FDA Grants Orphan Drug Designation to Cellenkos’ First-in-Class CXCR4hi Treg Therapy CK0804 for Myelofibrosis

HOUSTON— January 6, 2026 — Cellenkos Inc., a clinical-stage biotechnology company focused on allogeneic regulatory T cell (Treg) therapies, announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation to CK0804 for the treatment of myelofibrosis, a rare and life-threatening blood cancer.

CK0804 is a first-in-class CXCR4hi Treg therapeutic designed to preferentially traffic toward CXCL12, a chemokine highly expressed in the bone marrow and spleen in myelofibrosis. Following homing to disease-relevant tissues, CK0804 Tregs engage with local antigen-presenting cells, undergo in vivo proliferation, and secrete the immunosuppressive cytokine IL-10, leading to resolution of inflammation through a non–MHC-restricted mechanism. The therapy also modulates PDGF-driven pathways associated with disease remodeling.

Clinical data from a 13-patient study presented at the 67th American Society of Hematology (ASH) Annual Meeting in December 2025 demonstrated meaningful clinical activity in a heavily pretreated population. Reported outcomes included spleen volume reduction greater than 10% in 45% of evaluable patients, symptom burden reduction exceeding 50% in 78%, and improvement in transfusion burden in all evaluable patients. Biomarker analyses showed reductions in pro-fibrotic and inflammatory mediators, including TGFβ1, TGFβ2, FGF, PDGF, and sCD40L, along with decreased pathogenic monocytes and normalization of bone marrow myeloid-to-erythroid ratios.

CK0804 is an off-the-shelf, cryopreserved allogeneic Treg cell therapy derived from clinical-grade umbilical cord blood and manufactured using Cellenkos’ proprietary CRANE® process. The product does not require HLA matching, escapes innate immune surveillance, retains long-term viability, and can be administered intravenously in an outpatient setting.

The Orphan Drug Designation supports continued clinical development of CK0804 as a disease-modifying immunotherapy for patients with myelofibrosis who have limited treatment options.