Federal regulators have granted priority review to a closely watched leukemia drug candidate developed by Ariad Pharmaceuticals Inc., promising to decide by March 27 whether the Cambridge company can start selling the treatment.
Priority review is typically extended to medicines that may work better than existing treatments, or are effective in patients who haven’t responded to drugs already on the market.
Ariad’s drug, called ponatinib, will compete with several leukemia treatments now available — such as Gleevec and Tasigna from Novartis AG, and Sprycel from Bristol-Myers Squibb Co. — that treat tens of thousands of patients.
Ariad, a 20-year-old company, has begun building a commercial sales force for the first time in anticipation of getting the go-ahead from regulators to market ponatinib. Under its accelerated review process, a decision by the Food and Drug Administration could come any time in the next five months, though company executives have said they expect it in the first quarter of 2013.
“The granting of priority review and the formal acceptance of our new drug application are two very important steps,” Ariad chief executive Harvey J. Berger said. “It’s important to recognize that priority review is only given to investigational medicines that have the potential to provide significant improvement in the treatment of patients.”
If the drug is approved for sale, as industry analysts expect, Ariad would join other Cambridge biopharmaceutical companies, such as Vertex Pharmaceuticals Inc. and Ironwood Pharmaceuticals Inc., that have been making the transition from research organizations to full-service commercial drug companies after winning approval for potentially significant therapies.
Berger said Ariad has doubled its workforce to 280 employees, the majority of them in Cambridge, since the start of the year. The company has also started leasing more space near its headquarters.
“We’re ready to go,” Berger said. “We’re launch-ready as we stand here today. Whenever the approval comes, we have the sales and distribution force, the manufacturing people, the medical liaisons, all the people we need to commercialize successfully.”
Shares of Ariad, which have climbed since it submitted its drug application with the FDA in late July, edged down 28 cents, or 1.2 percent, to close at $22.03 on the Nasdaq exchange Wednesday.
In a note to investors, Matthew Harrison and Matthew Roden, stock analysts for the UBS investment bank in New York, suggested Wednesday that Ariad’s shares weren’t likely to rise on news of the priority review — which will shave months off the approval process — because Wall Street expected regulators to take that action.
Noting that the FDA began scrutinizing Ariad’s application last summer, the analysts said they anticipate a decision earlier than the March date. “To us,” they wrote, “the main driver of timing will likely be the time it takes to complete label negotiations.”
Ponatinib, developed in-house at Ariad, treats two forms of leukemia: chronic myeloid leukemia and acute lymphoblastic leukemia. Both are characterized by excessive and unregulated production of white blood cells by the bone marrow due to a genetic abnormality. Ponatinib is in a class of drugs known as BCR-ABL inhibitors — they work by blocking the abnormality.
In addition to its FDA submission, Ariad has applied for approval by the European Medicines Agency in Brussels to sell ponatinib across Europe. A decision by that agency is expected in the third quarter of next year, and Ariad already has begun assembling a continentwide sales force from its European headquarters in Lausanne, Switzerland, near Geneva.
At the same time, Ariad has been moving forward with clinical trials of another experimental drug to treat two forms of lung cancer. That drug won’t likely be on the market until later in the decade.