Another attempt for vaccine against drug addiction
SEATTLE – It’s been nearly 50 years since a group of researchers in Chicago reported an extraordinary finding: They’d created a vaccine against drug addiction and an early test showed it might work.
The scientists provided a rhesus monkey with drugs like heroin and cocaine; it became addicted. But when they injected the monkey with a compound they’d developed – one designed to coax the immune system into fighting addictive drugs as if they were pathogenic invaders – the animal stopped seeking drugs.
Their finding, published in the top scientific journal Nature in 1974, heralded a new frontier in treating addiction.
But despite millions of dollars in research – and decades’ worth of studies, including a high-profile but failed attempt at a nicotine vaccine – there’s still no Food and Drug Administration-approved shot against any addictive substance.
Scientists at a new University of Washington research center hope that will soon change.
“What I’m hoping to achieve is pretty much every year, we’re going to start a new clinical trial,” said professor Marco Pravetoni, who was recently recruited from the University of Minnesota to lead UW’S new Center for Medication Development for Substance Use Disorders.
The center has raised more than $2 million in initial funding.
Nationwide, more than 70,000 Americans died from drug-induced overdoses in 2019, according to the National Institute on Drug Abuse, nearly 50,000 of which were tied to opioids such as heroin, fentanyl and prescription drugs.
Public and scientific perspectives on the nature of addiction have changed over time. Once thought of as the result of personal moral failure, scientific advancements have shown addiction is instead driven primarily by genetic and environmental influences.
Currently, people seeking help with addiction can take medications like naltrexone, methadone and buprenorphine: These often life-changing medications prevent cravings, feelings of being high or both. For people addicted to opioids, medications like methadone and buprenorphine also dampen withdrawal symptoms.
But the medications also come with downsides. Methadone itself can be addictive. And such medications have to be taken regularly – every day or so – and require a prescription or visit to a specialized clinic.
Vaccines, on the other hand, hold long-lasting and potentially cost-effective promises that available medications don’t, experts say. Similar in nature to vaccines against disease, addiction vaccines stimulate the body to create antibodies that recognize a drug, and prevent or slow it from reaching the brain. A shot every few months, or once a year, has the potential to seriously ease a person’s path to recovery.
“(Existing medications) don’t work for everyone. And a lot of people don’t stay on them in the long term,” said Rebecca Baker, director of the National Institutes of Health’s Helping to End Addiction Long-term Initiative, which has funded Pravetoni’s work. “Would the outcomes be better if we had more options?”
A vaccine, Baker said, could make treatment more accessible.
In animal studies, Pravetoni and other researchers have shown vaccines against a variety of drugs are safe and effective. Now, he and collaborators in New York and New Jersey are running the first-ever opioid vaccine trial in humans in the U.S.; they intend to enroll about 45 people to test a vaccine against oxycodone, a commonly abused prescription pain medication.
UW’S new center will build on this research and prior animal studies on other drugs like fentanyl and heroin, he said. But Pravetoni admits he’ll be up against the same challenges that have bedeviled addiction vaccine development for decades. Clinical trials in people are incredibly expensive – Pravetoni estimates it would take more than $200 million to $300 million to get a vaccine to market – and big pharmaceutical companies have shown little interest in chipping in.
“[Researchers] are trained to overcome adversity,” he said. “I don’t give up.”
For the past decade or so, Pravetoni has led a laboratory of scientists in Minnesota dedicated to discovering vaccines and other substance use disorder medications.
Opioids interested him because some of them can be effective medications – but their effects can also be toxic; a single dose could kill someone. “I sort of felt I could have more of an immediate impact,” Pravetoni said.
This year, he and a Columbia University researcher launched the first Phase 1 clinical trial of an opioid vaccine. They’re studying the safety and efficacy of the vaccine, which is intended to stop the euphoric and dangerous effects of oxycodone.
The vaccine is being tested in people who are already addicted and not being treated for substance use disorder; some participants will be given a placebo, while others will receive either a low or high dose of the vaccine.
If the vaccine works, Baker said she could imagine it being used by people who aren’t currently using drugs, such as those in prison or long-term treatment recovery programs who worry about relapsing when they’re released.
Pravetoni’s goal, he said, is to get enough funding to get through at least Phase 1 and 2 – prove his vaccines are safe and likely work – and then get a pharmaceutical company to fund the rest.