Challenges in developing drugs for pediatric CNS disorders: A focus on psychopharmacology

[Particularities and problems of psychopharmacology in childhood and adolescence]

The drug treatment of mental illness in childhood and adolescence poses a particular clinical and legal challenge. Reasons for this include the often necessary off-label use and existing knowledge gaps regarding the long-term effects of the neuro-/psychotropic drugs used. In this article, the prerequisites for therapy with neuro/psychotropic drugs, such as the need for age-appropriate inclusion of children and adolescents in the decision-making and education process, as well as the evaluation of medication, the consideration of biological age- and maturation-related factors, and the special measures for off-label use, are discussed. We further discuss general problems in the development and use of neuro-/psychotropic drugs, such as the difficulties in relation to proof of effectiveness, reimbursement and liability issues of off-label administration, and the problems of conducting clinical trials with children and adolescents.

Sequential bilateral accelerated theta burst stimulation in adolescents with suicidal ideation associated with major depressive disorder: Protocol for a randomized controlled trial

BACKGROUND

Suicide is a leading cause of death in adolescents worldwide. Previous research findings suggest that suicidal adolescents with depression have pathophysiological dorsolateral prefrontal cortex (DLPFC) deficits in γ-aminobutyric acid neurotransmission. Interventions with transcranial magnetic stimulation (TMS) directly address these underlying pathophysiological deficits in the prefrontal cortex. Theta burst stimulation (TBS) is newer dosing approach for TMS. Accelerated TBS (aTBS) involves administering multiple sessions of TMS daily as this dosing may be more efficient, tolerable, and rapid acting than standard TMS.

MATERIALS AND METHODS

This is a randomized, double-blind, sham-controlled trial of sequential bilateral aTBS in adolescents with major depressive disorder (MDD) and suicidal ideation. Three sessions are administered daily for 10 days. During each session, continuous TBS is administered first to the right DPFC, in which 1,800 pulses are delivered continuously over 120 seconds. Then intermittent TBS is applied to the left DPFC, in which 1,800 pulses are delivered in 2-second bursts and repeated every 10 seconds for 570 seconds. The TBS parameters were adopted from prior research, with 3-pulse, 50-Hz bursts given every 200 ms (at 5 Hz) with an intensity of 80% active motor threshold. The comparison group will receive 3 daily sessions of bilateral sham TBS treatment for 10 days. All participants will receive the standard of care for patients with depression and suicidal ideation including daily psychotherapeutic skill sessions. Long-interval intracortical inhibition (LICI) biomarkers will be measured before and after treatment. Exploratory measures will be collected with TMS and electroencephalography for biomarker development.

DISCUSSION

This is the first known randomized controlled trial to examine the efficacy of sequential bilateral aTBS for treating suicidal ideation in adolescents with MDD. Results from this study will also provide opportunities to further understand the neurophysiological and molecular mechanisms of suicidal ideation in adolescents.

TRIAL REGISTRATION

Investigational device exemption (IDE) Number: G200220, ClinicalTrials.gov (ID: NCT04701840). Registered August 6, 2020. https://clinicaltrials.gov/ct2/show/NCT04502758?term=NCT04701840&draw=2&rank=1.

Drug Development for New Psychiatric Drug Therapies

Drug development is an expensive, high risk, and highly regulated process. Only about 6.2% of new molecules tested for mental disorders eventually achieve Food and Drug Administration (FDA) approval. New molecular entities are produced, and extensive in vitro animal testing is performed before they are evaluated in humans. The compound is used in animals to predict clinical effects in humans, and studies addressing pharmacodynamics, pharmacokinetics, toxicology, and mutagenicity are conducted. Human research proceeds in three stages with the ultimate goal of proving that a new agent is efficacious and safe for a treatment of a specific disease in humans. If efficacy and safety are demonstrated in two Phase III studies, then the sponsor can submit a new drug application (NDA) to the FDA. The FDA oversees each step of the process to assure that good research practices are followed, data integrity is assured, and human research subjects are protected.

