The NIDA Methamphetamine Clinical Trials Group: a strategy to increase clinical trials research capacity.
In order to increase the number of investigative teams and sites conducting research on pharmacological treatments for methamphetamine use disorders, the National Institute on Drug Abuse (NIDA) established an infrastructure of clinical sites in areas where methamphetamine addiction is prevalent. This multi-site infrastructure would serve to run multiple Phases II and III protocols effectively and expeditiously. NIDA collaborated with investigators from the University of California at Los Angeles (UCLA) to set up the Methamphetamine Clinical Trials Group (MCTG). This paper describes the development process, as well as data from a test trial to assess the capability of research-naive sites to recruit research participants and conduct study procedures according to research protocol. Subsequent trials are also described. A total of 151 candidates signed consent; 65 individuals were enrolled and 35 (53.8%) completed the 12 weeks' behavioral trial. Self-reported substance use report (SUR) showed comparable use of methamphetamine across sites with the individual site means ranging from 59% (site 5) to 80% (site 3). Drug use as measured by urinalysis was greatly reduced at week 13 compared to the baseline measure; the average rate of methamphetamine-free urine samples across all participants in sites at week 13 was 53%. The highest percentage of methamphetamine-free samples was 85% at site 5; the lowest was at site 1 (40%). Addiction severity index (ASI) composite scores at baseline and protocol completion for all participants demonstrated improvement in all categories over time, except for the medical composite score. The largest composite score reduction in baseline-protocol completion was in the drug domain (0.23 versus 0.15). The changes in the ASI scores from baseline to week 13 were consistent across all five sites. Outcomes of the behavioral trial indicated that the MCTG recruited well; collected study data accurately and reliably; and created a vehicle that can assess promising pharmacotherapies for methamphetamine addiction treatment medications. The MCTG strategy appears to be a feasible approach to increase NIDA's capacity to conduct clinical trials to evaluate potential pharmacotherapies for methamphetamine addiction.