New rheumatoid arthritis pill tofacitinib backed by FDA panel

(CBS/AP) A new rheumatoid arthritis drug considered to be the first of its kind got backed by a Food and Drug Administration (FDA) advisory panel Wednesday, putting the drug a step closer to hitting the market.

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The panel of health advisers voted 8-2 in favor of Pfizer's tofacitinib for patients who have not responded to one or more other drugs, though they recommended follow-up studies to gauge the pill's long-term side effects.

The FDA is not required to follow the group's advice, though it often does; a final decision is expected in August. If approved, tofacitinib would be the first pill for rheumatoid arthritis from a new class of pain medications called JAK inhibitors. The drugs work by interfering with enzymes that contribute to the inflammation process that causes joint pain, particularly in the hands and feet.

Panelists said the drug could be an important option for patients, but voiced concern over reports of lymphoma and infection among patients taking the pill. That's difficult to study, however, because patients with rheumatoid arthritis are already predisposed to health problems, including cancer.

"The observation of malignancy rates increasing over time was unexpected and is of major concern," panel reviewer, Dr. Nikolay P. Nikolov, told The New York Times.

Pfizer studies showed patients improved 20 percent or more on a medical questionnaire that measures arthritis pain and symptoms. However, the FDA said the company's results were less conclusive in X-ray images tracking the rate of joint damage. Despite that shortcoming, panelists said Pfizer's pill could be an important option for patients who haven't responded to other drugs or aren't comfortable with injectable medications.

The most common side effects of treatment with tofacitinib have included bronchitis, headache, infections, and gastrointestinal symptoms like nausea, vomiting, and diarrhea. More serious side effects include higher cholesterol levels and increased creatinine levels.

"I voted yes because I would like to have this drug available for rheumatoid arthritis patients, given that we know a third of them will not respond to available therapies," said Dr. Maria Suarez-Almazor of the MD Anderson Cancer Center in Houston.

For more than a decade, rheumatoid arthritis has been treated with injectable drugs like Humira, which block a messaging protein related to inflammatory diseases. Humira and rival Enbrel were the 10th and 11th best-selling drugs in the U.S. last year, with combined sales of $7 billion, according to IMS Health. The drugs are also prescribed for psoriasis and other diseases of the immune system.

Tofacitinib is a key product in Pfizer's pipeline, following patent expirations on several blockbuster drugs, including the world's best-selling prescription medication, Lipitor. Pfizer is studying tofacitinib as a potential treatment for psoriasis, inflammatory bowel disease, and renal transplant.

Rheumatoid arthritis is an autoimmune disease that occurs when the immune system attacks the body's own joints and tissue, causing inflammation. It differs from traditional arthritis, which is caused by long-term deterioration of bones and joints. Rheumatoid arthritis can occur at any age, but it's more common in middle age and in women. Symptoms typically include pain in the wrists, fingers, knees, feet and ankles on both sides. The disease often begins slowly, usually with only minor joint pain, stiffness, and fatigue.

The Mayo Clinic has more on rheumatoid arthritis.