Can IGF-1 treat autism symptoms? A clinical trial aims to find out
The following is the transcript of the ASF Weekly Science Podcast episode titled, “Can IGF-1 treat autism symptoms? A clinical trial aims to find out,” published on September 10, 2018. If you would like to learn more about the Mount Sinai clinical trial led by Dr. Alex Kolevzon, please go here.
Mahir Rahman (MR): Hello, everyone, this is Mahir Rahman. Welcome to the Autism Science Foundation Weekly Science Podcast. I’m subbing in for Alycia for an interview I conducted with Dr. Alex Kolevzon of Mount Sinai. Hope you enjoy the story.
MR: A Mount Sinai research team led by Dr. Alex Kolevzon is investigating if a compound known as insulin-like growth factor 1, also known as IGF-1, can be used as a treatment for autism. Dr. Kolevzon is a child psychiatrist and the clinical director of the Seaver Autism Center in the Icahn School of Medicine at Mount Sinai in New York. He received the Autism Science Foundation Treatment Grant in 2013. He sat down with ASF to discuss his current study. We began the interview by discussing the autism-related disorder Phelan-McDermid syndrome, also known as PMS.
Alex Kolevzon (AK): Phelan-McDermid syndrome is a neurodevelopmental disorder that causes autism. It is due to a deletion or mutation of the SHANK3 gene, which is located at the terminal end of chromosome 22. There’s two copies of the SHANK3 gene, we all have two copies of it. And so, in Phelan-McDermid syndrome, you’re basically missing one copy and that’s called haploinsufficiency.
MR: Are you wondering what happens if you miss one copy of the SHANK3 gene? Well, SHANK3 is a gene that codes for a protein that helps brain cells communicate with each other in order to make useful connections during development. When one copy of the SHANK3 gene is missing, certain brain cells cannot communicate with each other, leading to a number of problems.
AK: So based on very large genetic studies, it seems as if Phelan-McDermid syndrome or SHANK3 deletions and mutations account for about 1% of autism, and not everyone with Phelan-McDermid Syndrome has autism, so there’s going to be additional cases beyond that. So really it’s very common. We’re just now starting to routinely diagnose people.
MR: How can some kids with PMS have autism and others not?
AK: Well, autism is a behavioral diagnosis. It’s really just a collection of symptoms, social impairments, language impairments, restricted and repetitive behaviors, and, you know, many different people with autism look very, very different. So some kids have… with Phelan-McDermid syndrome have a lot of social motivations, social interests, social engagements. And despite being significantly cognitively delayed, the social domain is a relative strength for them, and as a result, they don’t really meet the criteria for an autism spectrum disorder. We’re talking about maybe 15% to 20% of them. So the vast majority of people with Phelan-McDermid syndrome do meet the criteria for autism. But it’s important to understand that if you take a given biological cause of a syndrome, the clinical features of that syndrome could be very, very wide.
MR: To reiterate, it’s important to understand that, like autism, the symptoms of PMS can vary. They can vary enough that some children with PMS don’t meet the criteria for an autism diagnosis, but most of the time, they will. That said, the symptoms seen in autism might be based on biology similar to that of PMS.
AK: Within the broader universe of people with autism, and especially people with autism where there isn’t a known cause — what we call idiopathic autism, it seems as those a subset of them appear clinically, and even on some biological measures, look like people with Phelan-McDermid syndrome.
MR: If two conditions have similar biology, the same treatment may be able to help both. The search for a treatment for PMS and idiopathic autism led Dr. Kolevzon’s team to a group of compounds known as growth factors. Growth factors can help cells grow, change, and make new connections, what scientists call plasticity.
AK: A growth factor can promote growth, promote synaptic plasticity, which is what is essentially absent in Phelan-McDermid syndrome. So we started doing this study with a drug called insulin-like growth factor, which we know crosses into the brain, we know it promotes synaptic maturity, synaptic plasticity, nerve cell growth, and we did a couple of small studies, both of which were very, very promising.
MR: In a pilot clinical trial using IGF-1, Dr. Kolevzon’s team found children with PMS tolerated the drug. They also found that the children treated with IGF-1 had reduced expression of two core symptoms of autism – social withdrawal and repetitive behaviors.
AK: We looked at social symptoms and repetitive behavior symptoms because those are core domains of autism. And those are both studied in this trial using a parent-report measure, and we saw improvement in both those domains in the trial with IGF-1.
