Expanding the phenotype of UPF3B-related disorder: Case reports and literature review.

UPF3B encodes the Regulator of nonsense transcripts 3B protein, a core-member of the nonsense-mediated mRNA decay pathway, protecting the cells from the potentially deleterious actions of transcripts with premature termination codons. Hemizygous variants in the UPF3B gene cause a spectrum of neuropsychiatric issues including intellectual disability, autism spectrum disorder, attention deficit hyperactivity disorder, and schizophrenia/childhood-onset schizophrenia (COS). The number of patients reported to date is very limited, often lacking an extensive phenotypical and neuroradiological description of this ultra-rare syndrome. Here we report three subjects harboring UPF3B variants, presenting with variable clinical pictures, including cognitive impairment, central hypotonia, and syndromic features. Patients 1 and 2 harbored novel UPF3B variants-the p.(Lys207*) and p.(Asp429Serfs*27) ones, respectively-while the p.(Arg225Lysfs*229) variant, identified in Patient 3, was already reported in the literature. Novel features in our patients are represented by microcephaly, midface hypoplasia, and brain malformations. Then, we reviewed pertinent literature and compared previously reported subjects to our cases, providing possible insights into genotype-phenotype correlations in this emerging condition. Overall, the detailed phenotypic description of three patients carrying UPF3B variants is useful not only to expand the genotypic and phenotypic spectrum of UPF3B-related disorders, but also to ameliorate the clinical management of affected individuals.

Trends in oral anticoagulant co-prescription with antiepileptic drugs among adults with epilepsy, 2010-2018.

Treatment considerations for epilepsy patients requiring anticoagulation are changing, and actual prescribing practices have not been characterized. We used the 2010-2018 Optum Clinformatics® Data Mart Database to estimate the annual prevalence and distinguish the patterns of oral anticoagulants (OACs) co-dispensed with antiepileptic drugs (AEDs) among adults with epilepsy. Monotonic trends were assessed using the Spearman rank correlation coefficient (ρ). Multivariable logistic regression models were built to evaluate the associations of sociodemographic characteristics. Among 345,892 adults with epilepsy (56.5% female; median age 61, IQR 46-74) on studied AEDs, the prevalence per thousand of concurrent OACs increased from 58.4 in 2010 to 92.0 in 2018 (OR 1.63, CI 1.58-1.69). Direct-acting oral anticoagulant (DOAC) use rapidly increased from 2010 to 2018 (ρ = 1.00; P < 0.001), with a corresponding decrease in warfarin use (ρ = -0.97; P < 0.001). Among OAC/AED dispensings in 2018, warfarin was more likely to be co-dispensed with potentially interacting, enzyme-inducing antiepileptic drugs (EI-AEDs) versus presumably non-interacting, non-enzyme inducing antiepileptic drugs (OR 1.48, CI 1.38-1.59). Characteristics independently associated with concurrent OAC/EI-AED use included younger age, female sex, white race, net worth <$250 K, and lower education levels. Our findings demonstrate the expanding use and evolving patterns of OAC/AED co-dispensing, and ensuing critical need to further understanding regarding postulated interactions.

Inhaled alprazolam rapidly suppresses epileptic activity in photosensitive participants.

OBJECTIVE: Treatment options for seizure clusters are limited; the need for easy-to-administer treatments remains. The Staccato system delivers drug deep into the lung via inhalation. In this phase 2a study, we investigated the ability of three different doses of Staccato alprazolam to suppress the electroencephalographic (EEG) photoparoxysmal response (PPR) compared with placebo in participants with photosensitive seizures. METHODS: Adults (18-60 years) with a diagnosis and history of PPR on EEG with or without an epilepsy diagnosis were eligible to participate. Participants received Staccato alprazolam 0.5, 1.0, and 2.0 mg, and Staccato placebo (twice) in random order. Intermittent photic stimulation and clinical assessments were performed at one predose and seven postdose time points. The primary endpoint of the study was the change in standardized photosensitivity range (SPR) in participants receiving each dose of Staccato alprazolam. RESULTS: Fifteen participants with a prior epilepsy diagnosis were screened; five were enrolled, randomized, and completed the study. All participants were white females with a mean (SD) age of 27.2 (6.8) years. All doses of Staccato alprazolam reduced the SPR at 2 minutes; the effect was sustained through 4 hours for the 0.5-mg dose and 6 hours for the 1.0- and 2.0-mg doses. The magnitude and duration of sedation and sleepiness were dose-related. Four participants (80%) experienced ≥1 adverse event (AE); none was severe or serious. Cough, diarrhea, dysgeusia, oral dysesthesia, sedation, and somnolence were experienced by two participants (40%) each. SIGNIFICANCE: This proof-of-concept study demonstrated that Staccato alprazolam 0.5, 1.0, and 2.0 mg rapidly suppressed epileptiform activity in photosensitive participants with epilepsy. The AE profile of Staccato alprazolam was similar to what has been reported for alprazolam for other indications. The results support further development of Staccato alprazolam as a rescue medication for the acute treatment of seizures.

