Long-term safety and efficacy of guanfacine extended release in children and adolescents with ADHD

Mining and analysis of adverse events profile of Guanfacine using FDA Adverse Event Reporting System (FAERS) database

OBJECTIVE

This study aims to evaluate the Guanfacine-associated adverse events (AEs) in real-world using data mining in FAERS database, seeking to provide safety profile and guidance for the potential therapeutic practices.

METHODS

We retrospectively extracted Guanfacine-associated AEs reports in the FAERS database from the first quarter of 2004 (Q1) to the fourth quarter of 2023 (Q4). All data were strictly collected and comprehensively analyzed. Disproportionality analyses, including the reporting odds ratio (ROR), the proportional reporting ratio (PRR), the Bayesian confidence propagation neural network (BCPNN), and the empirical Bayesian geometric mean (EBGM).

RESULTS

Out of 16,985,532 reports collected from the FAERS database, 2,709 reports of Guanfacine as the 'primary suspected (PS)' and 8,464 AEs induced by Guanfacine were identified. Most AEs reports (67.45%) occurred within the first 30 days of treatment (excluding unreported or unknown onset time reports). A total of 158 significant PTs that meet all four algorithms were detected. Known neuropsychiatric events and cardiovascular events documented in the drug's leaflet were found. Besides, unexpected significant AEs such as homicidal ideation, self-injurious ideation, growth failure, excessive eye blinking were also found.

CONCLUSION

Our study has unveiled novel Guanfacine-associated AEs signals and might provide guidance for its rational use.

Recent advances in pharmacological management of attention-deficit/hyperactivity disorder: moving beyond stimulants

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioral disorder characterized by impairing inattention and/or hyperactivity and impulsivity in children and adults. Although medications have been available to treat ADHD symptoms for decades, many are stimulant formulations. Stimulants, such as amphetamine and methylphenidate, are available in more than two dozen formulations, but all have similar adverse effects and carry a risk of misuse and dependence.

AREAS COVERED

In the United States (US), several nonstimulants are available to treat ADHD. Two, including atomoxetine and viloxazine extended-release (ER), are approved by the Food and Drug Administration for the treatment of ADHD in children and adults. Two others, clonidine ER and guanfacine ER, are only approved for children and adolescents in the US. Several other compounds are under investigation. Drugs in Phase 3 trials include centanafadine, solriamfetol, and L-threonic acid magnesium salt. Efficacy and safety data for nonstimulants is presented.

EXPERT OPINION

Although many effective formulations for the treatment of ADHD are available, more than 33% of children and 50% of adults discontinue treatment during the first year. The lack of individual drug response and tolerability are reasons many stop treatment. The development of new nonstimulants may offer hope for patients who need medication alternatives.

A systematic review of pharmacotherapy for attention-deficit/hyperactivity disorder in children and adolescents with bipolar disorders

INTRODUCTION

The data suggests that in children and adolescents, bipolar disorder (BD) and attention deficit hyperactivity disorder (ADHD) may be strongly correlated. Even though drugs for ADHD and BD are largely accepted, there is relatively little research on the management of comorbidity in children and adolescents, particularly in terms of safety. We provide a synthesis of these findings because one hasn't been made yet.

AREAS COVERED

As a primary outcome, we wanted to determine whether stimulant or non-stimulant treatment of children and adolescents with ADHD and comorbid BD was effective. As a secondary outcome, we wanted to determine tolerability, especially the risk of mood switch.

EXPERT OPINION

The findings of this systematic review suggest that methylphenidate, when used with a mood stabilizer, may be safe and not significantly increase the risk of a manic switch or psychotic symptoms when used to treat ADHD that co-occurs with a BD. In situations where stimulants are ineffective or have low tolerance, atomoxetine also seems to be a good alternative, and also in cases of co-morbid anxiety, oppositional defiant disorder, conduct disorders, ICT disorders, and substance use disorders. Additional research with a higher level of evidence is necessary to corroborate these preliminary findings.

