Rodelis, which increased the price of the tuberculosis drug, said last week it needed to invest to make sure the supply of the drug remained reliable. Rodelis reveals almost no information about itself, such as the names of its executives, directors or investors, on its web page.

Cycloserine, which went on sale in 1955 and is also known by the brand name Seromycin, was long produced by Eli Lilly and Company, which around 2000 decided to drop the drug, in part because the company was getting out of antibiotics.

Starting in 2003, as part of a philanthropic initiative on TB, Lilly transferred rights and manufacturing skill to generic drug companies in India, China, South Africa and elsewhere to supply the regions most affected. In 2007 it gave the rights for the United States and Canada to the Chao Center for Industrial Pharmacy and Contract Manufacturing, which is under the auspices of the Purdue Research Foundation.

Mr. Hasler, a former Lilly executive, said the Chao Center had lost about $10 million on the drug since 2007 because of the small number of patients and high regulatory costs. So the Chao Center was interested when it was approached by Rodelis. “They found us,” Mr. Hasler said.

A patient with multidrug-resistant tuberculosis might take two capsules a day of cycloserine, along with other drugs, for 18 to 24 months, according to the Centers for Disease Control and Prevention. Under the price Rodelis planned to charge, a full course of treatment would have cost more than $500,000 for cycloserine alone. With the new price from the Chao Center, it will be closer to $50,000.

The drug made by generic companies abroad costs only about $20 for 100 capsules.

Amir Attaran, an expert on pharmaceutical access issues at the University of Ottawa, said it would have made much more sense to just import the drug from abroad, rather than have it produced in America for so few patients at such high cost.

Mr. Hasler said this was probably not done because foreign manufacturers were not willing to bear the expense of applying for regulatory approval in the United States.