3 Surging Biotechs That Made Investors Rich in November

Perhaps no industry defines boom-or-bust potential like the biotech industry. Fortunately for investors, it's been much more of the former than the latter this year: The Nasdaq Biotechnology Index has jumped more than 57% year to date, and over the past month the index has climbed another 5.5% to record highs.

But even the NBI's great gains have paled in comparison to the industry's leaders. Which biotech stocks have rewarded investors' faith with huge returns? Let's check out three of November's biggest hits.

Idenix's comeback bounce highlights November's winners
Few biotech stocks have shot up with anywhere near the momentum of Idenix Pharmaceuticals (NASDAQ: IDIX) over the past month. Idenix has had a sluggish year, gaining less than 5% since 2013 kicked off. However, since the start of November, this stock has blown up for gains of nearly 47%, much of which came in one giant leap to start the month.

While Idenix took a tougher net loss for the third quarter than investors were expecting to kick off the month, the company impressed investors with an update on its pipeline. Idenix has had trouble with delays and other issues regarding its hepatitis C treatments in the past that have left it trailing the two big leaders in the oral hep C race, AbbVie (ABBV -0.30%) and Gilead Sciences (GILD -2.70%). However, Idenix announced early in the month alongside its downbeat quarterly results that its developmental hep C treatment IDX21437 received regulatory approval to move into clinical trials in Canada and Belgium.

It's welcome news for a company that's suffered tough setbacks, but is it really enough to get all that excited over? Gilead and AbbVie have surged ahead in the chase to open the oral hepatitis C market, which some analysts project could reach or exceed $20 billion. As fellow Fool analyst Sean Williams notes, Gilead's sofosbuvir already has won FDA advisory committee support for approval, while AbbVie's unnamed oral hep C treatment has won breakthrough status from the agency. Idenix's surge is nice for investors, but this company's hope of keeping up with the leaders in this promising market looks all but shot.

One stock that's done much better in 2013, Geron (GERN -0.56%), also ranks among November's big winners. Geron's stock has boomed by more than 270% so far this year, and it only added to its strong year-to-date gains with a 35% jump through November.

Geron made a big leap early in the month after the company reported that its developmental myelofibrosis therapy imetelstat posted strong results in an early-stage trial, a performance that, according to Geron, warranted its advance to phase 2 studies. Imetelstat helped 44% of clinical patients in the study show progression, from clinical improvement to complete disease remission in the case of one patient.

It's still early for Geron's drug, and investors shouldn't get too excited just yet. However, the study was a big step forward for this firm from last year, when Geron had to dump developmental brain cancer therapy GRN1005. If imetelstat can keep moving forward in mid-stage trials without suffering a big hiccup, Geron could be on pace to rise much more in the future.

Finally, ViroPharma (NASDAQ: VPHM) hit the biotech jackpot midway through the month after Shire agreed to a $4.2 billion acquisition of the company. A successful buyout like this is an endpoint to a stock that few investors can argue with, as ViroPharma's stock has jumped around 30% for the month and more than 110% through 2013.

ViroPharma's Cinryze, a treatment for angioedema that was first approved back in 2008, appealed to Shire in the deal. Cinryze helped ViroPharma to total sales of around $428 million last year, and Shire investors no doubt will be eager for the company to tap into that financial success. There's not much more that investors will be able to get out of ViroPharma with the acquisition in place, but it's a classic tale of a biotech company that unearthed a strong drug and courted a buyer -- all to the benefit of investors. It's the biotech industry's booming potential at its finest.