Omeros Corporation (NASDAQ: OMER) today announced positive results from a Phase 2 clinical trial evaluating the effects of a peroxisome proliferator-activated receptor (PPAR)-gamma agonist in heroin-dependent subjects. The trial was designed and conducted by Dr. Sandra Comer and her colleagues at the Division on Substance Abuse, New York State Psychiatric Institute and Department of Psychiatry, Columbia University. The clinical trial demonstrated that the compound statistically significantly reduced drug craving and measures of anxiety in heroin users maintained on sublingual buprenorphine/naloxone. Omeros' issued and pending patents in its OMS405 program cover the use of any PPAR-gamma agonist, alone or in combination with other addiction therapies, to treat all forms of addiction, including opioids, cocaine, nicotine, alcohol and other substances of abuse as well as addictive or compulsive behaviors. Although opioid pharmacotherapies like buprenorphine and methadone are often used to treat heroin abuse and dependence, these medications have abuse potential themselves and can be diverted for non-therapeutic use. PPAR-gamma agonists are neither opioids nor addictive and, when used in combination with buprenorphine or methadone, may increase their therapeutic effectiveness and/or allow use of lower opioid maintenance doses. In a double-blind, placebo-controlled Phase 2 clinical trial, 30 non-treatment-seeking heroin users were admitted to an inpatient unit and randomized to receive either a PPAR-gamma agonist (n=14) or placebo (n=16) daily for up to three weeks. All patients were maintained on buprenorphine/naloxone (8/2 mg). Measures of heroin self-administration, positive subjective drug effects, craving and anxiety were recorded at multiple time points. The data reveal a statistically significant reduction in heroin craving in patients treated with the PPAR-gamma agonist compared to placebo controls. The PPAR-gamma agonist also attenuated anxiety, a behavior often associated with relapse, though no effect was detected on heroin self-administration or heroin-induced positive subjective effects. These findings are consistent with recent results in cocaine-dependent individuals in which 12 weeks of treatment with a PPAR-gamma agonist attenuated craving and resulted in an improvement in brain white matter integrity. In both studies, side effects were minimal and similar between the PPAR-gamma agonist and placebo groups. These clinical observations are also consistent with preclinical studies showing that PPAR-gamma agonists block reinstatement of heroin, cocaine and alcohol seeking in animal models of drug abuse.