FDA Grants Fast Track Designation to T-Cell Agent CK0803 for ALS

The FDA has granted Fast Track designation to CK0803, an investigational allogeneic, cord blood-derived T-regulatory (Treg) cell therapy being developed for the treatment of amyotrophic lateral sclerosis (ALS), according to developer Cellenkos. The designation applies to the company's investigational new drug (IND) application (IND 28681) for CK0803, which is designed to express neurotropic homing markers that facilitate trafficking to sites of central nervous system (CNS) inflammation.¹

The designation follows early clinical findings, as previously reported by NeurologyLive, from an ongoing phase 1/1b study (NCT05695521) in which 6 evaluable patients received up to 9 infusions of CK0803.² According to the company, the trial reported changes in measures of disease progression and inflammation, including ALS Functional Rating Scale–Revised (ALSFRS-R) decline, plasma neurofilament light chain (NfL), and plasma interleukin-10 (IL-10).

“By leveraging enriched, tissue-directed regulatory T-cells derived from healthy, allogeneic, umbilical cord blood, our therapy actively homes to inflamed microglia via the CXCR3/CXCL10 axis,” said Simrit Parmar, MD, founder of Cellenkos, in a statement.¹ “This targeted approach interrupts the inflammation-injury cycle and restores neuroimmune homeostasis—offering transformative potential for neuroinflammatory diseases.”

The FDA communicated the designation in a letter dated August 21, 2026, from the Office of Therapeutic Products within the Center for Biologics Evaluation and Research. According to Cellenkos, CK0803 is the first Treg product to receive Fast Track designation for ALS.

The phase 1/1b study is currently evaluating 6 patients, including 3 with spinal-onset disease and 3 with bulbar-onset disease. In the study, participants received up to 9 infusions of a fixed 100 million-cell dose, consisting of 4 weekly induction infusions followed by 5 monthly consolidation infusions.

According to Cellenkos, findings from this cohort demonstrated stabilization of decline on the ALSFRS-R, an approximately 60% reduction in plasma NfL, and an approximately 200% increase in plasma IL-10. The company said the biomarker findings are consistent with the proposed anti-inflammatory mechanism of CK0803.

CK0803 is engineered to express high levels of CXCR3 and CD11a (LFA-1), which are intended to facilitate trafficking across the blood-brain and blood-spinal cord barriers and migration toward sites of active CNS inflammation along CXCL10 chemokine gradients. The therapy is designed to suppress Th1 and Th17 effector programs and microglial activation while increasing IL-10 secretion to promote immune regulation.

The product is manufactured using Cellenkos’ CRANE platform and does not require human leukocyte antigen or ABO matching, according to the company. CK0803 is administered as an outpatient peripheral intravenous infusion without conditioning chemotherapy or interleukin-2 support.

No dose-limiting toxicities have been observed across CK0803 and the company’s related cord blood-derived Treg programs, Cellenkos said. CK0803 remains investigational and has not been approved for the treatment of ALS.

The company’s development strategy for CK0803 is based on the premise that neuroinflammation contributes to neuronal injury in ALS. Rather than targeting a disease-specific antigen, the therapy is designed to home to inflamed CNS tissue through the CXCR3/CXCL10 and CD11a/LFA-1 pathways and modulate immune activity at sites of inflammation.

Cellenkos is also exploring whether this tissue-directed approach could have applications in other neuroinflammatory and neurodegenerative diseases, including Alzheimer disease, Parkinson disease, and multiple sclerosis. The company has cited research suggesting abnormalities in Treg number or suppressive function, blood-brain barrier disruption, and chronic microglial or astrocytic activation across these conditions.

However, CK0803 has not yet been clinically established for these additional indications. Cellenkos said any expansion into other diseases would require additional preclinical validation, regulatory discussions, and sufficient funding. The company plans to continue advancing CK0803 in ALS as it evaluates the investigational therapy’s safety and potential biological activity.

REFERENCES
1. Cellenkos Receives FDA Fast Track Designation for CK0803 in Amyotrophic Lateral Sclerosis (ALS). Cellonkos Inc. News Release. August 2026. Accessed Mugust 25, 2026. https://www.prnewswire.com/news-releases/cellenkos-receives-fda-fast-track-designation-for-ck0803-in-amyotrophic-lateral-sclerosis-als-302859365.html
2. Cellenkos announces first patient dosed with CK0803 cell therapy for treatment of amyotrophic lateral sclerosis. Cellenkos Inc. News release. May 2, 2023. Accessed May 3, 2023. https://www.prnewswire.com/news-releases/cellenkos-announces-first-patient-dosed-with-ck0803-cell-therapy-for-treatment-of-amyotrophic-lateral-sclerosis-301812682.html