The Omicron variant concerns were front and center in the markets in the week ended Dec. 3, and biotech stocks did not escape the brunt of selling in the wake of the negative development. The sector recorded weekly losses, reversing course from the previous week’s advance. Regulatory decisions scheduled for the week turned in mixed outcomes. VBI Vaccines Inc. and Merck & Co. Inc. received greenlights from the FDA, the former for its PreHevbrio, a preventative treatment for hepatitis B virus infection, and latter for an expanded label for its cancer drug Keytruda. On the other hand, BeyondSpring Inc. faced an outright rejection for its Plinabulin, in combination with granulocyte colony-stimulating factor, for the prevention of chemotherapy-induced neutropenia. The review period for CTI BioPharma Corp. myelofibrosis treatment was extended by three months. With Omicron concerns raging, Pfizer Inc.-BioNTech SE, and Moderna Inc. announced new vaccine supply deals with the UK …