per management the reason they didn't pursue an SPA at the outset is it woudl likely have committed them to a 2 year exposure of drug, similar to the standard set for SERMs. with the holiday periods this translates to about 2.5 years trial duration. i think rprx is going to try and argue that the standard shouldn't apply to proellex given the holiday periods and fact endometrium is refreshed, particularly if they have a couple cycles to show there is no residual drug effect on biopsies during the drug-free interval..clinically this is reasonable, but its not clear to me the FDA will allow the company to forgo this current 2 year safety requirement, but i think rprx didn't want to be backed into a corner ahead of time with an SPA, but rather come to the FDA with some reassuring biopsy data in hand to negotiate this point
just a guess..