Study of Laquinimod Does Not Meet Primary Endpoint: Initial Results Announced in Press Release
August 2, 2011
Teva Pharmaceutical Industries Ltd. and Active Biotech announced in a press release that the phase III BRAVO study, in which the experimental oral drug laquinimod was tested against inactive placebo in a study involving over 1300 people with relapsing-remitting MS, did not reach its primary goal of reducing the average number of relapses in a year. However, when the investigators adjusted the data to correct for differences in magnetic resonance imaging characteristics at the start of the study, a significant reduction in average annual relapse rate was observed in the group receiving the laquinimod. Further analysis is ongoing, and the results are being submitted for presentation at a scientific meeting later this year. The companies state that they plan to submit applications to regulatory authorities for the treatment of MS in the United States and European Union.
Background: Multiple sclerosis occurs when the immune system mistakenly attacks nerve fiber-insulating myelin and other brain and spinal cord tissues. Laquinimod is an immunomodulator believed to affect the immune attack. In an earlier phase II study involving 306 people with relapsing-remitting MS, oral laquinimod reduced disease activity by 40.4% compared with inactive placebo. (Lancet 2008; 371: 2085–92) In one phase III study – the ALLEGRO study – laquinimod reduced the annual relapse rate in those completing the trial by 23%, compared to those on placebo. (Late-Breaking News – American Academy of Neurology, 2011)
The Study: In the BRAVO study, participants were randomly assigned to receive either laquinimod 0.6 mg (one capsule daily), inactive placebo, or Avonex® (interferon beta-1a, Biogen Idec) 30 mcg/wk for 24 months. The primary goal of the study was to determine the effect of laquinimod on the rate of relapses. Secondary goals included impacts on disease activity as observed on MRI scans, and accumulation of disability. Laquinimod was not directly compared to Avonex, but just to the inactive placebo.
Laquinimod did not reduce the annualized relapse rate significantly more than placebo. According to the press release, there were differences in MRI characteristics between the treatment groups at the beginning of the study, and when the data were adjusted to account for these differences, laquinimod was found to reduce annualized relapse rate, disability progression (as measured by the EDSS scale of disease activity), and brain tissue volume loss significantly more than placebo. No details were released related to safety, except to state that “laquinimod demonstrated a favorable safety and tolerability profile compared to placebo.”
According to the companies, further analysis is ongoing, and the results are being submitted for presentation at a scientific meeting later in the year. The companies plan to submit applications to regulatory authorities for the treatment of MS in the United States and European Union. The complete data from the BRAVO and ALLEGRO studies should help define the safety and promise of laquinimod as a potential new oral therapy for relapsing-remitting MS.