The Food and Drug Administration has approved an expensive new drug to treat adults with moderate to severe rheumatoid arthritis, even though the agency has not fully evaluated its safety and wants further testing. A one month supply will cost patients or their insurance companies thousands of dollars.
The drug, tofacitinib citrate, will be marketed by Pfizer (NYSE: PFE) under the brand name Xeljanz. It is designed for patients who can’t tolerate treatment with the standard pill, methotrexate, or haven’t fully responded to it.
Xeljanz is a new class of drug that works by blocking molecules called “Janus kinases,” which are important in the joint inflammation of rheumatoid arthritis (RA). The 5 mg dose that was approved is meant to be taken twice daily.
“Xeljanz provides a new treatment option for adults suffering from the debilitating disease of RA who have had a poor response to methotrexate,” said Badrul Chowdhury, MD, a director in the FDA’s Center for Drug Evaluation and Research.
The FDA said in seven clinical trials, the safety and effectiveness of Xeljanz were evaluated in adult patients with moderately to severely active RA. In all of the trials, it says patients treated with Xeljanz experienced improvement in clinical response and physical functioning compared to patients treated with placebo.
“RA is a serious and disabling disease that affects people in their everyday lives, and many patients do not adequately respond or are intolerant to currently available therapies,” said study investigator Stanley Cohen, MD, clinical professor of rheumatology at the University of Texas Southwestern Medical School and co-medical director of Metroplex Clinical Research Center. “In clinical trials, Xeljanz significantly reduced the signs and symptoms of RA and improved physical function. As a physician, I am pleased that we have another choice for patients living with inadequately controlled, moderately to severely active RA.”
But the drug is not without its share of safety concerns and side effects.
The FDA approved Xeljanz with a Risk Evaluation and Mitigation Strategy which includes a medication guide advising patients about important safety information, and a communication plan to inform health care providers about the serious risks associated with Xeljanz.
Those risks include a possible increase in serious infections, tuberculosis, cancers and lymphoma. The drug is also associated with increases in cholesterol and liver enzyme tests and decreases in blood counts. The most common side effects in clinical trials were upper respiratory tract infections, headache, diarrhea, nasal congestion, sore throat and runny nose.
Besides a boxed warning on the drug’s label, the FDA is requiring Pfizer to conduct a post-marketing study to gauge the drug’s effects on heart disease, cancer and serious infections. The study will evaluate two doses of Xeljanz (5 mg and 10 mg) and include a group of patients on another drug to serve as a comparison.
Pfizer says the drug will cost $2,055 per 30-day supply, or about $24,000 per year, which is slightly less than Abbott Laboratories’ (NYSE: ABT) Humira and Amgen’s (NASDAQ:AMGN) Enbrel, which also treat rheumatoid arthritis. Humira and EnBrel are both injectable drugs.
Some analysts predict sales of Xeljanz could eventually hit $3 billion annually. Worldwide, RA treatments account for about $20 billion annually.
RA is an autoimmune disease, in which the body’s immune system mistakenly attacks healthy tissue leading to inflammation of the joints and surrounding tissues. According to the Centers for Disease Control and Prevention, RA affects an estimated 1.5 million Americans.