Cell Therapeutics (Nasdaq: CTIC) is one step closer to a Food and Drug Administration decision after announcing that a second independent radiology assessment confirmed the data for its cancer drug pixantrone that was in the first marketing application.

Whether the decision is a pop-the-bubbly approval or another complete response letter remains to be seen.

You'll recall the company threw up a Hail Mary pass after the FDA rejected the drug. Rather than run a new clinical trial, Cell Therapeutics went over the reviewers' heads to appeal the decision. The higher-ups at the agency didn't overrule the rejection, but they did agree that Cell Therapeutics could reapply after taking care of a few issues.

One of those concerns was with the first assessment by the independent panel of radiologists, so Cell Therapeutics repeated the data analysis with a second panel of three radiologists. The radiologists look at the scans without knowing whether the patient received pixantrone or another drug already on the market, and then they determine whether the non-Hodgkin's lymphoma patient responded to whatever treatment given.

According to Cell Therapeutics, the second analysis "confirmed the statistical robustness" of the efficacy data from the trial. That would be the same efficacy data that wasn't sufficient for approval the first time, although Cell Therapeutics hopes the agency will reconsider the statistical analysis that made the data insufficient.

The problem here is that there's no way for investors to know whether the higher-ups at the FDA have convinced the reviewers that they made the wrong decision the first time or whether Cell Therapeutics is painting a rosy picture of the potential outcome. Except for Gilead Sciences' (Nasdaq: GILD) Cayston, I don't know of any drugs that have entered the appeals process and exited a winner.

Approvals are never black and white, and that's further complicated by the fact that Cell Therapeutics' application is for an accelerated approval, a subjective process that allows drugs for unmet needs to be approved with less data. The Division of Oncology Drug Products takes accelerated approvals very seriously. It wouldn't even accept Roche and ImmunoGen's (Nasdaq: IMGN) T-DM1 application. At the advisory panel for Seattle Genetics' (Nasdaq: SGEN) Adcetris, there was a lot of talk of whether it qualified for accelerated approval and Adcetris' data was arguably cleaner than the data for pixantrone.

As I see it, buying shares in Cell Therapeutics is closer to gambling than investing. Admittedly a bet on Cell Therapeutics is akin to betting on a single number in roulette than it is betting on black or red; at a market cap of $220 million, the company has a lot more than a double in it if it can gain FDA approval. But at least with roulette it's easy to calculate your chance of hitting it big.

Fool contributor Brian Orelli holds no position in any company mentioned. Check out his holdings and a short bio. Motley Fool newsletter services have recommended buying shares of Gilead Sciences and Immunogen. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.