Drug testing lab Dominion Diagnostics and nutrigenomics firm LifeGen announced an agreement last month giving Dominion exclusive licensing rights to a biomarker signature LifeGen has developed to predict a patient's risk for addiction.
The two companies are currently collaborating on a validation trial of the predictive signature, which measures SNPs known to be associated with addiction in a set of about 10 genes involved in the brain's reward circuitry.
The test yields a measure called the Genetic Addiction Risk Score, or GARS, which stratifies patients based on their relative predisposition toward addictive behaviors.
In the trial, the two companies are comparing GARS results in a cohort of about 300 to 400 patients entering pain treatment and other centers with a currently used psychological addiction risk assessment tool called the Addiction Severity Index.
The self-reporting-based ASI is a standard tool for establishing addiction severity, often to support insurance approval for addiction treatment. According to Mary Hauser, Dominion Diagnostics' vice president of Addiction Services, the companies believe it will be important to examine the ways GARS and the ASI match up, and where they diverge.
"We believe genetic is a stronger test," she told PGx Reporter. "But how does that match with what treatment centers are seeing in known addicts?
According to Hauser, Dominion believes that the test, if successfully validated in the trial, could be useful in many different aspects of clinical care for pain and addiction treatment.
"The goal, once the study is completed, is that we'll be able to look at rolling out a useful tool to clinicians and practitioners working in addiction and in healthcare in general," she said.
At the most basic level, the risk score could be used to guide pain management therapy, Hauser said. If a patient scores in the high-risk group for addiction, a physician might choose to start him or her on a lower dose or a different medication for pain.
"We have heard from a number of pain practitioners anecdotal information that they often find themselves with a patient who reports no history of alcohol or drug abuse. They've been injured and come in to be treated for pain, they are prescribed an analgesic and suddenly the doctor has to start counting pills," Houser said.
"The question is, would a tool like this be useful, and we think it would be," she said. If the risk could be identified before treatment, "that patient could go to other interventional medicines first, or if they have to go to a [potentially addictive medication], they would be monitored very closely to be sure it is a limited usage."
Additionally, the GARS test could find use in addiction treatment, Hauser said. "In the addiction treatment world, clinics we work with are excited to have a genetic test that helps them to understand the risk factors and potentially what medications might be useful in the treatment of that patient. So the study isn’t done yet, but we see it having profound applications," she added.
According to LifeGen's Kenneth Blum, who is leading the trial and is an advisor to Dominion, the GARS test measures the presence of SNPs in around 10 genes that have been associated with addiction in "thousands of studies." Blum did not detail the SNPs covered by the test, but said that overall, the approach looks at about 18 SNPs for females and 17 SNPs for males.
In the trial, he and his colleagues are recruiting patients from 10 addiction centers across the country, and comparing their GARS results with the results of their assessment using the ASI.
Blum said that some preliminary data has already come in, showing that in 70 initial subjects, GARS stratified about 14 percent in a low-risk group, 81 percent into a moderate-risk group, and 5 percent to a severe-risk group.
He told PGx Reporter that the researchers expect to wrap up the trial in about three months.
Toward developing the signature for clinical, commercial use, the companies are also working on refining a mathematical algorithm to calculate the GARS risk score.
Hauser said Dominion is looking into the possibility of partnering with academic researchers for that work.