If you're eager to send 2011 off into the history books, you're not alone. It has been a tough year for many companies out there, sending gobs of stocks down near their 52-week lows. Here are a few that have disappointed investors this year:

Company

Year-to-Date Return

Recent Price

52-Week Price Range

Cell Therapeutics (Nasdaq: CTIC)(52.2%)$1.06$0.95-$3.30
Keryx Biopharmaceuticals (Nasdaq: KERX)(47.3%)$2.41$2.27-$5.55
Dendreon (Nasdaq: DNDN)(78.5%)$7.50$6.46-$43.96

Data: Morningstar.com.

Let's take a closer look at what's been ailing these outfits.

Cell Therapeutics has been turning investors off by boosting its share count, earlier this month announcing its second stock offering since June. When companies issue new shares of stock, they dilute the ownership stake of existing shares. Presumably, the company is accumulating cash to help promote its drug pixantrone, but as my colleague David Williamson has pointed out, it might have waited for FDA approval first. An approval would likely propel shares upward, making a stock offering more effective. Approval is not a sure thing, though -- the FDA already dissed the drug once.

Keryx Biopharmaceuticals looks promising in some respects, such as its pipeline. It's developing a colorectal cancer drug, perifosine, with Aeterna Zentaris (Nasdaq: AEZS), which is in phase 3 clinical trials. A kidney-failure treatment, Zerenex, is also near the end of the trial process. If these drugs win FDA approval, Keryx's fortunes will rise considerably. But in the meantime, the company suffers quarter after quarter of losses with only minimal revenue offsetting its normal expenses.

You might think that Dendreon would be in good shape, with its prostate cancer drug Provenge approved and in production. But alas, it has had a tough year, too. First it wasn't able to meet demand, and then after beefing up its production capacity, its expected demand wasn't there. Part of the problem is Provenge's daunting price tag, costing $93,000 total for a one-month treatment. Meanwhile, new competitors are around the corner, such as Medivation (Nasdaq: MDVN) with its MDV3100 prostate drug, and Exelixis' (Nasdaq: EXEL) cabozantinib. OncoGenex Pharmaceuticals and partner Teva Pharmaceutical (Nasdaq: TEVA) have a prostate drug, OGX-011, already in phase 3 trials.

These stocks are far from doomed. Like any biotech enterprise, their fortunes are tied to the drugs that they successfully bring to market and how well they're sold and received. If you're intrigued by the sector but are skittish about investing in any particular company, consider a biotech ETF, which offers instant diversification.

Looking for promising investments? Here are "5 Stocks with Explosive Potential" and "4 Stocks as Cheap as They've Ever Been."

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.