How Compounding Pharmacies Fill Critical Gaps in Pediatric Drug Development Processes: Suggested Regulatory Changes to Meet Future Challenges

Drugs administered to children in the United States fall into two broad categories: (1) those that have followed the US Food and Drug Administration (US-FDA) pediatric drug approval process and are marketed as finished dosage forms with pediatric labeling; and (2) all others, many of which are used "off-label". The use of most drug products in pediatrics is still off label, often requiring special preparation, packaging, and, in some cases, compounding into preparations. The latter category includes compounded preparations that incorporate either a US-FDA approved finished dosage form (e.g., a sterile solution, sterile powder, nonsterile capsules, oral solution, crushed tablets, etc.), or rely on bulk active pharmaceutical ingredients (APIs). Compounded preparations are prepared for individual patients in 503A pharmacies, or on a larger scale and not just for specific patients, in licensed 503B establishments. Critical gaps in the current drug approval process for finished dosage forms have created a proverbial "Gordian knot" that needs to be untangled thoughtfully to facilitate increased production and approval of vitally needed medications for pediatric patients. This opinion will describe current regulatory processes pertaining to pediatrics-only drug approval in the United States. Additionally, discussed are steps required for a product to acquire pediatric labeling. Gaps in regulatory approval pathways for both manufactured and compounded pediatric drugs will be identified, especially those that complicate and slow development and availability to patients. Finally, suggestions for regulatory modifications that may enhance pediatric product development strategies for both manufacturers and compounders are suggested.

Epidemiological and Psychopharmacological Study About Off-Label Treatment in Child and Adolescent Psychiatric Emergencies: A Tertiary/Single Center Experience

OBJECTIVE

The study used an epidemiological and pharmacological description of child and adolescent psychiatric emergencies (CAPEs), during which psychotropic medications are frequently administered as off-label therapies.

METHODS

We retrospectively describe CAPE in 190 patients (mean age, 14.7 years) referring in the emergency department of a single tertiary center, from June 2016 to June 2018, focusing on off-label administration rate, most of all in emergency setting.

RESULTS

An intrinsic fragility was observed in this population, where 28.4% of patients present a history of self-harm, 24.7% a concomitant neurodevelopmental disorder, and 17.3% a history of substance abuse. Psychomotor agitation was the most frequent referral reason, and it represents an unspecified clinical presentation of several conditions, while self-harm showed a stronger association with depressive disorders (55.2%).Globally, 811 medications were administered both as baseline therapy (67.8% of off-label rate) and/or in the emergency setting, where the off-label rate raised to 78.3%. Benzodiazepines had the highest rate of off-label use (98.2% as baseline therapy, 92.9% in acute context). Nevertheless, in 83.5% cases of acute administrations, a singular oral benzodiazepine (mostly lorazepam) guaranteed psychomotor agitation resolution, with a lower rate of adverse effects in contrast with atypical antipsychotics.

CONCLUSIONS

Off-label drug use in CAPEs is a recurrent clinical practice. An international agreement about off-label drugs is crucial to obtain standard long-term pharmacoepidemiological, safety, and efficacy data. Pharmacological pediatric trials and international guidelines are also required to regulate pharmacological treatments of CAPEs, most of all in emergency settings.

Management of Depression in Adolescents in Japan

Objectives: In Japan, there are currently no approved antidepressant treatments for pediatric patients with depression. This study aimed to estimate the prevalence of depression among adolescents under medical care in Japan, the pharmacological treatments used, and the perceived unmet needs among the medical specialties treating depression in the pediatric population. Methods: The study was conducted in November 2014 as an internet survey among physicians in clinical practice. It included a sample of 731 physicians with the potential to treat adolescent patients with depression and 161 physicians who had treated at least one adolescent with depression with pharmacotherapy in the previous 12 months. Of the sample of 161 treating physicians, 60 were internal medicine specialists, 73 were psychiatrists, and 28 were certified specialists from the Japanese Society of Child and Adolescent Psychiatry, Japanese Society of Psychosomatic Medicine Pediatrics, or Japanese Society of Pediatric Psychiatry and Neurology. The participants completed questionnaires concerning their patient population with depression, drug-treated population, and drugs prescribed. Results: Estimates of prevalence data indicated that there were ∼550,000 adolescent patients with depression in Japan (10% of the patient population with depression) under medical care of different medical specialties; ∼64% of these patients were receiving pharmacotherapy. Pharmacotherapy for adolescents with depression was prescribed mainly by psychiatrists (62% of prescriptions for these patients). The most common first-choice agent was sertraline (23% of respondents) followed by anxiolytics (17%) and fluvoxamine (13%), while antipsychotics were the preferred choice for 7%. Conclusion: The study indicates a high prevalence of depression among adolescents in Japan. These patients are seen by different medical specialties; the use of pharmacotherapy is relatively common and comprises various drug classes, including antidepressants, anxiolytics, and antipsychotics. This study shows that there is a medical need for approved treatments for adolescents with depression in Japan.

