Oral Cladribine Efficacy Trials Slated to Begin This Year
Recently, Serono (makers of Rebif) and Ivax Corporation announced their test results from two clinical trials with a new oral formulation of cladribine. The study results showed that the formulation of oral cladribine has met the targets for an orally administered product, with blood levels of cladribine reaching the desired levels. Cladribine inhibits immune reactions by disrupting the production of certain white blood cells, particularly lymphocytes, which are involved in the disease process of multiple sclerosis. Investigators are planning further efficacy studies of oral cladribine in MS patients for late 2004.
Previous phase II and phase III clinical trials of injectable cladribine demonstrated some effects in people with MS. In these trials there was a reduction in new lesion development in the brain as seen on MRI scans, although total lesion volume did not appear to be affected. Individuals with relapsing-remitting MS also experienced clinical benefits (with an exacerbation rate approximately half of the rate experienced by individuals taking placebo). Disability in terms of EDSS was not affected. The results of these studies, however, were considered to be mixed and could not be replicated in a recent phase III study (which may be due to participants having more advanced MS than in previous studies).
Researchers determined that further studies were needed, employing participants who have MS in earlier stages. But in these upcoming trials, investigators will be able to use an oral formulation rather than giving the drug through injections. Medications in drug trials are frequently administered via injection, as this method can deliver higher amounts into the blood system as opposed to drugs taken orally. As mentioned earlier, however, the oral formulation of cladribine was able to reach the desired level in the blood. For this reason, investigators are now able to conduct trials with the oral version, which is both painless and more convenient for the participants.
