This invention discloses the use of an E-selectin antagonist and a mobilizer of hematopoietic stem cells or progenitor cells in methods and compositions for treating or preventing immunocompromised conditions resulting from medical treatment. The present invention is particular relevant for prophylaxis and/or treatment of hematopoeitic disorders including neutropenia, agranulocytosis, anemia and thrombocytopenia in individuals receiving or proposed to receive treatments that target rapidly dividing cells or that disrupt the cell cycle or cell division.