Momenta Pharmaceuticals (NASDAQ:MNTA) has had a rocky couple of days. Shares fell 22% last week, slashing $160 million from its market capitalization, after a positive patent litigation decision opened up the market to a generic version of Sanofi-Aventis' (NYSE:SNY) $3 billion blood-clot treatment Lovenox. Stock market movements like this are crazy, especially considering that shares weren't overvalued ahead of the court decision, and that the ruling was the first step in removing one of three roadblocks currently keeping Momenta from marketing a generic version of Lovenox.

Momenta announced its quarterly financial results yesterday, providing an update on the patent litigation front as well. Based on historical timelines, it expects Sanofi's appeal of the court ruling to take six to nine months. This has no effect on when the FDA will rule on its generic drug application for Lovenox.

If Momenta or other generic competitors like Teva Pharmaceuticals (NASDAQ:TEVA) get the go-ahead from the FDA before the appeals process is complete, they can always launch their version of Lovenox "at-risk" before the ruling is in. If they do, though, they'll be liable for damages if Sanofi subsequently wins in court

Speaking of which, Momenta expects to hear back sometime between now and August on whether it can market a generic Lovenox, based on its previous estimates of an 18-to-24-month review period for its Abbreviated New Drug Application. On the conference call, though, Momenta said that this was its own estimate of the review period length, not any sort of official FDA guidance, so there may be some degree of optimistic spin on this timeline.

In regards to its finances, Momenta expects cash burn in the range of $50 million to $60 million for 2007, which will leave it at year's end with $131 million to $141 million in cash. That gives it more than enough money to move anticoagulant drug M118 into phase 2 trials later in the year. Investors don't seem to be giving this early-stage compound much thought at the moment, but if the phase 1 study results are positive, this drug could be worth more than Momenta's generic Lovenox -- if it can make it to market.

With so much going on, the rest of 2007 is sure to be a wild ride for Momenta investors.

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Fool contributor Brian Lawler owns shares of Momenta but has no financial position in any other company mentioned in this article. The Fool has a disclosure policy.