CK0803

Cellenkos is a small private company in Houston, founded in 2016, that makes cord blood Treg products for several diseases, including aplastic anaemia, graft-versus-host disease and myelofibrosis. CK0803 is its ALS product. The company says more than 70 people have been treated across all its programmes. The ALS trial is led at Columbia University in New York.

Regulatory T cells are immune cells that keep inflammation in check, and in ALS they tend to be fewer and weaker. CK0803 uses Tregs from healthy donor cord blood, grown so they carry high levels of homing proteins (CXCR3 and CD11a) that the company says steer them to inflamed areas of the brain and spinal cord. No donor matching or chemotherapy beforehand is needed. We found no published evidence yet that the cells reach the nervous system in people.

The registered REGALS trial (listed as Phase 1) has a 6-person open-label safety run-in, dosed by January 2024, followed by a randomised, placebo-controlled part for 60 more people whose main goal includes function and survival (CAFS). That part would measure whether CK0803 works, and we will move it to the main table once it is confirmed to have started. So far Cellenkos has not announced that anyone has been randomised: the registry has said "active, not recruiting" since April 2025, in October 2025 the company said a randomised trial was "planned" for 2026, and in October 2026 the expected completion moved from May 2026 to May 2027. The FDA granted Fast Track status in August 2026, which speeds up contact with the agency but is not a judgement that the treatment works.

In a 2025 NEJM Evidence paper, 6 people treated under compassionate use with an earlier version of Cellenkos's cord blood Tregs had no serious infusion problems; in the 4 with enough data, decline slowed from 1.66 to 0.41 ALSFRS-R points a month during treatment. In the 6-person REGALS run-in with CK0803 itself, the company reports little decline in early spinal-onset patients, later benefit in bulbar-onset patients and, pooled with the earlier study, about 60% lower blood NfL, a nerve-damage marker; these figures are from press releases, not a paper. Comparing people with their own earlier decline is unreliable, because ALS often progresses unevenly, and no placebo results exist yet.

This is the most favourable result reported. See all key studies for the full picture.

REGALS takes adults with ALS whose symptoms began no more than 5 years earlier, with an ALSFRS-R score of 36 to 45 and breathing capacity of at least 50%. People on blood thinners or daily aspirin are excluded. Treatment is 100 million cells by drip into a vein, weekly for 4 weeks then monthly for 5 months, as an outpatient.

ClinicalTrials.gov estimates the main part of REGALS will finish in May 2027, a year later than previously listed. Separately, Cellenkos said in October 2025 that a randomised placebo-controlled trial was planned for 2026; it has not announced a start.

REGALS has not been recruiting since April 2025. It ran at Columbia University in New York and at Baylor College of Medicine and the Michael E. DeBakey VA Medical Center in Houston. The 2025 paper treated people under compassionate use, but we found no current expanded access programme.

• REGALS (CK0803-101-1) (NCT05695521) active not recruiting · New York (Columbia) and Houston (Baylor, Houston VA), USA