The US Food and Drug Administration has approved Johnson & Johnson's (JNJ.N) oral pill for psoriasis, paving the way for a more convenient treatment for patients with the chronic autoimmune condition. This move comes as J&J's blockbuster injectable Stelara is under increasing competition from low-cost copycat drugs. The drug, known as Icotyde, has been deemed a "blockbuster potential" by analysts and could capture significant market share.