Guanfacine for the Treatment of Attention-Deficit Hyperactivity Disorder: An Updated Systematic Review and Meta-Analysis

Background: Non-stimulant guanfacine is a common second-line medication for attention-deficit hyperactivity disorder (ADHD). Numerous randomized controlled trials (RCTs) have explored the efficacy of guanfacine in ADHD treatment. This meta-analysis combined data from selected RCTs to analyze the efficacy and safety of guanfacine in treating ADHD. Methods: RCTs were identified from published sources through searches in PubMed, Cochrane Library, Web of Science, and Embase (up to February 2022), defining the Clinical Global Impression of Improvement (CGI-I) treatment response score of ≤2 as the primary outcome. Subgroup analysis was performed with a bound treatment duration of 10 weeks. Safety was defined by treatment-emergent adverse events (TEAEs). Results: Twelve out of 332 studies with 2653 participants were included. All studies compared guanfacine with placebos. Guanfacine was significantly more effective in treating ADHD (Risk Ratio [RR] 1.78, 95% CI: 1.59-2.01). In the <10 weeks subgroup, the efficacy in the guanfacine group compared with the placebo group was 58.5% versus 29.4%, respectively (RR 1.97, 95% CI: 1.71-2.26). In the >10 weeks subgroup, the efficacy in the guanfacine group compared with the placebo group was 63.6% versus 39.7%, respectively (RR 1.57, 95% CI: 1.37-1.79). Both subgroups lacked heterogeneity (I² = 0), and a funnel plot showed a low publication bias risk. Around 80% of participants in the guanfacine group experienced at least one TEAE, compared with 66.5% in the placebo group (RR 1.23, 95% CI: 1.14-1.32), with low heterogeneity (I² = 46, p = 0.05). The most common TEAEs in the guanfacine group were somnolence (38.6%), headaches (20.5%), and fatigue (15.2%). Conclusions: Guanfacine is safe and effective for treating ADHD, with no serious adverse events. Guanfacine should be considered as an effective treatment option where effectiveness or tolerability of the central nervous system stimulant is of concern. There is stronger evidence of efficacy for children; more clinical studies are needed for adults.

The use of attention-deficit hyperactivity disorder medications in cardiac disease

Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder with onset usually in childhood characterized by inattention, impulsivity, and hyperactivity causing a functional impairment. Untreated ADHD, or treatment delay is associated with adverse outcomes and poor quality of life. Although conservative management strategies such as behavioral and psychological interventions are important, pharmacological treatment has a strong evidence base with improved outcomes. ADHD medications are broadly divided into stimulant and non-stimulant medications. Stimulant medications are generally more effective than non-stimulants. Cardiovascular safety of ADHD medication has been a matter of debate for decades. Treatment guidelines advise the careful consideration of risks and benefits in people with cardiovascular diseases such as congenital heart disease or cardiomyopathy. Although stimulants can increase systemic blood pressure and heart rate, no significant associations were found between their use and serious cardiovascular events. Concerns regarding QT effects and attendant sudden cardiac death risks deter clinicians from initiating much-needed ADHD medications in patients with heart disease. This overly cautious approach is potentially depriving low-risk individuals from significant benefits associated with timely ADHD drug treatment. This review discusses the cardiovascular risks reportedly associated with ADHD medications, the evidence base for their safe usage in persons with established cardiovascular disease, and highlights future research directions.

Predictors of Changes in Height, Weight, and Body Mass Index After Initiation of Central Nervous System Stimulants in Children with Attention Deficit Hyperactivity Disorder

OBJECTIVE

To identify predictors of changes in height, weight, and body mass index (BMI) in children with attention deficit hyperactivity disorder (ADHD) starting central nervous system (CNS) stimulants.

STUDY DESIGN

There were 230 medication-naïve children aged 5-12 years with ADHD who participated in a randomized trial evaluating the impact of CNS stimulants on growth over 30 months. This observational analysis focused on the 141 participants using study medication for 65 or more days in the first 6-months after starting medication. Biometric variables, ADHD, and oppositional defiant disorder symptom scores at medication initiation, and medication use over the study were examined as predictors of changes in standardized (z) height, weight, and BMI.

RESULTS

Mean changes in z-BMI, z-weight. and z-height were negative throughout the study. The most consistent predictors of change in z-BMI, z-weight, and z-height were percent days medicated and total medication exposure. Children with lower z-height and z-weight at medication initiation experienced greater z-BMI and z-weight decreases over the first 6 months on medication. Greater appetite suppression during dose optimization predicted greater decreases in z-weight over the entire study and a greater decrease in z-height over the first 6 months on medication. z-weight change correlated with z-height change. Behavioral symptoms did not predict changes in z-BMI, z-weight, or z-height.

