Experimental Medications: Other Therapeutic Strategies
RPC1063 is a selective modulator of one type of S1P receptor, S1P1. It is given as a once-daily pill, and was studied in a Phase II trial called RADIANCE, where the experimental medicine was compared at two different doses with placebo. A total of 258 RRMS patients were studied in this trial, which began with a seven-day gradual titration of RPC1063 up to the full dose under investigation. The double-blind study then ran for 24 weeks, followed by a yearlong safety-extension period.
At the end of the initial 24-week treatment period, patients in both groups taking RPC1063 showed an 86-percent decrease in the cumulative number of gadolinium-enhanced lesions compared to the placebo group. The relapse rates also decreased in the treatment groups compared with placebo, with a 31-percent decrease in the 0.5-mg group and a 53-percent decrease in the 1-mg group.
The most common side effects reported were nasopharyngitis, headache, and urinary tract infections, as well as mild elevations in liver enzymes in some participants. Notably, no serious cardiac events were reported in the subjects receiving RPC1063. The drug is moving into a larger, Phase III version of the RADIANCE trial57, where it will be compared with Avonex in 1,200 subjects with RRMS. This trial is expected to run through the end of 2017.