In the mean time, my working hypothesis is that each drug company to which IPT was disclosed dropped the idea for the simple reason that it did not fit in with their business model. IPT is a method, not a new drug, and so is difficult to convert into cash flow. And a reduction of drug dose commonly used in IPT could be temporarily disruptive to drug markets and might affect short term profits. The easiest path was to just walk away from IPT and forget it. This is understandable.
Pharmaceutical companies exist to bring profits to their shareholders.
And in current financial markets, companies are especially focused on short-term profits. But pharmaceutical companies also have a responsibility to the human race, of which their employees and stockholders are members. It is possible that 75 years of ignorance of IPT has cost humanity trillions of dollars and millions of lives. Comparable to the effects of a major war. Conversely, it is possible that IPT research and widespread implementation could earn humanity trillions of dollars of shared wealth, and save millions of lives.