Send to

Choose Destination
Bone Marrow Transplant. 2015 Jul;50(7):924-30. doi: 10.1038/bmt.2015.74. Epub 2015 Apr 27.

Efficacy and safety of CDX-301, recombinant human Flt3L, at expanding dendritic cells and hematopoietic stem cells in healthy human volunteers.

Author information

1] The Laboratory of Cellular Physiology and Immunology, The Rockefeller University, New York, NY, USA [2] Department of Dermatology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
The Laboratory of Cellular Physiology and Immunology, The Rockefeller University, New York, NY, USA.
Department of Pediatrics, Weill Cornell Medical College, New York, NY, USA.
Celldex Therapeutics, Inc., Needham, MA, USA.


Fms-like tyrosine kinase-3 ligand (Flt3L) uniquely binds the Flt3 (CD135) receptor expressed on hematopoietic stem cells (HSCs), early progenitor cells, immature thymocytes and steady-state dendritic cells (DCs) and induces their proliferation, differentiation, development and mobilization in the bone marrow, peripheral blood and lymphoid organs. CDX-301 has an identical amino-acid sequence and comparable biological activity to the previously tested rhuFlt3L, which ceased clinical development over a decade ago. This Phase 1 trial assessed the safety, pharmacokinetic, pharmacodynamic and immunologic profile of CDX-301, explored alternate dosing regimens and examined the impact of rhuFlt3L on key immune cell subsets. Thirty healthy volunteers received CDX-301 (1-75 μg/kg/day) over 5-10 days. One event of Grade 3 community-acquired pneumonia occurred. There were no other infections, dose-limiting toxicities or serious adverse events. CDX-301 resulted in effective peripheral expansion of monocytes, hematopoietic stem and progenitor cells and key subsets of myeloid DCs and plasmacytoid DCs, with no clear effect on regulatory T cells. These data from healthy volunteers support the potential for CDX-301, as monotherapy or in combination with other agents, in various indications including allogeneic HSC transplantation and immunotherapy, but the effects of CDX-301 will need to be investigated in each of these patient populations.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Nature Publishing Group Icon for PubMed Central
Loading ...
Support Center