As complaints grow about exorbitant drug prices, pharmaceutical companies are coming under pressure to disclose the development costs and profits of those medicines and the rationale for charging what they do. So-called pharmaceutical cost transparency bills have been introduced in at least six state legislatures in the last year, aiming to make drug companies justify their prices, which are often attributed to high research and development costs. If a prescription drug demands an outrageous price tag, the public, insurers and federal, state and local governments should have access to the information that supposedly justifies the cost," says the preamble of a bill introduced in the New York State Senate in May. In an article being published Thursday, more than 100 prominent oncologists called for support of a grass-roots movement to stem the rapid increases of prices of cancer drugs, including by letting Medicare negotiate prices with pharmaceutical companies and letting patients import less expensive medicines from Canada. "There is no relief in sight because drug companies keep challenging the market with even higher prices," the doctors wrote in the journal Mayo Clinic Proceedings. Pressure is mounting from elsewhere as well. The top Republican and Democrat on the United States Senate Finance Committee last year demanded detailed cost data from Gilead Sciences, whose hepatitis C drugs, which cost $1,000 a pill or more, have strained the budgets of state and federal health programs.