A Phase II, single institution, double blind, randomized, placebo controlled, cross-over study exploring the safety and efficacy apremilast in patients with active RA with concomitant use of TNF inhibition. Following a screening period, patients with active disease on stable TNF inhibition will be randomized to receive either apremilast or placebo for a period of 12 weeks. At the end of 12 weeks patients will be assessed for efficacy using the ACR responder index looking for a 20% improvement, then all patients initially randomized and treated in a blinded fashion with apremilast will be crossed over to placebo while those patients initially randomized and treated with placebo will be crossed over to apremilast. Patients will be followed for an additional 12 weeks on treatment to assess both safety and efficacy of this combination treatment. Following 24 weeks of active treatment or early termination, patients will undergo a 28 day safety visit.