CONCLUSIONS

How much and how often CNS stimulants are used predicts changes in z-BMI, z-weight, and z-height in children. Even smaller and lighter children may be at risk for decreases in z-weight and z-BMI. Parent ratings of appetite during dose titration may serve as feasible indicators of future weight and height change in children using CNS stimulants.

TRIAL REGISTRATION

Clinicialtrials.gov: NCT01109849.

Impact of CNS Stimulants for Attention-Deficit/Hyperactivity Disorder on Growth: Epidemiology and Approaches to Management in Children and Adolescents

Central nervous system stimulants are established treatments for pediatric attention-deficit/hyperactivity disorder with robust efficacy data. Reductions in appetite, weight, and growth velocity are some of the most common concerns regarding the long-term use of central nervous system stimulants in developing children. They are associated with suppression of weight and body mass index in childhood. However, both weight and body mass index often progressively increase over adolescence at rates faster than those seen in non-attention-deficit/hyperactivity disorder youth to the degree that attention-deficit/hyperactivity disorder is associated with elevated body mass index by the end of adolescence regardless of medication use. The capacity of central nervous system stimulants to slow growth was identified 50 years ago. Recent work has established that the growth deficits accumulate during the first 2 years of use and may persist provided medication is used. Early initiation coupled with persistent use through adolescence is most likely to be associated with clinical impactful growth suppression. There has been limited formal investigation of treatments for stimulant-associated reductions in weight and height. The most robust evidence exists for drug holidays improving weight gain. Observational studies suggest that limiting lifetime exposure or discontinuing medication is associated with greater adult height. Additional research is needed to identify the causal mechanisms driving the observed slowing in growth as well as the identification of predictors of clinically impactful growth suppression.

Efficacy and Safety of Medication for Attention-Deficit Hyperactivity Disorder in Children and Adolescents with Common Comorbidities: A Systematic Review

Introduction

Comorbid psychiatric conditions in children and adolescents with attention-deficit hyperactivity disorder (ADHD) occur frequently, complicate management, and are associated with substantial burden on patients and caregivers. Very few systematic reviews have assessed the efficacy and safety of medications for ADHD in children and adolescents with comorbidities. Of those that were conducted, most focused on a particular comorbidity or medication. In this systematic literature review, we summarize the efficacy and safety of treatments for children and adolescents with ADHD and comorbid autism spectrum disorders, oppositional defiant disorder, Tourette’s disorder and other tic disorders, generalized anxiety disorder, and major depressive disorder.

Methods

We searched MEDLINE, Embase, and ClinicalTrials.gov (to October 2019) for studies of patients (aged < 18 years) with an ADHD diagnosis and the specified comorbidities treated with amphetamines, methylphenidate and derivatives, atomoxetine (ATX), and guanfacine extended-release (GXR). For efficacy, placebo-controlled randomized controlled trials (RCTs) or meta-analyses of RCTs were eligible for inclusion; for safety, all study types were eligible. The primary efficacy outcome measure was ADHD Rating Scale IV (ADHD-RS-IV) total score.

Results

Of 2177 publications/trials retrieved, 69 were included in this systematic literature review (5 meta-analyses, 37 placebo-controlled RCTs, 16 cohort studies, 11 case reports). A systematic narrative synthesis is provided because insufficient data were retrieved to combine ADHD-RS-IV total scores or effect sizes. Effect sizes for ADHD-RS-IV total scores were available for ten RCTs and ranged from 0.46 to 1.0 for ATX and from 0.92 to 2.0 for GXR across comorbidities. The numbers and types of adverse events in children with comorbidities were consistent with those in children without comorbidities, but treatment should be individualized to ensure children can tolerate the lowest effective dose.

Conclusion

Limited information is available from placebo-controlled RCTs on the efficacy (by ADHD-RS-IV) or safety of medication in children with ADHD and psychiatric comorbidities. Further studies are required to support evidence-based drug selection for these populations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-021-00249-0.

