A double-blind, placebo-controlled crossover study investigating the effect of porcine secretin in children with autism

Recent Developments in Treatment Outcome Measures for Young Children With Autism Spectrum Disorder (ASD)

Significant advancements have been made in early intervention programs for children with Autism spectrum disorder (ASD). However, measuring treatment response for children with ASD is difficult due to the heterogeneity of changes in symptoms, which can be subtle, especially over a short period of time. Here we outline the challenge of evaluating treatment response with currently available measures as well as newly developed or refined measures that may be useful in clinical trials for young children with ASD. Continued development of treatment outcome measures will help the field identify and compare efficacious interventions and tailor treatments for children with ASD.

Randomized controlled trial of transdermal secretin on behavior of children with autism

Previous trials of secretin for the treatment of autism have utilized a single or double dose administered intravenously. This is a report of a double-blind, randomized, controlled crossover trial of transdermally applied secretin in 15 children diagnosed with autism or pervasive developmental delay. Secretin or placebo was applied daily, in ointment form, to the backs of the children in randomized, successive 4 week periods with an intermediate 6 week washout period. Behavioral outcomes were measured by parents and teachers using the Autism Treatment Evaluation Checklist. Overall, there were no statistically significant differences in speech, sociability, sensory, and health scores for treatment versus placebo periods. In addition, there were no differences in such scores for children with a history of diarrhea. Severity of autism was significantly greater at baseline in children receiving concomitant medications. Improvement in speech was found during the treatment phase of the trial ( p = 0.0479 for secretin versus placebo) only in children not using other medications.

Measuring social communication behaviors as a treatment endpoint in individuals with autism spectrum disorder

Social communication impairments are a core deficit in autism spectrum disorder. Social communication deficit is also an early indicator of autism spectrum disorder and a factor in long-term outcomes. Thus, this symptom domain represents a critical treatment target. Identifying reliable and valid outcome measures for social communication across a range of treatment approaches is essential. Autism Speaks engaged a panel of experts to evaluate the readiness of available measures of social communication for use as outcome measures in clinical trials. The panel held monthly conference calls and two face-to-face meetings over 14 months. Key criteria used to evaluate measures included the relevance to the clinical target, coverage of the symptom domain, and psychometric properties (validity and reliability, as well as evidence of sensitivity to change). In all, 38 measures were evaluated and 6 measures were considered appropriate for use, with some limitations. This report discusses the relative strengths and weaknesses of existing social communication measures for use in clinical trials and identifies specific areas in need of further development.

Intravenous secretin for autism spectrum disorders (ASD)

BACKGROUND

In 1998 secretin, a gastrointestinal hormone, was suggested as an effective treatment for autism spectrum disorders (ASD) based on anecdotal evidence.

OBJECTIVES

To assess whether intravenous secretin improves the core features of ASD, other aspects of behaviour or function such as self-injurious behaviour, and the quality of life of affected individuals and their carers. We also assessed whether secretin causes harm. This is an updated version of our review of this topic originally published in 2005.

SEARCH METHODS

We searched CENTRAL (2010 Issue 1), MEDLINE (1950 to January 2010) , EMBASE (1980 to 2010 Week 2), PsycINFO (1806 to 2010 Week 2), CINAHL (1938 to January 2010), ERIC (1966 to January 2010), Sociological Abstracts (1952 to January 2010). Sociofile and HealthStar were searched in March 2005 when this review was first published, but were not available for this update. Records were limited to studies published since 1998 as this is when secretin was first proposed as a possible treatment for ASD. We searched reference lists of trials and reviews; we also contacted experts and trialists to find unpublished studies.

SELECTION CRITERIA

Randomised controlled trials of intravenous secretin compared to a placebo treatment in children or adults diagnosed with ASD, where at least one standardised outcome measure was reported.

