With the SPDR S&P Biotech Index up 44% over the trailing-12-month period, it's evident that investment dollars are willingly flowing into the biotech sector. Keeping that in mind, let's have a look at some of the rulings, studies, and companies that made waves in the sector last week.

With earnings absolutely packing this week full of big gainers and losers, and me not wanting to bore you with a laundry list of earnings reports, I've chosen a mix of five non-earnings-based movers this week that stood out from the crowd.

What's popping
As always, let's start off with the week's most exciting positive stories. There can be little question this week that the most intriguing news has to go to Geron (GERN -0.29%), which soared more than 100% at one point after reporting positive study data on investigational myelofibrosis drug, imetelstat. According to the 18-patient Mayo clinic study, 44% of patients experienced clinical improvement, partial remission, or complete remission of the disease, which affects a patients' bone marrow and subsequent production of red blood cells. It's probably a bit too early and too small of a study to get overly excited about imetelstat, but Geron is certainly back on the radar when it comes to exciting new pipelines worth watching. Shares finished the week higher by just 17%.

On Tuesday, shares of Keryx Biopharmaceuticals (KERX) also jumped when it reported that experimental drug zerenex met both its primary and secondary endpoints in a mid-stage study of non-dialysis dependent chronic kidney disease patients with elevated serum phosphorus and iron deficient anemia. The co-primary endpoints in this trial were statistically significant changes in serum phosphorus and transferrin saturation while the secondary endpoint included increasing ferritin and hemoglobin and decreasing fibroblast growth factor-23. There were also far fewer people removed from the study in the zerenex arm relative to the placebo, so this was all around a positive for Keryx's kidney drug. Shares rose by 22% on the week.

Rounding out the positives for the week, and the only non-clinical story to speak of, was anti-obesity drugmaker Arena Pharmaceuticals (ARNA) which expanded its licensing deal with partner Eisai for weight control management drug Belviq. According to the new deal, Arena will receive $60 million upfront and Eisai will have global marketing rights with the exception of South Korea, Taiwan, Australia, Israel and New Zealand. Although sales of anti-obesity drugs have been disappointing thus far, having a pharmaceutical juggernaut like Eisai at its disposal, as well as having Belviq boasting a more favorable safety profile, should give Arena an opportunity to outrun VIVUS' Qsymia.

What's dropping
It certainly wasn't a perfect week for shareholders of Curis (CRIS 0.54%), which saw their stock tumble 30% this week after providing an update on early stage cancer drug CUDC-427. According to the company's press release, CUDC-427 was placed on a partial clinical hold by the Food and Drug Administration after a patient with breast cancer metastatic to other organs of the body, including the liver, died a month after discontinuing CUDC-427 because of liver complications. Ultimately, this could be a poor case of coincidence where CUDC-427 played no role in this patients' passing, but it nonetheless will require Curis to supply the FDA with safety data prior to its ability to continue ongoing early stage trials of the drug.

Also getting the ax this week was targeted-antibody payload developer ImmunoGen (IMGN), which sank 16% after announcing on Tuesday the discontinuation of a mid-stage study for IMGN901 for the study of small cell lung cancer. According to the press release, ImmunoGen, following the recommendation of the independent Data Monitoring Committee, shelved its study after the DMC suggested that there was unlikely to be a statistically significant benefit for IMGN901 with etoposide/carboplatin (E/C) than the combination of E/C by itself. The good news is that there are more than a dozen other ongoing clinical trials to make up for IMGN901's loss, but it does take the company's most advanced wholly owned experimental cancer therapy out of the mix.