Pfizer Arthritis Study May Push Pill Into $12 Billion Market

Pfizer Inc.’s experimental pill for rheumatoid arthritis reduced pain and inflammation without unforeseen side effects in a study that may help the company supplant injectable drugs with $12 billion in yearly sales.

The treatment, called tasocitinib, lessened inflammation by 20 percent or more for patients after six months, according to Saeed Fatenejad, head of late-stage trials in inflammation and immunology at New York-based Pfizer. While the medicine raised bad as well as good cholesterol levels during the study, there was no increase seen in heart attacks or strokes.

Pfizer, the world’s largest drugmaker, is racing three biotechnology companies to sell the first pill in a decade for rheumatoid arthritis, which destroys joints in 1.3 million Americans. The drug may post annual sales of $2 billion, said Tim Anderson, an analyst with Sanford C. Bernstein & Co. in San Francisco. Pfizer plans to complete four more studies in the first half of next year before seeking U.S. clearance.

“We see the ability, with all of these studies, to get a very broad label,” Fatenejad said in a telephone interview. “This might be the first drug that is going for the original filing with everything: signs and symptoms, quality of life, X-ray data, and then really looking at the various types where the drug could be used.”

Pfizer’s most recent finding, in the last of three phrases of research usually needed for U.S. marketing approval, will be reported Nov. 10 at the American College of Rheumatology meeting in Atlanta. Revenue from tasocitinib may help offset Pfizer losses when its top-selling Lipitor cholesterol pill, with $11.4 billion in annual sales, faces competition next year from cheaper copies in the U.S.

Market Leaders

The rheumatoid arthritis market is dominated by three injectable drugs known as anti-TNF treatments, which cost as much as $20,000 a year and leave patients susceptible to infections.

This includes Enbrel, which Pfizer gained in last year’s $68 billion purchase of Wyeth, and is co-marketed with Thousand Oaks, California-based Amgen. The other two are Humira, sold by Abbott Park, Illinois-based Abbott Laboratories, and Remicade, sold by New Brunswick, New Jersey-based Johnson & Johnson and Merck & Co., of Whitehouse Station, New Jersey.

Tasocitinib is the most advanced pill in a family of experimental treatments targeting a protein called JAK that leads to joint destruction.

‘Drug Works’

“Now we know the drug works, and we know the drug works as a monotherapy, by itself,” said Roy Fleischmann, the study’s lead investigator and professor of internal medicine at the University of Texas Southwestern Medical Center in Dallas, in a telephone interview. “We also have a pretty good handle on the safety profile, which has been consistent.”

Tasocitinib raised levels of LDL, often called bad cholesterol because it is linked to heart disease, and increased HDL, or good cholesterol, which lessens heart disease. The ratio between the two, a measure used by some heart doctors to gauge risk of disease, was unchanged. The elevation occurred early in the course of treatment and didn’t increase over time, making it easier to treat if necessary, Fleischmann said.

At the mid-point point in the study, the drug didn’t reach one of its three goals, to increase a measure of disease remission; the results were numerically positive, though not statistically significant, the company said in a statement.

In the Pfizer study, 25 of 611 patients, or 4.1 percent, reported serious adverse events during the six months. Among them, 6 patients had serious infections. That’s “probably a little bit better” than the anti-TNF drugs, though doctors and patients would need to be vigilant, Fleischmann said.

Adverse Events

A 79-year-old woman with a history of heart disease and diabetes died after developing diarrhea followed by renal failure, according to the study.

Even if tasocitinib isn’t safer or more effective than anti-TNF treatments in next year’s head-to-head tests, similar results may help the pill win patients who don’t want regular injections or are among the 20 percent to 40 percent who don’t respond to anti-TNF drugs, Fatenejad said.

The three biotechnology companies developing JAK drugs are: South San Francisco, California-based Rigel Pharmaceuticals Inc., Incyte Corp. of Wilmington, Delaware, and Cambridge, Massachusetts-based Vertex Pharmaceuticals Inc. Pfizer’s pill is the only one with results from the third and final stage of tests generally needed for U.S. approval.

Slow to Adopt

Doctors may be slow to adopt new JAK drugs for patients who are getting relief from older treatments, said David Pisetsky, professor of rheumatology and immunology at Duke University School of Medicine in Durham, North Carolina.

While high levels of bad cholesterol linked to tasocitinib may be treatable, physicians may resist adding a drug to patients’ daily treatment regimens.

“Because it’s a new mode of action, there’s great interest, but what’s going to happen in terms of efficacy and safety when you really put it out there?” Pisetsky said in a telephone interview. “There’s always a difference between what happens in a trial setting and what happens in real life.”

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