In March 2017, the authoritative U.S regulatory body, FDA, approved the first ever, medication used to specifically treat multiple sclerosis. Until then, this chronic and degenerative condition was managed with drugs that had not yet been approved for the condition.

Ocrevus (ocrelizumab is the new entrant in the fight against the debilitating multiple sclerosis. The drug, developed by the world giant pharmaceutical company, Roche, under its subsidiary Genentech has had both patients and doctors excited not to mention the dynamic world of pharma.

The mode of action of Ocrevus involves inhibiting specific types of a patient’s B cell lymphocytes that are associated with the development of the condition.

Multiple sclerosis is an immune-mediated disorder where the body’s immune system fights its own central nervous system tissues. The exact cause or the antigen responsible for this abnormal process is unknown. The main pathology involves the sheath that insulates the nerves (myelin). This sheath is destroyed which exposes the nerve. Scarring tissue then follows (sclerosis) and symptoms set-in.

With time multiple sclerosis progressively damage more nervous tissue and can lead to paralysis and cognition problems. The disorder can have periods of remission only to flare-up later and cause more damage. Every relapse leads to more irreversible nervous system damage. The disease strikes people between the ages of 20 and 40 with more females affected than males.

Studies on Ocrevus

Rebif® has been one of the main medications used for the management of multiple sclerosis. During the development of Ocrevus, studies were conducted to compare the two drugs’ action in the management of the common forms of multiple sclerosis. These are the primary progressive multiple scleroses (PPMS) where the disease progressively cause nervous system damage from the time it sets-in. The other is the relapsing multiple sclerosis (RMS) type.

According Roche two identical studies were carried out to find out the efficacy of Ocrevus versus Rebif®. These studies found that Ocrevus offered better outcome in these areas: reduced MS relapses per year, slowed down disability progression and markedly reduced MS related lesions as per MRI imaging. Treatment complications (adverse reactions and serious infections) incidence was the same.

Another study confirmed that Ocrevus was the only, and first medication to slow down the progression of disability and lowered signs of the disease in the brain. These studies were published in the January 19 2017 issue of The New England Journal of Medicine.

Who should avoid Ocrevus?

As promising as this medication is, some classes of patients should avoid it. These include patients with viral inflammation of the liver (hepatitis B) and those with a history of adverse reactions to Ocrevus infusion.

According to FDA, this drug can cause serious reactions. For this reason, a Patient Medication Guide must accompany every prescription with the details about the drug uses and potential risks. Symptoms of reactions include skin symptoms such as hives, itchiness, redness and flushing. More serious systemic reaction symptoms include congested throat, difficulty in breathing, low blood pressure and increased heartbeat rate.

FDA further warns that, Ocrevus can increase the risk of developing cancer and especially breast cancer. Patients suffering from an active infection should also not use the drug until the infection has cleared. Vaccination with live-attenuated vaccines is also contraindicated for patients on Ocrevus.

The studies found that both upper and lower respiratory infections and skin infections were the commonest side effects of Ocrevus on the study subjects.

The serious nature of multiple sclerosis is exemplified by the way FDA expedited its approval. Ocrevus application was granted breakthrough therapy designation, fast track designation and priority review. All these are given to drugs believed to play an important role in improving the quality of life of patients suffering specific conditions such as multiple sclerosis.

Should you switch from your current MS drugs to Ocrevus?

Switching to a new drug for a chronic condition such as multiple sclerosis creates both anxiety and excitement. Apart from the buzz about the drug, there are several things to consider. These include:

  • How is your response to the current medications that you are using?
  • What is the cost of the switch to Ocrevus
  • What is the opinion of your neurologist?
  • Are you prepared for the yet to be identified side effects of Ocrevus (considering that its duration of clinical use is relatively short)?
  • If you are tolerating your current medications fairly well, are you ready to risk the potentially serious side effects of Ocrevus?

What experts think about Ocrevus

Multiple sclerosis specialists are both enthusiastic and cautious about Ocrevus. Annette M. Langer-Gould, MD, PhD is a research scientist at Kaiser Permanente Research who feels that the excitement about Ocrevus should be tempered with the reality. According to her, the potential for this drug to cause tumors in patients on it is a major concern. According to her, another drug Rituximab from the same manufacturers of Ocrevus is not only safer but also cheaper although not approved by FDA for use in multiple sclerosis patients.

The International Multiple Sclerosis Management Practice in New York shares the same feelings with Annette M. Langer-Gould. They feel that patients on Rituximab should not be in a hurry to switch to Oclerizumab until they, the experts, are in a better position to offer informed advice about the facts of the new drug.

References
New England Journal of Medicine. (2017). 376(3): 209-234. Available at: http://www.nejm.org/toc/nejm/376/3.