Suspected tick-borne flavivirus meningoencephalomyelitis in dogs from the UK: six cases (2021)

OBJECTIVES

Tick-borne encephalitis virus and louping ill virus are neurotropic flaviviruses transmitted by ticks. Epidemiologically, tick-borne encephalitis is endemic in Europe whereas louping ill's predominant geographical distribution is the UK. Rarely, these flaviviruses affect dogs causing neurological signs. This case series aimed to describe the clinical, clinicopathological, and imaging findings, as well as the outcomes in six dogs with meningoencephalitis and/or meningomyelitis caused by a flavivirus in the UK in 2021.

MATERIALS AND METHODS

Observational retrospective case-series study. Clinical data were retrieved from medical records of dogs with positive serological or immunohistochemical results from three different institutions from spring to winter 2021.

RESULTS

Six dogs were included in the study. All dogs presented an initial phase of pyrexia and/or lethargy followed by progressive signs of spinal cord and/or intracranial disease. Magnetic resonance imaging showed bilateral and symmetrical lesions affecting the grey matter of the thalamus, pons, medulla oblongata, and thoracic or lumbar intumescences with none or mild parenchymal and meningeal contrast enhancement. Serology for tick-borne encephalitis virus was positive in five dogs with the presence of seroconversion in two dogs. The viral distinction between flaviviruses was not achieved. One dog with negative serology presented positive immunohistochemistry at post-mortem examination. Three dogs survived but presented neurological sequelae. Three dogs were euthanased due to the rapid progression of the clinical signs or static neurological signs.

CLINICAL SIGNIFICANCE

These cases raise awareness of the presence of tick-borne encephalitis as an emergent disease or the increased prevalence of louping ill virus affecting dogs in the UK.

Integration of spatial and single-cell transcriptomic data elucidates mouse organogenesis

Molecular profiling of single cells has advanced our knowledge of the molecular basis of development. However, current approaches mostly rely on dissociating cells from tissues, thereby losing the crucial spatial context of regulatory processes. Here, we apply an image-based single-cell transcriptomics method, sequential fluorescence in situ hybridization (seqFISH), to detect mRNAs for 387 target genes in tissue sections of mouse embryos at the 8-12 somite stage. By integrating spatial context and multiplexed transcriptional measurements with two single-cell transcriptome atlases, we characterize cell types across the embryo and demonstrate that spatially resolved expression of genes not profiled by seqFISH can be imputed. We use this high-resolution spatial map to characterize fundamental steps in the patterning of the midbrain-hindbrain boundary (MHB) and the developing gut tube. We uncover axes of cell differentiation that are not apparent from single-cell RNA-sequencing (scRNA-seq) data, such as early dorsal-ventral separation of esophageal and tracheal progenitor populations in the gut tube. Our method provides an approach for studying cell fate decisions in complex tissues and development.

The Alzheimer's Prevention Registry: A Large Internet-Based Participant Recruitment Registry to Accelerate Referrals to Alzheimer's-Focused Studies

BACKGROUND

Recruitment for Alzheimer's disease (AD)-focused studies, particularly prevention studies, is challenging due to the public's lack of awareness about study opportunities coupled with studies' inclusion and exclusion criteria, resulting in a high screen fail rate.

OBJECTIVES

To develop an internet-based participant recruitment registry for efficiently and effectively raising awareness about AD-focused study opportunities and connecting potentially eligible volunteers to studies in their communities.

METHODS

Individuals age 18 and older are eligible to join the Alzheimer's Prevention Registry (APR). Individuals provide first and last name, year of birth, country, and zip/postal code to join the APR; for questions regarding race, ethnicity, sex, family history of AD or other dementia, and diagnosis of cognitive impairment, individuals have the option to select "prefer not to answer." The APR website maintains a list of recruiting studies and contacts members who have opted in by email when new studies are available for enrollment.

