Trying to knock off an orphan drug for rare maladies isn't the easiest feat. But with cheaper manufacturing and a marketing machine in partner Pfizer (NYSE: PFE), Protalix BioTherapeutics (AMEX: PLX) might have a shot.

That is if it can get Food and Drug Administration approval.

The agency is set to make a decision on Protalix's Uplyso on Friday. Of course, that's assuming the decision doesn't get delayed again.

There's little doubt that Uplyso works. It passed its phase 3 trial and the FDA has already signed off on the clinical trial design with a Special Protocol Assessment.

It's the manufacturing of Uplyso that makes it both interesting and a little risky.

The drug is produced in plant cells, which makes it cheaper to make than competing Gaucher disease treatments: Cerezyme from Genzyme (Nasdaq: GENZ), soon to be sanofi-aventis (NYSE: SNY), and Shire's (Nasdaq: SHPGY) Vpriv. Pricing the drug lower than competitors could help persuade patients to switch from their current medication.

There's a downside to the novel manufacturing system: It causes a bit of uncertainty with gaining FDA approval. Unfortunately, these things are a bit of a black box for investors. Unlike clinical trials, investors aren't usually privy to exactly what issues the FDA might have with the manufacturing techniques.

We do know that the previous delay was tied to the "validation of the manufacturing process." Whether Protalix has satisfied the FDA with additional information is a bigger unknown.

With a market cap under $800 million, Protalix has room to run if the company can get Uplyso approved and use its manufacturing techniques to develop other protein-based drugs. Just realize that you're investing without being able to see the full landscape.

That's my take. Let us know what you think by taking our Motley Poll and then explain your reasoning in the comments box below.

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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.