WASHINGTON — Some members of Congress believe pharmaceutical companies are colluding to keep cheaper, generic versions of drugs out of consumers' hands.

In half of the 28 recent settlements on challenges to drug patents, brand-name companies gave some form of compensation to a generic challenger that agreed to delay production, according to the Federal Trade Commission.

"It is critical to eliminate the pay-for-delay settlement tactics employed by the pharmaceutical industry," FTC commissioner Jon Leibowitz recently told the Senate Judiciary Committee. "Companies should be not be able to play 'deal or no deal' at the expense of American consumers."

Both sides have an incentive to settle patent challenges this way because the brand-name company's payment is less than what it would lose in sales, but it's more than what the generic maker could make selling the drug at a discount.

"Congress never intended for brand-name companies to be able to pay off generic companies not to produce generic medicines," said Sen. Patrick Leahy, the Vermont Democrat who heads the committee.

Banning the practice could mean a loss of profits for the pharmaceutical industry. Some drugs are so popular that delaying generic competition can save the company $1 million a day, according to Merril Hirsh, an antitrust lawyer.

COSTLY TO CONSUMERS

But the delay comes at a price to consumers. The cost of a generic drug can be as much as 80 percent less than the brand-name alternative.

And it's not just individuals filling their prescriptions who can save from generics.

Lower drug prices also benefit businesses that pay for their employees' healthcare and benefit taxpayers, who foot the bill for government healthcare programs for the poor, disabled and elderly.

Consumers and health plans spend more than $100 billion a year on prescription drugs.

Generic competition to four major brand-name drugs, including Eli Lilly & Co.'s Prozac, saved consumers more than $9 billion, according to the Generic Pharmaceutical Association.

Best-selling drugs whose patents are currently being challenged by generic companies include the ulcer medication Nexium, the anti-psychotic Seroquel and the cancer drug Gemzar.

PATENT FIGHTS

Congress passed a law in 1984 aimed at striking a balance between allowing brand-name companies to benefit from the patents they earn through hundreds of millions of dollars in research and preventing them from unfairly extending the patents. As part of the law, Congress made it easier for generic-drug companies to challenge invalid or narrow patents.

The FTC has tried to prevent payoffs to settle the patent challenges, but court rulings in 2005 reversed FTC rulings and opened the door to such settlements.

Trade groups for the brand-name and generic drug companies argue that rather than prohibiting cash settlements in exchange for delayed competition, all settlements should continue to be reviewed by the FTC and the courts.

Billy Tauzin, a former House member who heads the Pharmaceutical Research and Manufacturers Association, said some settlements are good because they end costly litigation and set a date certain for market entry.

"Don't shoot the good," Tauzin said. "Let's just keep shooting the bad and the ugly."

But the FTC's Leibowitz said it's better for Congress to draw a bright line on what's allowed because that would be a "swifter, more certain and more comprehensive solution," than letting the settlements be hashed out in the legal system.