injuries vary, injury occurs at different locations on the spinal cord, and the severities of the injuries vary widely.
Because of the relatively small numbers of potential patients—an estimated 247,000 people in the United States have a spinal cord injury, and an estimated 11,000 new cases occur each year—and because of the heterogeneity of the secondary complications, the population of individuals with spinal cord injuries is small and is further fragmented, making the market for medications and other therapeutic interventions for spinal cord injuries even smaller.
Additionally, a variety of other issues confront the development of any new therapeutic product:
Financial costs. It is estimated that it costs an average of $800 million to go through the drug development and approval process from the identification of a drug target through FDA approval of an efficacious product (Tufts Center for the Study of Drug Development, 2001). The expense of launching a new drug is even more expensive, and the cost increased 55 percent from 1995 to 2002 (FDA, 2004b).
Time. The drug and device development process is also very time-consuming. For example, it takes on average 12 to 15 years before a drug is ready to market to the general patient population. As a result, from the time that a compound is discovered and a 20-year patent is filed, it takes on average 17 to 18 years for a pharmaceutical company to recoup its costs.
Competition. The therapy could be displaced by a newer and more effective treatment before the company realizes a profit.
One mechanism used to provide incentives to pharmaceutical companies is the Orphan Drug Act (P.L. 97-414). Signed into law in 1983 to stimulate the research, development, and approval of drugs for the treatment of rare diseases (defined as conditions that affect 200,000 people or less in the United States), the federal legislation provides two major incentive mechanisms: sponsors are granted 7 years of marketing exclusivity after approval of the orphan drug product, and sponsors receive tax incentives for clinical research on the product.
In 2004, 21 years since the legislation was enacted, only approximately 200 drugs and biological products have qualified for orphan drug status (FDA, 2004a). It is unclear whether the incentives provided by the Orphan Drug Act are sufficient to attract pharmaceutical industry investment in therapeutic interventions for spinal cord injuries. For diseases that affect more than 200,000 people, it is possible to obtain orphan drug status for interventions needed by certain patient subgroups for specific indications.