- The disease
- Acute graft-versus-host disease (aGvHD) is a serious complication that can occur after an allogeneic stem cell transplant, where immune cells from the donor attack the recipient's tissues. It most commonly affects the skin, liver, and gastrointestinal tract and can be life-threatening. Standard first-line treatment is corticosteroids, but a substantial proportion of patients do not respond adequately. Patients whose disease does not respond to steroids face limited treatment options and poor outcomes.
- What the asset is trying to do
- CYP-001 consists of mesenchymal stem cells (MSCs) derived from induced pluripotent stem cells (iPSCs) using Cynata's proprietary Cymerus manufacturing process (per ClinicalTrials.gov NCT05643638). Unlike conventional donor bone marrow-derived MSCs, the iPSC starting point is intended to allow scalable, consistent batch manufacture from a single cell line rather than requiring repeated donor collections. MSCs are not thought to engraft permanently; they are understood to act transiently through anti-inflammatory and immunomodulatory signalling before being cleared by the body. CYP-001 is administered alongside corticosteroids, the current standard of care, rather than replacing them (per ClinicalTrials.gov NCT05643638).
- What the trial is measuring, and why it matters
- The Phase 2 trial (NCT05643638) is evaluating CYP-001 in combination with corticosteroids versus corticosteroids plus placebo in adults with high-risk aGvHD. The primary completion date listed on ClinicalTrials.gov is 17 March 2026, and the trial is recorded as active, not recruiting, with a target enrolment of 60 patients (per ClinicalTrials.gov NCT05643638). Specific primary and secondary endpoints as listed in the registry are noted in the design section below. Response rates at defined timepoints are standard endpoints in aGvHD trials because early steroid response is a validated predictor of downstream outcomes.
- Efficacy benchmarks in this setting
- In the first-line treatment of aGvHD with corticosteroids, overall response rates at day 28 have historically ranged across trials; published data from the control arms of randomised studies and registry analyses vary by patient risk stratification and GvHD grade. Remestemcel-L (Ryoncil, Mesoblast), the only MSC product currently FDA-approved, received clearance in December 2024 specifically for paediatric steroid-refractory aGvHD, not first-line adult disease (per Ryoncil FDA approval, December 2024). The earlier completed Phase 1 trial of CYP-001 in steroid-resistant aGvHD (NCT02923375, n=16) was a single-arm, uncontrolled safety and tolerability study; any figures from that study are not statistically comparable to controlled randomised evidence or to the current Phase 2 trial population.