issued new rules to expedite approval of drugs for life-threatening diseases, and expanded pre-approval access to drugs for patients with limited treatment options. The first of these new rules was the "IND exemption" or "treatment IND" rule, which allowed expanded access to a drug undergoing phase II or III trials (or in extraordinary cases even earlier) if it potentially represented a safer or better alternative to treatments currently available for terminal or serious illness. A second new rule, the "parallel track policy", allowed a drug company to set up a mechanism for access to a new potentially lifesaving drug by patients who for various reasons would be unable to participate in ongoing clinical trials. The "parallel track" designation could be made at the time of IND submission. The accelerated approval rules were further expanded and codified in 1992. All of the initial drugs approved for the treatment of HIV/AIDS were approved through accelerated approval mechanisms. For example, a "treatment IND" was issued for the first HIV drug, AZT, in 1985, and approval was granted just two years later in 1987. Three of the first five drugs targeting HIV were approved in the United States before they were approved in any other country. Challenges to FDA authority by states In two instances, state governments have sought to legalize drugs which have not been approved by the FDA. Because federal law passed pursuant to Constitutional authority overrules conflicting state laws, federal authorities still claim the authority to seize, arrest, and prosecute for possession and sales of these substances, even in states where they are legal under state law. The first wave was the legalization by 27 states of laetrile in the late 1970s. This drug was used as a treatment for cancer, but scientific studies both before and after this legislative trend found it to be ineffective. Federal law enforcement prevented interstate shipment, making the drug infeasible to manufacture and sell. Further studies based on a Mexican formulation also showed no effectiveness in treating cancer, but did find that some patients experienced symptoms of cyanide poisoning. Though the political movement died out in the 1980s, FDA enforcement actions against laetrile purveyors continued into the 2000s. The second wave concerned medical marijuana in the 1990s and 2000s. Though Virginia passed a law with limited effect in 1979, a more widespread trend began in California in 1996. In 2009, the Obama Administration de-prioritized enforcement