“Explain, explain, explain and disclose, disclose, disclose,” Mr. Clinton said, according to The Philadelphia Inquirer. “Don’t expect everybody to love you, but at least they will hear your side of the story.”

The pharmaceutical industry has already had the veil lifted on various practices. Drug companies now have to report the payments, including meals and entertainment, that they make to doctors for research, consulting and giving promotional speeches. The companies have also had to disclose more results of their clinical trials and in some cases have started to provide raw data to outsiders.

It is unclear if cost and pricing will become the next such area. The state bills, which are supported by some health insurers and consumer groups, have not progressed. The two senators, Republican Charles E. Grassley of Iowa and Democrat Ron Wyden of Oregon, have not reported the results of their inquiry. And shareholders of Gilead, Vertex and Celgene voted down the resolutions proposed by the U.A.W. trust, though the trust says it reached settlements with Eli Lilly and with two other drug companies it would not identify.

The pharmaceutical and biotechnology industry trade groups say the transparency bills would be costly to comply with and would provide misleading information.

Even some people concerned about drug prices say that the cost to develop a particular drug has little to do with that drug’s price and that knowing such information will not keep prices down.

“The past R&D cost is really kind of a red herring,” said Len Nichols, a health care economist at George Mason University, referring to research and development. “The current revenue doesn’t pay for past R&D; it pays for current R&D.”

Prices for cancer drugs, some of which extend lives by only a couple of months, routinely exceed $100,000 a year, and some new ones exceed $150,000. And it is not unusual for the list prices of existing drugs to rise 10 percent or more year after year, far beyond the rate of inflation. The prices of older drugs for multiple sclerosis have risen from about $10,000 per year in the late 1990s to more than $60,000 now, according to a study, even as competition in the market has intensified with the introduction of new products.