Momenta Pharmaceuticals (Nasdaq: MNTA) registered its second year of profitability last year. The biotech brought in $283 million in revenue last year, and since its partner Novartis (NYSE: NVS) covers the sales and manufacturing of enoxaparin -- their generic version of Sanofi's (NYSE: SNY) Lovenox -- most of that revenue trickled through to the income line. The company had an operating margin of 63%, which is pretty impressive even for a drugmaker.

Too bad all good things must come to an end.

Momenta and Novartis' enoxaparin became a blockbuster generic -- literally, it sold more than $1 billion in a year -- because Lovenox was already a multibillion-dollar drug and the duo had no competition for 18 months. Recently, though, Sanofi launched an authorized generic, and Watson Pharmaceuticals (NYSE: WPI) and Amphastar launched their version of enoxaparin.

That's a triple whammy for Momenta, losing market share and pricing power as a monopoly. Plus, its agreement with Novartis shifts from a profit share to a royalty.

Since the launch of the second generic just occurred, Momenta wasn't willing to ponder a guess as to how much in royalties it might get from Novartis this year. The only guidance was that it expects to report a net loss in the second through fourth quarters of next year. In the first quarter, Momenta plans to close its deal with Baxter (NYSE: BAX) to develop biosimilars, which will result in a $33 million upfront payment.

While Momenta is back to its losing ways, it's not in quite as bad a shape as your typical development-stage drugmaker since it will have royalty revenue coming in to cover some of its expenses. And with the Baxter payment, Momenta plans on exiting the first quarter with $400 million in the bank, which should give it a nice runway to get another drug approved, hopefully before needing to go back to the markets to raise more capital.

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