AMSTERDAM—Monthly subcutaneous daclizumab monotherapy demonstrated a robust and clinically meaningful effect on MS activity, including evidence for early impact on disability progression, according to phase 3 data presented at the ECTRIMS/ACTRIMS 5th Joint Triennial Congress.
Researchers randomized 600 patients with relapsing-remitting MS and at least one MS relapse in the prior 12 months or one new gadolinium-enhancing lesion in the prior six weeks to receive low-dose daclizumab (150 mg), high-dose daclizumab (300 mg), or placebo as a subcutaneous injection once every four weeks for 52 weeks.
A total of 559 patients (93%) completed the treatment period. Annualized relapse rate, the study’s primary endpoint, was 0.21 for low-dose daclizumab, 0.23 for high-dose daclizumab, and 0.46 for placebo. The proportion of relapse-free patients was 81% in the low-dose group, 80% in the high-dose group, and 64% in the placebo group. There were significant reductions in the mean number of new or newly enlarging T2 lesions at one year (2.4 for low dose, 1.7 for high dose, and 8.1 for placebo). Among 309 patients in an MRI substudy, the mean number of new gadolinium-enhancing lesions between weeks 8 through 24 was 1.5 for low-dose daclizumab, 1.0 for the high-dose group, and 4.8 for placebo. The risk of three-month sustained disability progression at one year was reduced by 57% in the low-dose group and by 43% in the high-dose group.
Serious adverse events, excluding MS relapses, occurred in 5% of the placebo group, 6% in the low-dose group, and 8% in the high-dose group. One daclizumab-treated patient died due to a complication of a psoas abscess. Serious adverse events in the daclizumab-treated patients included an increase in serious infections (2%), serious cutaneous events (1%), and elevations in liver function tests (4%).