DATA COLLECTION AND ANALYSIS

Sixteen studies met the inclusion criteria but for two of these, conducted by Repligen, the only available multisite data were reported in press releases. All outcome data from the other 14 trials were continuous. Where trials used cross-over designs, we conducted analysis on results from the first treatment phase. Where mean change from baseline was reported, we used this in preference to post-treatment scores for meta-analyses or forest plots. Meta-analysis was able to be attempted for only one outcome (Childhood Autism Rating Scale). Insufficient data were available to conduct sensitivity or subgroup analyses to assess the impact of study quality, clinical differences in the intervention or clinically relevant differences between groups, such as age or presence of gastrointestinal symptoms.

MAIN RESULTS

Over 900 children were recruited for the secretin trials. Twenty-five established standardised outcome measures were reported to assess core features of ASD, communication, behaviour, visuospatial skills, affect and adverse events. One standardised measure of global impression was also used. No more than four studies used any one outcome measure similarly. When duration from the start of the intervention to outcome assessment was known, outcomes were reported at between three and six weeks. Meta-analysis of data was not possible but there is now consistency of findings, with RCTs of the efficacy of secretin in autism not showing improvements for core features of ASD.

AUTHORS' CONCLUSIONS

There is no evidence that single or multiple dose intravenous secretin is effective and as such currently it should not be recommended or administered as a treatment for ASD. Further experimental assessment of secretin's effectiveness for ASD can only be justified if there is new high-quality and replicated scientific evidence that either finds that secretin has a role in neurotransmission in a way that could benefit all children with ASD or identifies important subgroups of children with ASD who could benefit from secretin because of a proven link between the action of secretin and the known cause of their ASD, or the type of problems they are experiencing.

Management of symptoms in children with autism spectrum disorders: a comprehensive review of pharmacologic and complementary-alternative medicine treatments

In the care of children with autism spectrum disorders (ASD), medical treatment is typically considered an adjunct to educational and behavioral interventions. Nonetheless, large proportions of children with ASD are managed medically and receive both pharmacologic and complementary-alternative medicine (CAM) treatments. Although many medical treatments have been studied in children with ASD, studies vary widely in terms of the sample, sample size, research design, purposes of treatment, and measurements of change. Surprisingly, comprehensive reviews of the options for medical management in ASD are lacking, particularly reviews that address both pharmacologic and CAM treatments. Furthermore, reviews to date tend to emphasize general effects of medication; this perspective contradicts medical practice, which targets particular symptoms during treatment selection and monitoring. This review of 115 studies adds to the ASD treatment literature by (1) including studies of individuals 0 to 22 years of age; (2) aggregating studies of pharmacologic treatments and CAM treatments; and importantly, (3) organizing treatment response by ASD symptoms, differentiating core and associated symptoms.

Gastrointestinal factors in autistic disorder: a critical review

Interest in the gastrointestinal (GI) factors of autistic disorder (autism) has developed from descriptions of symptoms such as constipation and diarrhea in autistic children and advanced towards more detailed studies of GI histopathology and treatment modalities. This review attempts to critically and comprehensively analyze the literature as it applies to all aspects of GI factors in autism, including discussion of symptoms, pathology, nutrition, and treatment. While much literature is available on this topic, a dearth of rigorous study was found to validate GI factors specific to children with autism.

Advances in drug treatments for children and adolescents with autism and other pervasive developmental disorders

Autism is a disorder characterised by abnormalities in language and social development, and repetitive behaviours. Antipsychotics, including haloperidol and risperidone, are the most widely studied drugs for reducing symptoms in children and adolescents with autism. When administered at relatively low dosages, antipsychotics have been shown to reduce repetitive behaviours (stereotypies) and social withdrawal, as well as a number of related symptoms, such as hyperactivity, aggression, self-abusive behaviour, temper tantrums, lability of mood and irritability. Adverse effects of antipsychotics include sedation, dizziness, increased appetite, weight gain, changes in the electrocardiogram parameters, drooling, hyperprolactinemia and a risk of drug-related dyskinesias. Other agents have been less well studied for the treatment of autism, but there are suggestive data regarding their safety and efficacy. Of these agents, a number have been investigated, based on theories about the aetiology of autism, including SSRIs and naltrexone, although the efficacy of these agents has been limited. Stimulant drugs have been shown to reduce hyperactivity and improve focus, but they may cause behavioural worsening, weight loss and stereotypies de novo. Secretin is a treatment that has received much media attention after reports of efficacy from small open studies, but all controlled studies have failed to show any benefit. In autism, alternative treatments have also been used, but none have shown benefit in well-designed studies.

