Number needed to treat and cost per responder of Janus kinase inhibitors approved for the treatment of moderate-to-severe rheumatoid arthritis in Japan.

ABSTRACT

OBJECTIVE: This study evaluated the effectiveness and cost-effectiveness of baricitinib, tofacitinib, and upadacitinib regimens, compared to conventional synthetic disease-modifying antirheumatic drug (csDMARD) alone, among Japanese patients with moderate-to-severe rheumatoid arthritis (RA) inadequately responsive to csDMARD, measured in terms of number needed to treat (NNT) and cost per responder (CPR). METHODS: Efficacy data were derived from two recent network meta-analyses among global and Japanese population. The cost perspective was that of the Japanese Health Service. Both NNT and CPR were based on disease activity score for 28 joints with C-reactive protein (DAS28-CRP) remission and American College of Rheumatology (ACR) 20/50/70 at 12 and 24 weeks. RESULTS: Over 12 weeks, the median NNT and the median CPR to achieve DAS28-CRP remission were 4.3 and JPY 1,799,696 [USD 16,361], respectively, for upadacitinib 15 mg + csDMARD. The equivalent results were 6.0 and JPY 2,691,684 [USD 24,470] for baricitinib 4 mg + csDMARD and 5.6 and JPY 2,507,152 [USD 22,792] for tofacitinib 5 mg + csDMARD. Similar rankings were observed at 24 weeks and for other outcomes. CONCLUSIONS: Upadacitinib 15 mg was associated with the lowest NNT and CPR among the three Janus kinase inhibitors used in treatment regimens for Japanese patients with moderate-to-severe RA inadequately responsive to csDMARD.