TMJ 'dysfunction' - Health implications

Research: beta-interferon & progression

Posted: 12 Nov 2012 05:00 PM PST
Epub: Greenberg BM et al. Interferon Beta Use and Disability Prevention in Relapsing-Remitting Multiple Sclerosis. Arch Neurol. 2012 Nov 5:1-4. doi: 10.1001/jamaneurol.2013.1017.

CONTEXT:  Interferon beta is widely prescribed to treat MS; however, its relationship with disability progression has yet to be established.

OBJECTIVE: To investigate the association between interferon beta exposure and disability progression in MSers with relapsing-remitting MS.

DESIGN, SETTING, AND PATIENTS:  Retrospective cohort study based on prospectively collected data (1985-2008) from British Columbia, Canada. MSers with relapsing-remitting MS treated with interferon beta (n = 868) were compared with untreated contemporary (n = 829) and historical (n = 959) cohorts.

MAIN OUTCOME MEASURES:  The main outcome measure was time from interferon beta treatment eligibility (baseline) to a confirmed and sustained score of 6 (requiring a cane to walk 100 m; confirmed at 150 days with no measurable improvement) on the Expanded Disability Status Scale (EDSS) (range, 0-10, with higher scores indicating higher disability). A multivariable Cox regression model with interferon beta treatment included as a time-varying covariate was used to assess the hazard of disease progression associated with interferon beta treatment. Analyses also included propensity score adjustment to address confounding by indication.

RESULTS:  The median active follow-up times (first to last EDSS measurement) were as follows: for the interferon beta-treated cohort, 5.1 years (interquartile range [IQR], 3.0-7.0 years); for the contemporary control cohort, 4.0 years (IQR, 2.1-6.4 years); and for the historical control cohort, 10.8 years (IQR, 6.3-14.7 years). The observed outcome rates for reaching a sustained EDSS score of 6 were 10.8%, 5.3%, and 23.1% in the 3 cohorts, respectively. After adjustment for potential baseline confounders (sex, age, disease duration, and EDSS score), exposure to interferon beta was not associated with a statistically significant difference in the hazard of reaching an EDSS score of 6 when either the contemporary control cohort (hazard ratio, 1.30; 95% CI, 0.92-1.83; P = .14) or the historical control cohort (hazard ratio, 0.77; 95% CI, 0.58-1.02; P = .07) were considered. Further adjustment for comorbidities and socioeconomic status, where possible, did not change interpretations, and propensity score adjustment did not substantially change the results.

CONCLUSION:  Among MSers with relapsing-remitting MS, administration of interferon beta was not associated with a reduction in progression of disability.

Addendum:
Another comment on a popular pharmaceutical agent (PA) blog:
"What would you want from your DMT; being relapse-free, without the DMT necessarily having an impact on long-term disability, or brain atrophy? Would you prefer a DMT to delay the rate of brain atrophy, with the promise of this will translate into long-term disease progression? Many of you will say this is a no-brainer; i.e. I want to be relapse-free, disease-progression free, MRI disease activity-free and with a reduction in the rate of brain atrophy to a rate that is expected for age. I agree that it may be a no-brainer, but is it achievable? The current crop of DMTs don't offer this treatment target, or we don't have the data yet, to show that we can achieve this in the long-term."

"May be you should be asking your neurologist what is the evidence that the DMT they are recommending prevents or delays the acquisition of long-term disability and what does the DMT do in relation to brain atrophy? I would be interested in knowing their answers."