New kid on the block reduces influenza symptoms, severity

A new first-in-class therapeutic agent indicated for the treatment of acute, uncomplicated influenza in persons aged 12 years and above is now available in Malaysia.

The new drug, baloxavir marboxil (Xofluza™, Roche), is taken as a single dose within 48 hours after the onset of influenza symptoms. When compared to placebo, baloxavir has been shown to significantly reduce the median time to alleviation of symptoms and median time to resolution of fever (p<0.001 for both). When compared to placebo and oseltamivir, baloxavir significantly reduced the infectious viral load within a shorter duration. Furthermore, the new drug has a favourable safety profile, with side effects comparable to oseltamivir. [N Engl J Med 2018;379:913–923]

Speaking at the virtual launch of the new drug, Dr Petrick @ Ramesh K. Periyasamy, head of infectious diseases unit, Universiti Kebangsaan Malaysia Medical Centre, said one of the main challenges of physicians when diagnosing influenza is that it can be easily confused with other respiratory illnesses, such as the common cold. This is because some milder symptoms, for example, cough, nasal discharge and sore throat, are similar. However, influenza is characterized by more severe systemic symptoms such as fever, muscle pain and general unwellness. It has the potential to cause a variety of complications, ranging from sinus or ear infections to more severe complications such as pneumonia.

Petrick said: “Symptoms of influenza include sudden onset of fever, cough (usually dry), headache, muscle and joint pain, sore throat and a runny nose. The symptoms usually start 24 to 48 hours after infection and lasts up to 8 days. Most adults are contagious 1 day before their symptoms start and remain contagious up to 7 days after becoming sick.”

Dr Charles Li, medical and regulatory director, Roche Malaysia, said the new drug represents a new chapter in influenza treatment with it being convenient (thereby improving patient compliance) and efficacious. At the same time, Roche Malaysia has launched the ‘Axe The Flu’ campaign, targeting the public to increase awareness of influenza symptoms and severity. Li said: “Recognizing the symptoms of influenza early is key to effective treatment and prevention of the virus spreading. If patients see their doctors within 48 hours of symptom onset, one dose of baloxavir marboxil can significantly reduce the duration of influenza symptoms.”

The treatment could be covered by medical insurance, however it would depend on the policy and patients are advised to check with their provider for confirmation of coverage. It is already available at hospitals, GP clinics and pharmacies. However, Li said patients may find it easier to access the treatment in the hospital setting for the time being. The expected price for a dose of baloxavir marboxil is around RM250.

About baloxavir marboxil
The new therapeutic agent is the first-in-class antiviral with a novel mechanism of action. Unlike previous antiviral agents, baloxavir marboxil inhibits a subunit of viral polymerase and stops viral replication early in the disease cycle. This mechanism works on both A and B strains of influenza.

The evidence for baloxavir marboxil came from the CAPSTONE-1* trial, a phase III multicentre, randomized, placebo-controlled study which looked at 1,436 participants aged 12 to 64 years who were diagnosed with symptomatic, uncomplicated influenza. Participants were randomly assigned to receive a single oral administration of 40 mg or 80 mg (40 mg if they weighed less than 80 kg and 80 mg if more than 80 kg) of baloxavir marboxil; placebo or 75 mg of oseltamivir twice a day for 5 days. Baloxavir marboxil met its primary endpoint of significantly reduced duration of influenza symptoms compared to placebo. It further demonstrated similar efficacy to oseltamivir with regard to symptom duration and adverse events. 

*CAPSTONE-1: A Study of S-033188 (Baloxavir Marboxil) Compared With Placebo or Oseltamivir in Otherwise Healthy Patients With Influenza