Long COVID Clinical TrialPhase IIa · Peer-Reviewed Results

Efficacy Results

In a 30-patient, randomized, placebo-controlled study (NCT05682560), patients treated with cord blood cell therapy showed significant improvement in chronic fatigue, the most debilitating feature of post-COVID syndrome. The Chalder Fatigue Questionnaire (CFQ-11) measured fatigue severity at weeks 6, 12, 18, and 26.

Statistically significant improvements were observed at all measured timepoints: week 6 (p<0.001), week 12 (p<0.001), week 18 (p=0.002), and week 26 (p=0.007). Physical fatigue severity also improved significantly. The Patient Global Impression of Severity (PGI-S) scale confirmed durable symptom relief.

Safety Profile

The trial met its primary safety endpoint. In the treatment group, 2 of 20 participants (10%) experienced mild, transient adverse events. All resolved within one hour. No severe adverse events were observed. The placebo group had a 20% TEAE rate, with events unrelated to treatment.

Cognitive Function

Montreal Cognitive Assessment (MoCA) scores showed slight improvement from baseline (24 to 26) in the treatment group, though the difference was not statistically significant.

Regulatory Pathway

RMAT Designation (October 2024)

The FDA granted Regenerative Medicine Advanced Therapy designation for HPC, Cord Blood in Long COVID, enabling accelerated development and priority review. As of 2026, REGENECYTE® is the only FDA-licensed cord blood product under evaluation in a U.S. clinical trial for Long COVID.

Expanded Access Program (January 2026)

The FDA cleared a compassionate use pathway for patients with serious or life-threatening Long COVID symptoms who have exhausted standard treatment options. StemCyte works directly with treating physicians to facilitate access.

As reported by AABB →

Phase III (Preparing)

Following a positive End-of-Phase 2 meeting with the FDA in March 2025, StemCyte received guidance supporting the design of a pivotal Phase III trial. The agency's recommendations may reduce participant requirements and shorten the overall timeline.

Implications for Cord Blood Science

This study demonstrates that cord blood-derived HPCs may have broader therapeutic applications beyond hematopoietic reconstitution — potentially addressing chronic inflammatory and post-infectious conditions. These findings support further clinical development targeting fatigue in post-COVID and potentially other fatigue-related conditions.

Sources: eClinicalMedicine (2026) 91:103737. StemCyte press release, Jan 26, 2026. AABB, Feb 4, 2026. ClinicalTrials.gov NCT05682560.