An azamacrocycle consisting of two cyclam rings connected by a 1,4-phenylenebis(methylene) linker. It is a CXCR4 chemokine receptor antagonist and a hematopoietic stem cell mobilizer. It is used in combination with grulocyte-colony stimulating factor (G-CSF) to mobilize hematopoietic stem cells to the perpheral blood for collection and subsequent autologous transplantation in patients with non-Hodgkin's lymphoma and multiple myeloma.