AMD 3100 for Treatment of Myelokathexis

This is an initial study to determine if CXCR4 inhibitor AMD 3100 or plerixafor may be a potential treatment for neutropenia due to CXCR4 mutations, the myelokathexis or WHIM (warts, hypogammaglobulinemia, immunodeficiency and myelokathexis) syndrome. This is the initial study of this concept and will involve up to 6 patients to receive increasing doses of plerixafor administered subcutaneously or on an alternate day basis. It is unknown if these patients will be highly sensitive to a blockade of CXCR4 activity and release more white blood cells than normal volunteers or cancer patients given the same dose of this drug. Therefore doses will begin at a level 12 fold less than currently used to mobilize stem cells and will be increased stepwise to achieve an acceptable circulating level of neutrophils.