Will the mutant strains affect the prospects of Xofluza, Roche's newcomer, who fights the flu?

Roche's Xofluza, which is seeking to replace sales of generic Tamiflu, has not yet gained ground in the US, and new reports on viral resistance in Japan will not help the drug case. .

Some doctors in the country have slowed the prescription of Xofluza in the light of new evidence that mutant strains of viral influenza may prevent the drug from working as expected in some patients, the Wall Street Journal reported. The Tokyo National Institute of Infectious Diseases had six resistant strains on 6 February.

As the institute noted, resistance issues have emerged in clinical trials with developer Shionogi; almost 25% of children in the advanced trials had resistant strains, which means the problem is not new.

But that bodes ill for Roche, which seeks to stimulate the growth of Xofluza against imitators of his predecessor, Tamiflu. The new drug, which costs $ 150 for patients without insurance, has so far been little used, partly because of its price; In the fourth quarter, it generated only $ 13 million, after receiving the green light from the FDA in October.

"Xofluza is very expensive and has just been approved, so not many people take it," said Susan Wilder, MD, Arizona-based family doctor at the WSJ.

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Of course, Tamiflu is not without its own problems of resistance. Xofluza is "extremely promising, especially in the treatment of Tamiflu-resistant strains of flu," said Wilder, adding that "Xofluza has a broader efficacy range than other available anti-flu drugs" .

But some doctors worry that Xofluza will lose its advantage if it plays too much this year.

"It is possible that Xofluza may not be effective in the next influenza season if it is widely used now, as this would result in the rapid spread of drug-resistant viruses," Naoto Hosokawa, head of the infectious diseases department at Kameda Medical Center near Tokyo, said the WSJ.

Roche, for its part, pointed out that Xofluza still has some utility for mutant strains. Although they showed "reduced sensitivity" to Xofluza, the drug still had an effect on them, that is, they did not withstand US standards. Further study is needed to determine the extent of the problem and the communicability of the strains in question, and a comprehensive study of how Xofluza affects the spread of the flu begins this year, the company said in the Journal.