Willem Stemmer

Willem P. C. "Pim" Stemmer Resident of Los Gatos Aged 56, a scientist and entrepreneur who invented numerous biotechnologies that have led to successful products and multiple business ventures, lost his battle with cancer on April 2, 2013. Born in the Netherlands, Dr. Stemmer studied biology at the University of Amsterdam, obtained his Ph.D. from the University of Wisconsin, Madison and then conducted postdoctoral research with Professor Fred Blattner at the same institution. Working as a research scientist at Affymax, Stemmer invented and developed "gene shuffling," a directed evolution process used to engineer novel enzymes and biocatalytic processes for various pharmaceutical and chemical products, allowing researchers to endow proteins and cells with properties that resulted in food ingredients, pharmaceuticals, toxicology, agricultural products, and biofuels. The gene shuffling approach proved exceptionally powerful, and the resulting intellectual property formed the basis for the founding of the biotech company Maxygen in 1997, co-founded by Dr. Stemmer, Dr. Alejandro Zaffaroni, Dr. Russell Howard and Isaac Stein. The discovery and success of gene shuffling led to Dr. Stemmer being awarded the Charles Stark Draper Prize, the United States' top engineering honor, along with Dr. Frances Arnold, in 2011. A prolific inventor, having been named on well over 100 issued patents, Stemmer's portfolio of patents from Maxygen was ranked as the #1 portfolio in pharma/biotech for 2003 by MIT's Technology Review. In order to further commercialize DNA shuffling, now called molecular breeding, Maxygen and Stemmer founded both Verdia which was sold to DuPont in 2004 and Codexis, which went public in April 2010. Continuing his interest in innovation, Stemmer then founded Avidia in 2003, after inventing its Avimer protein subunit technology. Avidia was purchased by Amgen in 2006. Pim was most recently CEO of Amunix, a company he co-founded with Dr. Volker Schellenberger. Amunix created XTENylation to increase half-life and enhance other pharmaceutical properties of biologics and small molecules. Amunix applied the technology to growth hormone and the peptide exenatide and outlicensed the resulting products for development. Dr. Stemmer served on the board of directors of Versartis and Diartis, which are in clinical trials with these two protein-based drugs for growth hormone deficiency and type 2 diabetes, respectively. Dr. Stemmer is survived by his mother, wife, sister, son and daughter.