Clinical outcomes of baloxavir versus oseltamivir in patients hospitalized with influenza A

Objectives: To date, clinical trials evaluating baloxavir have excluded patients hospitalized with influenza infection and therefore this study sought to evaluate the efficacy of baloxavir in inpatients with influenza A.

Methods: This study was a multicentre, retrospective chart review of adult patients admitted to the hospital within the Yale New Haven Health System who received oseltamivir or baloxavir for the treatment of influenza A. Patients were screened for inclusion between January 2018 and April 2018 in the oseltamivir group, while patients in the baloxavir group were screened for inclusion between January 2019 and April 2019. Influenza A diagnosis was confirmed by RT-PCR using a nasopharyngeal swab specimen.

Results: Of the 2392 patients assessed, 790 met the inclusion criteria. There were 359 patients who received baloxavir and 431 patients who received oseltamivir. Patients who received baloxavir were younger compared with those who received oseltamivir [median = 69 (IQR = 57-81) years versus 77 (IQR = 62-86) years; P < 0.001]. Patients who received baloxavir had no significant difference in hospital length of stay [median = 4 (IQR = 3-6) days versus 5 (IQR = 3-6) days; P = 0.45] or 30 day all-cause mortality [12 (3.3%) versus 26 (6%); P = 0.079] compared with those who received oseltamivir. However, patients who received baloxavir had a significantly faster time to hypoxia resolution [median = 51.7 (IQR = 25.3-89.3) h versus 72 (IQR = 37.5-123) h; P < 0.001].

Conclusions: The results of this study support the use of baloxavir for the treatment of influenza A in hospitalized patients with the potential benefit of a faster time to resolution of hypoxia.