Synthetic insulin

Synthetic insulin marked the moment when recombinant DNA technology crossed from laboratory curiosity to commercial medicine. On October 29, 1982, the FDA approved Humulin—human insulin produced by genetically engineered bacteria—as the first protein therapeutic made through recombinant DNA technology. The review took only five months when the agency's average approval time was over thirty. The revolution had arrived faster than anyone expected.

The race began in 1976 when venture capitalist Robert Swanson and biochemist Herbert Boyer founded Genentech. Boyer, a pioneer in recombinant DNA from UC San Francisco, partnered with scientists at City of Hope National Medical Center: geneticist Arthur Riggs and organic chemist Keiichi Itakura. They were joined by David Goeddel and Dennis Kleid. On August 24, 1978, the team successfully expressed human insulin in E. coli bacteria—a feat requiring the separate synthesis of the insulin A and B chains from chemically synthesized DNA, then combining them in the bacterial host.

The problem Genentech solved was not merely technical but economic. Before Humulin, diabetics depended on insulin extracted from pig and cow pancreases. The supply was limited, the product variable, and some patients developed allergic reactions to the animal proteins. Recombinant technology could produce unlimited quantities of protein identical to human insulin.

Eli Lilly, with its century of pharmaceutical manufacturing expertise and existing insulin distribution networks, partnered with Genentech to commercialize the product. Lilly conducted the pre-clinical testing and clinical trials involving thousands of diabetics while Genentech provided the manufacturing organisms. The FDA, examining exhaustive data on safety and efficacy, approved with unprecedented speed.

Humulin's success jump-started the biotechnology industry. The template was established: academic research identifying therapeutic proteins, startup companies engineering production methods, pharmaceutical partners handling trials and distribution, regulatory pathways adapting to novel technologies. Hundreds of recombinant therapeutics followed—growth hormone, clotting factors, monoclonal antibodies. The bacteria programmed in a San Francisco laboratory in 1978 became the ancestors of a $400 billion industry.