WASHINGTON - The new orphan drug compromise takes a subtle approach to limiting prices on new orphan drugs, and will force some companies to make trade offs between short-term revenue and longer-term market exclusivity under the law.

The compromise amendment to the Orphan Drug Act of 1983, announced on Friday, was reached in triangular negotiations between the Biotechnology Industry Organization, members of Congress and patient advocacy groups. The industry won in its efforts to exclude current orphan drugs and drugs in the clinic from the bill's coverage, and succeeded in eliminating any strict revenue limit on orphan products.

But while the deal does not contain outright revenue caps feared by the industry, its provisions clearly would bounce "blockbuster" products out of the orphan fold after four years, and force some companies to decide whether to sacrifice their orphan monopoly in order to maximize the pricing of their drugs.

Attempts to revoke

The Orphan Drug Act was enacted to promote the development and marketing of drugs, biologicals and other products to prevent or treat rare diseases. The emergence of blockbuster drugs with orphan status resulted in several failed attempts by Congress to amend the act.