A Study to Evaluate 608 in Patients With Non- Radiographic Axial Spondyloarthritis (Nr-axSpA)

Inclusion Criteria: 1. Female and male patients at least 18 years of age at the time of screening. 2. Diagnosis of axial spondyloarthritis according to Ankylosing Spondylo Arthritis International Society (ASAS) axial spondyloarthritis criteria 3. Objective signs of inflammation (magnetic resonance imaging (MRI) or abnormal C-reactive protein) 4. Total back pain as measured by NRS ≥ 4 at baseline Exclusion Criteria: 1. Patients with other uncontrolled active inflammatory diseases. 2. Clinical laboratory tests and other tests that reveal abnormalities with clinical significance 3. Patients who have active Hepatitis B, Hepatitis C or HIV infections as determined by positive results at Screening. 4. History of cancer. 5. Known or suspected history of immunosuppression. 6. Known with allergic or intolerant to mometasone furoate spray or 608/placebo.