Hepatitis C: The More the Merrier
Excitement around the development of new therapies and combinations for hepatitis C continues unabated, as the need for safer
and more convenient products creates significant commercial opportunities. Just in the last seven months, the "overall tenor
of discussion on what's going to be the future of hepatitis C therapy has completely changed," asserts Raghuram Selvaraju,
head of healthcare equity research at Aegis Capital Corp. He noted that in April, attendees at the European Association for
the Study of the Liver (EASL) were all talking about the NUCs—nucleoside analog polymerase inhibitors—and how they were in
a position to steal the show. "That's clearly no longer the case," says Selvaraju.
Now that development of the Bristol-Myers Squibb/Inhibitex NUC compound has been halted due to cardiovascular side effect
issues (resulting in a $1.8 billion BMS write-off in the third quarter), and Idenix Pharmaceuticals' lead NUC put on hold
a second time by FDA over safety concerns, the only NUC left standing is Gilead's sofosbuvir (GS-7977), a Phase III drug obtained
through Gilead's recent $10.8 billion acquisition of Pharmasset. Sofosbuvir stands tall, and tops several forecast lists—assuming
it gets approved—with peak sales estimated at $2 billion in 2018 (Adis Insight), $4.5 billion in 2017 (Thomson Reuters Cortellis),
and a whopping $5.8 billion in 2018 (EvaluatePharma). These numbers anticipate the promise of the NUC class as an interferon-free
treatment, which could also be achieved through a spate of emerging non-NUC products and combinations.
Bristol-Myers Squibb/J&J/Medivir's protease inhibitor simeprevir is currently being tested in combination with Bristol's daclatasvir,
an NS5A inhibitor, and could potentially launch in 2014 without interferon. Abbott's ABT-450, an oral NS34A inhibitor, is
being tested in Phase III combination trials with other Abbott compounds plus ribavirin, with a target approval date in 2015.
ABT-450 posted strong initial data from a Phase IIb trial (AVIATOR), with a full data read-out scheduled for the American
Association for the Study of Liver Diseases (AASLD) in Boston this November. Adis Insight predicts blockbuster sales for ABT-450
Roche continues its focus on non-NUCs, namely setrobuvir, danoprevir, and mericitabine, and several combinations thereof.
All three remain in Phase II at the moment. Aegis Capital's Selvaraju is bullish on a fast-tracked Achillion Pharmaceuticals
protease inhibitor called sovaprevir, currently in Phase II, which he says has "significant advantages" over orally bioavailable
classmates including denoprovir, Vertex's Incivek, simeprevir, and ABT-450. Achillion is the company to watch at the upcoming
AASLD meeting, predicts Selvaraju. "I think the long-term future is going to be some combination of GS-7977, ABT-450, Roche's
denoprovir, and Achillion's sovaprevir. These cocktails will render their forefathers—like Incivek and Merck's Victrelis—completely
irrelevant," he says.
"The interesting thing about hepatitis C is that it's a virus infection so prone to mutation that we need to build up a big
armory of treatments, so that when a patient becomes refractory to one, they've got something else to move on to," says Kiran
Meekings, a consultant at Thomson Reuters Life Sciences in London. "People are rightly focusing on drug combinations, which
are likely to be the best pathway to resistance."
"I think within five years we will have an all oral, interferon free hepatitis C regimen that works at least in some of the
mutations," says Funtleyder. "That's a big deal in the United States, and to a lesser degree in Western Europe. But in Asia,
where patients really need new hepatitis C products, these new combinations will find challenges to uptake due to their high