Real-world Study on Secukinumab Effectiveness in Biologic-naïve Ankylosing Spondylitis (AS) Patients in Korea.

Change from baseline in C-Reactive Protein (CRP)

CRP is a blood test that indicates levels of inflammation * CRP\< 5mg/L: Normal * CRP\>=5 mg/L: High

Time frame: Baseline, 16 and 28 weeks

Change from baseline in Ankylosing Spondylitis Disease Activity Score - C-Reactive Protein (ASDAS-CRP

ASDAS-CRP is the score for participant's evaluation of low back pain, peripheral pain/swelling, duration of morning stiffness, disease activity, and the disease activity score of ankylosing spondylitis calculated from CRP levels. Ranges for Disease activity status are defined as follows: * Disease activity status \<1.3: Inactive disease * Disease activity status 1.3-2.1: Low disease activity * Disease activity status 2.1-3.5: High disease activity * Disease activity status \>3.5 (No maximum limit): Very high disease activity

Time frame: Baseline, 16 and 28 week

Change from baseline in Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) stratified by specific variables

The BASDAI consists of 6 questions to measure the participant's symptoms and disease activity, and each question is evaluated using a numeric rating scale from 0 to 10 or a 10 cm Visual Analog Scale (VAS) with 0 being no problem and 10 being the worst problem. Stratified by different baseline variables

Time frame: Baseline, 16 and 28 weeks

Adverse events and Serious Adverse events

Incidence of Adverse events and Serious Adverse events