He and his colleagues studied 106 consecutive patients with secondary progressive MS who had been on immunomodulators for at least 6 months, were taken off the immunomodulators, and were followed for a mean of 5 years.
Results showed that 16% of the patients had a clinical relapse after discontinuation, nearly all within the first 3 years. The annualized rate of clinical relapse actually fell from 0.13 in the 3 years before discontinuation to 0.07 in the 3 years afterward.
Overall, 35% of patients had either a clinical relapse and/or new contrast enhancement on MRI. Again, most of these events occurred within the first 3 years of discontinuation.
Patients had a lower risk of this outcome after treatment discontinuation if they had an Expanded Disability Status Scale (EDSS) score of 6 or greater at the time of discontinuation (hazard ratio, 0.4) and if they had not had any gadolinium enhancement on MRI in the 3 years before treatment discontinuation (HR, 0.4).
“Disease activity remained low after treatment withdrawal. We found no rebound of relapse rate in our population,” Dr. Bonenfant summarized. “There was no consequence on the slope of disability progression,” nor on the finding of enhancement on MRI alone.
Thirty patients were restarted on immunomodulators, about half of them solely because of MRI findings, he noted. This raises “the controversial question, is it relevant or not to resume treatment in these patients?”
“This study suggests that immunomodulatory treatment withdrawal seems reasonable for patients with advanced secondary progressive MS, especially with an EDSS of 6 or greater and no focal inflammatory disease [clinical or radiologic] at least in the past 3 years,” Dr. Bonenfant maintained. “It shows the importance of MRI monitoring to define the patients who are still in a focal immunoreactive state.”
“The results are far from being definitive, and further prospective studies are needed to provide evidence-based recommendations for clinical practice,” he concluded.
Dr. Kantarci disclosed that he has given scientific presentations at meetings supported by Novartis Pharmaceuticals and has presented as an invited speaker for Biogen but has received no personal compensation from either company. Dr. Bonenfant disclosed that he had no relevant conflicts of interest.