BioMarin has announced that the FDA ( Food and Drug Administration ) has approved Vimizim ( Elosulfase alfa ) for patients with mucopolysaccharidosis type IVA ( MPS IVA; Morquio A syndrome ).
Vimizim is an enzyme replacement treatment for Morquio A syndrome, which affects an estimated 3,000 patients in the developed world.
The disease occurs as a result of a deficiency of activity in an enzyme involved in glycosaminoglycan ( GAG ) metabolism. The pervasive and progressive accumulation of GAGs leads to significant morbidities and multisystemic clinical impairments resulting in diminished functional capacity, impaired quality of life, and early mortality.
The most common features of the disease are progressive skeletal dysplasia, the need for frequent surgical procedures related primarily to musculoskeletal or respiratory dysfunction, and significant limitations in mobility, endurance, and breathing.
The safety and efficacy of Vimizim were assessed in a 24-week, randomized, double-blind, placebo-controlled clinical trial of 176 patients with MPS IVA ( MOR-004 ). The primary endpoint of the trial, change in six-minute walk distance at 24 weeks, was statistically significant in patients receiving weekly infusions of Vimizim at the dose of 2 mg/kg with a mean increase of 22.5 meters ( p=0.0174 ) over placebo.
In patients who continued to receive Vimizim 2 mg/kg once per week for another 48 weeks ( for a total of 72-week exposure ), walking ability was sustained to a similar level that was achieved during the first 24 weeks of treatment in the placebo-controlled trial, MOR-004.
Overall, sustained improvements across multiple efficacy measurements and across multiple clinical trials provided evidence of clinical benefit to patients with MPS IVA, a chronic, progressive disease in which clinical deterioration is the expected course.
The adverse events observed in clinical trials were similar to those seen in other enzyme replacement therapies. In the phase 3 trial, the most common adverse reactions ( greater than or equal to 10% and a higher incidence than placebo ) that occurred were pyrexia, vomiting, headache, nausea, abdominal pain, chills, and fatigue.
No new types of adverse reactions were reported in the phase 3 extension trial. The most common adverse reactions ( greater than or equal to 10% ) observed across pre-marketing clinical trials were similar in type and frequency as those observed in the placebo-controlled trial.
Acute reactions requiring intervention were managed by either temporarily interrupting or discontinuing infusion, and administering additional antihistamine, antipyretics, or corticosteroids. ( Xagena )
Source: BioMarin, 2014