With the SPDR S&P Biotech Index up 62% 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.

Just as in the previous weeks, this was another wild week for the volatile biotech sector. A quartet of bad-news items from the Food and Drug Administration and European Medicines Agency weighed heavily on a handful of companies, while two positive clinical trial results, an announced asset purchase, and a return of the buyout rumors for another struggling biotech stock attempted to even out the pessimism.

Today, we'll break a bit from tradition and focus on the five regulatory decisions that ruled the week to start, and in Part 2 of "This Week in Biotech," we'll examine those trials and deals that made headlines. First, though, let's have a look at the quartet of negative opinions and rejections that sent four companies lower at some point during the week, and end with one company that managed to get an A-OK from the FDA this week.

Misery loves company
Perhaps no rejection was more highly profiled this past week than that of the Food and Drug Administration's Division of Metabolism and Endocrinology Products, which on Tuesday declined to reinstate the Special Protocol Assessment for Amarin's (AMRN 3.28%) Vascepa in the ANCHOR trial. The news isn't a real shock for anyone who has been following Amarin's attempt to expand the uses of triglyceride-lowering drug, Vascepa, to a broader population with the FDA's panel concerned about long-term cardiovascular effects and efficacy of the drug. Because of this, Amarin is going to have no choice but to run a lengthy and costly cardiovascular outcomes study known as REDUCE-IT. Even if this trial turns out favorably, it'll still be three or more years before we know the results and Amarin will likely have used much of its existing cash on hand.

Joining Amarin in the corner with the dunce cap on is AMAG Pharmaceuticals (AMAG), which received a complete response letter (i.e., a rejection letter) for its supplemental new drug application for Feraheme. Currently, AMAG's Feraheme is approved to treat chronic kidney disease, but AMAG is seeking to expand its usage to all adult iron deficiency anemia patients. The FDA saw things differently, however, and noted that its trials didn't adequately establish the safety and efficacy of Feraheme for this expanded indication. The FDA's guidance to gain this all-adult IDA approval includes running additional trials that test for hypersensitivity/anaphylaxis and cardiovascular events, and trying out different dosing options and/or administration options. I doubt this is the last we'll see of Feraheme's sNDA, but we can probably move an adult-IDA indication to the back burner for the next year or two.

Jumping across the pond didn't help, either, with PTC Therapeutics (PTCT -0.77%) and even biopharmaceutical giant Novartis (NVS 2.32%) receiving negative opinions from the Committee for Medicinal Products for Human Use, or CHMP.

On Friday, PTC Therapeutics vacillated wildly after the CHMP announced a negative opinion on PTC's marketing authorization application for ataluren as a treatment for nonsense mutation Duchenne muscular dystrophy, or nmDMD. The move, though, wasn't a huge shock as PTC had been predominantly cautious about receiving the go-ahead to market its drug prior to completing its phase 3 nmDMD study. The results of that study are expected by mid-2015 with PTC anticipating a resubmission to CHMP sometime next quarter. While I would certainly prefer to wait for the broader-scale data here, any major sell-off may prove unwarranted on this negative opinion.

Similarly, Novartis' breakthrough therapy designated drug in the U.S., serelaxin, received no red carpet welcome in the EU with the CHMP also announcing a negative opinion on the acute heart failure drug. The CHMP noted that while there was some benefit in dyspnea (i.e., shortness of breath) relief over five days, clinical relevance could not be determined; nor could the effect of serelaxin within the first 24 hours. In addition, as FierceBiotech noted, the CHMP questioned the background treatments given to the patients in its acute heart failure study, and if that may have influenced the results. Although the European Medicines Agency isn't required to follow the opinion of its panel, the CHMP, it's looking very unlikely that an approval is around the corner and that further testing will need to be done if an EU approval is to occur. 

The lone bright spot
There was but one lone bright spot this week when it comes to regulatory decisions, and clinical-stage biopharmaceutical company CytRx (NASDAQ: CYTR) was the lucky beneficiary. On Tuesday, CytRx announced that it had been given the OK from the FDA to extend the dosing of aldoxorubicin for soft-tissue sarcomas in phase 3 trials until disease progression. Previously, the trial design was set up for just six treatment cycles then analysis. Clearly, if CytRx is being given the opportunity to extend dosing, the FDA must like what it sees from a safety perspective, and it could give CytRx an opportunity to really extend progression-free survival in its late-stage study. Despite the markets' rough week, CytRx ended it 3% higher.

In Part 2 of "This Week in Biotech," we'll examine two overwhelmingly positive clinical trials, a win-win asset development sale, and look at how plausible takeover rumors could be for one struggling biotech stock.