Short report: Autistic gastrointestinal and eating symptoms treated with secretin: a subtype of autism

Pervasive Developmental Disorders (PDD) are chronic, lifelong disorders for which there is as yet no effective cure, and medical management remains a challenge for clinicians. The current report describes two patients affected by autistic disorder with associated gastrointestinal symptoms. They received multiple doses of intravenous secretin for a six-month period and were assessed with several specific outcome measures to evaluate drug effect. The administration of secretin led to some significant and lasting improvement in only one case. Gastroesophageal reflux may contribute to some of the behavioural problems and explain the effect of secretin since its suppressive effect on gastric secretion is well known. It is also true that autistic children with gastroesophageal reflux and a higher IQ could constitute a subtype which responds to secretin administration and that could be labelled as a "gastrointestinal subtype".

Autism spectrum disorders: emerging pharmacotherapy

Autism, Asperger and other pervasive developmental disorders (PDDs) are an increasingly commonly identified group of conditions wherein patients experience significant difficulty in social interactions, communicating with others, and inflexible adherence to unusual, unhelpful and frequently stereotyped routines and behaviour. These autism spectrum disorders are now being diagnosed earlier in life (approximately 15 months), and often remain a chronic, daily burden for those afflicted. In addition to the often profound impact on an individual's quality of life, the familial, social and economic burdens of PDDs can be enormous. No treatments are curative, and most pharmacological treatments are employed to treat specific troubling symptoms rather than the core features of the disorder itself. Therefore, more effective pharmacotherapies are desperately needed. This review describes current and emerging pharmacotherapies that may advance care of people with PDDs.

Intravenous secretin for autism spectrum disorder

BACKGROUND

Secretin is a gastro-intestinal hormone which has been presented as an effective treatment for autism based on anecdotal evidence.

OBJECTIVES

To determine if intravenous secretin:1. improves the core features of autism (social interaction, communication and behaviour problems); 2. improves the non-core aspects of behaviour or function such as self injurious behaviour;3. improves the quality of life of affected individuals and their carers; 4. has short term and long term effects on outcome; 5. causes harm.

SEARCH STRATEGY

Results of electronic searches of CENTRAL, MEDLINE, EMBASE, PsycINFO, CINAHL, ERIC, HealthStar and Sociofile (1998 - March 2005) were independently examined by two authors. Reference lists of trials and reviews were searched; experts and trialists were contacted to find unpublished studies.

SELECTION CRITERIA

Randomised controlled trials of intravenous secretin comparing secretin with a placebo treatment in children or adults diagnosed with autism spectrum disorders, where at least one standardised outcome measure was reported.

DATA COLLECTION AND ANALYSIS

Fourteen studies met inclusion criteria. All outcome data were continuous. Where trials used cross-over designs, analysis was conducted on results from first treatment phase, allowing combined analysis with parallel design trials. Where standardised assessment tools generated scores as outcome measures, comparisons were made between means of these scores. Where baseline means were reported, differences between treatment and control were determined to assess possible bias. Where mean change from baseline was reported, this was used in preference to post-treatment scores for meta-analyses or forest plots. As meta-analysis was possible for only one outcome (Childhood Autism Rating Scale), it was impossible to use sensitivity or subgroup analyses to assess impact of study quality, clinical differences in the intervention, or clinically relevant differences between groups, such as age or presence of gastrointestinal symptoms.

MAIN RESULTS

Twenty-five established standardised outcome measures were reported to assess core features of autism, communication, behaviour, visio-spatial skills, affect and adverse events within fourteen included studies. No more than four studies used any one outcome measure similarly. Outcomes were reported between three and six weeks. RCTs of efficacy of secretin in autism have not shown improvements for core features of autism.