Retrospective analysis of adverse events associated with non-stimulant ADHD medications reported to the united states food and drug administration

Attention deficit hyperactivity disorder (ADHD) is one of the most common neurobehavioral disorders in children and although stimulant medications remain first line to treat the disorder, some families prefer nonstimulants. The goal is to analyze the adverse events (AE) associated with nonstimulant medications using post-marketing drug surveillance data. We aim to increase awareness and aide patient education. A retrospective study of adverse drug events with atomoxetine, clonidine, and guanfacine was performed using the Federal Drug Administration Adverse Event Reporting System (FAERS) Database. Results show that the most commonly reported AEs, as defined by FAERS, were ineffectiveness (9.91-14.15%) fatigue (8.93%), and somnolence (8.8-10.16%). Of those taking atomoxetine, suicidal and self-injurious ideation was reported to a similar degree amongst all age groups. Suicidal ideation was listed within the top 20 most reported AEs for all three medications. It is more likely that some patients will experience milder side effects. We suggest providing these data to patients to help overcome the stigma of starting medication, especially if they prefer nonstimulants. Serious AEs are still reported to a small degree, thus monitoring and consistent patient education remains important. We also recommend educating a wider demographic of patients about recognizing potential development of suicidal thoughts.

Efficacy and safety of guanfacine extended-release in Japanese adults with attention-deficit/hyperactivity disorder: Exploratory post hoc subgroup analyses of a randomized, double-blind, placebo-controlled study

Aim

Previously, we reported on the efficacy and safety of guanfacine extended‐release (GXR) in Japanese adults with attention‐deficit/hyperactivity disorder (ADHD) from a phase 3, double‐blind, placebo‐controlled, randomized trial. In this exploratory post hoc analysis, we assessed the efficacy and/or safety of GXR in the following subgroups: ADHD‐combined (ADHD‐C) and ADHD‐predominantly inattentive (ADHD‐I) subtypes, age (≥31, <31 years), sex (male, female), and body weight (≥50, <50 kg).

Methods

The primary efficacy endpoint was change from baseline in the Japanese version of the investigator‐rated ADHD‐Rating Scale‐IV (ADHD‐RS‐IV) with adult prompts (total scores) at week 10.

Results

The efficacy analysis population included 200 patients (GXR, 100; placebo, 100). ADHD‐RS‐IV total score effect sizes (GXR vs placebo) were similar across all subgroups (total population: 0.52, ADHD‐C: 0.51, ADHD‐I: 0.52, ≥31 years: 0.61, <31 years: 0.47, male: 0.50, female: 0.57). There were no major differences in the incidence/types of treatment‐emergent adverse events (TEAEs) across the subgroups. The incidence of significant TEAEs (34.3%, 10.6%) and TEAEs leading to discontinuation (34.3%, 12.1%) were approximately three times higher in females than males, respectively. The incidence of TEAEs in patients weighing <50 kg and ≥50 kg was 100% and 73.6% during dose optimization and 40% and 24.4% during the maintenance period, respectively.

Conclusion

Findings from this post hoc analysis in adults with ADHD support the efficacy and safety of GXR regardless of ADHD subtype, age, or sex and suggest that careful monitoring for TEAEs and GXR dose optimization is considered for all patients, as needed.

In this exploratory post hoc analysis, we assessed the efficacy and/or safety of guanfacine extended release (GXR) in the following subgroups: attention‐deficit/hyperactivity disorder (ADHD) subtypes (ADHD‐combined, ADHD‐predominantly inattentive), age (≥31 years, <31 years), sex (male, female), and body weight (<50 kg, ≥50 kg). ADHD‐Rating Scale‐IV with adult prompts total score effect sizes (GXR vs placebo at 10 weeks) were similar across all subgroups. The findings support the efficacy and safety of GXR in adults regardless of ADHD subtype, age, or sex and suggest that careful monitoring for TEAEs and GXR dose optimization is considered for all patients, as needed.

