RBC Capital analyst Brian Abrahams downgrades IGM Biosciences (NASDAQ:IGMS) from Outperform to Sector Perform and lowers the price target from $90 to $51.RBC Capital analyst Brian Abrahams downgrades IGM Biosciences (NASDAQ:IGMS) from Outperform to Sector Perform and lowers the price target from $90 to $51.