This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Psoriasis, Subject name: Dental
Ixekizumab is novel drug approved by the FDA for treatment of psoriasis, MOA of this drug is : 
Select and explain. 
A. IL-17A agonist, B. IL-17A antagonist, C. IL-12/23 antagonist, D. PDE 4 inhibitor
B: IL-17A antagonist
Answer: B: IL-17A antagonist 
Explanation: Ixekizumab, approved for treatment of plaque psoriasis. It is a humanized IL-17A antagonist that works when IgG4 monoclonal antibodies selectively bind with IL-17A cytokines and inhibit their interaction with the IL-17 receptor. Secukinumab, similar to Ixekizumab, this injectable is an IgG1 monoclonal antibody that selectively binds to the IL-17A cytokine and inhibits its interaction with the IL-17 receptor. It is approved for the treatment of plaque psoriasis and psoriatic ahritis. Ustekinumab : Anti IL-12/23 Apremilast: PDE-4 inhibitor