Long-term effectiveness of initiating biologics on lung function in patients with severe uncontrolled asthma in the multi-biologics era: PROSPECT study

<bold>Introduction:</bold> There is limited evidence regarding the effectiveness of initiating biologics (BIOs) at the appropriate time on long-term asthma control, including lung function and asthma exacerbation in real-world settings. <bold>Aim:</bold> To clarify the long-term effectiveness of initiating BIOs on lung function of patinets with severe uncontrolled asthma in multi-BIO era in Japan. <bold>Methods:</bold> PROSPECT study (UMIN000038006) was a 24-months, multicenter, prospective, observational study with severe uncontrolled asthma patients in Japan. Patients were divided into BIO and non-BIO groups depending on if a BIO was started within 12 weeks after enrollment. The primary objective was to compare the change in post-bronchodilator (BD) forced expiratory volume in 1 s (FEV1) from baseline to 24 months between the two groups, analyzed using mixed model for repeated measures. Secondary objective included other asthma outcomes. <bold>Results:</bold> Of 306 patients enrolled, 285 were analyzed, 125 in the BIO group and 160 in the non-BIO group. The adjusted mean of post-BD FEV1 were +0.17 L in BIO group and +0.04 L in non-BIO group (p<0.01). <bold>Conclusion:</bold> A significant difference in improvement of lung function was observed between patients who timely initiated BIOs and those who did not.