FDA Clears IND for Off-the-Shelf Treg Therapy CK0802 in Chronic GVHD

The FDA has cleared an investigational new drug (IND) application for CK0802, an off-the-shelf allogeneic regulatory T-cell (Treg) therapy, to enter a multicenter phase 1b/2a clinical trial in patients with steroid-refractory graft-vs-host disease (GVHD), according to a news release from Cellenkos.¹ Trial initiation is planned for the second half of 2026, and the sponsor hopes to provide a clinical readout in early 2027.

Unmet Need in Steroid-Refractory GVHD

GVHD remains one of the most significant complications of allogeneic hematopoietic stem cell transplantation, with acute GVHD occurring in approximately 50% of the roughly 11,000 allogeneic transplants performed annually in the United States. Chronic GVHD affects 30% to 70% of transplant recipients and carries significant nonrelapse mortality burden. High-dose corticosteroids are the first line of treatment for GVHD, with additional options including ruxolitinib (Jakafi) in patients with steroid-refractory GVHD.

Mechanism of Action

CK0802 is derived from qualified US public cord blood units and is cryopreserved for immediate intravenous administration without HLA matching, with a shelf life of approximately 3 years, making it an “off-the-shelf" Treg therapy easily available to patients. The therapy is manufactured using Cellenkos's proprietary CRANE platform.

CK0802 Tregs are designed to function under intense inflammatory conditions through several proposed mechanisms including release of the suppressor cytokine IL-10 to inhibit pro-inflammatory mediators including TNF-α, IL-6, IL-12, and IL-17; consumption of IL-2 via high-affinity surface receptors to deplete cytotoxic T cells of a key survival signal; neutralization of antigen-presenting cells that drive GVHD pathology; and induction of endogenous Treg activity to promote sustained immune homeostasis.

Trial Design

The phase 1b/2a study will be an open-label, multicenter trial evaluating the safety, tolerability, and preliminary efficacy of multiple infusions of CK0802 in patients who have failed systemic corticosteroid therapy following allogeneic stem cell transplantation. The primary end point is safety and early efficacy as assessed by overall response rate at day 29.

Prior Clinical Data

In the prior randomized, placebo-controlled RESOLVE trial (NCT04468971) of CK0802 in 45 patients with COVID-19–related acute respiratory distress syndrome requiring mechanical ventilation and vasopressor support, Bayesian regression analysis showed an 89.7% probability of beneficial effect for being alive and extubated at day 28 with multiple infusions of CK0802 at 100 million Tregs vs placebo, and a 98.6% probability of beneficial effect for overall survival at 1 year.^1,2 The company characterized the cytokine storm biology in that setting as analogous to GVHD, providing the translational rationale for the current trial. No patients in this trial had a grade 3 or higher toxicity related to CK0802.

Another of the company’s Treg therapies, CK0804, is being investigated in a phase 1b study (NCT05423691) as add-on therapy in patients with myelofibrosis who have suboptimal response to ruxolitinib.

"FDA clearance to advance CK0802 into a phase 1b/ 2a trial marks a hopeful step forward for patients facing the dire prognosis of steroid-refractory GVHD," Simrit Parmar, MD, MSCI, founder of Cellenkos and associate professor at the Texas A&M School of Engineering and Medicine, stated in the news release.¹

REFERENCES

1. Cellenkos announces FDA clearance of investigational new drug (IND) application for phase 1b/ 2a trial of CK0802 in steroid-refractory graft-versus-host disease (GVHD). News release. Cellenkos. May 4, 2026. Accessed May 4, 2026. https://tinyurl.com/3npbyhet

2. Gladstone DE, D'Alessio F, Howard C, et al. Randomized, double-blinded, placebo-controlled trial of allogeneic cord blood T-regulatory cells for treatment of COVID-19 ARDS. Blood Adv. 2023;7(13):3075-3079. doi:10.1182/bloodadvances.2022009619