A Study of Ixekizumab (LY2439821) in Participants With Nonradiographic Axial Spondyloarthritis

Inclusion Criteria: * Are ambulatory. * Diagnosis of nonradiographic axial spondyloarthritis (nr-axSpA) and fulfilling the 2009 Assessment of Spondyloarthritis International Society (ASAS) classification criteria. * Have a history of back pain ≥3 months with age at onset \<45 years. * Have active nr-axSpA defined as BASDAI ≥4 and total back pain ≥4 on a numeric rating scale (NRS) at screening and baseline. * Have objective signs of inflammation by presence of sacroiliitis on MRI and/or presence of elevated C-reactive protein (CRP). * In the past had an inadequate response to at least 2 non-steroidal anti-inflammatory drugs (NSAIDS) for duration of 4 weeks or cannot tolerate NSAIDS. * If taking NSAIDS be on stable dose for at least 2 weeks prior to randomization. * Have a history of prior therapy for axSpA for at least 12 weeks prior to screening. Exclusion Criteria: * Have radiographic sacroiliitis fulfilling the 1984 modified New York criteria. * Have received any prior, or are currently receiving treatment with biologics, tumor necrosis factor inhibitors or other immunomodulatory agents. * Have received a live vaccine within 12 weeks or have had a vaccination with Bacillus Calmette-Guerin (BCG) within the past year. * Have an ongoing or serious infection within the last 12 weeks or evidence of active tuberculosis. * Have a compromised immune system. * Have any other serious and/or uncontrolled diseases. * Have either a current diagnosis or a recent history of malignant d…