Evaluation of alternative methods for Leptin production

Team Masters Projects 2007-2008

April 30, 2008

TMP Sponsor: Amylin Pharmaceuticals Company Advisors: Dr. Mary Erickson

Consulting Scientists:
                            Dr. Anasua Kusari
                            Dr. Ilya Tolstorukov

Over the past decade, several advances have been made in recombinant DNA technology and heterologous protein expression. Such advances have had a direct impact on the efficiency with which pharmaceutical and biotechnology companies can produce therapeutic protein products, thus fueling growth for a market which now accounts for 10% of all pharmaceutical sales. Leptin is a naturally occurring protein hormone secreted by adipose tissue and acts as a signal to the hypothalamus to regulate food intake and energy expenditure. Studies have shown that leptin given in combination with amylin, a second hormone linked to fat metabolism, results in sustained, fat-specific weight loss in a leptin-resistant animal model of obesity. Thus, leptin, in combination with pramlintide, an amylin analog, is currently being investigated by Amylin Pharmaceuticals as a treatment for obesity. The primary objective of the project undertaken by the KGI team was to evaluate the yeast Pichia pastoris as a possible manufacturing cell line and analyze the commercial feasibility of using a P. pastoris expression system for the production of human leptin.

Since the company is investigating leptin for use in a combination therapy, a crucial factor is to minimize the drug substance cost of goods manufactured (COGM). One way to keep COGM low is to find an efficient expression host that may also minimize downstream processing. The project helped Amylin determine whether P. pastoris can be a commercially acceptable alternative to the current system for producing the leptin protein. The technical assessment provided results for product titer, yield, and quality, as well as data that can be used to perform a matrix analysis to estimate cost of goods manufactured. The report also included an intellectual property analysis, a contract manufacturing assessment, evaluation of regulatory issues, and bioprocess models produced using SuperPro™. Combined, this information provides Amylin with the information necessary to begin assessing P. pastoris as an alternative expression system for the manufacture of human leptin.