MR: Dr. Kolevzon’s team made sure every participant had the opportunity to receive the IGF-1 treatment in the trial by employing a crossover design.
AK: Patients got drugs for 12 weeks, or placebo, and they switched to the other condition, so each patient essentially acted as their own control and treatment was for 12 weeks and placebo was for 12 weeks in random order. We applied the exact same design to the trial in idiopathic autism.
MR: Employing a crossover design was an intentional decision by his team.
AK: One of the biggest obstacles to success in clinical trials is recruitment. One of the biggest obstacles to families wanting to participate is the idea of being on placebo and not getting access to the active treatment. So we purposely designed the trial with everyone getting active treatment.
MR: Based on the findings made by Dr. Kolevzon’s team, IGF-1 appears to be a safe treatment that offers notable improvements in core symptoms of autism, so why is it not considered an effective treatment yet? Dr. Kolevzon hopes to address that question with his current study.
AK: The fear in the field in general is we might be studying an effective medicine but we are not able to show improvement because our measures are not ideal. Either we’re not measuring the right thing, measures aren’t sensitive enough, we’re not able to really account for the placebo effect because they’re so biased. So we’ve been focusing a lot more on more objective, more quantifiable measures, trying to develop new ways of looking at symptoms.
MR: His current study is focusing on sensory reactivity symptoms. Many people with PMS and autism have sensory issues, including varying sensitivity to light and sound and atypical interests in specific textures and temperatures. In order to examine brain activity in general and during periods of sensory reactivity, his lab uses a technique called electroencephalography, or EEG. Dr. Kolevzon’s team will be examining how IGF-1 affects sensory reactivity and brain activity following IGF treatment
AK: That’s really an important symptom, it’s a symptom that’s virtually universal. All kids with Phelan-McDermid syndrome, at least all the kids that we have evaluated, have some sensory reactivity symptoms. Often, they are hyporeactive.
MR: Meaning that these kids often have a decreased response to sensory stimuli. Say a child with sensory hyporeactivity entered a room with very loud speakers. The child might not be bothered by, or let alone react to, the volume. With IGF-1 treatment, Dr. Kolevzon believes his team will be able to observe any change of those sensory reactivity symptoms over the course of the clinical trial.
AK: This is a trial that is pretty burdensome for families because the way that IGF-1 is delivered is through subcutaneous injection. So families are taught to monitor their children’s glucose levels because one of the main side effects can be low blood sugar, and they’re also taught how to inject the children twice a day with small amounts of IGF-1. It’s a very, very small needle and actually, it’s probably the element of the study that people are most concerned about when they first consider it, and it ends up in actually 19 out of 19 cases not to be a really big issue. The children, because they have the sensory hyporeactivity, aren’t especially averse to the shots and the parents become remarkably expert very, very quickly. We give them a big manual with lots of instructions. We show them exactly how big, and in this case, how tiny the needle is, but then, the very first day that they actually get the injection, I give it to them myself.
MR: Dr. Kolevzon and his team understand that they’re asking a lot from the families choosing to participate in the study. They take great strides in order to prepare and help the families throughout the recruitment and trial process.
AK: For me to say things like, “Oh, this is not a big deal,” isn’t helpful. Obviously, this is a big deal, we acknowledge that on the onset, but for me to also encourage them and say, “Look, it’s going to feel scary and then you’re going to be quite good at it.” That’s one thing. I think the other thing is that they don’t feel alone in this, right? They don’t have to make decisions on their own. They don’t have to worry about dosing on their own. You know, if they see anything concerning, they don’t need to decide what to do about that. They have unfettered access to me. We exchange cell phone numbers early on and then, the other thing I say to them is, “You know, if you have any concerns at all, skip the dose. That’s it. You get to control that. If you don’t want to give your child the does for whatever reason, just skip the dose. There will not be any harm in that.” Then, we just take it from there.
MR: For those autism families that are listening, Dr. Kolevzon has a message for you.
AK: “Come participate!” I’d say that if you’re not convinced that a clinical trial is a good idea, that’s okay also. Come just to get to know us. Let us get to know you. And then, you know, we’ll figure it out. Nobody has ever required anybody to participate in a clinical trial. We definitely respect how scary it can be and how hard it can be. So it’s really all about just the fit.
MR: You can learn more about this study on asfpodcast.org. Thanks for listening.