Approvable isn't the same as approved, but it's close enough for a 60% gain in MELA Sciences' (Nasdaq: MELA) shares.

The company has been fighting for years to gain Food and Drug Administration approval of its melanoma detection device, MelaFind. After MELA applied to market the device in the middle of 2009, the FDA asked for more information in March 2010, and convened an advisory panel later in the year, where MelaFind barely squeaked by with a positive recommendation.

More than two years after its original application was filed, MELA announced this morning that it had received an approvable letter laying out five items that need to be completed prior to actual approval.

Even with the jump today, the shares are trading well below where they did before the advisory panel last year. Either investors are still worried about an approval or they think the market for MelaFind has diminished. I'd guess it's mostly the latter.

MELA CEO Joseph Gulfo wasn't willing to give an exact date on when he thought the company could wrap up the five issues with the FDA, but did say MELA was shooting for a U.S. commercial launch in the first quarter of next year. Three of the issues are just paperwork -- labeling and instructions -- that shouldn't be a barrier to approval. Neither should the training program that the FDA needs to sign off on.

That only leaves the protocol for a post-approval study. Assuming there's no outlandish request -- like Orexigen Therapeutics' (Nasdaq: OREX) 100,000-patient clinical trial -- investors needn't be all that worried about the post-approval study, either. Besides, it's a post-marketing trial, so MELA could always just agree to any outlandish demands by the FDA and then run the post-marketing trials really slowly. Slow clinical-trial progress for drugs already on the market helped Merck (NYSE: MRK) and Schering-Plough on the ENHANCE trial and cancer drugmakers including Amgen (Nasdaq: AMGN) and Bristol-Myers Squibb (NYSE: BMY).

On the commercial side, the prospects look slimmer after the FDA slapped a whole bunch of restrictions on the use of MelaFind. The device will only be used by dermatologists, which diminishes the potential practices that would buy the device. And doctors will have to be trained in its use, which, considering how busy doctors are, could be a hard sell for MELA.

The company is shooting for installing 200 systems in the first year of sales in the U.S. and another 75 during the first year of sales in Germany. I'm not sure those numbers are enough to get it to cash-flow positive, but if it can really install that many systems, it'll give investors confidence that dermatologists are willing to use this thing. Until then, MELA remains a risky investment even though an approval seems more likely than it did earlier this year.