RESULTS

As of December 1, 2019, 346,661 individuals had joined the APR. Members had a mean age of 63.3 (SD 11.7) years and were predominately women (75%). 94% were cognitively unimpaired, 50% reported a family history of AD or other dementia, and of those who provided race, 76% were white. 39% joined the APR as a result of a paid social media advertisement. To date, the APR helped recruit for 82 studies.

CONCLUSIONS

The APR is a large, internet-based participant recruitment registry designed to raise awareness about AD prevention research and connect members with enrolling studies in their communities. It has demonstrated the ability to recruit and engage a large number of highly motivated members and assist researchers in meeting their recruitment goals. Future publications will report on the effectiveness of APR for accelerating recruitment and enrollment into AD-focused studies.

The Alzheimer's Prevention Registry: A Large Internet-Based Participant Recruitment Registry to Accelerate Referrals to Alzheimer's-Focused Studies

BACKGROUND

Recruitment for Alzheimer's disease (AD)-focused studies, particularly prevention studies, is challenging due to the public's lack of awareness about study opportunities coupled with studies' inclusion and exclusion criteria, resulting in a high screen fail rate.

OBJECTIVES

To develop an internet-based participant recruitment registry for efficiently and effectively raising awareness about AD-focused study opportunities and connecting potentially eligible volunteers to studies in their communities.

METHODS

Individuals age 18 and older are eligible to join the Alzheimer's Prevention Registry (APR). Individuals provide first and last name, year of birth, country, and zip/postal code to join the APR; for questions regarding race, ethnicity, sex, family history of AD or other dementia, and diagnosis of cognitive impairment, individuals have the option to select "prefer not to answer." The APR website maintains a list of recruiting studies and contacts members who have opted in by email when new studies are available for enrollment.

RESULTS

As of December 1, 2019, 346,661 individuals had joined the APR. Members had a mean age of 63.3 (SD 11.7) years and were predominately women (75%). 94% were cognitively unimpaired, 50% reported a family history of AD or other dementia, and of those who provided race, 76% were white. 39% joined the APR as a result of a paid social media advertisement. To date, the APR helped recruit for 82 studies.

CONCLUSIONS

The APR is a large, internet-based participant recruitment registry designed to raise awareness about AD prevention research and connect members with enrolling studies in their communities. It has demonstrated the ability to recruit and engage a large number of highly motivated members and assist researchers in meeting their recruitment goals. Future publications will report on the effectiveness of APR for accelerating recruitment and enrollment into AD-focused studies.

1891. Invasive Group A Streptococcus Infections Among Residents of Multiple Nursing Homes—Denver, Colorado, 2017–2018

Background

Older adults residing in nursing homes (NH) are at increased risk for invasive group A Streptococcus (GAS) infections due to advanced age, presence of wounds, and comorbidities; approximately one-third of infected patients die. Beginning in 2015, increasing numbers of GAS infections in NH residents and several NH clusters were reported from the Denver metropolitan area. Colorado Department of Public Health and Environment (CDPHE) and CDC investigated to characterize cases and assess if outbreaks resulted from interfacility transmission.

Methods

We reviewed data from Active Bacterial Core surveillance (ABCs) in the 5-county Denver area from January 2017 to June 2018. We defined a case as isolation of GAS from a normally sterile site in an NH resident. GAS isolates underwent whole-genome sequencing (WGS) at CDC’s Streptococcus Laboratory to determine emm types for genotyping. Among isolates with the same emm type, pairwise single-nucleotide polymorphism (SNP) distances were calculated using Nucmer software. In October 2018, a CDPHE-CDC team assessed infection control at NHs with cases of the most common emm type.

Results

Over 18 months, among >100 NHs in the Denver area, ≥1 GAS case was identified in 29 NHs, with 6 having ≥3 cases. During this period, 68 cases in NH residents were identified. WGS identified 17 emm types among isolates from these cases; most common was emm11.10 (34%, n = 22), a rare subtype in ABCs. All emm11.10 isolates had nearly identical genomes (average pairwise SNP distance: 3.2), and were isolated from 10 NHs, with 2 NHs having ≥ 4 cases. Multiple infection control lapses were noted during site visits to 8 NHs.

