The massive filing came more than a month earlier than expected and was the electronic equivalent of “700 bound volumes, each two and a half inches thick,” Ariad chief executive Harvey J. Berger said. If the FDA grants Ariad’s request for accelerated approval of the leukemia drug—to be used in patients for whom other treatments haven’t worked—it could be on the market by the first quarter of next year, Berger said.

“We were able to put the pedal to the metal and get it done ahead of schedule,” he said.

Berger said the Cambridge company received “fast-track” designation from the FDA two years ago, enabling it to use a rolling submission process, something the agency permits for potentially breakthrough drug candidates in areas of high medical need. That process allowed Ariad to submit more than 99 percent of the application Monday so regulators can begin reviewing it even before the remaining information—mostly chemical and manufacturing data—is filed by Sept. 30.

Ariad disclosed its application after financial markets closed Monday. The company’s shares edged up 18 cents, or 0.9 percent, to $19.10 on the Nasdaq during the trading day.

The drug, known as ponatinib, is the latest experimental cancer treatment in a class of drugs known as BCR-ABL inhibitors. They work by blocking the genetic abnormality found to cause chronic myeloid leukemia, a cancer of the white blood cells that affects about 58,500 people worldwide, according to consulting firm Kantar Health.

Currently, patients are treated with existing drugs in that class, such as Gleevec and Tasigna from Novartis AG or Sprycel from Bristol-Myers Squibb Co., which together generate annual sales of about $4.5 billion. Some oncologists have said ponatinib, based on its performance in recent clinical trials, could prove to be more potent in overcoming the cancer’s resistance to drugs.

While the Ariad application covers only patients who failed to respond to existing therapies, the company eventually hopes to win approval to expand its treatment to newly diagnosed patients. To do that, it will have to convince the FDA that ponatinib is superior to the current standard of care. Last week, the company said it was beginning a late-stage clinical trial comparing the potaninib to Gleevec in 500 patients with chronic myeloid leukemia.

Ponatinib’s initial target patient population could result in peak worldwide annual sales of $600 million to $800 million for Ariad, according to company projections. About a third to a half of the sales are anticipated in the United States. Ariad is finalizing its preparations to apply later this summer for approval of the drug in Europe.

If data from the head-to-head trial with Gleevec is positive, approval of the drug for new patients could result in additional annual sales of more than $1 billion. Ariad does not expect to report the results of that study until 2014.

In a note to investors Monday, biotechnology analyst Howard Liang, managing director at health care investment bank Leerink Swann in Boston, said ponatinib has shown a “best-in-class profile” and has the potential to generate annual sales of more than $1.5 billion.

Liang suggested a likely future treatment option will be starting patients on a generic version of Gleevec and switching those who don’t respond well to ponatinib or other drugs.

Ariad has picked up the pace of its hiring as it prepares to transition from a research company to a fully-integrated commercial company with a potential blockbuster drug. The company has added about 60 employees since the start of the year, boosting its workforce to about 200, Berger said. He said Ariad expects to end 2012 with between 250 and 300 employees.

The company suffered a setback last month when the FDA rejected a drug application filed by its partner, Merck & Co., for ridaforolimus, a drug developed to treat patients with metastatic soft tissue or bone sarcoma. The agency said it couldn’t approve the drug in its present form and that additional clinical trials would be needed to prove its safety and effectiveness.