Tysabri Treatment Lessens Sexual Dysfunction in MS Patients, Study Finds

Treatment with Tysabri (natalizumab) can help lessen sexual dysfunction in patients with multiple sclerosis (MS), a new study shows.

The study, “Patient perceived changes in sexual dysfunction after initiation of natalizumab for multiple sclerosis,” was published in the Multiple Sclerosis Journal – Experimental, Translational and Clinical.

MS is an autoimmune disease of the central nervous system (CNS), and patients can present a wide range of symptoms that affect multiple organ systems in the body. In particular, sexual dysfunction is frequently experienced by MS patients. It affects an estimated 40-80% of patients and can be due to a variety of reasons.

Sexual dysfunction can be caused by damage induced by MS lesions in areas that are involved in sexual response, which can lead to difficulty with arousal and orgasm. It may develop due to MS-related motor weakness, muscle spasticity, fatigue, and pain related to insufficient lubrication. It also can occur due to psychological and sociological impairment that often characterizes patients with MS.

Sexual dysfunction carries many negative consequences, including low self-esteem and a decrease in health-related quality of life (HRQoL). In fact, a 2013 study showed that sexual dysfunction is MS patients has a more detrimental impact on HRQoL than physical disability.

Tysabri, marketed by Biogen, is an approved disease-modifying therapy for the treatment of relapsing MS. Beyond its clinical benefits, Tysabri has been shown to improve HRQoL parameters, particularly fatigue and cognition.

Researchers hypothesized that Tysabri could help address sexual dysfunction in patients with MS, leading to an improvement in HRQoL.

To test their theory, they investigated changes in MS patients’ perceived sexual dysfunction for 24 weeks after starting treatment with Tysabri.

Adults with relapsing MS (mean age of 41 years) who were starting Tysabri treatment and had a baseline level of sexual dysfunction were enrolled in the study. Sexual function was assessed using the MS Intimacy and Sexuality Questionnaire-19 (MSISQ-19) score.

Results indicated that patients treated with Tysabri experienced significantly less sexual dysfunction within the first 24 weeks of starting therapy, as demonstrated by a decrease of approximately 0.7 in MSISQ-19 score. (The MSISQ-19 score is rated from 1 to 5; a lower score reflects a reduced impact of MS on sexual dysfunction).

Additionally, patients experienced an overall improved quality of life while on Tysabri, as demonstrated by higher scores on FAMS (functional assessment of multiple sclerosis), a validated tool for assessing QoL in MS.

However, the researchers noted the study had limitations, including the small sample size, and suggested that a bigger study should be undertaken to further investigate sexual dysfunction in the MS population.

“Given the high prevalence of sexual dysfunction in MS patients and the significant impact it has on HRQoL, more research on this often overlooked symptom of MS could be very informative for patients that are deciding to initiate a new disease-modifying therapy,” the researchers wrote.