Conclusion

Multiple outbreaks due to GAS were noted in 5-county Denver area NHs in 2017–2018. WGS of surveillance isolates identified a rarely seen emm subtype 11.10 from multiple facilities with temporal and genomic clustering suggesting interfacility GAS transmission.

Disclosures

All Authors: No reported Disclosures.

B-43 Adolescent Recovery Following TBI: Moderators of Change Over Time

Objective

The study aimed to assess (1) whether the severity of a TBI affects performance on a measure of memory, and (2) whether FSIQ, VIQ, and PIQ moderate recovery following TBI, over time, after controlling for severity of injury.

Method

TBI patients (n = 60) were recruited from admissions to the Loma Linda University Children’s Hospital (LLUCH). Indicators of memory and learning were assessed with the CMS for all the children (ages 6 to 16), while overall cognitive abilities were assessed with the WASI-II. These data are a component of a larger neuropsychology assessment battery collected at 3 and 12 months post-injury.

Results

Simple Linear Regression was conducted in SPSS. Results indicated that severity of injury explained a significant amount of the variance in participant’s performance on overall memory at the initial evaluation (R2 = .154). As severity of injury increased by one-point, general memory declined by .392 points, 95%CI [.820, 3.233] (p < .001). Three moderation analyses using model one of the PROCESS macro for SPSS were conducted to assess whether FSIQ, VIQ, or PIQ moderated recovery from TBI over time. We controlled for the severity of injury. FSIQ, VIQ, and PIQ did not significantly moderate verbal, nonverbal, or general memory recovery of moderate-to-severe TBI over time (ps > .05).

Conclusions

Results of the study suggest that, after controlling for severity of injury, FSIQ, VIQ, and PIQ did not significantly moderate recovery following a TBI. Given that research suggests that higher premorbid IQ is associated with more favorable outcomes, further investigation is warranted.

Draft genome and reference transcriptomic resources for the urticating pine defoliator Thaumetopoea pityocampa (Lepidoptera: Notodontidae)

The pine processionary moth Thaumetopoea pityocampa (Lepidoptera: Notodontidae) is the main pine defoliator in the Mediterranean region. Its urticating larvae cause severe human and animal health concerns in the invaded areas. This species shows a high phenotypic variability for various traits, such as phenology, fecundity and tolerance to extreme temperatures. This study presents the construction and analysis of extensive genomic and transcriptomic resources, which are an obligate prerequisite to understand their underlying genetic architecture. Using a well-studied population from Portugal with peculiar phenological characteristics, the karyotype was first determined and a first draft genome of 537 Mb total length was assembled into 68,292 scaffolds (N50 = 164 kb). From this genome assembly, 29,415 coding genes were predicted. To circumvent some limitations for fine-scale physical mapping of genomic regions of interest, a 3X coverage BAC library was also developed. In particular, 11 BACs from this library were individually sequenced to assess the assembly quality. Additionally, de novo transcriptomic resources were generated from various developmental stages sequenced with HiSeq and MiSeq Illumina technologies. The reads were de novo assembled into 62,376 and 63,175 transcripts, respectively. Then, a robust subset of the genome-predicted coding genes, the de novo transcriptome assemblies and previously published 454/Sanger data were clustered to obtain a high-quality and comprehensive reference transcriptome consisting of 29,701 bona fide unigenes. These sequences covered 99% of the cegma and 88% of the busco highly conserved eukaryotic genes and 84% of the busco arthropod gene set. Moreover, 90% of these transcripts could be localized on the draft genome. The described information is available via a genome annotation portal (http://bipaa.genouest.org/sp/thaumetopoea_pityocampa/).

