Efficacy and safety of avalglucosidase alfa in Japanese patients with late-onset and infantile-onset Pompe diseases: A case series from clinical trials

Background: The efficacy and safety of avalglucosidase alfa for Pompe disease (PD) have been demonstrated in a global Phase 3 trial (COMET) in patients with late-onset PD (LOPD) and a global Phase 2 trial (Mini-COMET) in patients with infantile-onset PD (IOPD). This case series examines the individual results of three Japanese patients enrolled in these trials. Methods: Case reports were assembled from data collected in the COMET and Mini-COMET trials. Detailed methods have been reported previously. The primary endpoint of COMET was change from baseline to week 49 in upright forced vital capacity percent (FVC %) predicted. The primary endpoint of Mini-COMET was safety and tolerability of avalglucosidase alfa. In both trials, key secondary endpoints included motor function tests and other qualitative measures of improvement. Changes in biomarkers and anti-drug antibodies were also assessed in both trials. Results: Results for Japanese patients were representative of those from the overall populations in the COMET and Mini-COMET trials. We detail results for one Japanese patient with LOPD enrolled in the COMET trial and two Japanese patients with IOPD enrolled in the Mini-COMET trial. Importantly, avalglucosidase alfa was well tolerated at doses of both 20 mg/kg and 40 mg/kg in Japanese patients with LOPD and IOPD, respectively. Conclusions: Although the number of patients was small, avalglucosidase alfa provides an efficacy and safety profile in Japanese patients representative of the overall populations from key global clinical trials.