With the SPDR S&P Biotech Index up 40% 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.

Yet again, this week was absolutely dominated by earnings-driven events. Given that we at the Fool have covered many of these stories already this week I want to instead focus on five non-earnings driven events that caught my attention.

As I prefer to always start you off with the good news, let's turn our attention to Celgene (CELG), which, on Friday, announced that the European Commission had approved its oral relapsed and refractory rare blood cancer drug pomalidomide in combination with dexamethasone. Celgene will be launching the drug in Europe under the trade name Imnovid, and it'll be used in cases where patients have tried at least two previous cancer therapies. In late-stage trials, Imnovid delivered progression-free survival of 15.7 weeks, which was a dramatic improvement over the placebo. Worldwide peak sales estimates for the drug are around $1 billion, so this is certainly a good start.

On Monday, small-cap biotechnology company Compugen (CGEN 4.76%) gave investors something to cheer about when it announced a collaboration and licensing agreement with Bayer for two of its antibody-based immunotherapies. The deal could be worth as much as $540 million for Compugen and gives the company $10 million upfront, as well as the potential for $30 million more in milestone payments during preclinical trials. The two companies will co-develop these drugs, with Bayer getting worldwide rights upon commercialization (though Compugen would still receive a mid- to high-single-digit royalty). This is great news for Compugen, as it solves the problem of seeking out a partner later, helps reduce its clinical testing costs, and staves off the need to dilute shareholders with a secondary offering to raise cash. Shares added 44% this week.

But as you might imagine, not all news this week was good. Although Isis Pharmaceuticals' (IONS 1.88%) share price hardly moved, it delivered disappointing news on Monday that ISIS-CRPrx failed to demonstrate a statistically significant improvement in inflammation reduction as compared with the placebo in a mid-stage rheumatoid arthritis trial. Isis noted that its drug did cut the C-reactive protein by 67%, but it was done in by an exceptionally strong performance by the placebo. Isis will still be researching CRPrx for other indications. However, as I noted earlier this week, having 31 potential sources of revenue as well as 12 ongoing collaborations, I'd suggest Isis is in much better shape than investors realize.

The end of the week didn't bring good tidings for shareholders of Novo Nordisk (NVO 2.70%), which, according to a report from BioCentury, received a second complete response letter (i.e., a rejection letter) from the FDA for its recombinant Factor XIII therapy to treat a form of hemophilia. According to the report, the rejection is based on unresolved issues at Novo Nordisk's manufacturing facility and merely adds to a series of struggles the company has had with regard to advancing its hemophilia-related pipeline. As you might expect, Novo Nordisk is working with the FDA to resolve this issue as quickly as possible. 

Finally, off in its own world this week is Onyx Pharmaceuticals (NASDAQ: ONXX), which purportedly has received a $130-per-share buyout offer, or $9.5 billion, from Amgen, as Reuters reported earlier this week. According to people familiar with the matter, Onyx is still exploring interest from other suitors, but it may be interested in accepting Amgen's offer, which is $10 a share higher than its original offer roughly six weeks ago. This news comes on the heels of Onyx's second-quarter results, which showed losses were halved to just $53 million and revenue more than doubled to $153 million. If Onyx accepts the deal at $130 per share, I'd suggest Amgen is still getting itself a decent bargain.

Editor’s Note: A previous version of this article incorrectly stated that Novo Nordisk’s CRL was for its recombinant Factor VIII therapy instead of Factor XIII. The Fool regrets the error.