Commercially Available Enzyme-Linked Immunosorbent Assay and Polymerase Chain Reaction Tests for Detection of Feline Immunodeficiency Virus Infection

BACKGROUND

Feline immunodeficiency virus (FIV) infection is an important cause of disease of cats worldwide. Initial screening is commonly performed by commercially available point-of-care (POC) ELISA tests. Confirmatory testing for positive POC test results is recommended. Polymerase chain reaction (PCR) tests for FIV are commonly used additional testing methods; however, reported measures of diagnostic accuracy vary widely between PCR tests, making interpretation of results difficult.

HYPOTHESIS/OBJECTIVE

There is very good agreement between results of a commercially available PCR test and a POC ELISA test for FIV for specimens collected from owned and shelter-housed cats.

ANIMALS

Blood samples from 168 cats from 2 adoption guarantee shelters, an FIV Sanctuary, and 64 private homes were used.

METHODS

This was a prospective study. Whole blood samples were collected in K₂ -EDTA, divided, and submitted for PCR and ELISA testing. Follow-up whole blood samples were collected in lithium heparin from cats with discordant results and submitted for virus isolation (VI).

RESULTS

There was very good agreement between ELISA and PCR (kappa 0.87; P < .001; 95% CI 0.79, 0.95). Of 168 cats, eleven had discordant ELISA/PCR results: 7 ELISA+/PCR- and 4 ELISA-/PCR+. Using VI as a reference standard, there were 4 false-positive PCR results, 5 false-positive ELISA results, and 1 false-negative PCR result (1 cat lost to follow-up).

CONCLUSIONS AND CLINICAL IMPORTANCE

While there was good agreement between the POC ELISA and PCR tests, the discordant results highlight the importance of cautious interpretation of test results and the necessity of confirmatory testing.

Mesoscale blood cell sedimentation for processing millilitre sample volumes

We demonstrate the efficient separation of blood cells from millilitre volumes of whole blood in minutes using a simple gravity sedimentation device. Blood cell and plasma separation is often the initial step in clinical diagnostics, and reliable separation techniques have remained a major obstacle for the success of point-of-care or remote diagnostics. Unlike plasma collection devices that rely solely on microchannels that restrict sample volume and throughput, we demonstrate the use of a hybrid micro/mesoscale sedimentation chamber to enable >99% capture of cells from millilitre blood samples in less than two minutes.

Utility of ¹⁸fluoro-deoxyglucose positron emission tomography for prognosis and response assessments in a phase 2 study of romidepsin in patients with relapsed or refractory peripheral T-cell lymphoma

BACKGROUND

For patients with peripheral T-cell lymphoma (PTCL), the value of (18)fluoro-deoxyglucose positron emission tomography (FDG-PET) scans for assessing prognosis and response to treatment remains unclear. The utility of FDG-PET, in addition to conventional radiology, was examined as a planned exploratory end point in the pivotal phase 2 trial of romidepsin for the treatment of relapsed/refractory PTCL.

PATIENTS AND METHODS

Patients received romidepsin at a dose of 14 mg/m(2) on days 1, 8, and 15 of 28-day cycles. The primary end point was the rate of confirmed/unconfirmed complete response (CR/CRu) as assessed by International Workshop Criteria (IWC) using conventional radiology. For the exploratory PET end point, patients with at least baseline FDG-PET scans were assessed by IWC + PET criteria.

RESULTS

Of 130 patients, 110 had baseline FDG-PET scans, and 105 were PET positive at baseline. The use of IWC + PET criteria increased the objective response rate to 30% compared with 26% by conventional radiology. Durations of response were well differentiated by both conventional radiology response criteria [CR/CRu versus partial response (PR), P = 0.0001] and PET status (negative versus positive, P < 0.0001). Patients who achieved CR/CRu had prolonged progression-free survival (PFS, median 25.9 months) compared with other response groups (P = 0.0007). Patients who achieved PR or stable disease (SD) had similar PFS (median 7.2 and 6.3 months, respectively, P = 0.6427). When grouping PR and SD patients by PET status, patients with PET-negative versus PET-positive disease had a median PFS of 18.2 versus 7.1 months (P = 0.0923).

