IGM Biosciences Inc., a Mountain View, Calif.-based biotech developing engineered immunoglobulin M antibodies for the treatment of cancer, has filed to raise up to $100 million in a Nasdaq IPO little more than a month after closing a $102 million series C financing. The company's lead candidate, IGM-2323, is expected to enter phase I testing for the potential treatment of relapsed/refractory (r/r) B-cell non-Hodgkin lymphoma (NHL) this year.