Early Interferon Therapy in MS Reduces Progression Risk

BASEL, Switzerland, Aug. 3 -- Interferon therapy in early multiple sclerosis significantly reduced the risk of progression to clinical disease and disability, investigators reported.

Patients who started interferon beta-1b at the first sign of MS had a 41% reduction in the risk of clinically definite disease over three years compared with patients who had delayed therapy, a multinational team reported in the Aug. 4 issue of The Lancet.

Early therapy reduced progression to disability by 40%, said Ludwig Kappos, M.D., of University Hospital here, and colleagues.

The results suggest that "a delay of such treatment by essentially, just one event, even at this early stage of the disease, has an effect on later accumulation of disability," they concluded.

"Even though patients in both groups remained at a low level of disability three years after the initial event, the delay in accumulation of disability with early treatment seen here is clinically relevant," the researchers added.

However, in a commentary that accompanied the report, Mayo Clinic neurologist Sean J. Pittock, M.D., said that the benefit was small, and he questioned whether the effect was clinically relevant.

The findings came from an open-label extension phase of the placebo-controlled BENEFIT trial. The primary results of that study showed that intervention with interferon beta-1b at the first clinical event suggestive of multiple sclerosis significantly reduced the risk of progression to clinically definite MS.

In the current study, 418 of 468 randomized patients (292 on active treatment and 176 on placebo) entered an open-label phase of treatment, and 392 completed three years of post-randomization follow-up. The principal objectives of the extension phase were the time to diagnosis of clinically definite MS, time to progression by the expanded disability status scale (EDSS), and score on a patient-reported functional assessment scale (FAMS-TOI).

After three years of follow-up (randomized plus open-label treatment), 37% of patients in the early-treatment group had developed clinically definite multiple sclerosis compared with 51% in the patients who had delayed treatment (P=0.0011).

EDSS progression (defined as an increase of at least one step) occurred in 16% of the early group versus 24% of the delayed group (P=0.022). FAMS-TOI scores remained high and stable throughout follow-up in both groups and did not differ between groups.

Discussing the implications of the study, the authors noted, "Relapsing-remitting MS presents with a first neurological attack and most patients recover fully from their initial symptoms within a short period of time. Recent evidence, however, suggests that subclinical damage persists and is frequently progressive."

They added, "An effective immumodulatory treatment initiated early after the presenting symptoms of MS would be expected not only to delay a second demyelinating event but also to prevent or delay permanent disability."

In his commentary, Dr. Pittock acknowledged that "Kappos and colleagues have set a new standard against which future extension trials will be compared."

However, he emphasized, the small benefit demonstrated in the extension phase "should not be construed as evidence for a treat-all approach."