Generic-drug giant Mylan ( MYL ) agreed to develop six biosimilar drugs with biotech Momenta Pharmaceuticals ( MNTA ) Friday while also announcing the retirement of its CFO. Momenta got an upgrade as a result. Mylan agreed to pay $45 million upfront plus up to $200 million in milestone payments should the candidates be successful, in exchange for commercialization rights. Momenta has the option to "co-commercialize in a supporting commercial role, any approved products in the United States," according to a company statement. Momenta didn't name any of the candidates expect M834, which is a biosimilar version of Bristol-Myers Squibb 's ( BMY ) rheumatoid arthritis drug Orencia. Orencia sold $1.7 billion last year and is projected to sell $2.7 billion by 2020, Momenta CEO Craig Wheeler said on a conference call with analysts.