[Photo of baloxavir marboxyl (Xofluza)]
Photo source: Fierce Pharma
KEY POINTS
- Baloxavir marboxyl (Xofluza) is a polymerase acidic endonuclease inhibitor that is active against the influenza virus
- Interferes with viral RNA polymerase complex that is necessary for viral gene transcription, which inhibits influenza virus replication
- Has activity versus influenza A and influenza B
- Viral resistance has been found due to amino acid substitutions in the polymerase acidic protein
- As seasonal flu strains in circulation may vary, beware this may impact the utility of baloxavir marboxyl
- FDA-approved on October 24th of 2018 for treatment of uncomplicated influenza in patients 12 years or greater who have been symptomatic for no more than 48 hours
- Expanded in October 2019 to include patients who are:
- otherwise healthy, or
- at high risk of developing influenza-related complications
- Expanded in October 2019 to include patients who are:
- FDA-approved August 12th of 2022 for or the treatment of acute uncomplicated influenza in otherwise healthy children aged five to less than 12 years of age who have been symptomatic for no more than 48 hours
- Available oral only
- Body weight 40kg – 80kg: 40mg x1
- Body weight > 80kg: 80mg x1
- Avoid co-administration with cations (e.g., calcium, iron, magnesium, zinc)
- No dose-adjustment listed for renal or hepatic impairment, but it has not been studied in severe renal or hepatic impairment
- May impact effectiveness of live attenuated influenza vaccines
- The most common side effects reported are: diarrhea, bronchitis, nasopharyngitis, headache, and nausea
- The ISMP August 2019 Acute Care Medication Alert Newsletter listed concerning post-market adverse event data, including 382 reports of which all but 14 had a serious or fatal outcome. They noted 50 cases of anaphylactic shock, 7 of which were fatal and all were reported by a healthcare professional.
- Anticipated to cost $150 per course (regardless of dose)
- Approximately $100 more than a course of oseltamivir
RESOURCES
- Xofluza Package Insert
- Xofluza FDA Approval Press Release
- Roche announces U.S. FDA approval of Xofluza to treat influenza in children aged five years and older
- Baloxavir Marboxil for Uncomplicated Influenza in Adults and Adolescents. NEJM 2018.
- A Step Forward in the Treatment of Influenza. NEJM 2018.
- Sixty seconds on . . . baloxavir. BMJ 2018.
- New flu drug offers convenience, fast activity, and a novel mechanism – but at a cost. NEJM Journal Watch: HIV and ID Observations 2018.
