MS Therapies & Onset of Disability

"I heard recently that MS drugs do not delay disability? Why should I bother taking them, especially when they cost so much and have side-effects?" In July 2012, there was a flood of articles after research found that there wasn't a significant delay in the onset of disability with interferons, one of the most common disease modifying therapies on the market. This can be a scary thought since ultimately we want to delay the onset of significant disability. Here is a one article from the NY Times: http://www.nytimes.com/2012/07/18/health/research/multiple-sclerosis-drug-doesnt-stop-disability-study-finds.html I emailed my MS specialist and this is what he replied with: "This is an well executed study that attempts to address the vital but extremely difficult to answer question of the effect of a disease modifying therapy on the accrual of long term disability. The original study can be found here: http://jama.jamanetwork.com/article.aspx?articleid=1217239 but let me point out a few significant features. "This study compared the development of sustained disability in patients taking interferon beta against two comparator groups: 1) patients who met criteria to be treated for MS but chose not to, and 2) historical controls of patients who were diagnosed before the availability of disease modifying therapy, but would have been recommended to be treated had they presented at a later time. Let me address these two comparisons separately. "The authors point out that there are many reasons why patients with MS may choose not to start on disease modifying therapy such as needle phobia, concern about side effects etc. Let me say as a physician who has gone through this process with innumerable patients, that while this is true, the one variable that trumps all of these concerns is disease severity. Patients with a mild course and minimal to no problems, may be quite hesitant to be treated for many of the listed reasons, whereas patients with significant and or frequent relapses quickly put all such concerns aside. This is clearly reflected in this study in which the baseline characteristics of the contemporary control patient group, which have a lower relapse rate and develop disability at a slower rate prior to entering the study or becoming eligible to receive treatment. And in fact the contemporary control group appears to do better than the interferon beta treated group although this does not reach significance. I would agree that MS is a highly variable disease and the difference between patients with mild and severe disease is much greater than the effect of standard treatments. (It's better to be lucky than to be good) "The second comparison between interferon treated patients and historical controls is probably the more valid test. While this did not quite reach the threshold of statistical significance, there was a strong trend towards benefit with treatment with a Hazard Ratio of 0.77 (95% CI, 0.58-1.02, P=0.07). While generally I would be cautious of making too much out of claims of "trends toward significance," it must be pointed out that this study was powered and designed to detect a 40% decrease in the rate of disability. These drugs are well recognized as only reducing relapse rate by 30%, and I would assume that the effect on disability accumulation would be comparable. Perhaps if it had been powered to detect a 30% difference, it would have achieved statistical significance. That of course would have required many more patients than even this large study could manage. "While this is not great news in that it does not show a standard disease modifying therapy having a strong effect on disability, I think it would be rash to interpret this as proving that there is no benefit. If there is a 30% effect, that might make all the difference in the world to someone with milder disease. I am not sure if any or all of the above will apply equally to copaxone as it works by different pathways as you point out. In the near future the options for disease modification will include several more options which will hopefully change all of this."

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