Detection of generalized tonic-clonic seizures using surface electromyographic monitoring.

OBJECTIVE: A prospective multicenter phase III trial was undertaken to evaluate the performance and tolerability in the epilepsy monitoring unit (EMU) of an investigational wearable surface electromyographic (sEMG) monitoring system for the detection of generalized tonic-clonic seizures (GTCSs). METHODS: One hundred ninety-nine patients with a history of GTCSs who were admitted to the EMU in 11 level IV epilepsy centers for clinically indicated video-electroencephalographic monitoring also received sEMG monitoring with a wearable device that was worn on the arm over the biceps muscle. All recorded sEMG data were processed at a central site using a previously developed detection algorithm. Detected GTCSs were compared to events verified by a majority of three expert reviewers. RESULTS: For all subjects, the detection algorithm detected 35 of 46 (76%, 95% confidence interval [CI] = 0.61-0.87) of the GTCSs, with a positive predictive value (PPV) of 0.03 and a mean false alarm rate (FAR) of 2.52 per 24 h. For data recorded while the device was placed over the midline of the biceps muscle, the system detected 29 of 29 GTCSs (100%, 95% CI = 0.88-1.00), with a detection delay averaging 7.70 s, a PPV of 6.2%, and a mean FAR of 1.44 per 24 h. Mild to moderate adverse events were reported in 28% (55 of 199) of subjects and led to study withdrawal in 9% (17 of 199). These adverse events consisted mostly of skin irritation caused by the electrode patch that resolved without treatment. No serious adverse events were reported. SIGNIFICANCE: Detection of GTCSs using an sEMG monitoring device on the biceps is feasible. Proper positioning of this device is important for accuracy, and for some patients, minimizing the number of false positives may be challenging.

Lateral Transorbital Endoscopic Access to the Hippocampus, Amygdala, and Entorhinal Cortex: Initial Clinical Experience.

BACKGROUND/AIMS: Transorbital approaches traditionally have focused on skull base and cavernous sinus lesions medial to the globe. Lateral orbital approaches to the temporal lobe have not been widely explored despite several theoretical advantages compared to open craniotomy. Recently, we demonstrated the feasibility of the lateral transorbital technique in cadaveric specimens with endoscopic visualization. We describe our initial clinical experience with the endoscope-assisted lateral transorbital approach to lesions in the temporal lobe. METHODS: Two patients with mesial temporal lobe pathology presenting with seizures underwent surgery. The use of a transpalpebral or Stallard-Wright eyebrow incision enabled access to the intraorbital compartment, and a lateral orbital wall 'keyhole' opening permitted visualization of the anterior temporal pole. RESULTS: This approach afforded adequate access to the surgical target and surrounding structures and was well tolerated by the patients. To the best of our knowledge, this report constitutes the first case series describing the endoscope-assisted lateral transorbital approach to the temporal lobe. We discuss the limits of exposure, the nuances of opening and closing, and comparisons to open craniotomy. CONCLUSION: Further prospective investigation of this approach is warranted for comparison to traditional approaches to the mesial temporal lobe.

Kinetic and mechanistic characterisation of Choline Kinase-α.

