New Study Will Assess Tysabri Effects on MS Cognitive Fatigue

Researchers from the Kessler Foundation will launch a new study investigating the effects of Tysabri (natalizumab) on cognitive fatigue — the type of fatigue that happens after strong mental concentration, such as in problem-solving — in people with relapsing-remitting multiple sclerosis (RRMS).

Cognitive fatigue, which is very common in MS, is considered the most disturbing symptom of the disease by about 40% of patients, according to the Kessler Foundation.

Despite this, there are few treatment options for cognitive fatigue — and none of the therapies used to slow the progression of physical disability in MS patients are indicated for its treatment.

For this reason, a Kessler team decided to explore the role of Tysabri, an approved MS therapy, in relieving this symptom in people with RRMS.

“We expect to advance our knowledge of the effects of Tysabri on cognitive fatigue, which may be an important step toward expanding the options for treating this disabling symptom,” John DeLuca, PhD, Kessler’s senior vice president of research and training and the main investigator of the study, said in a press release.

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Titled “Biomarker for Cognitive Fatigue using Functional Imaging in Multiple Sclerosis,” the study (NCT04565431) is sponsored by Biogen, Tysabri’s developer.

The trial is not yet recruiting participants. Information on enrollment will be found here.

The main goal of the study is to assess the effects of Tysabri both on cognitive fatigue and on the specific brain areas that are known to be involved with this symptom in MS patients. The team will investigate how cognitive fatigue develops when a demanding task is performed, and also whether treatment duration has any influence on symptom reduction.

In total, the study will enroll 25 people, ages 18-64: 10 healthy individuals who will serve as controls and 15 MS patients who are planning to start Tysabri treatment. The healthy individuals in the control group will be matched for age, gender, and education to those in the MS group.

Functional MRI — a type of neuroimaging that allows researchers to detect which areas of the brain are active — will be used during the first six months of treatment. Those scans will assess which brain areas are associated with cognitive fatigue once participants complete a cognitively challenging activity.

In this case, participants will complete the Symbol Digit Modality Task, a test that involves a simple substitution task in which, based on a reference key, the individual has a certain time to pair specific numbers with given geometric figures.

Additionally, the team will investigate any changes in the onset of cognitive fatigue as treatment with Tysabri continues.

“Using this rigorous study design, we will add to our understanding of the neural mechanisms associated with Tysabri therapy,” DeLuca said.

The scientists previously used neuroimaging techniques in their research into this disabling symptom and identified a biomarker that pinpoints the most active brain areas associated with cognitive fatigue. Now, they will use this biomarker to determine the study’s outcomes.

“The biomarker enables us to objectively study disease-modifying therapies for MS such as Tysabri for their effects on cognitive fatigue,” DeLuca said.

Apart from Tysabri, the Kessler Foundation team also plans to study the influence of another MS approved therapy, Ocrevus (ocrelizumab), in relieving cognitive fatigue (NCT04448977).