The same rule applies to whenever they sell the IP to. Whoever buys the IP should be legally obligated to continue the experiment as a condition of buying it. The alternative—putting the IP in the public domain—doesn’t do a lot for people who need active, ongoing support for a medical device, implanted in their body. I’d make a separate, stricter rule for that case. I don’t have a clear idea what that rule should be, though, because we can’t require a medical experiment to continue indefinitely if we want anyone to develop new medical devices.