A drug patent is filed upon initial discovery of the molecule, often a decade before the development and clinical trials have been completed.
Early on in that molecule's lifespan, the NPV is low. It has to pass safety testing, demonstrate efficacy, and then pass large-scale testing, usually in head-to-head competition against the current standard of care. NONE of that research is funded by public entities; the pharma companies take those expenses on themselves.
If the molecule makes it to and through Phase III testing, the pharma company has to decide whether to pursue a submission and launch. Perhaps a billion to a billion and a half dollars (sometimes more) have been spent up to this stage, over 10-12 years' time.
So the pharma company submits to the FDA, and asks for approval. Are you suggesting that at this stage, the government steps in and buys out the patent? What could the government possibly offer at that point? What incentive is there to continue to operate in a model like this--ALL the risk is on the pharma company for pursuing medicines of their choosing.
It amazes me that the FreeRepublic community purports to be a freedom-loving, small government, keep-your-hands out of my business, pro-capitalism group. But when it comes to healthcare, posters like you embrace socialism like there's no tomorrow.
Keep in mind that any purchase of a patent by the HHS would have to cover all the costs you've outlined ... and would have to account for the financial value of the patent to the pharmaceutical company based on years of sales. In other words, it would function no differently than an eminent domain case where a government is obligated by law to compensate the property owner for the fair market value of the property.
Interestingly, the process here wouldn't be much different than what the government (as I understand it) typically does when dealing with vaccinations for serious diseases. All the standard regulatory processes, product liability concerns, and patent protocols go out the window if XYZ Pharmaceuticals develops a vaccination that shows promise against a deadly disease like Ebola. The government invariably ends up paying a lot of money to XYZ Pharmaceuticals because of the obvious public health interest.