Anthera Pharmaceuticals (Nasdaq: ANTH) could be a 36-bagger from here. Maybe more.

The company currently has a market cap around $100 million; Human Genome Sciences, which owned half of its lupus drug Benlysta, was taken out by GlaxoSmithKline (NYSE: GSK) for $3.6 billion. Anthera still owns the full rights to its lupus drug, blisibimod, although Human Genome's pipeline was arguably better than Antera's. Half a drug probably outweighs a weak pipeline, but let's call it a potential $3.6 billion valuation.

Of course, it could also be worthless. We are talking about a potential new treatment for lupus, after all.

It's notoriously hard to prove that a drug is effective in treating lupus. Before Benlysta was approved, there was a 52-year drought in the approval of drugs specifically developed for treating the disease. Not that companies didn't try; drugs from Biogen Idec (Nasdaq: BIIB), Teva Pharmaceutical (Nasdaq: TEVA), BioMarin Pharmaceutical (Nasdaq: BMRN), and many others all failed to show that they were effective in lupus patients. The waxing and waning nature of the disease makes it hard to measure whether a drug is working.

Anthera ran into that problem with its phase 2 trial for blisibimod. The drug only showed a substantial effect in the most severe patients using the most stringent measurements for improvement of patients' symptoms.

So that's what Anthera is going with. Its two phase 3 trials will enroll patients with severe lupus that haven't improved using corticosteroids. The primary endpoint will be the percent of patients that improved at least eight points or more on the Systemic Lupus Erythematosus Response Index, or SRI, which measures patients' symptoms.

I think there's a good chance that blisibimod works, but proving it won't be a walk in the park. In the phase 2 trial, 26% of the pooled placebo patients reported an eight-point increase in their SRI score. That's an awfully large -- and likely awfully variable -- placebo effect that blisibimod needs to overcome.

Despite the potential, investors are right to discount the stock substantially given the potential risk. Invest if you like the thrill of potential monster returns, just keep it to a small percentage of your portfolio.

If you want less risky stocks for the rest of your portfolio, Fool analysts have identified these three companies as appropriate for a smart retirement. Find out what they are and why analysts like them so much in the free report, "3 Stocks That Will Help You Retire Rich." Click here now to claim your free copy today.