HCV New Drugs

Winners, Losers From EASL Hep C Data Dump

The European Association for the Study of the Liver (EASL) finally released hepatitis C drug research abstracts Wednesday ahead of its closely followed conference in two weeks. But investors looking for clear winners and losers in the race to develop new all-oral hepatitis therapies came away disappointed.

As with all things hepatitis C, the EASL abstract "data dump" raised more questions than provided answers, in part because a lot of the data investors most wanted to see remains under wraps.
Still, Wall Street loves to make snap judgments, so Abbott(ABT) shares rose less than 1% to $61.60 on strong results from a small mid-stage study of a three-drug, all-oral regimen, which resulted in hepatitis C cure rates greater than 90%.

Abbott's gain was Gilead Science's(GILD) pain, causing the latter's shares to fall 2% to $47.13. Further hurting Gilead Wednesday was the absence of new data on GS-7977, the hepatitis C drug acquired in the $11 billion Pharmasset purchase. EASL chose not to make GS-7977 data available Tuesday, withholding for presentation at the meeting itself.

EASL also kept under wraps data from an important study combining Bristol-Myers Squibb's(BMY) daclatasvir with Gilead's GS-7977. A Bristol spokesperson did confirm, however, that interim results tracking early cure rates from this study will be presented at the EASL meeting.

The biggest loser Wednesday appears to be Idenix Pharmaceuticals(IDIX), with shares down 12% to $8.99 but not because of any new information released on its hepatitis C drugs. Instead, investors appear to be worried about the future of Idenix's lead drug IDX184 based on poor results released today on a similar drug being developed by Roche.

EASL's International Liver Congress is being held April 18-22.
More details on the hepatitis C research abstracts made public Wednesday:
Abbott: Today's results come from a phase II study of its own all-oral Hep C regimen consisting of protease inhibitor ABT-450, a ritonavir booster and the non-nuke polymerase inhibitor ABT-333. The study enrolled treatment naive genotype 1 patients as well as treatment-experienced non-responders. Patients were treated for 12 weeks.

In the treatment-naive patients, SVR12 or hepatitis C "cure" rates were 93% and 95% for the low- and high-dose arms, respectively. These are some of the strongest cure rates seen for new hepatitis C therapies, particularly for regimens that exclude injectable interferon. The high cure rates are even more impressive given that a majority of the patients enrolled were diagnosed with the more difficult-to-treat genotype 1A subtype.

In patients who failed to respond to previous treatment, the Abbott all-oral regimen resulted in a cure rate of 47%.

One looming concern about the Abbott hepatitis C regimen is convenience. As formulated now, patients must take one pill once per day and another two pills twice per day. For a relatively short treatment duration of 12 weeks, remembering to take a total of five pills per day may not be a problem, unless competing companies develop equally effective and simpler therapies.

Idenix: A Roche study combining the nucleoside polymerase inhibitor mericitabine, a protease inhibitor danoprevir and ribavirin proved to be relatively unsuccessful, with a cure rate of 41% overall (71% in genotype 1b patients and just 26% in the harder-to-treat genotype 1a patients.)
This study has nothing to with Idenix except that the company's own nucleoside polymerase inhibitor IDX184 is perceived by some investors to be similar to that of Roche's mericitabine. This raises concerns that any future combination regimen pairing IDX184 with a protease inhibitor may result in similarly poor cure rates.

Idenix CEO Ron Renaud calls comparisons between IDX184 and mericitabine "ridiculous," adding that data already presented shows '184 to be more like GS-7977 than mericitabine. "Comparing '184 to mericitabine, I don't know where that comes from," says Renaud. "It's just conjecture and assumptions being made by some… All we can do is continue to generate good data. We remain as optimistic about '184 as we've ever been." Hepatitis C data not yet released by EASL but expected at the meeting:

Gilead Sciences: Data from two separate but similar studies (ELECTRON and QUANTUM), both involving the two-drug combination of GS-7977 plus ribavirin in treatment-naive genotype 1 patients.
Gilead has said results from the QUANTUM study could be announced in a press release early in the second quarter i.e. before the start of the EASL meeting. Investors are sure to scour the EASL web site Thursday for any early patient data that may give a hint about the later '7977 results. Much is riding on the outcomes from these treatment-naive patient studies because '7977's potency was cast in doubt due to poor results in so-called "null responder" patients.

Bristol-Myers Squibb: Interim results from a phase II study combining Bristol's NS5a inhibitor daclatasvir (BMS-52) with Gilead's GS-7977 in genotypes 1, 2, and 3 is the most highly anticipated data presentation at the EASL meeting this year. The study is important because it will be one of the first glimpses at the Hep C-killing potency of these two classes of direct-acting antivirals combined into a single, all-oral therapy.

If this study is successful, Bristol is expected to swap out GS-7977 for its newly acquired nuke INX-189, gained from the Inhibitex acquisition. Gilead may also capitalize on the study by combining GS-7977 with its own NS5a inhibitor.

--Written by Adam Feuerstein in Boston.

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