Choline Kinase is a key component of the Kennedy pathway that converts choline into a number of structural and signalling lipids that are essential for cell growth and survival. One member of the family, Choline Kinase-α (ChoKα) is frequently up-regulated in human cancers, and expression of ChoKα is sufficient to transform cells. Consequently ChoKα has been studied as a potential target for therapeutic agents in cancer research. Despite great interest in the enzyme, mechanistic studies have not been reported. In this study, a combination of initial velocity and product inhibition studies, together with the kinetic and structural characterisation of a novel ChoKα inhibitor is used to support a mechanism of action for human ChoKα. Substrate and inhibition kinetics are consistent with an iso double displacement mechanism, in which the γ-phosphate from ATP is transferred to choline in two distinct steps via a phospho-enzyme intermediate. Co-crystal structures, and existing site-specific mutation studies, support an important role for Asp306, in stabilising the phospho-enzyme intermediate. The kinetics also indicate a distinct kinetic (isomerisation) step associated with product release, which may be attributed to a conformational change in the protein to disrupt an interaction between Asp306 and the phosphocholine product, facilitating product release. This study describes a mechanism for ChoKα that is unusual amongst kinases, and highlights the availability of different enzyme states that can be exploited for drug discovery.

Structure of human Bloom's syndrome helicase in complex with ADP and duplex DNA.

Bloom's syndrome is an autosomal recessive genome-instability disorder associated with a predisposition to cancer, premature aging and developmental abnormalities. It is caused by mutations that inactivate the DNA helicase activity of the BLM protein or nullify protein expression. The BLM helicase has been implicated in the alternative lengthening of telomeres (ALT) pathway, which is essential for the limitless replication of some cancer cells. This pathway is used by 10-15% of cancers, where inhibitors of BLM are expected to facilitate telomere shortening, leading to apoptosis or senescence. Here, the crystal structure of the human BLM helicase in complex with ADP and a 3'-overhang DNA duplex is reported. In addition to the helicase core, the BLM construct used for crystallization (residues 640-1298) includes the RecQ C-terminal (RQC) and the helicase and ribonuclease D C-terminal (HRDC) domains. Analysis of the structure provides detailed information on the interactions of the protein with DNA and helps to explain the mechanism coupling ATP hydrolysis and DNA unwinding. In addition, mapping of the missense mutations onto the structure provides insights into the molecular basis of Bloom's syndrome.

Selective killing of ATM- or p53-deficient cancer cells through inhibition of ATR.

Here we report a comprehensive biological characterization of a potent and selective small-molecule inhibitor of the DNA damage response (DDR) kinase ATR. We show a profound synthetic lethal interaction between ATR and the ATM-p53 tumor suppressor pathway in cells treated with DNA-damaging agents and establish ATR inhibition as a way to transform the outcome for patients with cancer treated with ionizing radiation or genotoxic drugs.

Suicidal ideation and behavior screening in intractable focal epilepsy eligible for drug trials.

PURPOSE: Three suicidal ideation and suicidal behavior instruments were used to assess the prevalence of lifetime and recent suicidal ideation and suicidal behavior in patients with frequent treatment-resistant focal seizures who would be eligible for randomized clinical trials. This was done to determine which instrument was optimal for use in epilepsy. METHODS: In a cross-sectional study, we compared lifetime and recent suicidal ideation and suicide attempt on the MINI International Neuropsychiatric Interview (MINI), Columbia Suicide Severity Rating Scale (C-SSRS), and Interactive Voice Response System CSSRS (E-CSSRS). A safety algorithm determined treatment referral. Coordinators and participants evaluated experiences with the C-SSRS. The proportion of participants that baseline assessment would exclude from clinical trial enrollment was determined. KEY FINDINGS: Among 208 participants, 1.6-3.9% had recent high risk suicidal ideation and 1.0-4.7% had a recent suicide attempt across all instruments. Lifetime high-risk suicidal ideation occurred in 12.1-14.1%. Lifetime suicide attempt occurred in 10.2-13.1% of participants. Of those with recent suicide attempt, 31.1% required referral to a health professional, and 3.9% needed urgent referral. Lifetime suicidal behavior (including aborted suicide attempt, interrupted suicide attempt, suicide attempt, preparatory acts or behavior, and nonsuicidal self-injurious behavior) was found in 21.1% on the E-CSSRS and 15.5% on the C-SSRS. Agreement (Kappa) was good to excellent for comparisons of all instruments. Fifty-two percent of subjects preferred either the CSSRS or E-CSSRS, whereas the rest had no preference; of those having a preference, 87.5% favored the CSSRS. Of the 18.9% of participants who might have been excluded from trials based on suicidal ideation and suicide attempt, the CSSRS identified high-risk suicidal ideation or suicide attempt in the preceding 2 years in only 4.4%. SIGNIFICANCE: Suicidality screening is feasible in people with epilepsy. Slightly more suicidal behavior is reported with the E-CSSRS than C-SSRS, suggesting the E-CSSRS may be optimal. The proportion of patients who may be excluded from clinical trials based on worrisome suicidal ideation or suicide attempt is small, suggesting that it is possible to enroll most eligible individuals.

