Gilead Sciences Shares Dropped: What You Need to Know

Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of biotechnology company Gilead Sciences (NAS: GILD) plunged 15% Friday after it reported disappointing trial results for its experimental hepatitis C drug.

So what: Gilead said that most of the hepatitis C genotype 1 patients it treated with its GS-7977 drug relapsed after a course of treatment, triggering fresh concerns over the drug's efficacy in some patients. Naturally, the news bodes well for rival hep C treatment developers Vertex Pharmaceuticals (NAS: VRTX) and Achillion Pharmaceuticals (NAS: ACHN) , whose shares are both up big today.

Now what: I'd look into this pullback as a possible buying opportunity. While Gilead was certainly dealt a setback, all companies in the hep C drug race will likely face the same challenge of treating the hepatitis C genotype 1 population with just one drug. Given the fact that it already has several drugs in its pipeline it can possibly combine with GS-7977, Gilead still seems like the smart bet to be the first to market.

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At the time thisarticle was published Fool contributor Brian Pacampara owns no position in any of the companies mentioned. Motley Fool newsletter services have recommended buying shares of Gilead and Vertex. Try any of our Foolish newsletter services free for 30 days.We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Fool's disclosure policy always gets a perfect score.

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