A study has revealed significant therapeutic inertia in the treatment of women with multiple sclerosis, highlighting gender disparities that could affect long-term health outcomes for women of childbearing age. The findings suggest that concerns related to pregnancy may lead to delayed or reduced use of disease-modifying treatments, even before pregnancy becomes a consideration.

In an extensive analysis of 22,657 patients with relapsing MS who were on the French MS registry, researchers found more than a median follow-up of 11.6 years women had a significantly lower probability of being treated with any DMT and were even less likely to be prescribed high-efficacy DMTs.

The difference in DMT usage varied across both different treatments and over time. Teriflunomide, fingolimod, and anti-CD20 therapies were significantly underused throughout their entire availability. Interferon and natalizumab were initially used less frequently, but their usage equalized over time. In contrast, glatiramer acetate and dimethyl fumarate were initially used equally between genders, but eventually became more commonly prescribed to women.

The study further highlighted the disparity in treatment emerged after two years of disease duration for DMTs and as early as one year for HEDMTs. Interestingly, this gender-based treatment gap did not significantly vary with patient age, indicating therapeutic inertia may persist regardless of a woman’s stage in life.

Both neurologists and patients contribute to this therapeutic inertia, many taking a precautionary approach and avoiding these treatments. According to the researchers, neurologists might be hesitant to prescribe DMTs, particularly if they are not comfortable with managing pregnancy-related issues. At the same time, women, understandably, do not want to take any risks for their child or pregnancy. Their primary concerns are congenital malformations, fetal loss, and fetal growth disorders. Women will also experience discomfort if their neurologist seems uncertain.

Moving forward, the research team plans to delve deeper into the factors contributing to this therapeutic inertia, with a focus on improving treatment strategies that prioritize both the long-term health of women with MS and their reproductive goals.

The findings were presented at ECTRIMS 2024.