CK0801 for Treatment of Aplastic Anemia

This Phase 2, multicenter, open-label study is evaluating CK0801 for the treatment of aplastic anemia in adults with persistent transfusion dependence after at least one prior line of therapy or intolerance to standard-of-care treatment. CK0801 is an allogeneic cord blood-derived regulatory T-cell therapy administered intravenously. The study is designed to assess safety and clinical activity, including hematologic response, transfusion independence, duration of response, survival outcomes, and patient-reported outcomes. Exploratory assessments include immune reconstitution, biomarkers, pharmacokinetics, immunogenicity, and donor-specific antibodies. The primary endpoint is overall response at Day 180.

Study Overview

• Status: Not yet recruiting
• Conditions: Aplastic Anemia
• Intervention / Treatment: Drug: CK0801

Detailed Description

Aplastic anemia is a rare, life-threatening bone marrow failure disorder caused by immune-mediated destruction of hematopoietic stem and progenitor cells. Regulatory T cells (Tregs), which help maintain immune homeostasis, are decreased and functionally impaired in aplastic anemia. CK0801 is an allogeneic cord blood-derived Treg cell therapy being studied as a potential treatment to restore immune balance and improve hematopoiesis. Prior clinical experience described in the protocol showed a favorable safety profile and early signs of activity, including reduced transfusion requirements in patients with bone marrow failure.

This Phase 2, multicenter, open-label, single-agent study will evaluate the safety and efficacy of intravenous CK0801 in adults with aplastic anemia who remain transfusion dependent after at least one prior line of therapy or who are intolerant to standard-of-care treatment. A total of 12 participants are planned. CK0801 will be administered as a weight-based intravenous infusion, with protocol-defined premedication before treatment.

The primary endpoint is overall response at Day 180. Secondary endpoints include response at Days 28, 56, 100, and 365, time to best response, time to transfusion independence, duration of transfusion independence, immunosuppression-free survival, overall survival, progression-free survival, clonal evolution, patient-reported outcomes, and safety. Exploratory endpoints include donor-specific antibodies, immunosuppressive medication discontinuation, cytokine and biomarker changes, pharmacokinetics, immunogenicity, and immune reconstitution.

Enrollment will proceed using Simon's two-stage design. In Stage 1, 6 participants will be enrolled. If predefined activity criteria are met, the study will proceed to Stage 2 and enroll 6 additional participants, for a total of 12 participants. Participants will undergo protocol-defined clinical, laboratory, disease, safety, and correlative assessments. The overall study duration is expected to be approximately 24 months.

• Study Type: Interventional
• Enrollment (Estimated): 12
• Phase: Phase 2

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18 years or older
• Diagnosis of aplastic anemia
• Transfusion dependent after at least one prior line of treatment, or intolerance to standard-of-care treatment
• Female subjects of childbearing potential must have a negative urine or serum pregnancy test
• Agrees to comply with all protocol-required procedures, including study-related assessments, visits, and long-term follow-up
• Willing and able to provide written informed consent

Exclusion Criteria:

• Known HIV seropositivity
• Uncontrolled infection not responding to appropriate antimicrobial agents after 7 days of therapy; the Protocol PI is the final arbiter of eligibility
• Uncontrolled intercurrent illness that, in the opinion of the investigator, would place the subject at greater risk of severe toxicity and/or impair the activity of CK0801
• Pregnant or breastfeeding
• Unable to provide consent or, in the opinion of the investigator, unlikely to fully comply with protocol requirements

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: CK0801; All enrolled participants receive CK0801 administered intravenously according to the protocol. CK0801 is given as a weight-based dose of 1 x 10^7 Tregs/kg using actual body weight, capped at 100 kg, on Study Day +1.	Drug: CK0801; CK0801 is an investigational allogeneic, cord blood-derived regulatory T-cell product administered by intravenous infusion. The planned dose is 1 x 10^7 CK0801 Tregs/kg using actual body weight, capped at 100 kg.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Primary Outcome-Overall Response Rate (ORR) at Day 180	Overall response rate (ORR), defined as the proportion of subjects achieving either a complete response (CR) or partial response (PR) following treatment with CK0801.	Day +180
Overall Response Rate at Additional Timepoints	Proportion of subjects achieving CR or PR at earlier and later timepoints following treatment	Days 28, 56, 100, and 365

Collaborators and Investigators

• Sponsor: Cellenkos, Inc.

Study record dates

Study Major Dates

• Study Start (Estimated): August 3, 2026
• Primary Completion (Estimated): August 3, 2028
• Study Completion (Estimated): August 3, 2029

Study Registration Dates

• First Submitted: March 24, 2026
• First Submitted That Met QC Criteria: March 24, 2026
• First Posted (Actual): March 30, 2026

Study Record Updates

• Last Update Posted (Actual): April 3, 2026
• Last Update Submitted That Met QC Criteria: March 30, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Allogeneic Cell Therapy; Regulatory T Cells; Immune Dysregulation; Aplastic Anemia; Bone Marrow Failure; CK0801; Treg Cell Therapy; Cord Blood-Derived Tregs; Transfusion Dependent; Open-Label Phase 2 Study; Cord Blood Unit
• Additional Relevant MeSH Terms: Hematologic Diseases; Bone Marrow Diseases; Anemia; Hemic and Lymphatic Diseases; Bone Marrow Failure Disorders; Anemia, Aplastic
• Other Study ID Numbers: CK0801-301-01

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No