AUTHORS' CONCLUSIONS

There is no evidence that single or multiple dose intravenous secretin is effective and as such it should not currently be recommended or administered as a treatment for autism. Further experimental assessment of secretin's effectiveness for autism can only be justified if methodological problems of existing research can be overcome.

The effectiveness of secretin in the management of autism

Autism is a complex neurological disorder that severely impacts a child's ability to communicate and interact socially. Many treatments have attempted to alleviate the symptoms of autism, but with limited success. After reports of improvements in autistic children who received secretin, this hormone became popular as a possible treatment for autism. Since then, the interest in secretin has greatly increased, as well as the demand for secretin by parents of autistic children. However, there is still limited experimental evidence that supports its effectiveness. Many biological studies and clinical trials were conducted to test the effectiveness of secretin in treating autism. This review discusses the autistic disorder, instruments used in the trials, and reports the findings of some of these studies.

Expression and spatial distribution of secretin and secretin receptor in human cerebellum

The expression and spatial distribution of secretin and its receptor in human cerebellum were investigated by in situ hybridization and immunohistochemical techniques. Secretin mRNAs are found in Purkinje cells whereas secretin receptor transcripts are present in Purkinje cells and basket cells in the molecular cell layer. In addition, secretin-immunoreactivities are localized in both the soma and dendrites of Purkinje cells. These data are the first demonstration of the spatial distribution of secretin and its receptor in distinct neurons within the human cerebellum. The cellular localizations of this ligand-receptor pair are consistent with the proposed actions of secretin in the cerebellum of rodents and hence suggest that secretin also serves specific neural functions in the human cerebellum.

Novel treatments for autistic spectrum disorders

In no area of developmental pediatric practice is there more controversy regarding the choice of treatment than related to children with autistic spectrum disorders (ASD). Complementary and alternative medical therapies (CAM) are often elected because they are perceived as treating the cause of symptoms rather than the symptoms themselves. CAM used for autism can be divided by proposed mechanism: immune modulation, gastrointestinal, supplements that affect neurotransmitter function, and nonbiologic intervention. Secretin as a therapy for autism is discussed as an example of how a clinical observation rapidly grew to a widespread treatment before well-designed studies demonstrated absence of effect. The plausibility for behavioral effect was not substantiated by clinical studies. CAM used for treatment of autism is examined in terms of rationale, evidence of efficacy, side effects, and additional commentary. Families and clinicians need access to well-designed clinical evidence to assist them in choice of therapies.

Secretin as a Treatment for Autism: A Review of the Evidence

Secretin is used in the United States for diagnosis of pancreatic gastrointestinal (GI) dysfunction and disease. Repeated therapeutic use has not been approved. Widespread interest in secretin as a treatment for autism followed media reports of behavioral improvements in an autistic child who received the hormone during a GI diagnostic procedure. International demand for secretin soared in the absence of experimental evidence of its efficacy for autism. This review presents a brief history of secretin's rise to popularity and summarizes research on secretin as a treatment for autism. Seventeen studies are reviewed comparing the effects of secretin forms, dosage levels, and dosing intervals on outcome measures with approximately 600 children. Twelve of 13 placebo-controlled studies failed to demonstrate the differential efficacy of secretin. Implications for advocating treatment in the absence of empirical evidence are discussed.

Children with autistic spectrum disorders. I: comparison of placebo and single dose of human synthetic secretin

AIMS

To examine the effect of a single dose of human synthetic secretin (HSS) on behaviour and communication in children with autism spectrum disorder (ASD) using an objective measure of communication and social reciprocity and standardised rating scales.

