Dr. True and Clinvest are seeking motivated research volunteers in the Springfield area. The purpose of this research study is to evaluate the effectiveness and safety of a medication in bio-naïve participants with Psoriatic Arthritis Axial Disease. Qualified volunteers will be randomly assigned to one of three arms—study medication every 8 weeks, study medication every 4 weeks, or placebo every 4 weeks. The placebo arm will cross over to the study drug every 8 weeks after week 20, which means you will receive the active medication at some period of the study. Completion of the study would involve coming into the office for 16 appointments over an approximate 66-week period. Your first appointment would last approximately 2 hours, additionally, you will be scheduled to complete an MRI of the spine and hip joints at MRI of Springfield. If you continue to qualify, you will be asked to return to the clinic for enrollment in the treatment phase.