We don't know the long term safety data on squalamine because it has not been used on a long term basis yet. With macular degeneration patients, it will probably have to be used for months or years, and may have to be used on a recurrent basis, as there is no promise that one incidence of AMD won't be followed by another at some point months or years later.
Of course, there is no proof that squalamine can't be safely administered for years on end. The question is what the FDA wants to see before they approve the drug. I think we can all agree that there is not enough data for GENR to submit an NDA to the FDA any time soon. They need data from a Phase III clinical trial before they can even think of that.
The "speculation" about the long term safety of squalamine is just that, speculation, as there is no long term data to make a judgement either way. The other aspect of this speculation concerns what the FDA thinks about long term safety issues. I am betting that the FDA does not like going before Congress and trying to explain why they didn't pull Vioxx from the market before Merck decided to do so.
Comparing the acceptable limits of toxicity for squalamine in cancer trials to that in AMD is a non-issue, because the acceptable side-effects for cancer drugs are beyond the pale for almost any other medical indication.