CONCLUSIONS

Routine use of FDG-PET does not obviate conventional staging, but may aid in determining prognosis and refine response assessments for patients with PTCL, particularly for those who do not achieve CR/CRu by conventional staging. The optimal way to incorporate FDG-PET scans for patients with PTCL remains to be determined.

TRIAL REGISTRATION

NCT00426764.

A thermostable bacterial cocaine esterase rapidly eliminates cocaine from brain in nonhuman primates

A long-acting, thermostable bacterial cocaine esterase (CocE) has been identified that rapidly degrades cocaine with a K(M) of 1.33+0.085 μM. In vivo evaluation of CocE has shown protection against convulsant and lethal effects of cocaine in rodents, confirming the therapeutic potential of CocE against cocaine overdose. However, the current study is the first to evaluate the effects of CocE on cocaine brain levels. Positron emission tomogrpahy neuroimaging of [(11)C]cocaine was used to evaluate the time course of cocaine elimination from brain in the presence and absence of CocE in nonhuman primates. Systemic administration of CocE eliminated cocaine from the rhesus-monkey brain approximately three times faster than control conditions via peripheral actions through attenuating the input function from blood plasma. The efficiency of this process is sufficient to alleviate or prevent adverse central nervous system effects induced by cocaine. Although the present study used tracer doses of cocaine to access brain clearance, these findings further support the development of CocE for the treatment of acute cocaine toxicity.

Tuning magnetic coupling in Sr2IrO4 thin films with epitaxial strain

We report x-ray resonant magnetic scattering and resonant inelastic x-ray scattering studies of epitaxially strained Sr2IrO4 thin films. The films were grown on SrTiO3 and (LaAlO3)0.3(Sr2AlTaO6)0.7 substrates, under slight tensile and compressive strains, respectively. Although the films develop a magnetic structure reminiscent of bulk Sr2IrO4, the magnetic correlations are extremely anisotropic, with in-plane correlation lengths significantly longer than the out-of-plane correlation lengths. In addition, the compressive (tensile) strain serves to suppress (enhance) the magnetic ordering temperature TN, while raising (lowering) the energy of the zone-boundary magnon. Quantum chemical calculations show that the tuning of magnetic energy scales can be understood in terms of strain-induced changes in bond lengths.

Physical and sexual abuse in orphaned compared to non-orphaned children in sub-Saharan Africa: a systematic review and meta-analysis

This systematic review assessed the quantitative literature to determine whether orphans are more likely to experience physical and/or sexual abuse compared to non-orphans in sub-Saharan Africa (SSA). It also evaluated the quality of evidence and identified research gaps. Our search identified 10 studies, all published after 2005, from Zimbabwe, South Africa, Kenya and Uganda. The studies consisted of a total 17,336 participants (51% female and 58% non-orphans). Of those classified as orphans (n=7,315), 73% were single orphans, and 27% were double orphans. The majority of single orphans were paternal orphans (74%). Quality assessment revealed significant variability in the quality of the studies, although most scored higher for general design than dimensions specific to the domain of orphans and abuse. Combined estimates of data suggested that, compared to non-orphans, orphans are not more likely to experience physical abuse (combined OR=0.96, 95% CI [0.79, 1.16]) or sexual abuse (combined OR=1.25, 95% CI [0.88, 1.78]). These data suggest that orphans are not systematically at higher risk of experiencing physical or sexual abuse compared to non-orphans in sub-Saharan Africa. However, because of inconsistent quality of data and reporting, these findings should be interpreted with caution. Several recommendations are made for improving data quality and reporting consistency on this important issue.

