(NBC) -- A new drug to treat Rheumatoid Arthritis is showing promise in large clinical trials.
It's a medication that does more than mask pain; it attacks the disease directly.
Rheumatoid Arthritis is a painful autoimmune disease that occurs when the immune system attacks its own joints and tissues.
There's no cure, but there are medications.
Often though, they simply treat the pain.
"Some drugs are aimed just to treat the signs and symptoms, and some actually change the progression of the disease," explains Dr. Elaine Husni of the Cleveland Clinic.
Falling into the latter category is the new experimental drug from Pfizer called Tofacitinib.
Other disease-altering drugs on the market must be injected.
This drug is taken in pill form.
Doctors say it's important for arthritis patients to have multiple drug options.
"There are a subset that are either not responding fully, or actually not responding at all. And that is the reason we have new drugs coming out," Dr. Husni says.
In two new large clinical trials Tofacitinib was found to be effective and improved physical function in patients.
It's also in a totally different class of drugs than pain medications like Vioxx, which is now off the market because of its link to severe heart problems.
So far doctors say the most common side effects of Tofacitinib have been headache and upper respiratory infections.
Advisors to the Food and Drug Administration recommended approval of the drug earlier this year.
A final decision is expected sometime this month.