Treatment of relapsing multiple sclerosis (MS) with beta-interferon therapies is associated with extended patient survival, particularly if taking such treatments for more than three years, according to a real-world study in Canada and France.
The study, “Multiple sclerosis: effect of beta interferon treatment on survival,” was published in the journal Brain.
Beta-interferon formulations — which currently include EMD Serono’s Rebif, Biogen’s Plegridy and Avonex, Bayer’s Betaseron/Betaferon, and Novartis’ Extavia — were the first disease-modifying therapies to be approved for people with MS, and remain among the most commonly prescribed worldwide. However, despite showing effectiveness in short-term clinical trials, the effects of these treatments in longer periods need more research.
As long-term trials specifically designed to assess how disease-modifying therapies affect survival are neither feasible nor ethical, a team at University of British Columbia and Vancouver Coastal Health Research Institute followed a group of 5,989 adults with relapsing MS. The group’s mean age was 42 years, 75% were female, and all were from British Columbia, Canada, and Rennes, France. The researchers explored the association of beta interferons with all-cause and MS-related mortality in the clinical setting.
More specifically, the group analyzed included patients with relapsing-remitting or secondary progressive MS, who were followed between 1986 and 2013 (average follow-up of 11 years). Neither patient had taken an immunosuppressant or a disease-modifying therapy at the study’s start.
The benefits of beta-interferons were compared to those of all other available therapies during the study, including Copaxone (glatiramer acetate, by Teva), immunosuppressants such as azathioprine or mitoxantrone, Tysabri (natalizumab, by Biogen), and Gilenya (fingolimod, by Novartis).
Over the study duration, 32% of the patients received a beta-interferon therapy for at least six months, 12% Copaxone for at least six months, and 13% another disease-modifying therapy for at least one day.
Results showed that taking beta-interferons for a minimum of six months was associated with a 32% lower mortality risk, compared to not receiving this type of treatment.
In line with previously reported results from the same analysis, taking beta-interferons for more than three years further extended survival. These benefits were similar in patients from both Canada and France, and between men and women, although women showed prolonged survival only with treatment for three or more years.
Also, starting treatment more than five years after MS onset, or after age 40, did not preclude the same benefit in survival.
A total of 742 deaths due to any cause occurred during the study (mean age of 61 years at death), 489 of which (66%) were MS-related. As with all-cause mortality, taking beta-interferons was associated with a 29% lower risk of MS-related death than not taking these medications.
“Our study provides evidence for a significant survival advantage among people with relapsing-onset [MS] who are exposed to beta-interferons during routine clinical practice,” the researchers wrote.
“This is a significant study,” Elaine Kingwell, PhD, the study’s first author, said in a press release.
“Although these drugs [beta-interferons] have been prescribed since the mid-1990s, it takes time before scientists can look at the effect of these treatments on a long-term outcome like survival. We found that patients who were treated with these drugs during routine clinical practice survived longer overall than patients who had not taken beta-interferon,” Kingwell said.
In turn, Helen Tremlett, PhD, the study’s senior author, mentioned other analyses worth conducting: “Now that we know that life might be extended for people with MS who take these drugs, we do have to consider quality of life.” Besides beta-interferons, the team also is planning to look at the impact of newer MS therapies.
Sharon Roman, a Vancouver resident, diagnosed with MS two decades ago, found the results “encouraging.”
“The study findings could impact a lot of people, not just because of the sheer number of patients that are on beta interferon worldwide, but also because it offers comfort in terms of our longevity,” Roman said. “This offers a potential incentive that could conquer a dislike or a fear of injections, and might encourage people to adhere to the prescribed dosing schedule.”
Of note, three of the study’s authors have received consulting fees, grants, speaker honoraria and/or travel expenses from Biogen, Novartis, Teva, Bayer, EMD Serono, and/or Biogen, but all were unrelated to this study.