The present disclosure provides therapeutic agents including those of the formula: wherein the variables are defined herein. Also provided are pharmaceutical compositions, kits and articles of manufacture comprising such therapeutic agents. Methods of using the therapeutic agents are also provided. The present disclosure further provides combinations of a VLA-4 inhibitor and an agent which interacts with a chemokine receptor, and methods of use thereof. In some embodiments, the disclosed combinations may be used in a method of mobilizing hematopoietic stem cells. In some embodiments, the disclosed methods may be used in the treatment of a condition which requires the collection of hematopoietic stem cells for transfusions or in chemotherapy. The present disclosure further provides methods of treating a patient comprising administering an agent which interacts with a chemokine such as G-CSF, plerixafor, or Gro-β and VLA-4 inhibitors.