There are tons of groups that are lobbying for drug policy reform in the United States; expanding clinical research and treatment options is just one of many. Many of the nonprofits and businesses that have been funding clinical research are also very involved in pushing for regulatory reform, most notably in the US MAPS. There are plenty of groups with a more international scope, such as Beckley Foundation.

There's excellent sociological science that's been produced that has examined the negative impact of the War on Drugs on marginalized populations that has in turn led to social justice-oriented reform initiatives by the ACLU, Drug Policy Alliance, and others. While the focus of organization efforts varies by local chapter, SSDP also does excellent work on the activism front as well.