First opioid vaccines in clinical trials in the US

Imagine being able to take a vaccine to avoid addiction to opioids. U.S. researchers have done more than just imagine: The first opioid vaccine clinical trials are already underway.

The research comes as the Centers for Disease Control and Prevention reports this month that more than 71,000 opioid overdose deaths occurred in the 12-month period that ended in February â€" a new record.

“We need new approaches to addressing the opioid crisis because we’re seeing these huge increases in opioid-related overdose deaths,” said Sandra Comer, the clinical trial’s lead investigator.

Ms. Comer, a professor of neurobiology and psychiatry at Columbia University Irving Medical Center, said that “highly effective treatments like methadone, buprenorphine and naltrexone” are not enough to curb the opioid crisis.

Relapse rates for those medications hover around 50% after six months of treatment, she noted.

“We’re hoping that the addition of a vaccine will serve as a ‘safety net’ against overdose if a patient does discontinue their treatment medication and relapses to opioid use,” Ms. Comer said. “It also may provide us with a window of time to re-engage patients in treatment if/when they relapse.”

Researchers are first testing a vaccine against oxycodone in currently untreated people with opioid use disorder in a phase one trial. They also are developing vaccines for heroin and fentanyl.

The clinical trial aims to enroll 45 participants, aged 18 to 59 years old, who are physically dependent on opioids. Participants receive a placebo or the vaccine in a shot once a month for three to four months.

As of this week, seven participants had enrolled in the trial, but two dropped out.

Unlike other drug treatments, the vaccine doesn’t require patients to have the opioid completely out of their systems, Ms. Comer said. It has no abuse liability, can be paired with existing treatments and has a potentially longer-lasting effect, she added.

The vaccine works by generating antibodies specific to the target opioid and binding to the drug to prevent it from getting into the brain, where it creates a euphoric feeling. If the drug reaches the brain, it also can stop brain signals that control breathing.

“So to speak, the vaccine-induced antibodies work like an antidote or like a sponge soaking up the circulating drug target so that the drug cannot exert its effects/actions,” said Dr. Marco Pravetoni, professor of pharmacology and medicine at the University of Minnesota Medical School who designed the vaccine.

If the vaccine proves successful, Dr. Pravetoni said it could help curb opioid use disorder and overdoses and “open up the road” for other vaccines or antibody-based treatments.

The vaccine has been tested in animal studies and “performed well,” WebMD reported last week.

Still, the opioid vaccine trial comes amid skepticism, debate and opposition to vaccines against diseases such as COVID-19 as employers, schools, hospitals and governments mandate those vaccinations.

Barbara Loe Fisher, president of the National Vaccine Information Center, said the organization would support the voluntary use of an opioid vaccine recommended by the CDC and licensed by the Food and Drug Administration.

She said her organization, which she described as pro-education and pro-informed consent, does not make vaccine use recommendations.

“We support flexible medical, religious and conscientious belief vaccine exemptions and oppose one-size-fits-all vaccine policies and laws that use coercion or societal sanctions, such as denial of education or loss of employment and health care, to compel people to get vaccinated,” Ms. Fisher said.

According to the most recent CDC data, opioids were involved in about 75% of drug overdose deaths over a yearlong span as of the end of February. Nearly 50,000 Americans died from opioid-related overdoses in 2019, while about 69,000 died from these overdoses last year, driven largely by synthetic opioids such as fentanyl.

An estimated 2 million Americans had an opioid use disorder in 2018, the CDC says.

“Novel approaches like an opioid vaccine could help save some of the many lives lost to opioids,” said Dr. Emily Einstein, chief of science policy for the National Institute on Drug Abuse. “We owe it to the millions of Americans whose lives have been impacted by the opioid overdose epidemic to pursue every therapeutic approach with strong potential.

“This vaccine would not have made it to the clinical trials stage without robust evidence in support of such therapeutic potential,” she said.

Dr. Einstein added that an opioid vaccine could help people who have difficulty following daily medication regimens or those who might not have naloxone on hand to reverse opioid overdose.

William Stauffer, executive director of PA Recovery Organization Alliance, said the shot could help people with opioid use disorder avoid relapse.

“I think any such tool is helpful, but most of our people are using multiple drugs,” Mr. Stauffer noted.

He said that while a vaccine could be an alternative in treating opioid use disorder, people in recovery will likely still need comprehensive care such as behavioral therapy. 

The goal of the clinical trial is to determine if the vaccine is safe and produces enough antibodies to prevent euphoria when the study volunteers are given oxycodone. Physicians and nurses will monitor study participants for several weeks in an inpatient setting during the trial.

The researchers also will assess participants’ drug use behavior on an outpatient basis.

Researchers anticipate enrolling up to 24 volunteers as part of a pilot study. If the vaccine seems safe and shows promise, they expect to expand the trial to include 45 volunteers.

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