Scripps Research Institute researchers have developed antibodies effective against synthetic opioids.

The opioid epidemic continues to be a serious crisis in the United States. Some of the most troubling synthetic opioids include fentanyl and fentanyl derivatives, such as carfentanil. These drugs are highly additive and very potent, a combination that often leads to overdoses and deaths. In 2017, slightly more than 40% of the deaths due to drug overdose were related to synthetic opioids. 

Current treatments for opioid addiction generally involve the use of less-addictive substitutes to help wean patients from their dependency. These drugs are themselves addictive, however, and do not present an ideal solution. Treatments for patients that have overdosed often do not work for the more powerful fentanyl derivatives.

Scientists at the Scripps Research Institute are pursuing an alternative approach based on the use of vaccines. The researchers have developed a series of monoclonal antibodies that bind to several synthetic opioids, including fentanyl, carfentanil and seven other analogs. They tested vaccines formulated with antibodies in mice using a common pain-response challenge that involves applying a heated beam of light to the tail. Rapid removal of the tail from the beam indicates that the animal feels pain, while a slow reaction suggests that the pain response is dulled. Mice not given the vaccines had slow tail withdrawal responses, while those given the vaccines exhibited normal pain responses.

The vaccines were also evaluated in lethality studies. Mice given the vaccine did not die from doses of opioids that proved fatal for mice that were not vaccinated.

The researchers are currently developing human antibodies to synthetic opioids and hope to evaluate their performance in clinical studies. In addition to treating addiction and preventing overdoses, such vaccines could also protect emergency responders who may come into contact with drugs and potentially suffer from overdoses due to unexpected exposure.