Reviewing the role of emerging therapies in the ADHD armamentarium

Introduction: Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioral disorder that can be treated with both pharmacologic and nonpharmacologic modalities. Effective drug treatments for ADHD have been available for more than six decades. However, initial treatments had limitations in duration of effect, need for multiple daily doses, requirement for patients to swallow intact tablets, adverse effects and risk for abuse and diversion. During the past 20 years, more than two dozen stimulant and nonstimulant drugs have been developed. Nonetheless, there remain unmet needs in the treatment of ADHD.Areas covered: New stimulant and nonstimulant formulations in development are reviewed with emphasis on drugs in phase II and III trials. Efficacy, mechanism of action and adverse effect data are described where available. Abuse liability studies are described for abuse-deterrent formulations in development.Expert opinion: The review found a robust pipeline of stimulants and nonstimulants. Medications in development are formulated to optimize onset and duration of effect, alter the time of administration, obviate the need to swallow whole capsules or tablets and to deter abuse. While each of these formulations may fill a unique niche, these incremental improvements based on new drug delivery technologies may lead to very significant clinical effects.

Safety and efficacy of guanfacine extended-release in adults with attention-deficit/hyperactivity disorder: an open-label, long-term, phase 3 extension study

BACKGROUND

To assess the safety and efficacy of long-term administration of guanfacine extended-release (GXR) in adults with attention-deficit/hyperactivity disorder (ADHD).

METHODS

In this open-label, long-term, phase 3 extension study in Japan, 150 patients transitioned from a double-blind trial, and 41 newly enrolled patients received once daily GXR (starting dose 2 mg/day, maintenance dose 4-6 mg/day) for 50 weeks. Primary outcome measures were the frequency and nature of treatment-emergent adverse events (TEAEs); secondary outcome measures included the change from week 0 in ADHD Rating Scale IV with Adult Prompts (ADHD-RS-IV; Japanese version) total and subscale scores, Conners' Adult ADHD Rating Scales (CAARS), Clinical Global Impression-Improvement (CGI-I) and Patient Global Impression-Improvement (PGI-I) scales, and quality of life (QoL) and executive functioning measures.

RESULTS

Of all patients, 94.2% (180/191) reported ≥1 TEAE and 19.9% (38/191) discontinued because of a TEAE. Most TEAEs were mild to moderate in severity; there were two serious TEAEs and no deaths. Commonly reported TEAEs (≥10% of patients) were somnolence, thirst, nasopharyngitis, decreased blood pressure, postural dizziness, bradycardia, malaise, constipation, and dizziness. Mean changes from week 0 in ADHD-RS-IV total and subscale scores and CAARS subscale scores were significantly improved in former placebo or GXR patients and new patients at last observation (p < .0001), and the percentage of patients with very much or much improved CGI-I and PGI-I scores increased.

CONCLUSIONS

There were no major safety concerns during long-term GXR administration in adults with ADHD. After long-term treatment, patients had significant improvements from baseline in ADHD symptoms, QoL, and executive functioning.

TRIAL REGISTRATION

Japan Primary Registries Network ( https://rctportal.niph.go.jp/en/ ): JapicCTI-163232, registered 04/21/2016.

Characterization of Severe and Extreme Behavioral Problems in Patients With Alternating Hemiplegia of Childhood

BACKGROUND

Alternating hemiplegia of childhood often manifests severe or extreme behavioral problems, the nature of which remains to be fully characterized.

METHODS

We analyzed 39 consecutive patients with alternating hemiplegia of childhood for occurrence of behavioral problems and categorized those by severity: mild (not requiring intervention), moderate (requiring intervention but no risk), severe (minor risk to self, others, or both), and extreme (major risk). We then analyzed behavioral manifestations, concurrent morbidity, and medication responses in patients with severe or extreme symptoms.

RESULTS

Two patients had mild behavioral problems, five moderate, 10 severe, six extreme, and 16 none. Extreme cases exhibited disruptive behaviors escalating to assaults. Triggers, when present, included peer-provocation, low frustration tolerance, limits set by others, and sleep disruption. Reversible psychotic symptoms occurred in two patients: in one triggered by infection and trihexyphenidyl, and in another triggered by sertraline. Of the 16 patients with severe or extreme symptoms, 13 had concurrent neuropsychiatric diagnoses. Occurrence of severe or extreme symptoms did not correlate with age, puberty, severity of intellectual disability, or mutation status (P > 0.05). A multidisciplinary team including mental health professionals comanaged all patients with severe or extreme symptoms with either behavioral therapy, medications, or both. When considering medications prescribed to more than four patients, medicines that demonstrated efficacy or partial efficacy in more than 50% of patients were alpha-adrenergic agonists and selective-serotonin-reuptake-inhibitors.

