A British company is conducting advanced clinical trials of the first drug developed from raw marijuana. The drug is a mouth spray designed to treat cancer-related pain. The company, GW Pharma, hopes to obtain approval from the U.S. Food and Drug Administration (FDA) by the end of 2013, according to the Associated Press.

The drug, Sativex, already has been approved in Canada, New Zealand and eight European countries to relieve muscle spasms associated with multiple sclerosis, the AP reports.

Currently the U.S. Drug Enforcement Administration categorizes marijuana as a dangerous drug with no medical value. The article notes that if the FDA approves a drug with a chemically similar makeup, it could increase pressure on the federal government to rethink its stand on marijuana, and encourage other drug manufacturers to conduct research on comparable drugs.

The FDA approved two drugs containing a synthetic version of the marijuana compound THC in 1985. These drugs, Marinol and Cesamet, were approved to treat side effects of chemotherapy in cancer patients. Marinol also can be prescribed to stimulate the appetite of AIDS patients.