Baltimore Washington Eye Center, Maryland

Thursday, February 9, 2012

Gilenya™, Multiple Sclerosis & Eye Exams

Late in 2010, the FDA approved Gilenya™ (fingolimod), the first oral medication available for the treatment of multiple sclerosis (MS).  MS is an autoimmune disorder that affects the central nervous system, occurs most commonly in women between the 20-40 years of age. Symptoms are the result of damage to the brain, spinal cord, or optic nerves; specifically the myelin sheath, which is the outer covering of the body’s nerves. MS is called “auto” immune because a person’s own immune system attacks the myelin sheath, resulting in inflammation and subsequent nerve malfunction/damage.

Typically, a person with MS experiences periods of no disease symptoms (remission), punctuated by acute episodes involving varying symptoms depending on what nerve(s) or part of the brain is being affected. Symptoms can include: numbness, tingling, muscle weakness, blurred vision, loss of vision, double vision, pain with eye movement, difficulty chewing and/or swallowing, dizziness, loss of balance, difficulty walking or talking, and urinary incontinence.

In MS, the body’s own white blood cells cause the nerve damage, Gilenya™ works by preventing white blood cells (WBC)  from exiting lymph nodes. The drug does this by inhibiting the chemical key WBC’s need to unlock the lymph node door. Because the WBC remain “locked” in the lymph nodes, they are unable to attack the myelin sheath and patients remain free from symptoms.

Studies show that Gilenya™ taken once daily significantly reduces MS attacks. However, it has serious side effects, with possible heart, lung, and eye toxicity and an increased risk of infection. Side effects include: elevated liver enzymes, macular edema (causes blurred and decreased vision), hypertension, shortness of breath, bronchitis, diarrhea, headaches, coughing and bradycardia.  Since bradycardia means a “slowing of the heart rate” and is seen only upon first treatment, the FDA panel recommended that patients be required to receive their first dose under medical supervision.

The risk of retinal macular edema (swelling) is higher in MS patients who also have diabetes or have a history of uveitis, which is inflammation inside the eyeball. It is recommended that all patients who are prescribed Gilenya™ undergo a thorough eye exam prior to beginning treatment, and again in 3-4 months after starting the medication.  This is because the retinal swelling associated with Gilenya™ usually occurs during the first 3-4 months of treatment.