James Bertram Collip, a talented biochemist, was included in the team to produce the required extracts and particularly to optimize its production procedure. He thoroughly reworked the experimental procedures and discovered that the active principle of the extract was still soluble at high ethanol concentrations, which enabled precipitation of other proteins. At an ethanol concentration of 90 %, the active principle itself would precipitate, which enabled an effective purification protocol. Resuspension of the precipitate yielded the desired material. He also developed a more practical activity test, which relied on injecting an aliquot into a vein in a rabbit's ear, avoiding experimentation on pancreatectomized dogs. At the time, one unit of insulin was defined as “the amount of insulin required to reduce the concentration of blood glucose in a fasting rabbit weighing 2 kg to the convulsion level of 45 mg/dL (2.5 mmol/L).” Later, after the structure and molecular weight of insulin were determined, the earlier definition was replaced by one unit of insulin being defined as the “biological equivalent” of 34.7 μg pure crystalline insulin, still relating to the pharmacological effect of insulin on the initially used rabbits. The definition of a unit of insulin is still relating to these criteria, whatever the derivative or its molecular weight is considered.
The first type I diabetic patient was treated on 11 January 1922, less than eight months after the initial research was started. Injection of 7.5 mL of extract led to a marked, but temporary decrease of blood glucose and a significant reduction of excreted urinary glucose. No reduction of ketone bodies was noted. A sterile abscess developed at site of injection, likely resulting from remaining impurities of the extract. These results, albeit clearly far from optimal, spurred further research, and the next months were characterized by extensive production of material and further clinical testing. When treating the same patient on 23 January 1922 with a new extract carefully produced by Collip, a marked drop in glucose from 520 to 120 mg/dL was observed. Ketone bodies disappeared and the physical state of the patient improved significantly. Six more patients were treated in February and in March of that year an initial report on the clinical experiments was published [84].
The scientific success was clouded by a strong argument between the researchers. Banting felt early on that the more established and experienced Macleod would try to steal his original idea and claim the discovery as his own success. He believed that Macleods' contributions were not significant and that his comments discouraged rather than encouraged Banting's research. He felt that the discovery of insulin was derived only through Best's and his own work. There was also some dispute about the value of the contributions of Collip, who, annoyed by the team atmosphere, announced that he would consider leaving the project and filing an individual patent on the purification procedure of insulin. It is reported that he and Banting even got into a physical fight over the project.
In the end, Banting and Macleod received the Nobel Prize for the discovery of insulin in 1923. Best and Collip were not included. The Prize was presented on 10 December 1923, less than 19 months after the group started their research. To this day, Banting remains the youngest Nobel laureate, being only 32 years of age when he received the Prize. Banting, upset with having to share the Prize with Macleod, initially wanted to reject the Prize but changed his mind later. He shared his monetary award with Best, as Macleod did with Collip. The decision of the Nobel committee also suffered criticism by other scientists, who had made important related discoveries before. In the case of insulin, particularly Georg Zuelzer [85], Ernest Scott [86], and Nicolas Paulescu [87] protested, but their contributions remained unacknowledged.
The discovery of insulin, albeit achieved many years ago, can still serve as a characteristic example of academic drug discovery. Clearly it began as an idea of an enthusiast, who was inspired by an ingenious thought and also clearly was not yet an expert in the research area he was about to enter. “Too much reading of the literature is inadvisable for wide diversity of opinion and confusion of thought” is a citation being connected to Banting. Also, the associated rivalry between the individual researchers is one point frequently observed particularly in academic settings. Necessarily, successful drug discovery is an interdisciplinary endeavor and calls for involvement of multiple experts willing to contribute their individual knowledge. Discussions on significance of individual contributions, e.g. reflected by debating first and last authorships, will poison the team spirit and easily compromise the joint research effort. It may even put the project as a whole at risk of a premature end. Also, decisions of the Nobel committee tend to cause criticism, particularly today, as the general research fields are broad and the selected questions are complex. Normally many scientists contributed valuable insights. With a maximal number of three laureates to be nominated for a particular topic, it is within the nature of this award that many scientists will find their contributions unconsidered.
1.5.2 Rituximab
In 1975, César Milstein, University of Cambridge, and his postdoctoral fellow Georges Jean Franz Köhler [88] first described the generation of monoclonal antibodies from hybridoma cells. Their high specificity and strong affinity quickly suggested that this concept may very well be suited for drug development. This discovery earned both of them the Nobel Prize for Medicine in 1984.
In 1980, a surface antigen of B‐cells was described [89], which was isolated and further described and termed CD20 in 1988 [90]. CD20 is present on almost all differentiation states of B‐cells, except the immature ones, and found on cancerous as well as healthy B cells. A treatment targeting CD20 would accordingly eliminate all B‐cells, but the immature ones, which then could form a new population after treatment, is finished.
Lee Nadler at Dana Farber Cancer Institute in Harvard University described and cloned the first antibody targeting a cancer‐associated antigen called CD20. In a historic proof of principle study [91], he treated a first patient with this antibody. A transient response was observed, providing first evidence that targeting CD20 with monoclonal antibodies could be a viable therapeutic option to treat B‐cell lymphomas.
Shortly after, the technology of generating chimeric antibodies was established, representing another milestone in the establishment of antibody therapies. Scientists at the University of Toronto and Columbia University demonstrated [92] that it was possible to generate antibodies bearing the human Fc region and bearing the mouse variable region. These antibodies were significantly less immunogenic, thus improving therapeutic prospects significantly.
Ronald Levy at Stanford University discovered that B‐cell lymphomas were composed of monoclonal cell populations and, influenced by the work of Köhler and Milstein, he directed his research toward development of personalized monoclonal antibody therapy to target these lymphomas [93].
As early as 1982, a first patient was treated [94]. The promising results lead to formation of a start‐up company called IDEC, which later turned into Biogen. The approach of developing personalized antibodies turned out too laborious and costly, instead CD20 was selected as a selective B‐cell marker. As a direct result, rituximab [95], a chimeric monoclonal antibody targeted against CD20, was discovered. In the following clinical trial [96], tumor regression could be observed in about 50 % of the patients. This antibody represents a hallmark in the treatment of cancer and was the first antibody drug to be approved by the FDA for treatment of cancer in 1997. It was licensed to Roche and is used for treatment of various cancers like non‐Hodgkin's lymphoma.
1.5.3 Alglucerase
Gaucher's disease is a rare disease that affects about 1 in 70 000 newborn children. It is characterized by a significant enlargement of the liver and spleen, fatigue, anemia, and decreased pulmonary function.
Dr. Roscoe Brady, a scientist at the National Institute of Health, was an expert on glycolipid metabolism. He discovered that symptoms of Gaucher's disease resulted from a deficiency of one specific enzyme, called α‐glucocerebrosidase [97]. This deficiency results in a disability to process glucocerebroside, which causes accumulation of this sphingolipid in various organs and tissues. In following work, he proposed to isolate the enzyme and
