A medicine that people hoped would聽treat chronic fatigue syndrome聽(CFS) has failed its first large placebo-controlled trial.
The drug, called rituximab, is used聽to treat cancer and autoimmune diseases in which the immune system makes antibodies that turn against the body. The medicine works by killing the cells that make antibodies.
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A few people who had cancer and also happened to have CFS saw their symptoms of fatigue resolve after taking rituximab. 脴ystein Fluge of Haukeland University Hospital in Norway thought rogue antibodies could be involved in CFS, also known as myalgic encephalomyelitis (ME).
These initial findings were borne out by some small studies. Fluge and his colleagues鈥� latest trial was larger, involving 151 people. Half had regular infusions of rituximab for a year, while聽the rest got placebo infusions. Their symptoms were measured over this time and for a further year, as the drug can take several months to work.
About 25 per cent of people in the treatment group saw their tiredness alleviate聽鈥� but so did 35 per cent of聽people in the placebo group. Rituximab also caused a higher rate of聽side effects that required going to聽hospital, such as infections.
Fluge says the first people who got better after taking rituximab may have done so because of the placebo effect, or because their condition naturally resolved. Alternatively, they聽could have been different in some way from other people with CFS.
The results are a blow to the idea that antibodies cause CFS, says Fluge, 鈥渂ut it doesn鈥檛 exclude that other parts of the immune system are active聽in this disease鈥�.
Charles Shepherd of the UK鈥檚 ME Association says some people with the condition have travelled to the聽US聽to get rituximab treatment even though it isn鈥檛 licensed to be used in this way.
Annals of Internal Medicine
