rate the prescriptions for clarity on four-point Likert items. RESULTS: The use of pictorial self-adhesive prescriptions significantly reduced errors in choice of preparation, from 20 with traditional handwritten charts to 6 with self-adhesive labels (OR 3.52, 95% CI 1.39 to 8.90, p=0.006), but the incidence of dose error was not significantly different (OR 1.47, 95% CI 0.80 to 2.70, p=0.281). Analysis of Likert items showed using pictorial printed labels significantly improved nurses' understanding of choice of preparation, dose and maximum four hourly dose (p<0.0001, p=0.006 and p=0.028, respectively). CONCLUSIONS: The use of pictorial prescribing appears to be a promising strategy that could reduce medication errors in choice of fentanyl preparations. There may be a wider use for pictorial prescribing where non-interchangeable preparations of the same drug exist.

Epac activation, altered calcium homeostasis and ventricular arrhythmogenesis in the murine heart.

The recently described exchange protein directly activated by cAMP (Epac) has been implicated in distinct protein kinase A-independent cellular signalling pathways. We investigated the role of Epac activation in adrenergically mediated ventricular arrhythmogenesis. In contrast to observations in control conditions (n = 20), monophasic action potentials recorded in 2 of 10 intrinsically beating and 5 of 20 extrinsically paced Langendorff-perfused wild-type murine hearts perfused with the Epac activator 8-pCPT-2'-O-Me-cAMP (8-CPT, 1 microM) showed spontaneous triggered activity. Three of 20 such extrinsically paced hearts showed spontaneous ventricular tachycardia (VT). Programmed electrical stimulation provoked VT in 10 of 20 similarly treated hearts (P < 0.001; n = 20). However, there were no statistically significant accompanying changes (P > 0.05) in left ventricular epicardial (40.7 +/- 1.2 versus 44.0 +/- 1.7 ms; n = 10) or endocardial action potential durations (APD(90); 51.8 +/- 2.3 versus 51.9 +/- 2.2 ms; n = 10), transmural (DeltaAPD(90)) (11.1 +/- 2.6 versus 7.9 +/- 2.8 ms; n = 10) or apico-basal repolarisation gradients, ventricular effective refractory periods (29.1 +/- 1.7 versus 31.2 +/- 2.4 ms in control and 8-CPT-treated hearts, respectively; n = 10) and APD(90) restitution characteristics. Nevertheless, fluorescence imaging of cytosolic Ca(2+) levels demonstrated abnormal Ca(2+) homeostasis in paced and resting isolated ventricular myocytes. Epac activation using isoproterenol in the presence of H-89 was also arrhythmogenic and similarly altered cellular Ca(2+) homeostasis. Epac-dependent effects were reduced by Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) inhibition with 1 microM KN-93. These findings associate VT in an intact cardiac preparation with altered cellular Ca(2+) homeostasis and Epac activation for the first time, in the absence of altered repolarisation gradients previously implicated in reentrant arrhythmias through a mechanism dependent on CaMKII activity.