Celgene shareholders have to be relieved On the flipside, Celgene and its shareholders are likely relieved by the safety concerns surrounding XP23829. An important component of Celgene's long-term growth plan is oral PDE-4 inhibitor Otezla, which is an anti-inflammatory drug that Celgene is hoping to gain more than a half-dozen label approvals for. Currently, the drug is approved by the FDA for psoriatic arthritis and psoriasis. Following its launch last year, Celgene has witnessed sales of Otezla ramp up to $90 million in the second-quarter.