REDWOOD CITY, Calif.--(BUSINESS WIRE)--Maxygen, Inc. (Nasdaq:MAXY), a biotechnology company focused on the development of improved protein drugs, today announced that its majority-owned subsidiary, Perseid Therapeutics LLC, achieved a second preclinical milestone under its collaboration with Astellas Pharma Inc. to co-develop and commercialize next-generation CTLA4-Ig therapeutics. Perseid has received a $5 million dollar payment from Astellas for achievement of this milestone. Perseid achieved the initial preclinical milestone under this collaboration in December 2009 and also received a $5 million dollar payment from Astellas for the achievement of that milestone.