The diagnosis and treatment of attention deficit hyperactivity disorder in patients with epilepsy.

Attention deficit/hyperactivity disorder (AD/HD) can cause significant impairment in psychosocial and scholastic achievement. AD/HD should be appropriately managed even if patients have comorbid epilepsy. The diagnosis and treatment of AD/HD in patients with epilepsy presents several challenges. Differentiating independent problems in attention from frequent epileptic seizures is the first step in evaluating these individuals. Once this is accomplished the formal independent diagnosis of AD/HD can be pursued. Data from non-epileptic AD/HD populations should be applied with caution to patients with epilepsy. Once attention deficit disorder has been diagnosed formally, choices in treatment can create other problems as some pharmacological treatments for AD/HD pose a risk of exacerbating seizures. This article serves as a review for the diagnosis and treatment of AD/HD spectrum disorders in patients with epilepsy.

Stereospecific antiseizure activity in mouse and rat epilepsy models by a pyridinium inhibitor of TNFα/NFκB signaling.

Epilepsy affects over 50 million people worldwide and increases the risk of death. An intrinsic state of central inflammation, mainly driven by TNFα/NFκB signaling, may contribute to the refractory nature of some epilepsies. We have therefore hypothesized that inhibitors of this signaling pathway might be therapeutic. To test this hypothesis, we have measured the antiseizure properties of the enantiomeric compounds MRS-2481 and MRS-2485 in rodent seizure model systems. In the 6 Hz (44 mA) induced seizure test in mice, the (S) species, MRS-2485, was found to have higher protective potency and lower toxicity than the (R) species MRS-2481. However, neither of these enantiomers were protective in the MES-induced seizure test. MRS-2485 was also found to be protective in the corneal kindled mouse test. Finally, MRS-2485 reduced the post-kainate rat hippocampal slice electrical burst rate and duration. We conclude that MRS-2485, the (S)-enantiomer, is a potent inhibitor of seizure activity in mouse and rat models of epilepsy.

Rescue therapies for seizures.

Most medical therapies for epilepsy consist of daily (or multiple-daily) dose, fixed-schedule, pharmacologic oral agents. Despite adherence, many patients continue to experience seizures. Various products have been discovered, designed, and marketed to serve as seizure-abortant therapies. These agents can be administered rapidly, as a "rescue" therapy, once a clinical seizure or cluster of seizures starts. Rescue medications are given as needed in an attempt to disrupt progression of a given seizure, and forestall what would otherwise be a more prolonged or more severe clinical event. Seizure-abortants also serve to aid in the management of seizure emergencies, such as prolonged, repetitive seizures, or status epilepticus. These compounds are not appropriate for all patients. Nevertheless, they do provide therapeutic benefit to several groups of patients: 1) those who perceive the onset of their seizures and have time to perform a self-intervention, 2) patients' caregivers who administer the therapy when they witness the onset of an ictal event, and 3) patients who are in the midst of an out-of-the-hospital seizure emergency (a seizure cluster or status epilepticus). In this article we will review currently available and future rescue therapies for seizures: US Food and Drug Administration (FDA) approved and FDA nonapproved drugs, nonpharmacologic behavioral treatments, the vagus nerve stimulator and the NeuroPace RNS® System (Mountain View, CA).

Exposure to CYP3A4-inducing and CYP3A4-non-inducing antiepileptic agents and the risk of fractures.