CONCLUSIONS

Patients with alternating hemiplegia of childhood (41%) often experience severe or extreme behavioral problems and, rarely, medication-triggered psychotic symptoms. These observations are consistent with current understanding of underlying alternating hemiplegia of childhood brain pathophysiology. Increasing awareness of these behavioral problems facilitates alternating hemiplegia of childhood management and anticipatory guidance.

Weight and Height in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder: A Longitudinal Database Study Assessing the Impact of Guanfacine, Stimulants, and No Pharmacotherapy

Objectives: To assess the impact of long-term pharmacotherapy with guanfacine immediate- or extended-release (GXR), administered alone or as an adjunctive to a stimulant, on weight and height in children and adolescents with attention-deficit/hyperactivity disorder (ADHD). Methods: Data were extracted from U.S. Department of Defense medical records for patients 4-17 years of age at index date (initiation of any study medication following a year without ADHD medications, or diagnosis if unmedicated) with weight/height measurements for the analysis period (January 2009-June 2013) and the previous year (baseline). Longitudinal weight and height z-scores were analyzed using multivariable regression in three cohorts: guanfacine (initial period of guanfacine exposure), first-line stimulant monotherapy (initial period of exposure), and unmedicated. Guanfacine cohort subgroups were based on previous/concurrent stimulant exposure. Results: The weight analyses included 47,910 patients (66.8% male) and the height analyses 41,248 (67.2% male). Mean initial exposure in the weight analyses was 237 days (standard deviation [SD] = 258, median = 142) for guanfacine and 257 days (SD = 284, median = 151) for first-line stimulant monotherapy, and was similar in the height analyses. Modeling indicated that guanfacine monotherapy was not associated with clinically meaningful deviations from normal z-score trajectories for weight (first-line, n = 943; nonfirst-line, n = 796) or height (first-line, n = 741; nonfirst-line, n = 644). In patients receiving guanfacine adjunctive to a stimulant, modeled weight (n = 1657) and height (n = 1343) z-scores followed declining trajectories. In this subgroup, mean standardized weight/height had decreased during previous stimulant monotherapy. For first-line stimulant monotherapy, modeled weight (n = 32,999) and height (n = 28,470) z-scores followed declining trajectories during year 1. In the unmedicated cohort, modeled weight (n = 11,515) and height (n = 10,050) z-scores were stable. Conclusions: Guanfacine monotherapy (first-line or nonfirst-line) was not associated with marked deviations from normal growth in this modeling study of children and adolescents with ADHD. In contrast, growth trajectories followed an initially declining course with stimulants, whether given alone or with adjunctive guanfacine.

Guanfacine Extended Release for the Reduction of Aggression, Attention-Deficit/Hyperactivity Disorder Symptoms, and Self-Injurious Behavior in Prader-Willi Syndrome-A Retrospective Cohort Study

Objective: To examine the role of Guanfacine Extended Release (GXR) in the management of behavioral disturbances in patients with Prader-Willi Syndrome (PWS). Methods: Twenty from a total of 27 individuals with genetically confirmed PWS, 6-26 years of age, with the following symptoms were identified: significant aggression/agitation, skin picking, and/or symptoms of attention-deficit/hyperactivity disorder (ADHD). Response to GXR for the above noted symptoms was categorized as improved, worsened, or unchanged, while assessing for side effects and tolerability. Results: Eleven of the 20 individuals reported skin-picking, 17 reported aggression/agitation, and 16 reported symptoms of ADHD. Nine (81.8%), 14 (82.3%), and 15 (93.7%) individuals showed an improvement in skin-picking, aggression/agitation, and ADHD, respectively, while on GXR treatment. Two patients with prior complaints of psychotic symptoms did not respond to GXR. Of note, no abnormal weight gain or significant adverse reaction was observed in this group, while on GXR. Conclusions: In this study, GXR demonstrated improvement in symptoms of skin picking, aggression/agitation, and ADHD in patients with PWS. GXR was not effective in reducing psychosis or agitation related to psychotic symptoms. Future studies are warranted to further establish the utility of GXR in PWS patients.