Genotype 2 and 3 patients are far more responsive to treatments than their genotype 1 counterparts, and analysts expect these patients to be the first successfully treated by all-oral regimens. Genotypes 2 and 3 also represent a much smaller portion of the population in the U.S., roughly 20%, although they are more prevalent than genotype 1 in parts of the Middle East and Asia. While notable, the data are not crucial to Gilead’s proposed regimen, but will be important to an approval from the FDA. The company has two more trials ongoing for genotype 2 and 3 patients, testing sofosbuvir in combination with peg-IFN and ribavirin, and plans to submit sofosbuvir to the FDA in 2013. The sofosbuvir/GS-5885 combination remains in the spotlight, however, considering the larger genotype 1 market and the regimen’s impressive efficacy in previous trials. Expectations are for the full regimen to produce close to a 100% SVR, hence Tuesday’s mixed response from the market.
PropThink previously noted the arguably overestimated HCV market, suggesting that Gilead's acquisition of Pharmasset last year may have been overpriced. We do, however, like Achillion Pharmaceuticals’ (NASDAQ:ACHN) differentiated approach to the segment, particularly after a recent pull-back from the stock. Read more about ACHN’s protease inhibitors here, in our previous coverage.