Pfizer's (NYSE: PFE) rheumatoid arthritis drug tofacitinib has a new name -- it use to be called tasocitinib -- but the data in the company's second phase 3 trial was the same as the first: a solid win.

The pharma giant didn't release the data -- it's saving it for a medical meeting -- but Pfizer did say the trial showed that the drug was better than placebo in multiple scales used to determine the severity of rheumatoid arthritis.

In the previous trial, 59.8% of patients reported 20% improvement of their symptoms, while the higher dose helped 65.7% of patients to report the same. The results were double the 26.7% of the patients taking placebo that improved their symptoms by 20%.

Tofacitinib should have little problem competing with the megablockbuster rheumatoid arthritis drugs -- Abbott Labs' (NYSE: ABT) Humira, Johnson & Johnson (NYSE: JNJ) and Merck's (NYSE: MRK) Remicade, and Pfizer and Amgen's (Nasdaq: AMGN) Enbrel -- because it's taken orally, unlike the others, which have to be injected or infused.

The biggest obstacle to tofacitinib's success isn't what's in front of it, but what's trailing behind. Rigel Pharmaceuticals (Nasdaq: RIGL) and Incyte (Nasdaq: INCY) are both developing oral rheumatoid arthritis drugs in combination with AstraZeneca and Eli Lilly, respectively.

If the drugs work as well or better than tofacitinib, the head start Pfizer has might not amount to much. However, if they stumble in their respective phase 3 trials, Pfizer will have a major seller on its hands. Sales might not approach Lipitor's $12-billion scale, but billions -- with an "s" -- certainly isn't out of the question.

Pfizer isn't ready to submit a marketing application just yet. Tofacitinib still has four more trials to read out for rheumatoid arthritis, and multiple others in additional inflammatory diseases such as psoriasis and inflammatory bowel disease. Assuming the drug continues the clinical trial success, the results will be worth the wait.

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