Seven might be Abbott Labs' (NYSE: ABT) Humira's lucky number. The anti-inflammatory is up for approval in its seventh indication and the data looks pretty good.

The indication? Ulcerative colitis, a chronic autoimmune disease that causes inflammation and ulcers in the lining of the colon or large intestine. As you can imagine, the inflammation and ulcers make bowel movement less than pleasant.

Humira was tested in patents that couldn't control their ulcerative colitis with conventional therapy. After two months of treatment, 16.5% of patients on Humira achieved clinical remission compared to 9.3% on placebo. After a year, the margin was even wider: 17.3% versus 8.5%.

The results shouldn't be too surprising. Humira is approved for other autoimmune diseases, and Johnson & Johnson (NYSE: JNJ) and Merck's (NYSE: MRK) Remicade -- which targets the same protein, TNF alpha -- is also approved to treat ulcerative colitis.

Simponi, Johnson & Johnson and Merck's follow up to Remicade, is also being tested in the indication, so Abbott may have some additional competition if both get approved. I couldn't find any indication that Pfizer (NYSE: PFE) and Amgen (Nasdaq: AMGN) were testing Enbrel, another drug that targets TNF alpha, in ulcerative colitis patients.

Rheumatoid arthritis will still be the mainstay of Humira's sales, but the added indications in less frequent diseases such as Crohn's disease and plaque psoriasis add incremental sales to the revenue line. Last year, Humira sales topped $6.5 billion, and they increased nearly 18% in the first quarter of this year.

An approval in ulcerative colitis probably isn't going to move the revenue number all that much, but every bit helps.

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