Professor Swerdloff's erudite exposition above is a hard act to follow. But I'm tempted to try with a recent discovery and quick favourite.
Before I began my course of Tamoxifen I did a lot of research into it. Dr Viviane Quirke's delightful history of the drug is a treasure that had me hooked after five sentences. I hope you'll like it too.
"Although designed to act as an anti-estrogen, the compound was found to stimulate, rather than suppress ovulation in women. This, and the fact that at first it could not be patented in the USA, its largest potential market, meant that ICI nearly stopped the project. If it was saved, it was partly because the team’s leader, Arthur Walpole, threatened to resign, and pressed on with another project: to develop tamoxifen as a treatment for breast cancer."
.And concludes,
"This (paper's) particular focus also throws into sharp relief the contribution made by applied research to the advancement of scientific knowledge: in the case of tamoxifen, more specifically to the understanding of basic physiological processes involved in human reproduction and malignant disease. Such a contribution is in part due to the fact that industry, perhaps more easily than academia with its rigid disciplinary boundaries, enables a to-ing and fro-ing between separate, yet contiguous research projects and therapeutic areas (in this instance, between contraception, fertility, and cancer). This to-ing and fro-ing between projects illustrates once again the non-linear nature of pharmaceutical innovation. Typified by blind alleys, fresh departures, feedback loops between the laboratory and the clinic, as well as serendipitous discoveries, the early history of tamoxifen brings to the fore the role of human agency, the institutional memory that is often associated with long-term investment in particular areas of expertise, and is embodied in individual researchers like Walpole".
Quirke VM (2017) Tamoxifen from Failed Contraceptive Pill to Best-Selling Breast Cancer Medicine: A Case-Study in Pharmaceutical Innovation. Front. Pharmacol. 8:620. doi: 10.3389/fphar.2017.00620