Clinical trials are helpful tools in deepening our understanding of certain diseases and evaluating and identifying effective treatment options. Unfortunately, these trials don’t always garner the necessary information. For example, pharmaceutical company Merck recently saw the downfall of its Phase 3 trial for evobrutinib. The company was exploring evobrutinib for relapsing and remitting multiple sclerosis (MS).

According to BioPharma Dive, Merck’s Phase 3 study sought to compare evobrutinib with Aubagio (teriflunomide). In particular, the researchers wanted to determine if evobrutinib was as effective as Aubagio, or even more effective, in reducing relapse rates. Learn more about the study and why it failed.

Unfortunately, the results were not favorable for evobrutinib. The drug did not perform better than Aubagio. In fact, Aubagio actually performed better than it had in prior studies. The annualized relapse rate for evobrutinib in two studies was 0.11 and 0.15 respectively, compared to 0.11 and 0.14 for Aubagio.

In the future, Merck plans to more deeply evaluate trial data to better understand the drug’s safety and efficacy, and to determine if there are any paths forward.

What is Evobrutinib?

The Multiple Sclerosis Trust describes evobrutinib as a Bruton’s tyrosine kinase (BTK) inhibitor that blocks BTK:

an enzyme which is essential for the survival and activation of B-cells, a type of white blood cell (lymphocyte) thought to be involved in the inflammation caused by MS which causes lesions in the brain and spinal cord and can lead to relapses. Evobrutinib [could] prevent the MS activity which leads to relapses as well as the longer-term damage to nerve cells which causes progression.

Evobrutinib is taken as a once- or twice-daily tablet. It is also under investigation for rheumatoid arthritis and lupus.

Understanding Multiple Sclerosis (MS)

Multiple sclerosis is a neurological disease that disrupts the vital communication pathways between the brain and body. While doctors don’t understand the exact cause of MS, it is widely believed to be an autoimmune disease. This means that the immune system mistakenly attacks healthy bodily tissue. In this case, the immune system attacks the myelin sheath, or the protective coating of nerve cells. MS is considered either progressive (no remission) or relapsing and remitting (periods of symptoms and periods of remission). Just under 1% of people in the U.S. have MS. Unfortunately, it’s difficult to know how this condition might progress.

MS is more common in females than males, and it normally manifests between ages 15 and 60. But it’s important to note that MS may occur at any age. Symptoms, which often appear between ages 20-40, may include:

• Fatigue
• Muscle weakness, numbness, or tingling
• Changes in urinary or fecal urgency, frequency, or retention
• Problems with balance and coordination
• Vision issues such as blurred or double vision; eye pain; difficulty controlling eye movements; or partial to complete vision loss
• Chronic pain
• Muscle spasticity
• Emotional changes such as anxiety or depression, mood swings, or pseudobulbar affect
• Sexual dysfunction such as erectile dysfunction or reduced libido