Clinical trials of non-psychological treatments are quite rare in ME/CFS, so it can be exciting when one comes along, particularly if the most severely affected patients are included. One example was a phase III randomised trial in which the TLR-3 agonist rintatolimod was compared with placebo in 234 people suffering with long-standing, debilitating ME/CFS at 12 different centres across the USA.
After 40 weeks, exercise tolerance (total achievable exercise time on a treadmill) was significantly improved in the patients on intravenous rintatolimod therapy (400 mg twice weekly) compared with those on placebo. The size of the improvement was around 20%, equating to approximately 68 seconds of additional treadmill activity. Indeed, the authors say that this level of improvement represents approximately twice the minimum considered medically significant by regulatory agencies. Rintatolimod also reduced dependence on symptom-relieving drugs compared with placebo, and it seems to have been well-tolerated with no serious adverse effects definitely related to the drug.
Under its more common name, Ampligen, rintatolimod has been well-known to ME/ CFS patients since the first preliminary report of its potential usefulness in 1994. Ampligen has known antiviral and immunomodulatory properties, and these positive results suggest that it may become part of the therapeutic armoury of treatments for ME/ CFS, providing FDA approval is finally granted.
Reference: A double-blind, placebo-controlled, randomized, clinical trial of the TLR-3 agonist rintatolimod in severe cases of chronic fatigue syndrome. Strayer et al., PLoS One 2012; 7(3): e31334