Rocket Flickr Steve Jurvetson

Source: Flickr user Steve Jurvetson

Biotech stocks can pop or drop on the faintest of whims and whispers, so I don't think it's a stretch to think that upcoming trial results from three companies could result in a significant move higher or lower in any of these three companies.

No. 1: Gilead Sciences (NASDAQ:GILD)
Gilead Sciences is enjoying tremendous success in protecting its hepatitis C dominance through the launch of Harvoni, a next-generation HCV drug for use in genotype 1 patients, which account for roughly 55% of all HCV cases.

We'll find out soon if Gilead Sciences could be in a position to enjoy a similar success in non-genotype 1 patients. That's because Gilead Sciences has wrapped up four phase 3 trials of a new combination therapy approach that includes GS-5816, and it plans to release the results of these trials this quarter.

If GS-5816-containing regimens are successful, it could significantly improve treatment for millions of non-genotype 1 patients whose current treatment options can still include the side-effect-laden drugs peginterferon and ribavirin and who may still need to take their medications for longer than 12 weeks.

Because that could mark a significant improvement over current treatment options -- and Harvoni and its competitor Viekira Pak's approvals are for genotype 1 rather than non-genotype 1 variations of the disease -- an approval of a best-in-class GS-5816-containing regimen could be worth billions of dollars to Gilead Sciences.

No. 2 Spark Therapeutics (NASDAQ:ONCE)
Although Spark Therapeutics doesn't have any products on the market, investors' hope that it can help ignite gene therapies has led to a market cap that's already north of $1.5 billion.

Because the company is expected to report phase 3 data for its SPK-RPE65 soon, investors should gain insight into whether that's an appropriate valuation shortly.

Spark Therapeutics' SPK-RPE65 studies are evaluating the gene-replacement injection in people with mutations to the RPE65 gene and, if trial results are positive, then the company could file for FDA approval by the end of this year. If that application results in an FDA green light, then SPK-RPE65 could bring new hope to as many as 3,500 people with this type of inherited retinal dystrophy in the U.S. and Europe.

SPK-RPE65's success could also help validate Spark Therapeutics' SPK-CHM, a therapy that relies on similar technology that could help restore vision in up to 12,500 patients. Since results for SPK-RPE65 could be a binary event, I wouldn't be shocked if shares head significantly higher or lower following the release of this data, and for that reason, investors should approach this one cautiously.

No. 3 Synergy Pharmaceuticals (NASDAQ:SGYP)
Last month, positive phase 3 trial results for Synergy Pharmaceuticals' plecanatide for chronic constipation sent shares soaring 40%, and that means investors are going to want to keep a close eye on additional results for this drug, which are expected to be released this quarter.

Previously, Synergy Pharmaceuticals reported that patients taking plecanatide saw a statistically significant improvement in treating constipation versus placebo. Importantly, results suggest that the incidence rate of diarrhea could be lower than that experienced by patients taking Ironwood's Linzess, a constipation therapy that posted sales of $95 million in the first quarter, up 57% from last year.

If the results from Synergy Pharmaceuticals' second phase 3 trial confirm the findings from its first trial, then the company will be in a position to file for FDA approval by the end of this year. That could mean that Synergy Pharmaceuticals could be competing for share against Linzess at some point in 2016.

Treading cautiously
Investors need to keep in mind that up to 40% of phase 3 trials fail, and that means that any of these companies could release disappointing news that could cause shares to fall. But if Gilead Sciences, Spark Therapeutics, and Synergy Pharmaceuticals report positive data, each one of the aforementioned key drugs has significant enough market potential to propel shares higher and, for that reason, I think these catalysts rate "can't-miss" status.

 

Todd Campbell owns shares of Gilead Sciences. Todd owns the equity research firm E.B. Capital Markets, LLC. E.B. Capital's clients may have positions in the companies mentioned. The Motley Fool recommends Gilead Sciences. The Motley Fool owns shares of Gilead Sciences. 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 Motley Fool has a disclosure policy.