OBJECTIVES::  To estimate and compare the long-term cost per responder based on the Assessment of SpondyloArthritis international Society (ASAS) outcomes following 52 weeks of treatment of ankylosing spondylitis (AS) with secukinumab relative to adalimumab. METHODS::  The cost per responder for each treatment was estimated by dividing the drug acquisition cost for the course of treatment with its response rate. Drug costs were estimated using the public price approved by Brazilian health authority and the number of doses required for 52 weeks. The long-term response rates were estimated using a matching-adjusted indirect comparison (MAIC) technique based on the data from MEASURE 2 and ATLAS clinical trials of secukinumab and adalimumab, respectively. RESULTS::  MAIC analysis showed that ASAS (20, 40 and 5/6) response rates were significantly higher for secukinumab compared to adalimumab at 52 weeks. ASAS 20, ASAS 40 and ASAS 5/6 response rates were 81% vs. 65%, 62% vs. 47%, 74% vs. 55% for secukinumab vs. adalimumab, respectively. The cost per ASAS 20 responder was BRL61,852 vs. BRL147,546, cost per ASAS40 responder was BRL80,407 vs. BRL205,127, whereas, costs per ASAS 5/6 responder was BRL69,240 vs. BRL175,514 for secukinumab vs. adalimumab, respectively. The costs per ASAS (20, 40 and 5/6) responders were about 60% lower for secukinumab compared to adalimumab for all outcomes at 52 weeks. Sensitivity analyses confirmed the robustness of our analysis. CONCLUSIONS::  The long-term cost per responder for all ASAS outcomes at 52 weeks were consistently lower for secukinumab vs. adalimumab. These findings indicated that it is more efficient to treat AS patients with secukinumab vs. adalimumab. In addition, more AS patients could be effectively treated in Brazil with secukinumab vs. adalimumab with a given budget, due to the cost-offsets.