At of September 30, 2013the six largest holdings in the BB Biotech portfolio were (in order of value): a 13% stake in Celgene; 11% of Isis Pharmaceuticals; 10.4% of Actelion; 9.6% of Gilead; 7.7% of Incyte and 4.5% of Vertex.
In 2012 Sutro formed a collaboration with Celgene worth over $500 million if all programs are successful to design and develop ADCs and bispecific antibodies for two undisclosed targets as well as manufacture a proprietary Celgene antibody using the company’s technology platform.