Efficacy and safety of memantine in children with autism spectrum disorder: Results from three phase 2 multicenter studies

Three phase 2 trials were conducted to assess the efficacy and long-term safety of weight-based memantine extended release (ER) treatment in children with autism spectrum disorder. MEM-MD-91, a 50-week open-label trial, identified memantine extended-release treatment responders for enrollment into MEM-MD-68, a 12-week randomized, double-blind, placebo-controlled withdrawal trial. MEM-MD-69 was an open-label extension trial in which participants from MEM-MD-68, MEM-MD-91, and open-label trial MEM-MD-67 were treated ⩽48 weeks with memantine extended release. In MEM-MD-91, 517 (59.6%) participants were confirmed Social Responsiveness Scale responders at week 12; mean Social Responsiveness Scale total raw scores improved two to three times a minimal clinically important difference of 10 points. In MEM-MD-68, there was no difference between memantine and placebo on the primary efficacy parameter, the proportion of patients with a loss of therapeutic response (defined as ⩾10-point increase from baseline in Social Responsiveness Scale total raw score). MEM-MD-69 exploratory analyses revealed mean standard deviation improvement in Social Responsiveness Scale total raw score of 32.4 (26.4) from baseline of the first lead-in study. No new safety concerns were evident. While the a priori-defined efficacy results of the double-blind trial were not achieved, the considerable improvements in mean Social Responsiveness Scale scores from baseline in the open-label trials were presumed to be clinically important.

The Role of Vitamins in Autism Spectrum Disorder: What Do We Know?

Vitamin or mineral supplementation is considered to be the most commonly used medical treatment for autism spectrum disorder (ASD), in addition to other interventions such as neurological and psychological interventions. There is not much evidence of therapeutic efficacy between vitamin and mineral supplementation and improvements in ASD. However, several researchers have noted that patients with ASD have various metabolic and nutritional abnormalities including issues with sulfation, methylation, glutathione redox imbalances, oxidative stress, and mitochondrial dysfunction. There is some evidence that vitamin and mineral supplementation may support these basic physiologic processes. Recently, the nutritional status of ASD patients has been gaining focus in this particular area. Pointing out the nutritional status as a potential etiological factor for attention/communication disorders, more importance has been given to this particular point. Moreover, autistic specific considerations like the feature and behavior of ASD might be increased or at least fall in the higher risk due to the sub-optimal nutritional status.

Transcranial Magnetic Stimulation for Adolescent Depression

Adolescent depression is a substantial global public health problem that contributes to academic failure, occupational impairment, deficits in social functioning, substance use disorders, teen pregnancy, and completed suicide. Existing treatment options often have suboptimal results and uncertain safety profiles. Transcranial magnetic stimulation may be a promising, brain-based intervention for adolescents with depression. Existing work has methodological weaknesses, and larger, neurodevelopmentally informed studies are urgently needed. Treatment with transcranial magnetic stimulation may modulate cortical GABAergic and glutamatergic imbalances. Future study will inform dosing approaches for TMS based on GABAergic and glutamatergic biomarkers.

Quetiapine extended release versus aripiprazole in children and adolescents with first-episode psychosis: the multicentre, double-blind, randomised tolerability and efficacy of antipsychotics (TEA) trial

BACKGROUND

Head-to-head trials to guide antipsychotic treatment choices for paediatric psychosis are urgently needed because extrapolations from adult studies might not be implementable. In this superiority trial with two-sided significance testing, we aimed to compare the efficacy and safety of quetiapine-extended release (quetiapine-ER) versus aripiprazole in children and adolescents with first-episode psychosis, to determine whether differences between the two treatments were sufficient to guide clinicians in their choice of one drug over the other.

