Wixela Inhub: Dosing Performance In Vitro and Inhaled Flow Rates in Healthy Subjects and Patients Compared with Advair Diskus

Background: Wixela™ Inhub™ is a fluticasone propionate/salmeterol dry powder inhaler developed as a generic equivalent of Advair Diskus(®) for the treatment of asthma and chronic obstructive pulmonary disease (COPD). Wixela Inhub and Advair Diskus are comparable in terms of functionality, user interface, and device resistance. The primary objectives of the studies were to evaluate in vitro dose delivery with Wixela Inhub compared with Advair Diskus at relevant flow rates and to explore inhalation profiles generated by patients with asthma or COPD. Methods: In vitro studies: Emitted dose (ED) and individual dose aerodynamic particle size distribution (APSD) were measured at flow rates ranging from 30 to 90 L min(−1). Patient inhalation study: Inhalation profile recording was conducted three times in each patient (40 children with asthma, 14 adults with asthma, and 14 adults with severe-to-very-severe COPD) with an empty Inhub in an open-label study. The primary endpoint was peak inhaled flow rate (PIFR). An additional endpoint was peak pressure drop. Results: In vitro studies: ED and APSD delivered from Wixela Inhub showed low flow dependency across the patient-relevant flow-rate range. Wixela Inhub gave in vitro performance comparable with Advair Diskus for all strengths and flow rates. Patient inhalation study: For Inhub, mean PIFR was lowest for children with asthma ages 4 to 7 years (50.6 L min(−1)) and highest for adults with asthma (74.8 L min(−1)). For adults with severe-to-very-severe COPD, mean PIFR was 69.5 L min(−1) with Inhub. The PIFRs observed with Diskus were higher than those with Inhub, consistent with slightly higher resistance measured in vitro. The difference in resistance did not impact demonstration of bioequivalence and does not impact substitutability of the product. Peak pressure drop values were comparable between Diskus and Inhub. Conclusions: Comparable in vitro performance of Wixela Inhub to Advair Diskus confirmed that Wixela Inhub is a generic equivalent to Advair Diskus across all patient groups.