Analysis of the long-term economic burden of omalizumab on patients with chronic spontaneous urticaria.

Omalizumab (OMA) is highly effective for refractory chronic spontaneous urticaria (CSU), but its high cost exerts a great economic burden on patients and society. Current knowledge is lacking regarding the economic impact of long-term administration of OMA on patients with CSU in the real-world setting. We retrospectively investigated drug costs relevant to CSU treatment during the period before through to 12 months after starting OMA in actual clinical practice. This study involved 32 patients who received at least two injections of OMA (300 mg/4 weeks) and achieved good responses of urticaria control test score of 12 or more and/or weekly urticaria activity score of 6 or less within 12 weeks. Median drug costs of the overall patient cohort increased from ¥14 496/month to ¥104 522 after starting OMA, but reduced to ¥48 810 in 12 months along with reduced amount of OMA administration and concomitant medication use. In patients pretreated with antihistamine alone or plus alternative medicines such as H2 blocker and antileukotriene prior to OMA, the increased drug costs by adding OMA decreased to approximately 30% in 12 months mainly due to the OMA dose reduction and interval extension of OMA. The drug cost reduction was also observed in patients pretreated with intensive multi-agents, due to discontinuation of expensive immunosuppressants. In conclusion, the introduction of OMA significantly increased the total drug costs relevant to CSU management, but the costs decreased to half in 12 months, along with dose-reduced and interval-extended OMA and discontinued concomitant drugs in patients with CSU who responded well to OMA.