Dermatologist prescribed me Apremilast.

Just back from the Dermatologist and was prescribed Apremilast. It inhibits the activity of phosphodiesterase type-4 (PDE4) which results in suppression of pro-inflammatory mediator synthesis Whilst there, I gave my normal history of treatments, explaining that the improvements I have had were mainly from changes in my diet. I was somewhat dismayed when the doctor said there is "No scientific study to prove that diet has positive impact on psoriasis"!!? Which I could have provided multiple scientific studies to the contrary, however I did not want to get into an disagreement as he wanted to try a different drug called Apremilast. Has anyone used this drug and if so what were the results? Thanks in advanced.