Local micromechanical properties of decellularized lung scaffolds measured with atomic force microscopy

Bioartificial lungs re-engineered from decellularized organ scaffolds are a promising alternative to lung transplantation. Critical features for improving scaffold repopulation depend on the mechanical properties of the cell microenvironment. However, the mechanics of the lung extracellular matrix (ECM) is poorly defined. The local mechanical properties of the ECM were measured in different regions of decellularized rat lung scaffolds with atomic force microscopy. Lungs excised from rats (n=11) were decellularized with sodium dodecyl sulfate (SDS) and cut into ~7μm thick slices. The complex elastic modulus (G(∗)) of lung ECM was measured over a frequency band ranging from 0.1 to 11.45Hz. Measurements were taken in alveolar wall segments, alveolar wall junctions and pleural regions. The storage modulus (G', real part of G(∗)) of alveolar ECM was ~6kPa, showing small changes between wall segments and junctions. Pleural regions were threefold stiffer than alveolar walls. G' of alveolar walls and pleura increased with frequency as a weak power law with exponent 0.05. The loss modulus (G″, imaginary part of G(∗)) was 10-fold lower and showed a frequency dependence similar to that of G' at low frequencies (0.1-1Hz), but increased more markedly at higher frequencies. Local differences in mechanical properties and topology of the parenchymal site could be relevant mechanical cues for regulating the spatial distribution, differentiation and function of lung cells.

Pulsed laser deposition with simultaneous in situ real-time monitoring of optical spectroscopic ellipsometry and reflection high-energy electron diffraction

We present a pulsed laser deposition system that can monitor growth by simultaneously using in situ optical spectroscopic ellipsometry (SE) and reflection high-energy electron diffraction (RHEED). The RHEED precisely monitors the number of thin-film layers and surface structure during the deposition, and the SE measures the optical spectra of the samples simultaneously. The thin-film thickness information obtained from RHEED facilitates the SE modeling process, which allows extracting the in situ optical spectra, i.e., the dielectric functions of thin-films during growth. The in situ dielectric functions contain indispensable information about the electronic structure of thin-films. We demonstrate the performance of this system by growing LaMnO(3+δ) (LMO) thin-films on SrTiO3 (001) substrates. By using in situ SE and RHEED simultaneously, we show that real-time thickness and dielectric functions of the LMO thin-films can be effectively extracted. The simultaneous monitoring of both optical SE and RHEED offers important clues to understand the growth mechanism of atomic-scale thin-films.

Scanning tunneling microscope with two-dimensional translator

Since the invention of the scanning tunneling microscope (STM), it has been a powerful tool for probing the electronic properties of materials. Typically STM designs capable of obtaining resolution on the atomic scale are limited to a small area which can be probed. We have built an STM capable of coarse motion in two dimensions, the z- and x-directions which are, respectively, parallel and perpendicular to the tip. This allows us to image samples with very high resolution at sites separated by macroscopic distances. This device is a single unit with a compact design making it very stable. It can operate in either a horizontal or vertical configuration and at cryogenic temperatures.

Dynamics of the hysteretic voltage-induced torsional strain in tantalum trisulfide

We have studied how the hysteretic voltage-induced torsional strain, associated with charge-density-wave (CDW) depinning, in orthorhombic tantalum trisulfide depends on square-wave and triangle-wave voltages of different frequencies and amplitudes. The strains are measured by placing the sample, with a wire glued to the center as a transducer, in a radio frequency cavity and measuring the modulated response of the cavity. From the triangle waves, we map out the time dependence of the hysteresis loops, and find that the hysteresis loops broaden for waves with periods less than 30 s. The square-wave response shows that the dynamic responses to positive and negative voltages can be quite different. The overall frequency dependence is relaxational, but with multiple relaxation times which typically decrease with increasing voltage. The detailed dynamic response is very sample dependent, suggesting that it depends in detail on interactions of the CDW with sample defects.

