Celgene (Nasdaq: CELG) recently announced positive results from two phase 3 studies of apremilast. The drug achieved statistical significance and clinically meaningful improvements among psoriatic arthritis patients at week 16.

What it means
Celgene relies heavily on Revlimid, its drug that's used primarily for treating multiple myeloma. Revlimid currently accounts for around two-thirds of the company's total revenue. Celgene hopes to build on the Revlimid's success, but the other drugs in its portfolio right now don't have the same firepower.

Vidaza, Celgene's next highest-selling drug, pulled in second-quarter revenue of $162 million compared with $795 million for Revlimid. While sales for Vidaza are still growing, the company lost patent exclusivity in 2011. No one has stepped forward with a generic version yet, but if and when that happens, Celgene faces the prospect of decreasing sales for Vidaza.

The company also encountered some bad news recently. European regulators rejected Revlimid for treating newly diagnosed patients with multiple myeloma. They also found problems with a study done for Istodax, a drug intended for treating peripheral T-cell lymphoma. 

All of these events heighten the impact of the good news about apremilast. However, there are still hurdles to overcome, including battling other drugs used in the treatment of psoriatic arthritis.

Teva Pharmaceuticals makes generic methotrexate -- the most common disease-modifying antirheumatic drug, or DMARD, used to treat psoriatic arthritis. Humira, made by Abbott Laboratories (NYSE: ABT), stands as the giant in the TNF-inhibitor category, with projected sales of $9 billion this year.

Enbrel presents another rival drug in the psoriatic arthritis market. The drug, marketed by Amgen (Nasdaq: AMGN) and Pfizer (NYSE: PFE), also ranks as a multi-billion-dollar franchise.

Despite strong competition, the potential for apremilast still seems quite positive. The drug looks to be one of Celgene's best opportunities for success.

Looking ahead
The next step for Celgene is to submit a New Drug Application, or NDA, for apremilast. The company expects to submit the first NDA to the Food and Drug Administration in the first quarter of 2013. It plans to submit a combined submission for treatment of psoriatic arthritis and moderate to severe psoriasis in Europe during the first half of next year.

Celgene also hopes to benefit in the future from more good news surrounding apremilast. The company announced that phase 2 trials went well for its use in the treatment of Behcet's disease, a rare inflammatory disorder.

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