Clinical trials for multiple sclerosis (MS) therapies demonstrate a success rate that is nearly triple that of other diseases, with small molecules and novel drugs appearing superior, according to an analysis published in Multiple Sclerosis and Related Disorders.

Over the last 20 years, there has been a rapid increase in the number of available disease-modifying therapies (DMT) for MS.

“MS is a ‘best in class’ disease area relative to other disease conditions when you look at the number of new drug approvals that have taken place and the fact that many represent very different mechanisms of action,” Jayson Parker, PhD, assistant professor at the University of Toronto Mississauga, told Neurology Advisor. “Within neurology this is simply not the case for conditions such as Alzheimer’s disease, depression, or Parkinson’s disease.”

CLINICAL CHART: Multiple Sclerosis Treatments

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In the current study, Dr Parker and colleagues aimed to highlight any specific risk factors for clinical trial failure of MS drugs by comparing clinical trial success rates. They collected data on Phase 1, 2, and 3 clinical trials from 1998 to January 2015 on drugs tested for MS and then compared the data to industry standard success rates.

Of the 53 distinct compounds that met inclusion criteria, 25 trials progressed and 5 compounds were FDA approved for MS during the study period. In all trial phases, MS clinical trials had a 27% success rate compared to an industry rate of 10%. Most of the clinical trials were conducted in a relapsing-remitting MS (RRMS) population (N=22), however those studied in a relapsing MS population were found to have a 100% phase III clinical trial success rate (N=3). The authors point out that there have been no successful phase III clinical trials exclusively studying patients with secondary-progressive MS (SPMS) or primary-progressive MS (PPMS).

There were more biologics being studied than small molecules (28 vs 24), however small molecules had a higher clinical trial success rate (31% vs 13%) than biologics (23% vs 32%) when compared to industry small molecules and biologics, respectively. Drugs studied for MS with a prior FDA approval for an alternative indication had a lower success rate than novel drugs.

“Our results suggest this prior approval history does not mitigate the risk of clinical trial failure,” Dr Parker said. “On the contrary, new drugs without any prior FDA approval history seem to carry less clinical trial risk in MS. Physicians should continue to embrace novel drugs with new mechanisms of action in this condition.”

“The best step for risk reduction is the use of biomarkers,” Dr Parker continued. “Physicians should push back on manufacturers and demand that biomarker use be explored in inclusion and exclusion criteria in phase 2 studies and be maintained into phase 3 if the data warrants.”

References:

De Gasperis-Brigante CD, Parker JL, O’Connor PW, Bruno TR. Reducing clinical trial risk in multiple sclerosis. Mult Scler Relat Disord. 2015; 5:81 – 88.