The multiple sclerosis study published in the journal The Lancet found that alemtuzumab significantly reduced the number of attacks or relapses by people with MS.
This result was seen both in patients who had not previously received any treatment and those who have continued to show disease activity while taking an existing treatment for MS.
In one trial with patients who had recently relapsed, new episodes were reduced by 49% more than that achieved by the current standard treatment.
Over a two-year period, 65% of patients on alemtuzumab compared with 47% of patients on interferon did not relapse.
More top news
Freezing and frosty for some of us
Laura Schwartz, former White House aide to Bill Clinton, tells ITV News about the importance of the inauguration.
The council blames Westminster for cutting funding and say the rise is crucial to be able to afford social care.