Yesterday at the AAPS (American Association of Pharmaceutical Scientists) Annual Conference in San Diego, Marco Praveloni of the University of Minnesota unveiled a preclinical vaccine which has shown success in blocking opiates from reaching the brains of rodents.
The studies immunized rats and mice to elicit serum antibodies for oxycodone and hydrocodone. The increased serum levels led in turn to decreased brain uptake of the opiate drugs.
The vaccine candidate, 60XY-KLH, was designed using a series of conjugates and involves no expression systems or cell lines, said Praveloni.
Studies showed the vaccine works best in subjects with the highest serum antibody levels, so researchers tried different adjuvants to activate B- and T-cell lymphocytes which in turn boost serum antibody levels. “We’re combining chemistry and immunology,” Praveloni told the conference.
The Minnesota team also found the candidate effective using differing routes of administration and with various carrier proteins (native KLH decamer, GMP-grade KLH dimer and tetanus toxoid).
Addicts' needs
Praveloni said an eventual vaccine could help both addicted users of both heroin and prescription opiates, such as oxycodone and hydrocodone. Alternative therapies include substitution pharmaceuticals (methadone), or antagonists (such as naltrexone).
Anti-opioid vaccines must overcome several challenges uncommon to other vaccines. They target multiple compounds and active metabolites; they must have the versatility to deal with addicts switching between different drugs; and they need to work against illicit opioid use but not interfere with opiate-based pain or addiction medicines. The 60XY-KLH researchers found it was selective and did not interfere with the opiate painkiller fentanyl.
Praveloni told this reporter his lab is looking for funding to advance to clinical stage.
Separately, University of Arkansas scientists also revealed this week an anti-methamphetamine antibody that could help meth users kick the habit.