With Tamiflu sales crumbling, Roche has pivoted to next-gen flu med Xofluza as a follow-up to the aging blockbuster. Getting an FDA nod as a flu preventative is a big part of that puzzle, and Xofluza could be well on its way with new data.
Xofluza decreased the spread of flu after exposure to an infected household member by 86% compared with placebo, according to data from Roche’s phase 3 Blockstone study, presented Sunday at the Options X 2019 Congress in Singapore.
Just 1.9% of trial patients treated with Xofluza contracted the flu compared with 13.6% of placebo patients, Roche said. Xofluza also achieved significant subgroup results, with Roche’s drug beating out placebo in influenza A subtypes, in household contacts who are at high risk of flu-associated complications and in children under the age of 12.
The newest data could also present a compelling case to payers, according to Barry Clinch, Roche's global head of influenza and infectious disease product development.
"If approved by the FDA, we believe that Xofluza in the preventative setting will be viewed favorably by payers as there are significant healthcare system and economic cost implications associated with the flu," Clinch said by email. "It is important for physicians and from a public health perspective to have new mechanisms of action available to address emergence of resistance toward existing mechanisms."
The data wasn’t all roses for Xofluza: The drug posted a 22.2% rate of side effects compared with 20.5% for placebo, but Roche called the safety profiles “comparable.”
In Singapore, Roche also released data from its Ministone-2 study showing one-dose Xofluza topped Tamiflu at reducing the rate of child patients showing at least one flu symptom. 46% of patients reported at least one flu symptom after 29 days compared with 53.4% in the Tamiflu arm, Roche said.
Xofluza also lowered the length of time patients were contagious—a metric known as “viral shedding”—by more than two days over Tamiflu. For Xofluza patients, the contagious period was recorded at a median 24.2 hours versus 75.8 hours for Tamiflu.
The strong preventative data for Xofluza could help Roche make up for the sales drop from Tamiflu, which went generic three years ago. In the first half of 2019, Tamiflu posted just $277 million in sales, a 29% drop from the same period in 2018.
In addition to preventative treatment, Roche is also pursuing indications for Xofluza as a single-dose oral treatment for people at high risk of complications from influenza, as an add-on to standard of care neuraminidase inhibitors, and in patients under 1 year of age, Clinch said.
In sales, Xofluza hasn’t yet hit pay dirt for Roche after its initial approval in late 2018. In the first half, the drug cleared just $6 million in sales, ranking as the second-lowest performer in Roche’s portfolio over Polivy, which the FDA approved in June.
However, there is some hope for Xofluza: Partner Shionogi, which owns the drug’s rights in Japan, recorded $243 million in domestic sales in fiscal 2018.
With copycats on the way in, Roche signed an exclusive deal with Sanofi in July to pass off over-the-counter rights to Tamiflu in the event of an Rx-to-OTC approval by the FDA. Under the agreement, Sanofi will handle FDA negotiations for the OTC switch and all future marketing, and it has first dibs on OTC rights in other markets.
Getting an OTC approval won’t be easy: With an antiviral drug like Tamiflu, there is likely the additional question of whether wider use by consumers might increase the risk of viral resistance. But a 2012 study in New Zealand—the first country to make Tamiflu available without a prescription—found that five years of nonprescription Tamiflu didn’t appear to spur development of resistance or trigger a decline in influenza immunization rates.