Add-on Tiotropium in Chinese Patients With Moderate Asthma: A Pooled Subgroup Analysis of MezzoTinA-Asthma 1 and 2

Asthma affects approximately 30 million patients in China; however, tiotropium data for Chinese patients is limited. This study aimed to assess the efficacy and safety of tiotropium in Chinese patients with moderate symptomatic asthma.

A post hoc subgroup analysis was conducted on 430 Chinese patients pooled from two 24-week, replicate phase 3 trials (NCT01172808 and NCT01172821), in which they received once-daily tiotropium 2.5 μg (Tio R2.5) or 5 μg (Tio R5) (n = 106 or 109, respectively), twice-daily salmeterol 50 μg (Sal 50) (n = 110), or placebo (n = 105), while maintaining inhaled corticosteroids (ICS). The co-primary endpoints assessed in week 24 were forced expiratory volume in 1 second (FEV1) peak_0-3h response, trough FEV1 response, and responder rate as assessed using the Asthma Control Questionnaire (ACQ).

For both FEV1 peak_0-3h responses and trough FEV1 responses, the mean treatment differences were greater for Tio R2.5, Tio R5, and Sal 50 compared with placebo at 0.249 L, 0.234 L, and 0.284 L, and 0.172 L, 0.180 L, and 0.164 L, respectively (P < 0.001). The ACQ responder rate in placebo, Tio R2.5, Tio R5, and Sal 50 was 58.7%, 62.3%, 59.3%, and 69.1%, respectively. Furthermore, 11 (2.6%) of 430 patients had serious adverse events (Tio R5, n = 4; Tio R2.5, n = 1; Sal 50, n = 1; and placebo, n = 5).

Once-daily tiotropium, as add-on to medium-dose ICS, was effective and well tolerated for Chinese patients with moderate symptomatic asthma, consistent with the main analysis.