This Week in Biotech: Gilead Sciences, Inc. (GILD), GlaxoSmithKline plc (ADR) (GSK)

With the SPDR S&P Biotech Index up 31% 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.

For a second week in a row we were privy to a little bit of everything: FDA panel reviews, new clinical data, detailed FDA updates, buyout rumors, and even snowstorms.

On Monday, Depomed Inc (NASDAQ:DEPO) announced that the Reproductive Health Drugs Advisory Committee was recommending against the approval of its hot-flash drug, Sefelsa, with 12 of 14 members ushering in a thumbs-down. The negative ruling wasn’t a huge shock, as Sefelsa didn’t meet its primary endpoints in the first two clinical trials and had what I deem an abnormally large number of patients drop out of all three trials. In the meantime, DepoMed plans to completely abandon all spending and research on Sefelsa unless it appears the drug has a good shot at gaining approval. Shares dipped by 9.5% this week.

Gilead Sciences, Inc. (NASDAQ:GILD)Gilead Sciences, Inc. (NASDAQ:GILD) continues to churn out nothing but fantastic news with its experimental oral hepatitis-C drug, Sofosbuvir. In a mid-stage combination trial with Johnson & Johnson (NYSE:JNJ) and Medivir‘s Simeprevir, the combo cleared all detectable levels of the virus in 100% of genotype 1 patients — the most common form of hepatitis-C. With no adverse events reported, Sofosbuvir once again proved to the biotech community that it could be the standalone and combination drug of choice in oral hepatitis-C care.

Pharmaceutical company Impax Laboratories Inc (NASDAQ:IPXL) was crushed on Tuesday, after it provided an update to investors regarding the FDA’s complete response letter on idiopathic Parkinson’s disease drug Rytary. According to the update, the FDA cited 12 points of concern with its Hayward, Calif., facility, of which three were repeat violations from a warning letter sent to the company in 2011. What this means for Impax is longer delays in attempting to rectify these problems and probably another nine months to a year before Rytary goes before the FDA for a third time. Shares fell nearly 17% on the week.

Finally, Theravance Inc (NASDAQ:THRX) and GlaxoSmithKline plc (ADR) (NYSE:GSK) had an exciting start to the week that ended more with a whimper than a bang. Earlier in the week, speculation arose from comments made by Piper Jaffray Companies (NYSE:PJC) that GlaxoSmithKline plc (ADR) (NYSE:GSK) may look to purchase Theravance if the two get FDA approval for their multiple COPD treatments currently under FDA review. I’d hardly call it speculation, as I called the potential for a hook-up of these two a distinct possibility in January. However, the week ended with a flameout rather than a bang, as their FDA panel meeting for their long-term COPD treatment Breo Ellipta was cancelled just days before a snowstorm was expected to strike the East Coast. No new FDA panel meeting date has been set as of yet.

The article This Week in Biotech originally appeared on Fool.com and is written by Sean Williams.

Fool contributor Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.The Motley Fool owns shares of Johnson & Johnson and recommends Gilead Sciences and Johnson & Johnson.

Copyright © 1995 – 2013 The Motley Fool, LLC. All rights reserved. The Motley Fool has a disclosure policy.