METHODS

In this multicentre, double-blind, randomised trial in seven Danish university clinics, we recruited children and adolescents aged 12-17 years with a diagnosis of ICD-10 schizophrenia-spectrum disorder, delusional disorder, or affective-spectrum psychotic disorder, and psychotic symptoms scoring at least 4 on at least one of the following Positive and Negative Syndrome Scale (PANSS) items: P1 (delusions), P2 (conceptual disorganisation), P3 (hallucinations), P5 (grandiosity), P6 (suspiciousness/persecution), and G9 (unusual thought content), and a total PANSS score greater than 60. Patients were randomly assigned (1:1) to 12 weeks of treatment with target doses of 600 mg/day of quetiapine-ER (starting from 50 mg/day) or 20 mg/day of aripiprazole (starting from 2·5 mg/day). The assigned drug was titrated over five levels, with 2 days at each dose, and the final dose achieved on day 9. Randomisation was done using a computer-generated concealed sequence with a block size of 8, and stratified by baseline PANSS positive score (≤20 points or >20 points) and age (12-14 years or 15-17 years). Study drugs were administered in identical capsules, and interventions, assessments, and data analysis were done masked. The primary outcome was PANSS positive score. Key adverse outcomes were bodyweight, homoeostatic model of insulin resistance (HOMA-IR), akathisia, and sedation. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01119014.

FINDINGS

Between June 10, 2010, and Jan 29, 2014, 231 participants were assessed for elegibility, of whom 113 were randomly assigned to quetiapine-ER (n=55) or aripiprazole (n=58). PANSS positive score did not differ between groups after 12 weeks (adjusted mean change -5·05 [5·46] for quetiapine-ER, -6·21 [5·42] for aripiprazole; p=0·98), but decreased over time in both groups (p<0·0001). Weight gain was more rapid with quetiapine-ER (p=0·0008), with an adjusted mean weight group difference at week 12 of 3·33 kg (SD 7·23; effect size 0·64; p<0·0001). The HOMA-IR group difference at week 12 favoured aripiprazole (adjusted mean log-transformed group difference 0·259 [SD 0·906]; effect size 0·35; p=0·0060). Akathisia was more common with aripiprazole at week 2 (observed in 34 [60%] of 57 patients; estimated 63·5%) than with quetiapine-ER (15 [30%] of 50; estimated 31·3%; p=0·0021), but not at other timepoints. Sedation proportions did not change significantly over time with either intervention (observed at weeks 2, 4, and 12, respectively, for quetiapine-ER in 43 [83%] of 52, 40 [83%] of 48, and 34 [72%] of 47 patients and for aripiprazole in 49 [89%] of 55, 52 [96%] of 54, and 44 [92%] of 48 patients), and the overall estimated probability combining all timepoints was significantly higher for aripiprazole (97·1%) than for quetiapine-ER (89·2%; p=0·012). In addition to sedation and akathisia, the most common adverse events were tremor (42 [79%] patients in the quetiapine-ER group vs 52 [91%] patients in the aripiprazole group), increased duration of sleep (47 [92%] vs 39 [71%]), orthostatic dizziness (42 [78%] vs 46 [81%]), depression (43 [80%] vs 44 [77%]), tension/inner unrest (37 [69%] vs 50 [88%]), failing memory (41 [76%] vs 44 [77%]), and weight gain (46 [87%] vs 38 [68%]).

INTERPRETATION

This first head-to-head comparison of quetiapine-ER versus aripiprazole in early-onset psychosis showed no significant group differences in severity of psychopathology after 12 weeks of treatment. Quetiapine-ER was associated with more metabolic adverse events and aripiprazole with more initial akathisia and, unexpectedly, more sedation. The limited antipsychotic efficacy and high level of adverse events were noticeable. This trial provides novel information for the treatment of early-onset psychosis and highlights the importance of adverse event profiles when choosing among antipsychotics for children and adolescents who often require chronic treatment.

FUNDING

The National Research Council for Health and Disease Foundation for Health Promotion, AP Møller Foundation, Rosalie Petersens Foundation, Stevn and Rindom Foundation, Foundation for the Promotion of Medical Science, The Capital Region Psychiatric Research Foundation, Tryg Foundation, Region of Southern Denmark Research Foundation, Danish Psychiatric Research Educational Fund, Psychiatry Foundation, Foundation of 17-12-1981, Psychiatric Research Foundation Region Zealand, Capital Region Strategic Research Foundation, Knud og Dagny Andresens Foundation, Psychiatric Research Foundation of 1967, The Capital Region Research Foundation, Dr Sofus Carl Emil Friis and Hustru Olga Friis Scholarship, Tømrerhandler Johannes Fogs Foundation, Brdr Hartmanns Foundation DKK, Aase and Ejnar Danielsens Foundation, Jacob Madsen and wife Olga Madsens Foundation, CC Klestrup and wife Scholarship, Lundbeck Foundation Scholarship, and Tømrermester Jørgen Holm and wife Elisas Scholarship.