Although Ampligen was cleared for use in Canada in 1997, and obtained orphan drug status for treatment of CFS in the European Union in 2000, it is so far without FDA approval, so is classed as experimental in the United States. In 2007, Hemispherx filed a new drug application with the U.S. Food and Drug Administration (FDA) to market and sell rintatolimod for the treatment of CFS, but this was rejected in December 2009, because the FDA concluded that the two randomized controlled trials "did not provide credible evidence of efficacy" and "because of clinical, statistical, clinical pharmacology, nonclinical, product quality, and facilities inspection deficiencies." The FDA requested Hemispherx conduct at least one additional controlled trial to demonstrate efficacy in treating CFS. In August 2012, Hemispherx submitted further analyses of the original clinical trial data, but did not submit additional trials for review. Four months later, a committee of the FDA voted 8-5 against approval for rintatolimod, again citing insufficient data. Ampligen continues to be evaluated, however, and as of 2021 is involved in phase 3 and phase 2 trials for chronic fatigue syndrome and several cancers.