This excerpt taken from the ELN 20-F filed Mar 30, 2006.
SENTINEL Phase 3 Add-on Trial
The SENTINEL trial, also a two-year study, was a randomized, multi-center, placebo-controlled, double blind study of 1,171 patients in 123 clinical trial sites worldwide. The trial was designed to determine if adding Tysabri to ongoing Avonex therapy is more effective than continuing Avonex treatment alone in slowing the rate of disability in MS at two years and in reducing the rate of clinical relapses at one and two years in patients with evidence of relapses despite Avonex therapy.
Patients in the SENTINEL trial were required to have relapsing forms of MS, be on Avonex treatment for at least one year, and have experienced at least one relapse in the previous year. All patients continued to receive once-weekly Avonex and were randomized to add either a 300 mg IV infusion of Tysabri (n= 589) or placebo (n=582) every four weeks.
At one year, the addition of Tysabri to Avonex resulted in a 54 percent reduction in the rate of clinical relapses over the effect of Avonex alone. An annualized relapse rate of 0.36 was seen with Tysabri when added to Avonex versus 0.78 with Avonex plus placebo.
All secondary endpoints were also met. In the group treated with Tysabri plus Avonex, 67 percent of patients developed no new or newly enlarging T2 hyperintense lesions compared to 40 percent in the Avonex plus placebo-treated group. On the one-year MRI scan, 96 percent of Tysabri plus Avonex-treated patients had no gadolinium-enhancing lesions compared to 76 percent of Avonex plus placebo-treated patients. The proportion of patients who remained relapse-free was 67 percent in the Tysabri plus Avonex-treated group compared to 46 percent in the Avonex plus placebo-treated group.
In July 2005, we and Biogen Idec announced that SENTINEL achieved the two-year primary endpoint of slowing the progression of disability in patients with relapsing forms of MS. The addition of Tysabri to Avonex resulted in a 24 percent reduction in the risk of disability progression compared to the effect provided by Avonex alone. Data from SENTINEL also demonstrated that the addition of Tysabri to Avonex led to a 56 percent relative reduction in the rate of clinical relapses compared to that provided by Avonex alone. The reduction in relapse rate was statistically significant and sustained over the entire two-year study period.
Other efficacy data from SENTINEL at two years, including MRI measures and immunogenicity, were similar to previously reported one-year results. Data from SENTINEL was published in the New England Journal of Medicine in March 2006.