It is time that we experienced a tale of failure. As I have stated repeatedly, most drug discovery efforts fail. Choice of the wrong target dooms the effort from the start. Screening may fail to turn up actives, and molecular design may do no better. Given active molecules, medicinal chemistry efforts to improve properties may fail. Senior management’s heavy hand may terminate a promising effort. If one gets as far as development, a safety or efficacy issue may derail the project. Then, too, competitors may outrun you or financial support may dry up. There are many ways to fail, not so many to succeed. All five stories told so far have been successes: finasteride, ACE inhibitors, statins, imipenem/cilastatin, and the avermectins. Chapter 12 provides another example of a success: the gliptins. In this chapter, however, I pull together the threads of a failure: fludalanine. It is the most interesting failed drug discovery story that I know. There is much to learn from it, particularly about problem solving. It has a couple of surprises. By way of background, Merck had set its mind on finding an effective orally active antibiotic, driven in substantial part by the insistence of Max Tishler, Merck’s determined head of research. Orally active antibiotics are attractive. A patient with a bacterial infection may be treated in the hospital with an oral or a parenteral agent, one given by injection or inhalation. An injectable antibiotic may be given intravenously, intramuscularly, or subcutaneously. However, when the patient has been released from the hospital and sent home, it is convenient to have an antibiotic that can be taken by mouth, a tablet or capsule, for continued action against the infection. Ideally, an antibiotic should be available in both a parenteral (intravenous, intramuscular, or subcutaneous) formulation and an orally active formulation. In this way, the patient can be maintained on the same antibiotic when returning home from the hospital. Merck was having trouble meeting its objective.
An orally active formulation of angiotensin-(1-7) produces an antithrombotic effect
