Impact of Age on Switching or Stopping Disease Modifying Therapies in Multiple Sclerosis

Older patients age ≥55 account for almost half of the total MS population. While focal inflammatory demyelinating processes and progressive processes such as compartmentalized CNS inflammation, neurodegeneration, and failure of compensatory mechanisms co-occur from disease onset, there is a shift in the predominant disease processes with notable clinical progression occurring in the fifth decade of life. Clinically, this manifests in reduction in clinical relapses and MRI activity as persons with MS age, with an increase in slow disability progression independent of relapses. As disease modifying therapies have demonstrated efficacy on relapse reduction, but not centrally mediated progressive processes, the benefit of DMT wanes with age due to change in underlying biological disease processes. Contrastingly, risks of DMTs increase due to biological changes related with age, setting up a scenario where considerations on switching or stopping DMT become more clinically important based on risk-benefit ratios. This review will cover evidence regarding DMT use in older patients with MS and discuss age considerations in the management of patients with MS.