"People who want to quit often enter a rehab program, (but) the relapse rates are very high the first two years after patients come out of rehab," said Jay Evans, director of UM's Center for Translational Medicine. "People who want to quit could benefit from a vaccine to help them through the critical period when the relapse rates are high."
Evans and a team of researchers at UM and Minnesota recently received a $3.3 million grant from the National Institutes of Health to develop a vaccine for opioid addiction. It's one of several awards the center has received since it launched in 2016, when GlaxoSmithKline Vaccines closed its Hamilton research office and its scientists negotiated employment contracts with UM.
The National Institutes of Health have since recognized the UM center's research prowess, awarding it $22.4 million in other grants this past summer and fall. Now, they’re a few weeks into a years-long effort to make that opioid addiction vaccine a reality.
“To most people, it's strange to think of using a vaccine to treat drug addiction,” Evans acknowledged. But in one of his labs Friday, he explained how a vaccine can train the body’s immune system to target opioids, in the same way it targets flu or tuberculosis, and help a patient avoid an overdose or relapse.
“We take the opioid, modify it to make (something called) a hapten, and we link it to a carrier protein, and that allows the immune system to recognize it,” he said. The opioid and carrier protein are packaged with a third chemical, called an adjuvant, that prompts the immune system to recognize the hapten and respond, like a plume of smoke alerting firefighters to a blaze.
With the right combination of adjuvant, carrier protein and hapten, the researchers say they can train the antibodies to attack a drug when it hits the bloodstream.
"As long as that antibody response is high enough in the bloodstream, when the patient relapses after rehab and uses the drug again, the antibody binds (to) the drug and prevents it from crossing the blood-brain barrier, so they see no effect from the drug abuse," Evans said. Not only does that prevent a relapse keeping it out of the brain should also help prevent overdosing, which kills an estimated 130 Americans each day.
This effort grew out of a workshop on the drug-abuse epidemic hosted last fall by the National Institute of Allergy and Infectious Diseases and the National Institute of Drug Abuse. The UM delegation at the conference had approximately 25 years’ experience developing adjuvants and vaccine formulation technology; a separate team from the University of Minnesota has been developing opioid haptens and carrier proteins. Together, they secured the $3.3 million National Institutes of Health grant to develop a vaccine.
Now, that effort is underway, with researchers here and in Minnesota putting carrier proteins, haptens and adjuvants through what Evans calls an “iterative process of testing.” They’re first tested on human cells in culture, then on mice, letting researchers look for both healthy immune responses and signs of toxicity or muscle inflammation — the cause of soreness after a shot.
Grace Bayley, a doctoral candidate working in the lab, has been helping analyze those cells. During a round of tests for potential adjuvants, she said the team tested vaccines on 250 mice. Three people harvested tissue while four others examined the effects. “It’s a huge team effort,” she said. It’s also time-consuming; Evans said a typical study with mice can take two to three months.
That will have to be repeated for every adjuvant, carrier protein and hapten they test, and the potential combinations they’ll use. The challenge isn’t lost on Casey Massena, a postdoctoral fellow involved with the project.
“We’re literally dealing with building blocks you can’t see,” he said. Once they find the right recipe, he explained, they’ll still have to make a product that’s shelf-stable and can be mass-produced.
The grant funding lasts for two years; Evans expects that developing a vaccine for clinical trials in humans will take three to five years and aims to secure another federal grant that will provide five more years of funding. Once a vaccine is developed, he predicts that clinical trials could take five to seven more years.
“You have to do good science,” Evans said. While he hopes that the approval process will be expedited given the urgent need for opioid treatments, “you’ve got to develop safe products that are effective and don't harm the people that you're giving them to, and to meet all those standards takes time.”
But he and his colleagues agree that they’re well-equipped for the challenge. “What we do is pretty unusual,” Massena said, explaining how the Center for Translational Medicine brings various specialties — immunology, chemistry and others — together under one roof. “We can literally walk down the hall” to exchange information, he said.
Currently, Evans said the group at UM counts about 35 people working on vaccine research. "And we have about 10 openings right now that we're looking to fill."
The center’s steady stream of project funding is a draw for aspiring scientists, including Bayley, who came here after completing her undergraduate at the University of Maine. “Knowing that you’re going to have a project in front of you is really important ... I know my lab was not only going to support me, but that I was going to have a lot of opportunities.”
“It’s just a well-woven project where you have so many people in so many disciplines ... I think it’s just the way science should work.”