Nearly every large-cap pharma is attempting to deal with the prospect of generic competition for its top drugs, and Sanofi-Aventis (NYSE:SNY) is no different. Its $3-billion-a-year blood thinner, Lovenox, is potentially facing generic competition as early as next year.

To help fill the void left by the loss of patent exclusivity on its top drugs, Sanofi has rapidly been ramping up sales of its Ambien insomnia treatment franchise, as well as trying to bring to market its weight-loss drug, Acomplia.

On Friday, Sanofi announced that the FDA has set April 26 as the new date to review Acomplia and give Sanofi a thumbs-up or -down on marketing it in the U.S. Back in February, the drug received an approvable letter for its weight-loss indication and was deemed non-approvable as a treatment to help people stop smoking.

Acomplia was approved in the European Union back in late June, but the U.S. is where the big money is, especially now that France and Germany have been enacting new measures such as higher taxes on drug sales and rules to encourage doctors to prescribe cheaper prescriptions or generic drugs.

Since the limited launch of the drug in the EU in the third quarter, Acomplia sales have been roughly $15 million. But sales should increase much faster as Sanofi gets the word out about Acomplia via marketing and other measures.

Earlier in the week, Sanofi released results from a medium-sized (278-person) phase 3 study that showed Acomplia improved blood sugar levels as well as helped with weight loss for patients with type 2 diabetes. According to the trial's investigators, this is important because Acomplia works differently than other drugs for the disease, which sometimes promote weight gain. While this trial is insufficient by itself for Acomplia to receive a label expansion in type 2 diabetes, it's another good proof-of-concept study in this billion-dollar indication.

The positive Acomplia study results aren't the only good news this week for Sanofi. A judge upheld an injunction stopping Apotex from selling its generic version of Sanofi's Plavix pending the results of a patent trial, which is expected to begin in late January. This doesn't lessen the risk that the Plavix patent will be overturned at trial, but at least Sanofi will keep exclusivity until the trial ends.

With the future of Sanofi's two top drugs, Plavix and Lovenox, in the hands of the courts, plus any Acomplia approval subject to the whims of the FDA, I'd wait on the sidelines until these judicial and regulatory decisions have been made.

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Fool contributor Brian Lawler does not own shares of any company mentioned in this article. The Fool has a disclosure policy .