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FDA Approves First New Flu Drug In 20 Years (popsci.com)
An anonymous reader quotes a report from Popular Science: The Food & Drug Administration just announced that they had approved the aptly-named Xofluza, the first new antiviral drug in two decades, to help alleviate the symptoms of a flu infection. The reason Xofluza got a priority review from the FDA is that it works through a different mechanism than Tamiflu. Both are antivirals, meaning they prevent the replication of the virus, but they work at different stages in that process. First, a quick primer on how viruses infect you: a virus is basically a packet of genetic material that injects itself into a cell and hijacks the cell's normal replication machinery, forcing it to produce millions of copies of the virus. A protein called viral neuraminidase allows those copies to exit the cell and go infect new parts of your body. Most of our effective antivirals are neuraminidase inhibitors -- the virus can still replicate, but it's prevented from escaping.
Xofluza works by preventing the viral replication in the first place. It blocks viral polymerase, an enzyme that helps make copies of the invading genetic material. This doesn't necessarily make it better or more effective -- the FDA notes that early trials suggest it's about as effective as Tamiflu -- but as the FDA Commissioner Scott Gottlieb pointed out in a press release, "Having more treatment options that work in different ways to attack the virus is important because flu viruses can become resistant to antiviral drugs."
Xofluza works by preventing the viral replication in the first place. It blocks viral polymerase, an enzyme that helps make copies of the invading genetic material. This doesn't necessarily make it better or more effective -- the FDA notes that early trials suggest it's about as effective as Tamiflu -- but as the FDA Commissioner Scott Gottlieb pointed out in a press release, "Having more treatment options that work in different ways to attack the virus is important because flu viruses can become resistant to antiviral drugs."
It's been 20 years already? Goodness, how time flu...
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There is another advantage of having drugs that work on different phases of the pathological process. It is that they can often show synergism when taken together, and such a combination has the potential to become the most effective treatment.
With Tamiflu, I think for it to be worth taking you have to take it within some short time window of developing symptoms (48 hours?). Since it's prescription, this means getting into a reasonable doctor's office right away. I think this prevents most people from getting any benefit out of it, but the time you're really sick it's too late, and even if you were somehow on top of it, now you have to get into the doctor, etc, in that time frame. Another drug with similar limitations doesn't seem like it would be of much use. They need some kind of anti-flu drug that's safe enough to get OTC and that doesn't contribute to drug resistance for all the people who would take it without actually having the flu.
As the summary says, that might be the best treatment. One reason NOT to do that is that the flu virus changes every year, becoming reistant to the anti-bodies that worked against last year's flu. If you routinely give both drugs, it's likely the fluvirus will adapt to be resistant to both. In some ways, it's better to keep one in reserve as a "secret weapon" that the virus doesn't know about, and only pull it out when needed. "When needed" might be vulnerable people (old, babies, aids patients) and/or when Tamiflu isn't working.