METHODS

Randomised, crossover, double blind, and placebo controlled trial of a single intravenous dose of human synthetic secretin (HSS) 2 CU/kg. The 62 subjects (3-8 years) were assigned to group 1 (saline placebo/HSS) or group 2 (HSS/saline placebo). Diagnosis was confirmed by ADI-R (Autism Diagnostic Interview-Revised) algorithm. Severity of symptoms was rated using the CARS (Childhood Autism Rating Scale). Outcome measures included Communication and Symbolic Behavior Scale (CSBS), Ritvo Real-life Rating Scale, weekly Global Rating Scale (GBRS) by parents and teachers, and daily log of gastrointestinal symptoms. The communication subscale of the CSBS, specifying communication function, reciprocity, and social-affective signalling was videotaped and scored by a blinded, trained observer.

RESULTS

Sixty one children completed the study. After randomisation, there were no significant differences in gender, race, age, and parent and teacher GBRS and Ritvo Scale between the two groups. Compared with placebo, secretin treatment was not associated with significant improvement of CSBS standard scores from baseline to 2 or 4 weeks post-infusion. Five children showed clinical improvement in standard scores: two after HSS and three after placebo. There were no significant changes in gastrointestinal symptoms after HSS or saline placebo.

CONCLUSIONS

A single dose of intravenous human secretin is not effective in changing behaviour and communication in children with ASD when compared to placebo.

A randomized, double-blind, placebo-controlled trial of porcine versus synthetic secretin for reducing symptoms of autism

OBJECTIVE

To compare the effects of a single dose of biologic and synthetic porcine secretin to placebo on a variety of autism symptoms.

METHOD

Eighty-five children with autism without other medical conditions and not taking other psychotropic medications participated (ages between 3 and 12 years, mean IQ = 55). Children were grouped into trios matched by age and communication level and then randomly assigned to one of three treatment groups: biologic secretin (2 CU/kg), synthetic secretin (0.4 microg/kg), and placebo. Measures collected 1 week before and 4 weeks after infusion included autism symptoms, language skills, and problem behaviors, gathered from parents, teachers, and investigators, who were all blind to treatment. Two-factor, repeated-measures analyses of variance (3 treatment levels by 2 repeated measures, pre- and postinfusion) were used to examine efficacy.

RESULTS

Direct observation measures did not show change over time related to secretin. Parent reports showed an overall reduction of symptom severity for all treatment groups, including the placebo group. One teacher-report measure showed decreases in autism symptoms in the placebo and synthetic secretin groups.

CONCLUSIONS

No evidence that either biologic or synthetic secretin provided amelioration of symptoms beyond placebo was observed. This held true when children with and without gastrointestinal problems were examined separately.

Secretin as a neuropeptide

The role of secretin as a classical hormone in the gastrointestinal system is well-established. The recent debate on the use of secretin as a potential therapeutic treatment for autistic patients urges a better understanding of the neuroactive functions of secretin. Indeed, there is an increasing body of evidence pointing to the direction that, in addition to other peptides in the secretin/glucagon superfamily, secretin is also a neuropeptide. The purpose of this review is to discuss the recent data for supporting the neurocrine roles of secretin in rodents. By in situ hybridization and immunostaining, secretin was found to be expressed in distinct neuronal populations within the cerebellum and cerebral cortex, whereas the receptor transcript was found throughout the brain. In the rat cerebellum, secretin functions as a retrograde messenger to facilitate GABA transmission, indicating that it can modulate motor and other functions. In summary, the recent data support strongly the neuropeptide role of secretin, although the secretin-autism link remains to be clarified in the future.

Secretin treatment for autistic disorder: a critical analysis

We assessed evidence of the effects of secretin on behavior in individuals with autistic disorder. Articles were obtained through a MEDLINE search of the English-language literature from January 1966-November 2001; all investigations and case reports on the topic were included. Press releases obtained from the World Wide Web also were included. Secretin, a gastrointestinal hormone, is suggested to improve autistic symptoms, particularly social function and communication. Two formulations, porcine and synthetic human secretin, were evaluated in humans. A small body of literature and popular belief in autistic disorder communities supported the agent's efficacy. A number of controlled clinical trials did not show improvement in autistic symptoms with secretin compared with placebo, possibly indicating no role for the drug in autistic disorder.