Rubius Therapeutics Inc. is taking a giant step back so that it can attempt taking a few steps forward. The company said it’s restructuring to focus on taking its Rubius Erythrocyte Design (RED) cell therapeutics platform from what it considers a good thing and turn it into a better one. Rubius engineers red blood cells to become cancer fighters but a lack of progress and the lure of similar but new technology could lead to bigger and better results.