Two-year-old IFM Therapeutics Inc. became the latest biopharma unicorn, as Bristol-Myers Squibb Co. (BMS) picked up the Boston-based company for $300 million up front and another $1.01 billion in potential development, regulatory and sales milestones for each of the first products from the deal's two oncology programs. IFM is eligible for more contingent milestone payments for additional products that emerge from the programs.