Nov. 11, 2011 (Chicago) -- An experimental pill called tofacitinib appears to reduce the pain and swelling of rheumatoid arthritis just as well as Humira injections, researchers say.
Biologic drugs have markedly improved RA treatment in recent years. But one of their main disadvantages is that they are given as an injection or directly into the vein.
If approved by the FDA, the new pill will offer an option for patients who don't like shots or for whom current drugs don't work, says Eric Matteson, MD, MPH, head of rheumatology at Mayo Clinic in Rochester, Minn.
Matteson, who was not involved with the study, reviewed the findings for WebMD. He has consulted for the makers of Humira and other arthritis drugs.
People taking tofacitinib in the company-funded study were more likely to have serious side effects, including infections, compared to people taking Humira or placebo.
Still, study researcher Ronald van Vollenhoven, MD, PhD, characterized the rate of serious infections as low. In this and other studies of tofacitinib, the rate of serious side effects was in line with those reported for other RA drugs on the market -- about 3% to 5% of patients per year, he says.
Van Vollenhoven is head of clinical therapy research in inflammatory diseases at the Karolinska Institute in Stockholm, Sweden.
Matteson says that people with rheumatoid arthritis are already prone to infections, "probably because of the immune system disturbances they have."
The findings were presented here at the annual meeting of the American College of Rheumatology.
Alternative to Injections
According to the Arthritis Foundation, about 1.3 million Americans have RA. In rheumatoid arthritis, the immune system inappropriately attacks the body's own tissues, causing inflammation, mostly in the joints. This, in turn, can cause pain and stiffness and lead to permanent joint damage.
Tofacitinib belongs to a new class of oral drugs, known as JAK inhibitors, which inhibits immune system cells that promote inflammation. These drugs target a different part of the immune system than other RA drugs.
The drug company Pfizer plans to submit the drug to the FDA for approval later this year. It's unclear at this point if the pill will be less expensive than the current injectables, such as Enbrel, Humira, and Remicade. Besides tofacitinib, several other JAK inhibitor drugs are in development.
Tofacitinib vs. Humira
The new, 12-month study involved 717 people with moderate to severe rheumatoid arthritis who had not fully responded to methotrexate. They continued methotrexate and also took the pill tofacitinib, Humira injections, or a placebo pill.
Among the findings:
- About half of people who received tofacitinib or Humira had a significant improvement in disease activity and symptoms after six months of treatment, compared with about one-fourth of those who received a placebo.
- Scores on a questionnaire that asked about dressing, arising, eating, walking, hygiene, reach, grip, and activities improved more than twice as much in people taking tofacitinib or Humira, compared with placebo.
People on tofacitinib and Humira had similar improvements, van Vollenhoven says.
Over a six-month period, serious side effects occurred in 5% of those on a lower tofacitinib dose, 4% of patients on a higher dose, and 3% of patients on either Humira or placebo.
People taking tofacitinib were also more likely to experience drops in white blood cell count and increases in LDL "bad" cholesterol levels. In findings that muddied the water, however, there was also an increase in HDL "good" cholesterol levels in some patients on tofacitinib.
"As with all drugs, we need long-term information on safety. But from both an effectiveness and safety view, tofacitinib looks to be very promising," Matteson says.
When Other Drugs Fail
Another study presented at the meeting was the first to evaluate tofacitinib in people who weren't helped by other biologic drugs or who could not tolerate them.
In the 399-person study, about 45% of people on tofacitinib had a significant improvement in disease activity and symptoms after three months of treatment, compared with about one-fourth of those who received a placebo.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.