Autism Research Review International, 2008, Vol. 22, No. 2, pp. 3 & 6
Stephen M. Edelson
Autism Research Institute
Secretin, a hormone involved in the process of digestion, was the talk of the autism world a decade ago. Unfortunately, the research on the efficacy of secretin has often been misinterpreted. Secretin was and still is a very promising treatment, and it has the potential to be one of the most effective interventions available for individuals on the autism spectrum. Here’s the real story.
The history of secretin
Victoria contacted the physician who performed the GI examination to find out if there were any additional tests given to Parker during the GI workup. She was told that he was simply given an endoscopy and the secretin challenge test, and that none of the tests could have had an impact on his bowel movements or behavior.
Victoria was then determined to find out whether or not secretin was responsible for Parker’s improvements. She was able to obtain a prescription for secretin, and again, she observed rather significant improvements in his bowel movements and behavior. Victoria shared her findings with other parents and the excitement began to grow. After hearing about the potential benefits of secretin, a physician decided to try secretin on his own autistic son and also observed improvements. However, the changes were not as dramatic as those seen in Parker.
Victoria contacted many researchers around the country and told them about Parker’s positive response to secretin. Since there were few interventions for autism at that time, she assumed that researchers would embrace the possibility of a new treatment for these children, but few showed interest except for Dr. Bernard Rimland, one of the true pioneers in the field.
Dr. Rimland, like Victoria, was excited about the possibility of a new treatment. He called many researchers and clinicians personally and shared Parker’s story with them. Many of these professionals were associated with ARI’s Defeat Autism Now! project. Their feedback was very encouraging; most of them were well aware of the GI problems commonly associated with autism, and some of them even thought of theories as to why secretin might be beneficial.
Word about secretin spread quickly through the autism community. When the media became aware of secretin, newspapers and television news program aired stories about Parker and described secretin as a potential new treatment for autism.
Repligen’s role
Although Parker and many other individuals on the autism spectrum had responded positively to porcine secretin, Repligen chose to develop a synthetic form that would be much easier and less expensive to manufacture. This form of secretin was evaluated in a rigorous three-phase approval process required by the Food and Drug Administration (FDA). Here is a summary of Repligen’s research findings:
Phase 1: Safety Studies
Many researchers were very interested in studying secretin since it was receiving a great deal of attention in the autism community as well as the media. Very few adverse effects were reported in these studies. As a result, secretin passed phase 1, and the FDA gave approval for a phase 2 study.
Disappointingly, most of the researchers who conducted the phase 1 studies concluded that secretin was ineffective because the participants’ behavior did not improve. As stated above, Phase 1 studies are designed only to assess whether or not adverse effects are associated with secretin—they are not intended to evaluate the efficacy of a drug.
Phase 2: Preliminary data, multi-center study
The results from phase 2 were impressive, and the FDA gave the go-ahead to proceed to the phase 3 evaluation process.
Phase 3: Large-scale study—where most of the confusion lies
After much of the data had been collected, the double-blind code was broken and the results were analyzed. Repligen sent out a highly-anticipated press release on January 5, 2004 stating that there were no differences on the Clinical Global Impression of Change (CGI) or the Autism Diagnostic Observations Schedule (ADOS). However, when the data only from those with high-functioning autism were analyzed, there was a significant difference on the ADOS. Interestingly, this subset (n=68), which improved dramatically, actually involved slightly more than half of the participants in the study (51.25%).
Thus, given that the majority of participants in the study improved on the ADOS, considered by many to be a valid assessment measure, shouldn’t this finding be viewed as a very positive result? No one would have expected everyone in the study to improve as a result of secretin, especially since less than one-third of the subjects suffered from any GI problems.
And finally, during a conference call with stockholders later that day, Dr. Herlihy stated that several children in the secretin group went from autistic to normal, and this type of improvement was not observed in the control group.
Soon after the press release, Repligen cancelled another ongoing multi-center study before completion. Supposedly (although I have not confirmed this) the majority of the participants in this later study had GI problems. At that point, when research on the efficacy of secretin was halted, the excitement surrounding its use evaporated, and the community moved on to other potential treatments.
(It is important to mention that these Repligen-sponsored studies involved a brand-new synthetic form of secretin. The effectiveness of porcine secretin, the drug which Parker Beck and many other individuals on the autism spectrum responded to so well, was not evaluated.)
The rationale for more research
It is also important to mention a study on secretin conducted by Dr. Janet Kern. In her study, 19 participants with autism were given porcine secretin in one condition and a saline solution (placebo) in a control condition. The results showed that a subset of the participants, five children who suffered from chronic diarrhea, improved in the secretin condition but not in the placebo condition. Kern documented a decrease in a number of behaviors such as irritability, agitation, withdrawal, hyperactivity, and stereotypy, and an increase in vocabulary.
For more than 30 years, the Autism Research Institute has surveyed parents about their children’s response to various treatments. Secretin has been rated more positively than most of the treatments commonly given to individuals on the autism spectrum. Of 468 individuals, 44% responded positively to a secretin infusion. Of 196 individuals, 37% responded positively to a transdermal application of secretin. Negative ratings (children scored as worse after secretin treatment) were 7% and 10%, respectively.
Overall, the studies investigating the efficacy of secretin have been very positive, with no serious adverse effects (although initially there were some case reports of seizures in children who already were diagnosed with epilepsy). Interestingly, the two terms that keep reappearing together in my discussions with physicians and parents are “porcine secretin” and “chronic diarrhea.” This possible relationship needs to be examined in detail.
ARI would very much like to fund controlled studies investigating the effects of porcine secretin on autistic individuals suffering from chronic diarrhea. If you are a researcher and/or know of a top-notch researcher who is interested in continuing this line of research, please write to us at Secretin @ Autism.com.
Previous editorials and articles on secretin published in the Autism Research Review International
Secretin more beneficial for autistic children with chronic diarrhea
Secretin: new studies reveal GI effects; which autstic children benefit
Secretin responders: biochemistry a clue
Secretin: the controversy continues
The Autism-Secretin Connection
The Secretin Story: still a promising treatment for autism
© 2007-2008 Autism Research Institute | Sitemap | Notices | Webcasts