We've got bonus tweets in this week's top biotech tweets -- eight for the price of five this week with multiple tweets on the same topic.

As a reminder, tweet me @BiologyFool if you have tweets you think are interesting enough to warrant a spot in the weekly top five. I can't see every educational and enlightening tweet.

Adam's right. There's little reason to bid up a company because it gained orphan drug status. Getting the designation is based on the potential of drugs to treat that specific disease than it is the specific drug's ability to be effective.

There were lots of tweets about shutdowns this week. As best I can tell, drugs that are already in process appear to be OK, but drugs that are about to enter the gauntlet might be delayed. The Food and Drug Administration even approved Pfizer and Ligand Pharmaceuticals' Duavee, their treatment for treating hot flashes.

That's good news for companies like Amarin and Gilead Sciences with advisory committee meetings this month. Of course, don't look for a press release from the agency about it; most of the FDA's press office is furloughed.

Achillion (ACHN) announced this week that the FDA was keeping its hepatitis-C drug sovaprevir on clinical hold because of issues with elevated liver enzymes in patients in its clinical trial. John, who used to work at BioMedTracker -- which keeps a database of events in the biotech industry -- confirms what I would have guessed: It's certainly not hard to impossible to get off a clinical hold, but it's pretty darn hard.

Companies on partial holds -- Vertex (VRTX -1.30%), for instance -- look like they have a much better shot at continuing development of their drugs. Vertex's hepatitis C drug, VX-135, also had issues with elevated liver enzymes, but the drug was only put on a partial hold because the problem was only seen at the higher dose.

GlaxoSmithKline (GSK -1.02%) and Prosensa (NASDAQ: RNA) are presenting data from their Duchenne muscular dystrophy drug, drisapersen. Years ago, you'd have to know someone at the medical conference to get the data. Now pictures of posters and slides are routinely posted on Twitter. Obviously, you should be careful trading on information if you're unsure of the source.

A good argument for investing in smaller biotechs compared to larger pharma companies.