PURPOSE: To evaluate whether exposure to Cytochrome P450, family 3, subfamily A, polypeptide 4 (CYP3A4)-inducing antiepileptics increases fracture risk compared to CYP3A4-non-inducing antiepileptics. METHODS: We performed a retrospective cohort study of initiators of antiepileptic agents using a UK medical record database (The Health Improvement Network) from 1995 to 2007. We considered an antiepileptic user an initiator if he or she had not received a prescription for an antiepileptic agent within the first year after entry in the database. Proportional hazards regression was used to calculate hazard ratios for fracture during long-term (≥ 6 months) exposure to CYP3A4 inducing versus CYP3A4 non-inducing antiepileptics. RESULTS: We identified 4077 initiators of CYP3A4-inducing antiepileptics and 6433 initiators of CYP3A4-non-inducing antiepileptics with at least 6 months of antiepileptic exposure. During 6006 person-years exposed to CYP3A4-inducing antiepileptics, 118 fractures were identified for an incidence rate of 1.96 (95% confidence interval (CI): 1.63-2.35) fractures per 100 person-years. During 7184 person-years exposed to CYP3A4-non-inducing antiepileptics, 127 fractures were identified, for an incidence rate of 1.77 (95% CI: 1.47-2.10) fractures per 100 person-years. The adjusted hazard ratio for CYP3A4-inducing antiepileptic versus CYP3A4-non-inducing antiepileptic was 1.21 (95% CI: 0.93-1.56). No duration-response relationship was evident. CONCLUSIONS: Our results do not support the hypothesis that CYP3A4 induction by antiepileptic agents increases the fracture risk. Further research will be needed to evaluate whether mechanisms other than CYP3A4 induction might explain some of the elevated risk of fractures associated with long-term use of antiepileptic agents.

Association of Epileptic and Nonepileptic Seizures and Changes in Circulating Plasma Proteins Linked to Neuroinflammation.

OBJECTIVE: To develop a diagnostic test that stratifies epileptic seizures (ES) from psychogenic nonepileptic seizures (PNES) by developing a multimodal algorithm that integrates plasma concentrations of selected immune response-associated proteins and patient clinical risk factors for seizure. METHODS: Daily blood samples were collected from patients evaluated in the epilepsy monitoring unit within 24 hours after EEG confirmed ES or PNES and plasma was isolated. Levels of 51 candidate plasma proteins were quantified using an automated, multiplexed, sandwich ELISA and then integrated and analyzed using our diagnostic algorithm. RESULTS: A 51-protein multiplexed ELISA panel was used to determine the plasma concentrations of patients with ES, patients with PNES, and healthy controls. A combination of protein concentrations, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), intercellular adhesion molecule 1 (ICAM-1), monocyte chemoattractant protein-2 (MCP-2), and tumor necrosis factor-receptor 1 (TNF-R1) indicated a probability that a patient recently experienced a seizure, with TRAIL and ICAM-1 levels higher in PNES than ES and MCP-2 and TNF-R1 levels higher in ES than PNES. The diagnostic algorithm yielded an area under the receiver operating characteristic curve (AUC) of 0.94 ± 0.07, sensitivity of 82.6% (95% confidence interval [CI] 62.9-93.0), and specificity of 91.6% (95% CI 74.2-97.7). Expanding the diagnostic algorithm to include previously identified PNES risk factors enhanced diagnostic performance, with AUC of 0.97 ± 0.05, sensitivity of 91.3% (95% CI 73.2-97.6), and specificity of 95.8% (95% CI 79.8-99.3). CONCLUSIONS: These 4 plasma proteins could provide a rapid, cost-effective, and accurate blood-based diagnostic test to confirm recent ES or PNES. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that variable levels of 4 plasma proteins, when analyzed by a diagnostic algorithm, can distinguish PNES from ES with sensitivity of 82.6% and specificity of 91.6%.

Classical Drug Digitoxin Inhibits Influenza Cytokine Storm, With Implications for Covid-19 Therapy.

