• Celldex Therapeutics Inc., of Needham, Mass., said it started dosing in a Phase I study of hematopoietic growth factor CDX-301 in healthy subjects. The dose-escalating trial is designed to determine the appropriate dose of CDX-301, a recombinant human FMS-like tyrosine kinase 3 ligand, for further clinical development. Celldex said its first priority is to develop the molecule for hematopoietic stem cell transplant, where it has demonstrated improvement of blood cell reconstitution in preclinical models.