Teams race for hepatitis-B drug
Developers of pill for liver disease hepatitis-C lead way
LONDON — Gilead Sciences raked in $10 billion last year with its Sovaldi pill for hepatitis-C. Many of the people responsible for the drug are now competing to repeat that success for a more common liver disease: hepatitis-B.
At OnCore Biopharma, the team seeking a cure for hepatitis-B is an honor roll of Sovaldi graduates.
The drug’s principal inventor, Michael Sofia, founded OnCore with a sales executive from Pharmasset, where Sovaldi originated. At ContraVir Pharmaceuticals and Chimerix, the leadership ranks are similarly peppered with Gilead and Pharmasset alumni.
“We’re gunning for a cure,” Sofia said. “With Sovaldi, we clearly brought innovation with the drug’s discovery and getting it to market. We feel we can translate that experience to hep-B.”
Biotechnology companies are captivated by liver disease because of the size of the market. About 240 million people suffer from a chronic hepatitisB liver infection — more than the hepatitis-C population. At least 780,000 people die from the infection every year, according to the World Health Organization.
ContraVir, based in New York, is led by James Sapirstein, who helped build Gilead’s antiviral portfolio. At hepatitis partner Chimerix in Durham, N.C., Chief Executive Officer Michelle Berrey was chief medical officer of Pharmasset, bought by Gilead for $10.6 billion in 2012.
“This is absolutely the next frontier,” Sapirstein said, explaining the flight of talent to the startups. “I have access to some of the best Pharmasset scientists who put Sovaldi on the map. The sky’s the limit for us.”
Both forms of the disease are transmitted by bodily fluids, though hepatitis-B is more complicated in terms of its ability to hide from the immune system. There are therapies, but no cure.
OnCore and ContraVir aren’t alone in the chase. Alnylam Pharmaceuticals Inc. and Arrowhead Research are working on hepatitis-B, and their biggest rival — Gilead — is in pursuit.
“These players think the market is gigantic,” worth billions of dollars, Michael Yee, an analyst at RBC Capital Markets, said in a note after Alnylam won a patent last year.
Both forms of hepatitis are prevalent in developed and emerging markets, so the winner of the race faces a lucrative payoff. Gilead originally priced Sovaldi at $84,000 in the U.S. for a 12-week course. China presents a huge untapped opportunity for hep-B, Sofia said.
Investors are eager. When Tekmira Pharmaceuticals Corp. of Canada agreed last month to buy OnCore, its shares surged 57 percent. ContraVir intends to list on the Nasdaq stock market this month, where Chimerix shares more than doubled last year.
Leerink Partners raised its recommendation on Tekmira’s stock after the OnCore purchase, citing the track record of Bill Symonds, the OnCore senior adviser who was responsible for running tests that sealed Sovaldi’s success.
OnCore has begun testing a medicine dubbed TKM-HBV, while ContraVir is banking on a more potent yet less toxic variant of Viread, a Gilead drug used for hepatitis-B and HIV. Viread can cause kidney damage and bone loss.
An early study of ContraVir’s medicine demonstrated safety and tolerability, which sets it apart from competitors, Sapirstein said. The company announced Wednesday that the U.S. has extended intellectual property protection on the drug, licensed from Chimerix, to at least 2031, from 2020.
Gilead may be first to market with a new hepatitis-B drug, but the ContraVir/Chimerix medicine will be competitive on safety and pricing, Sapirstein said. OnCore’s candidate is aimed at curing the disease, something that may not be achieved by some rivals, according to Sofia.
Gilead is farthest along in testing, with Arrowhead and ContraVir/Chimerix close behind. OnCore’s drug is in the earliest phase of study, and Alnylam is preparing for the first stage.
Arrowhead’s drug, which aims to reduce viral proteins that suppress the immune system, had a setback last month when the U.S. Food and Drug Administration asked that a trial be conducted at a lower dosage. The shares plunged 24 percent.
Alnylam expects that its RNA-based drug may become “best in class,” CEO John Maraganore said. It will seek approval for clinical trials “around year-end 2015.”
ContraVir may seek fasttrack FDA approval to start late-stage trials this year, as its candidate is a variant of an approved drug.
If the upstarts are to win, they have to beat their former employer. Gilead has finished enrolling patients for a late-stage trial of a hepatitis-B candidate, a spokesman said, declining to comment about competition from former employees.
But the challengers have a good shot, Sapirstein said. “Half the team at Pharmasset went to OnCore, the other half went to Chimerix. And now we’ve got that team on our side.”