If you like watching carnage, look no further than the health-care sector. This week saw several stocks crash and burn in spectacular fashion. Here are  three of the week's most horrendous health-care stocks.

Collapse by cancellation
Geron (GERN -1.07%) plunged nearly 27% this week, following cancellation of its GRN1005 cancer drug program. The company experienced a double whammy with two disappointments related to the drug.

Interim results from a phase 2 study focusing on brain metastases resulting from breast cancer found no evidence that the drug worked as hoped. Another phase 2 study for use of GRN1005 in treating brain metastases arising from non-small cell lung cancer couldn't find enough patients to enroll.

Employees at Geron received even more bad news. The company announced a restructuring as part of an effort to conserve cash.  This shake-up will result in 43 staff losing their jobs -- 40% of Geron's current workforce. The company plans to refocus on development of imetelstat, another cancer drug in its pipeline.

All by itself
Shares of Amarin (AMRN -1.43%) dropped over 21% for the week. The company announced that it was moving ahead on its own with a commercial launch of its triglyceride drug Vascepa. Management unveiled a "hybrid debt-like" deal with Pharmakon Advisers to raise $100 million to hire a sales force and market the drug.

Much speculation has centered on potential partners for Amarin. Most recently, rumors swirled about that Teva Pharmaceuticals (TEVA 0.63%) could be interested in buying Amarin. However, nothing has materialized with Teva (or anyone else) and the clock is ticking, so Amarin decided to go solo. 

Investors' hopes in an acquisition or partnership deal contributed to a nice run for Amarin over the last several weeks. With reality setting in that those deals might not materialize, some shareholders decided to bail out. 

Best to worst
Last on our horrendous list for the week is Acadia Pharmaceuticals (ACAD -1.47%). Shares for the biotech fell 13% over the past five days.

I doubt that many Acadia shareholders are shedding tears, though. Just last week, the company made our list of humongous performers of the week by jumping 137% in one day. That huge jump came after the company announced great results from its phase 3 study of pimavanserin in treating Parkinson's disease psychosis.

There really wasn't any bad news precipitating Acadia's slide this week. After more than doubling last week, a comparatively small pullback isn't surprising. 

Horrendous blip or trip?
My hunch is that two of the three stocks in this week's list of horrendous health-care performers are just experiencing a temporary blip. Amarin could be a buy after its big drop. I still wouldn't be shocked in the least if an acquirer or partner steps forward at some point in the future. Acadia seems positioned well, also. Assuming pimavanserin gains FDA approval down the road, shares should go well higher.

Geron, however, is experiencing a world of hurt. It could come roaring back from this week's devastation, but I wouldn't put my money on the line for that scenario playing out. A horrendous week could stretch into a longer period for this small biotech.