BACKGROUND/AIM: Influenza viruses, corona viruses and related pneumotropic viruses cause sickness and death partly by inducing cytokine storm, a hyper-proinflammatory host response by immune cells and cytokines in the host airway. Based on our in vivo experience with digitoxin as an inhibitor of TNFα-driven NFĸB signaling for cytokine expression in prostate cancer in rats and in cystic fibrosis in humans, we hypothesize that this drug will also block a virally-activated cytokine storm. Materials Methods: Digitoxin was administered intraperitoneally to cotton rats, followed by intranasal infection with 107TCID50/100 g of cotton rat with influenza strain A/Wuhan/H3N2/359/95. Daily digitoxin treatment continued until harvest on day 4 of the experiment. RESULTS: The cardiac glycoside digitoxin significantly and differentially suppressed levels of the cytokines TNFα, GRO/KC, MIP2, MCP1, and IFNγ, in the cotton rat lung in the presence of influenza virus. CONCLUSION: Since cytokine storm is a host response, we suggest that digitoxin may have a therapeutic potential not only for influenza and but also for coronavirus infections.

The Impact of COVID-19 on Epilepsy Care: A Survey of the American Epilepsy Society Membership.

The COVID-19 pandemic has impacted the delivery of care to people with epilepsy (PWE) in multiple ways including limitations on in-person contact and restrictions on neurophysiological procedures. To better study the effect of the pandemic on PWE, members of the American Epilepsy Society were surveyed between April 30 and June 14, 2020. There were 366 initial responses (9% response rate) and 337 respondents remained for analysis after screening out noncompleters and those not directly involved with clinical care; the majority were physicians from the United States. About a third (30%) of respondents stated that they had patients with COVID-19 and reported no significant change in seizure frequency. Conversely, one-third of respondents reported new onset seizures in patients with COVID-19 who had no prior history of seizures. The majority of respondents felt that there were at least some barriers for PWE in receiving appropriate clinical care, neurophysiologic procedures, and elective surgery. Medication shortages were noted by approximately 30% of respondents, with no clear pattern in types of medication involved. Telehealth was overwhelmingly found to have value. Among the limitation of the survey was that it was administered at a single point in time in a rapidly changing pandemic. The survey showed that almost all respondents were affected by the pandemic in a variety of ways.

Suppression of the photoparoxysmal response in photosensitive epilepsy with cenobamate (YKP3089).

OBJECTIVE: To evaluate the effect of cenobamate in patients with photoparoxysmal-EEG response (PPR) to intermittent photic stimulation (IPS) as proof of principle of efficacy in patients with epilepsy. METHODS: In this multicenter, single-blind study, adults with photosensitive epilepsy, with/without concomitant antiepileptic drug therapy, underwent IPS under 3 eye conditions after a single dose of placebo (day -1, day 2) or cenobamate (day 1; 100, 250, or 400 mg). Complete suppression was a standardized photosensitivity range reduction to 0 over ≥1 time points for all eye conditions. Partial suppression was a ≥3-point reduction over ≥3 testing times vs the same time points on day -1 in ≥1 eye condition. Pharmacokinetics and safety were assessed. RESULTS: Of 6 evaluable patients, 5 reentered to receive higher doses. Cenobamate 100 mg produced partial suppression in 1 of 3 patients; 250 mg produced complete suppression in 1 of 4 and partial suppression in 4 of 4 patients; and 400 mg produced complete suppression in 1 of 4 and partial suppression in 2 of 4 patients. PPR was consistently reduced on days 1 and 2 (>24 hours after cenobamate) vs day -1 (placebo) with the 250- and 400-mg doses. Area under the plasma concentration-time curve (before dose to last measurable concentration) values between 201 and 400 µg/h/mL resulted in partial suppression in 4 of 6 (66%) patients. Most common adverse events were dizziness and somnolence. CONCLUSIONS: This proof-of-principle study demonstrated that cenobamate is a potentially effective product for epilepsy. CLINICALTRIALSGOV IDENTIFIER: NCT00616148. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that, for patients with photosensitive epilepsy, cenobamate suppresses IPS-induced PPR.

Seletracetam, a small molecule SV2A modulator for the treatment of epilepsy.

UCB SA was developing the high-affinity synaptic vesicle glycoprotein 2A ligand, seletracetam, an analog of levetiracetam, for the potential oral treatment of epilepsy. Phase II epilepsy trials were underway, but in July 2007, the company stated that development of seletracetam had been put on hold and it is unknown whether planned phase IIb/III trials will begin.

The Impact of p53 Dysfunction in ATR Inhibitor Cytotoxicity and Chemo- and Radiosensitisation.

