Elosulfase alfa (Vimizim—Biomarin Pharmaceuticals) treats Morquio A syndrome, a rare autosomal recessive disease that causes problems with bone development, growth, and mobility. Pediatric patients with this disease have a deficiency in N-acetylgalactosamine-6-sulfate sulfatase (GALNS). Elosulfase alfa is the first FDA-approved medication to replace GALNS in the enzyme pathway.
Safety and efficacy of elosulfase alfa were established in a clinical trial involving 176 patients with Morquio A syndrome. Patients treated with elosulfase alfa walked 22.5 meters farther in 6 minutes compared with patients who received placebo. While elosulfase alfa is intended for pediatric use, safety and efficacy have not been established in pediatric patients younger than 5 years.
Elosulfase alfa comes with a boxed warning stating the risk of anaphylaxis. Life-threatening anaphylactic reactions have occurred during elosulfase alfa infusions in clinical trials.
Tasimelteon (Hetlioz—Vanda Pharmaceuticals), a melatonin receptor agonist, treats non–24-hour sleep–wake disorder (“non-24”) in totally blind individuals. Non-24 is a chronic circadian rhythm disorder in the blind that causes problems with the timing of sleep. This is the first FDA approval of a treatment for the disorder.
Non-24 occurs in persons who are completely blind. Light does not enter their eyes, and they cannot synchronize their body clock to the 24-hour light–dark cycle. Those with the disorder may have difficulty falling asleep or staying asleep, and may wake up groggy or feeling as if they need more rest. People with non-24 may find their sleep patterns reversed—needing to sleep during the day and to be awake at night.
The drug’s effectiveness was evaluated in 104 participants in two clinical trials of totally blind individuals with non-24 disorder. In the trials, treatment with tasimelteon resulted in significant improvement compared with placebo, both in increasing nighttime sleep and decreasing daytime sleep duration. The most common adverse effects were headache, elevated liver enzymes, nightmares or unusual dreams, disturbed night’s sleep, upper respiratory or urinary tract infection, and drowsiness.
Tasimelteon can impair activities that require complete mental alertness. Patients should take it at the same time every night before bedtime and limit activities after taking the drug. Tasimelteon was approved under priority review and also received orphan-product designation because it is intended to treat a rare disease or condition. According to the manufacturer, it will be available in spring 2014.
Droxidopa (Northera—Chelsea Therapeutics) capsules treat neurogenic orthostatic hypotension (NOH), a rare, chronic, and often debilitating drop in blood pressure upon standing. The condition is associated with Parkinson disease, multiple-system atrophy, and pure autonomic failure.
Symptoms of NOH include dizziness, lightheadedness, blurred vision, fatigue, and fainting when a person stands.
FDA approved droxidopa under the accelerated approval program. Droxidopa also received orphan-product designation because it is intended to treat a rare disease or condition.
Droxidopa has a boxed warning about the risk of increased blood pressure while lying down, a common problem that affects people with primary autonomic failure and can cause stroke. Remind patients to sleep with their head and upper body elevated. Supine blood pressure should be monitored prior to and during treatment and more frequently when increasing doses. The most common adverse events reported by clinical trial participants were headache, dizziness, nausea, hypertension, and fatigue.
FDA expanded the approved use of ibrutinib (Imbruvica—Pharmacyclics, Janssen Biotech) to treat patients who have received at least one previous therapy for chronic lymphocytic leukemia (CLL).
Safety and effectiveness of ibrutinib for CLL were based on a study of 48 previously treated patients who were diagnosed with CLL 6.7 years before the study and had received previous therapy. Approximately 58% of participants had their cancer shrink after treatment, with a duration of response ranging from 5.6 to 24.2 months.