CDX-301 is soluble, recombinant human FMS-like tyrosine kinase-3 ligand (Flt3L) that acts by uniquely binding FMS-like tyrosine kinase-3 (Flt3, CD135), which is expressed on hematopoietic stem cells (HSC), early progenitor cells, immature thymocytes, and steady state dendritic cells, resulting in the proliferation, differentiation, development and mobilization of these cells in the bone marrow, peripheral blood and lymphoid organs. CDX-301 is in clinical development for multiple cancers. Celldex believes CDX-301 may hold significant opportunity for synergistic development in combination with other proprietary molecules in the Company's portfolio.

At the 2016 ASCO Annual Meeting, initial results from a Phase 2 study of CDX-1401 in combination with CDX-301 in malignant melanoma were presented that demonstrated the value of CDX-301 as a combination agent for enhancing tumor-specific immune response. CDX-301 greatly expanded peripheral blood dendritic cells and was highly effective at increasing cancer antigen specific T cells and antibodies when combined with CDX-1401. These results, which also showed rapid cellular immune responses in a majority of patients, suggests that pre-treatment with CDX-301 could provide a highly applicable, effective immunologic approach. This Phase 2 study was conducted by the Cancer Immunotherapy Trials Network under a CRADA with the Cancer Therapy Evaluation Program of the NCI. Based on these results, the CITN is planning to enroll additional cohorts to investigate alternate regimens of CDX-301. Other studies are being considered through investigator-sponsored and collaborative agreements.

For more information on the CDX-301 program, view recent scientific presentations and publications.