With the SPDR S&P Biotech Index up 33% year to date, it's very 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.

For a change, and to get you in the spirit of the holidays, I have nothing but positive news to report this week. Keep in mind this was a holiday-shortened week, but it's definitely a nice way to kick off the holiday season for the biotech sector.

Perhaps the biggest news of the week came out of the anti-obesity sector, with Aetna (AET) announcing that it will begin coverage on VIVUS' (VVUS) Qsymia and Arena Pharmaceuticals' (ARNA) Belviq (once it makes it to pharmacy shelves in early 2013). This is potentially big news for two reasons. One, in VIVUS' case, roughly 30% of all Qsymia prescriptions at pharmacies aren't picked up because of the out-of-pocket costs associated with the drug, according to its chief commercial officer, Mike Miller. With Aetna now covering Qsymia, it might help invigorate what's been nothing short of a face-plant from VIVUS' supposed blockbuster thus far.

Aetna's move is also noteworthy because it might get additional insurers to follow in its footsteps and expand coverage on both Qsymia and Belviq. The key to huge revenue for these two is going to be garnering the favor of insurers. Belviq still has the clear path to becoming the first internationally approved anti-obesity drug, but this is definitely a positive step for both companies.

Regeneron Pharmaceuticals (REGN -0.84%), known best for its wet age-related macular degeneration drug, Eylea, made waves last week for a completely different reason. Both Regeneron and developing partner Sanofi (SNY -0.47%) announced that the Committee for Medicinal Products for Human Use (essentially the FDA panel of Europe) recommended granting marketing authorization for Zaltrap, an intravenous chemotherapy for adults with metastatic colorectal cancer, in Europe. Zaltrap is already approved in the U.S. and was shown in late-stage studies to boost median survival rates by nearly 1.5 months. Seemingly nothing can go wrong for Regeneron at the moment.

Rounding out the week, MAP Pharmaceuticals (NASDAQ: MAPP) soared after announcing that the FDA had accepted its resubmitted new drug application for its orally inhaled migraine medications, Levadex. In March, the FDA sent MAP its decisions to reject the drug not based on efficacy or safety, but because of factors related to its manufacture, chemistry, or control of the treatment. With that now seeming resolved, MAP's drug, which it's licensed out to Allergan (NYSE: AGN) within the United States, appears poised to receive an approval or denial decision by April 15. 

The market giveth; the market taketh away
Is Aetna's recent announcement of insurance coverage on Qsymia enough reason for physicians to begin prescribing the fat-busting drug, or are the tables still stacked against VIVUS? Find out the answer to this question and much more by getting your copy of our latest premium research report on VIVUS. Packed with in-depth analysis on the opportunities and threats facing VIVUS -- and complete with a year of regular updates -- this report will give you the tools needed to make smart long-term investing decisions. Click here to learn more.