First, it wanted to encourage the discovery of innovative medicines. Patent restorations are limited. The effective patent life of a drug cannot exceed 14 years, regardless of how much time was lost to clinical testing and review. In a number of ways, the law has been a clear success. Title I of the Act has helped reduce drug prices for off-patent drugs and increased the generic industry's market share from 19 percent in 1983 to nearly 50 percent of the U.S. prescription drug market today.
Generics control the lion's share of the market for major off-patent drugs.
One further indication of the strength of the generic industry is the impact on sales of brand-name drugs once generics hit the market. In most cases, sales of brand-name drugs drop as much as 75 percent within weeks of the generic version being introduced into the marketplace. The Results Are In .