Sabrina Martucci Johnson
Management
Yes, that's a great question and thank you for that. So, as we think about a trial size for product like Ovaprene, the first thing to keep in mind is that Ovaprene because of its nature, given that it's a non-hormonal product with -- it's a combination product with the barrier component as well as release a locally acting spermiostatic agent. The FDA has determined that the device division of the FDA should leave the review of this product, because in terms of the safety consideration it's much more analogous to other types of non-hormonal products at the agency on the device side is accustomed to reviewing as opposed to hormonal products that typically the drug side of the agency used to reviewing. And that's really important because that likely will really influence what the pivotal study would look like. So, to be clear, in terms of a next step if the PCT is successful, the next step will be to file our investigational device exemption with the FDA to commence that pivotal clinical trial, and that really is an important step and also us engaging with the agency around the design of the pivotal study. However, even in advance of that we can give you a sense of what we think that pathway may look like really based on similar approvals and reviews that have been done through the device division of the FDA for contraceptive products. And specifically, we can look at the Caya diaphragm, which is the most recently-approved product to be reviewed by that division of the FDA. It is s diaphragm, so it's a peri-coital method, meaning it's used on demand in the moment as opposed to Ovaprene, which is once a month, but we believe that nonetheless, given that it's the most recent product to go through the FDA that it's a good surrogate for us to look at in terms of expected pivotal stage design. And so, based on those prior reviews by the device division, it's typically one pivotal study, so one contraceptive effectiveness study. They typically are six months in duration, where they're looking at rates of pregnancy over the course of that six months, and often they've had about 250 subjects make it out to that six months time point based on dropout rates that are typical in contraceptive studies, you're often maybe enrolling closer to 450 or 500 women that to get out to that about 250 completers at six months. So that's our preliminary thinking about what the pivotal study should look like, and the plans would be based on the timeline we talked about today, our expectation would be that would start in 2020 and run through 2021, putting us in a position to file in '22 for an approval in '23, based on our current expectations.