Early use of disease-modifying drug treatments for relapsing-remitting MS can reduce the risk of conversion to secondary progressive MS, according to a study published in JAMA.
The observational cohort study found fingolimod, alemtuzumab, or natalizumab were more effective in preventing progression than other disease-modifying treatments such as interferon beta and glatiramer acetate (HR 0.66).
And earlier treatment was more effective than later treatment.
The international study comprised 1,555 patients from 68 sites across 21 countries including Australia.
Compared with untreated patients, the probability of conversion to secondary progressive MS was highest with interferon beta and glatiramer acetate (HR 0.71) then alemtuzumab (HR 0.61), natalizumab (HR 0.52) and fingolimod (HR 0.37).
And patients who escalated from interferon beta and glatiramer acetate to fingolimod, alemtuzumab, or natalizumab within five years of disease onset were less likely to convert than patients who escalated later (HR 0.76).
One of the study leads Associate Professor Tomas Kalincik told the limbic we still do not fully understand what fuels the progressive component of MS.
“We are using conversion to progressive MS as an arbitrary cut off …but conversion doesn’t happen overnight. We are treating it as if it does.”
“In reality what probably happens is early in the disease, shortly after people start experiencing bouts of inflammation in the brain and spinal cord, they also start accumulating subclinical, slowly worsening damage to the central nervous system.”
Associate Professor Kalincik, head of the MS Service at The Royal Melbourne Hospital and the Clinical Outcomes Research Unit (CORe) at the University of Melbourne, said other research had shown that people with progressive disease who occasionally experience a relapse can be better off than people with purely progressive disease.
“A relapse indicates there are still bouts of inflammation and that is something we can treat with the medications we currently have available.”
“In people who were progressive with relapses we were able to slow the progression of disability with treatments that are used in relapsing-remitting disease. In people with a purely progressive phenotype of disease without any relapses, if these people were exposed to disease modifying therapy, this did not change the trajectory of disease.”
He said the most effective treatments used early after disease onset, were not only treating relapses but also delaying significant disability.
“We are delaying the time to when the disease becomes untreatable.”
“Awareness is growing and now there is clearly a trend to start treatment earlier in the disease.”
He added this was underpinned by each new iteration of the McDonald criteria, which supported earlier diagnosis of patients with MS.
An Editorial in JAMA Neurology said the study had a number of weaknesses such as drawing comparisons between patients from separate cohorts.
“The use of propensity matching is not sufficient to ensure that other differences between the populations did not influence outcomes,” it said.
However the editorial reiterated the importance of further understanding the process of progression.
“The signs are strongly pointing to the benefits of early and aggressive treatment to forestall damage. Waiting on the sidelines does not appear justified.”