In conjunction with its third-quarter earnings, Biogen Idec (NASDAQ:BIIB) management held a conference call to discuss the results from the third quarter and its future prospects. Here are the top five things management said on its earnings call.

We would like to inform you that we have confirmed the case of PML in a patient being treated with Tecfidera. -- George Scangos, CEO of Biogen Idec

Put this first one into things management might not want you to know. But, of course, they couldn't keep it from investors, because drug side effects are material to the biotech.

PML, or progressive multifocal leukoencephalopathy, is a potentially deadly brain infection caused by a relatively benign virus that can become active in patients with weakened immune systems. Tecfidera causes lymphopenia, or low lymphocytes, the white blood cells responsible for fighting infections, so it's not all that surprising that a patient eventually developed PML.

Given the plausible explanation because of the known side effect, it seems unlikely that this single case of PML is likely to have much of an effect on patients starting Tecfidera. It could increase the discontinuation rate in patients developing lymphopenia, but we won't know that for at least a few quarters.

In a market where oral therapies are growing rapidly, our interferon franchise saw 2% year-over-year revenue growth."-- Stuart (Tony) Kingsley, executive VP of global commercial operations

Tecfidera's growth has been amazing, which wasn't all that unexpected given the data and the fact that it can be taken orally. But many people thought the drug would cannibalize sales of Biogen Idec's other multiple sclerosis drug, Avonex, and hamper growth of recently approved Plegridy.

But sales of the two interferons, Plegridy and Avonex, actually increased a little year over year. Investors really can't ask for much more.

So I think it's pretty clear that the majority, the vast majority is going to be existing prophy patients. -- Kingsley

Biogen Idec's recently approved hemophilia drugs, Alprolix and Eloctate, are off to a good start with sales of $25 million and $21 million respectively in the third quarter. As Kingsley said, most of those initial sales have come from patients who were taking other medications as prophylactic (prophy) therapies because Biogen Idec's drugs offer fewer infusions.

To really grow sales, the biotech will need to convince hemophilia patients who are taking drugs on an as-needed basis to convert over to Alprolix and Eloctate, but that will take time.

We're also looking into gene therapy as a possibility to extend the franchise in hemophilia. -- Douglas Williams, executive VP of R&D

Speaking of taking time, we just jumped quite a few years, maybe a decade, perhaps more. But when it comes to drug development, companies need to be thinking that far in advance. Biogen Idec recently hired gene therapy expert, Olivier Danos, so the disclosure wasn't all that surprising.

While it's not something that's going to happen overnight, investors should keep an eye on Biogen Idec's foray into gene therapy. The technology is more developed than it was a decade ago, but all the technical difficulties have not been worked out quite yet.

As we move into 2015, we'll probably open and look toward figuring out what's the best way to return capital to shareholders as the cash flow continues to generate. -- Paul Clancy, CFO and exeutive VP of finance

Biogen Idec is sitting on more than $3 billion in cash and equivalents. It lowered guidance for business development expenses, but management said that was mostly due to timing of deals; they aren't actually cutting back on licensing and acquisitions.

I wouldn't expect to see a dividend anytime in the near future, but Biogen Idec might increase its share repurchases as cash flow increases. If it can't find any drugs to buy or license, share buybacks are certainly preferable to sitting on the cash.

Brian Orelli and The Motley Fool have no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.