ISIS INITIATES PHASE 1 CLINICAL STUDY OF ISIS-SMNRX IN PATIENTS WITH SPINAL MUSCULAR ATROPHY
CARLSBAD, Calif., December 19, 2011 – Isis Pharmaceuticals, Inc. (NASDAQ: ISIS) announced today that it has initiated a Phase 1 study of ISIS-SMNRx in patients with spinal muscular atrophy (SMA). SMA is a severe motor-neuron disease that is the leading genetic cause of infant mortality. Isis is developing ISIS-SMNRx as a potential treatment for all Types of SMA.
“SMA is a devastating disease that leads to the loss of motor neurons resulting in muscle weakness and respiratory failure in children. The genetic cause of this disease is well understood, but there are currently no effective disease-modifying therapies. Currently, treatment of SMA is entirely symptomatic and focuses on preserving muscle strength and lung function by physical therapy and assisted ventilation. This supportive approach has improved the natural history of SMA by extending life expectancy, but muscle weakness and atrophy are not affected. A disease-modifying drug like ISIS-SMNRx that specifically targets the cause of the disease could, for the first time, restore muscle strength and respiratory function and dramatically improve the children’s function and quality of life,” said Darryl C. De Vivo, M.D, Sidney Carter Professor of Neurology and Pediatrics and Co-Director of the Motor Neuron Center at Columbia University Medical Center.
SMA is a severe genetic disease that affects approximately 30,000 – 35,000 patients in the United States, Europe and Japan. One in 50 people, approximately 6 million people in the United States, are carriers of the SMA gene. Carriers experience no symptoms and do not develop the disease, however, when both parents are carriers, there is a one in four chance that their child will have SMA. SMA is caused by a loss of, or defect in, the survival motor neuron 1 (SMN1) gene leading to a decrease in the protein, survival motor neuron (SMN). SMN is critical to the health and survival of nerve cells in the spinal cord that are responsible for neuro-muscular growth and function. The severity of SMA correlates with the amount of SMN protein. Infants with Type 1 SMA, the most severe life-threatening form, produce very little SMN protein and have shortened life expectancy. Children with Type II and Type III have greater amounts of SMN protein and less severe, but still life-altering forms of SMA. ISIS-SMNRx is designed to treat all types of childhood SMA by altering the splicing of a closely related gene (SMN2) that leads to the increased production of fully functional SMN protein.



