The risk and benefit of Pfizer Inc.’s oral sickle cell disease drug Oxbryta (voxelotor) has flipped, prompted by what the company called new clinical data indicating “an imbalance in vaso-occlusive crises and fatal events” that need more study. Based on an EMA recommendation, Pfizer said it is voluntarily recalling all lots of Oxbryta from wherever it’s approved worldwide. Pfizer also is shuttering its Oxbryta clinical studies and expanded access programs.