Pooled analyses of two international, multicenter clinical studies of romidepsin in 167 patients with cutaneous T-cell lymphoma (CTCL)

8546

Background: Romidepsin is a novel pan-HDAC inhibitor with demonstrated single-agent activity in 2 open-label clinical studies of 167 patients (pts) with CTCL [mycosis fungoides or Sézary Syndrome (SS)]. Data for these 2 studies were pooled for more accurate estimates of endpoints and investigation of subpopulations. Methods: GPI-04–0001 (pivotal study) enrolled 96 pts with confirmed CTCL who had recieved ≥1 prior systemic therapy. NCI 1312 (supportive study) enrolled 71 pts with CTCL. Pts recieved romidepsin, 14mg/m2 as a 4-hr infusion on days 1, 8, and 15 every 28 days until disease progression (≥25% increase). The primary efficacy endpoint for both studies was overall response rate (ORR) using a composite endpoint that included skin assessment, lymph node and visceral involvement and abnormal circulating T-cells/Sézary cells. Results: 167 pts received romidepsin (as-treated); 135 pts (81%) were in the efficacy evaluable population. Mean age was 57±12 yrs, 67% men, 87% white. 103 pts (76%) had stage ≥IIB disease. Median number of prior systemic therapies was 2 (range 1–8). ORR in the table. Responses were noted in: 42% of pts with stage ≥IIB; 11 (58%) of 19 pts with SS (erythroderma + Sézary cells, >1000/ml or >20% ); and 20 (38%) of 52 pts who received prior bexarotene and 8 (40%) of 20 pts who had received denileukin diftitox. Most common drug-related adverse events (AE), all grades, included: nausea (67%), fatigue (49%), anorexia (37%), ECG T-wave changes (29%), anemia (26%), dysgeusia (23%), neutropenia (22%), leucopenia (20%). Related serious AEs in 2% of pts: supraventicular arrhythmia, ventricular arrhythmia, infection, neutropenia, WBC decreased, hyperuricemia, hypotension; all other serious AEs in ≤1 pt. 3 deaths reported as possibly related. Conclusions: Romidepsin is a valuable new therapy for pts with CTCL based on the ORR, CR, durability of response, improvement in all disease compartments and responses at all stages and in all subpopulations analyzed.

[Table: see text]

[Table: see text]

Systematic assessment of potential cardiac effects of the novel histone deacetylase (HDAC) inhibitor romidepsin

e19533

Background: Romidepsin is a novel pan-HDAC inhibitor with single-agent activity in T-cell lymphoma. HDAC inhibitors reportedly have cardiovascular effects, in particular, QTc prolongation. To systematically and rigorously evaluate the potential cardiac effects of romidepsin, a cardiac safety monitoring plan was developed after discussions with the FDA. Methods: The effect of romidepsin on the change from baseline QTcF (Fridericia's correction) at key pharmacokinetic and pharmacodynamic (PD) time points was investigated. ECGs from 110 pts with advanced malignancies in 3 open-label, clinical studies of romidepsin 14 mg/m2 administered on days 1, 8 and 15 of a 28 day cycle were evaluated by blinded, independent assessors. Results: A mean 2.7 msec increase (90% confidence interval [CI]: 0.2, 5.3) in QTcF interval from a baseline post-antiemetic administration to after infusion of romidepsin was measured. A subanalysis of 74 patients (pts) evaluated QTcF from pre-antiemetic to post-romidepsin showed a mean change in QTcF of 5.0 msec (90% CI: 2.3, 7.7). Thus, antiemetic comedications likely accounts for a portion of the clinically apparent QTc effect. The QTc returned to baseline within 48 hrs. No absolute QTc values >480 msec and no QTc changes >60 msec were observed. No relationship was observed in an analysis of romidepsin plasma concentration versus QT changes. Mean heart rate (HR) increased 10.1±9.0 bpm after romidepsin administration, with a return to baseline by 24 hrs. Several treatment-emergent morphological changes in ECGs (including T wave and ST-segment) were reported. Many of the ECG morphologic abnormalities (determined by automated machine reading) were also observed at baseline. These ECG changes were transient and were not associated with functional cardiovascular changes or with symptoms. Conclusions: Romidepsin has a slight effect on the QT interval but rigorous ECG evaluation found this effect to be mild, below the threshold of regulatory and clinical concern, and not associated with any observed clinical cardiovascular events. Concentration response modeling found no PD relationship between romidepsin concentration and changes in QTcF, but did suggest a relationship between romidepsin concentration and HR.

[Table: see text]