On the surface, sanofi-aventis' (NYSE: SNY) oral multiple sclerosis drug teriflunomide looks like a hit.

Below the surface? Who knows; the top-line result is all Sanofi gave us. In an announcement today, the company said teriflunomide met its primary goal of reducing the annualized relapse rate compared to placebo. But given that there were only four sentences of non-background information, that's about all we know. We'll know more once the full data set is presented at a scientific meeting in October.

Sanofi is behind Novartis (NYSE: NVS) and Merck KGaA in the hunt to bring the first oral multiple sclerosis drug to market. Novartis has already gotten a thumbs up for its drug Gilenia from the advisory panel and should hear back from the Food and Drug Administration in September. Merck KGaA's recently submitted application was given a priority review, which means it could hear back from the FDA near the end of the year.

Being third or even fourth to the market isn't disastrous, in this case. The current offerings from Biogen Idec (Nasdaq: BIIB), Elan (NYSE: ELN), EMD Serono and Pfizer (NYSE: PFE), Merck KGaA, and others have to be injected or infused. There's plenty of market share up for grabs for drugs that work as well as the current offerings, but don't require needle pokes.

Plus, Novartis' and Merck KGaA's drug both have side effect issues that probably won't keep them off the market, but could make them vulnerable to competition. In its press release, Sanofi said that both doses of teriflunomide had "similar number" of adverse events compared to placebo. That certainly sounds positive, but we'll have to wait until the full data is released before we know exactly how similar they are.

Today's announcement appears to be positive for Sanofi and potentially negative for Novartis and Merkc KGaA, but until we see the full data set, it's a little hard to get all that excited.

Matthew Argersinger is excited about this one; excited about how bad it's doing, that is.

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool has a disclosure policy.