Genentech, a biotechnology company owned by Roche Pharmaceuticals, has announced promising results from a phase III clinical trial of experimental therapy ocrelizumab in people with primary progressive MS.
In a press release from the company, researchers have reported that ocrelizumab treatment was found to significantly reduce clinical disability progression in comparison to a placebo. In the trial, clinical disability progression was defined as an increase in the Expanded Disability Status Scale (EDSS) sustained for a period of at least 12 weeks.
Ocrelizumab is a humanised monoclonal antibody, which is related to the mouse antibody known as rituximab that is sometimes used to treat MS and the related disorder neuromyelitis optica. Ocrelizumab targets B-cells of the immune system via molecule on their surface known as CD20. The treatment is given as an infusion every six months.
The press release indicates that the occurrence of adverse events in people given ocrelizumab was similar to that seen in the placebo group, with reactions to the infusion being most common. Previous trials in rheumatoid arthritis have suggested that ocrelizumab may be associated with an increase in opportunistic infections, however, in preliminary results released from studies in relapsing remitting MS the incidence of infections appeared to be similar to that seen in patients treated with interferon-beta. We will need to await publication of the full trial results to better understand the risks and potential benefits of ocrelizumab as a treatment for primary progressive MS.
The company has also previously released results from phase III trials of ocrelizumab in relapsing remitting MS, suggesting that the experimental treatment is also effective at suppressing relapses in this form of the disease. Both the relapsing remitting and primary progressive MS trials included patients in Australia.
The results of the trials of ocrelizumab in both primary progressive MS and relapsing remitting MS will be presented at the European Committee for Treatment and Research in MS (ECTRIMS) conference in Barcelona next week.
This is the first time that an experimental therapy has shown promise in clinical trials for both relapsing remitting and primary progressive MS.
The company has announced that they will be filing an application for marketing of ocrelizumab with the Food and Drug Administration in the USA early next year. We will need to await further information from the company regarding an application to the Australian Therapeutics Goods Administration.
‘The results of the ocrelizumab trial in people with primary progressive MS are an encouraging development in the search for effective treatments for this disabling form of MS,’ said Professor Alan Thompson, Chair of the International Progressive MS Alliance Scientific Steering Committee. ‘While the reported effects on progression are modest, the data clearly indicate that this treatment has potential benefit and is not only a source of hope, but also an important milestone that will further inform development for effective treatments for everyone with progressive forms of MS’.
You can read a statement from the International Progressive MS Alliance on these results here.