Ataxia telangiectasia mutated and Rad3 related kinase (ATR) signals replication stress and DNA damage to S and G2 arrest and promotes DNA repair. Mutations in p53, critical for G1 checkpoint control, are common in cancer and predicted to confer vulnerability to ATR inhibitors. Reported data on the impact of p53 status are variable possibly because of the use of unmatched cells and surrogate endpoints of survival. The cytotoxicity of VE-821 alone and its ability to potentiate radiation and gemcitabine cytotoxicity was determined in isogenic and unmatched p53 wild-type (wt) and null/mutant cells, as well as immortalised nonmalignant MCF10 (immortalised non-neoplastic) cells, by colony-forming assay. The effect on cell cycle checkpoints was determined by flow cytometry. The isogenic p53 defective cells were not more sensitive to VE-821 alone. Defective p53 consistently conferred greater chemo- and radiosensitisation, particularly at high dose levels in isogenic cells but not unmatched cells. VE-821 did not sensitise MCF10 cells. We conclude that p53 status is just one factor contributing to chemo- and radiosensitisation by ATR inhibition, the lack of chemo- or radiosensitisation in the noncancerous cells suggests an element of tumour-specificity that warrants further investigation. The greater sensitisation at high-dose irradiation suggests that ATR inhibitors may be most effective with hypofractionated radiotherapy.

Bioequivalence Between Generic and Branded Lamotrigine in People With Epilepsy: The EQUIGEN Randomized Clinical Trial.

Importance: Switching between generic antiepileptic drugs is a highly debated issue that affects both clinical care and overall health care costs. Objective: To evaluate the single-dose pharmacokinetic bioequivalence of 3 (1 branded and 2 generic drugs) on-market, immediate-release lamotrigine drug products. Design, Setting, and Participants: The Equivalence Among Antiepileptic Drug Generic and Brand Products in People With Epilepsy (EQUIGEN) single-dose study is a crossover, prospective, sequence-randomized, replicate pharmacokinetic study conducted at 5 US academic epilepsy centers. Fifty adults (≥18 years) with epilepsy who were taking concomitant antiepileptic drugs and not currently receiving lamotrigine were enrolled between July 18, 2013, and January 19, 2015. Every participant was randomly assigned to 1 of 3 equivalent sequences, each comprising 6 study periods, during which they had blood draws before and after medication administration. Forty-nine participants were included in intention-to-treat analyses. Interventions: Participants received a single 25-mg dose of immediate-release lamotrigine at the start of each period, with the branded and the 2 most disparate generic products each studied twice. Lamotrigine was selected as the antiepileptic drug of interest because of its wide use, publications indicating problems with generic switches, and complaints to the US Food and Drug Administration regarding generic products. Both participants and study personnel were blinded to the specific generic products selected. Main Outcomes and Measures: The primary outcome was bioequivalence between products. Maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC) were compared, and average bioequivalence (ABE) was established if the 90% CIs of the ratios of the 2 products were within equivalence limits (80%-125%). Results: Of the 50 randomized participants, 49 (98%) received all 3 lamotrigine products and completed at least 3 pharmacokinetic assessments and 46 (92%) completed all 6 pharmacokinetic assessments. Among the 49 participants, 28 (57%) were men and 21 (43%) were women, 42 (86%) self-identified as white, and 46 (16) years was the mean (SD) age. The 3 drug products were considered bioequivalent because the 90% CIs were within equivalence limits (lowest and highest CI limits for Cmax, 92.6% and 110.4%; for AUC0-96, 96.9% and 101.9%). Replicate testing demonstrated no significant differences in within-subject variability across the 3 products (likelihood ratios, χ22 for log-transformed variables: AUC0-96, 2.58; Cmax, 0.64; and AUC0-∞, 4.05; P ≥ .13) and that the 3 products were also bioequivalent according to scaled ABE and individual bioequivalence criteria with no subject × formulation interaction (Cmax, 0.00; AUC0-96, 0.54; and AUC0-∞, 0.36; P ≥ .76). Conclusions and Relevance: This study provides evidence that the disparate lamotrigine products studied are bioequivalent when tested in people with epilepsy taking concomitant antiepileptic drugs. Trial Registration: clinicaltrials.gov Identifier: NCT01733394.