New ACCESS Trial Results Widen Donor Pool and Expand Patient Access to Transplant Among Adults with High-Risk Blood Cancers

Data published in Blood Advances show young, <7/8 mismatched unrelated donor one-year patient outcomes are similar to fully matched donors

MINNEAPOLIS, August 20, 2026--New clinical trial results published today in the peer-reviewed journal Blood Advances show strong one-year outcomes for adult patients with blood cancers who received transplants with peripheral blood stem cell (PBSC) grafts from young, more extensively mismatched unrelated donors (MMUDs), when combined with a post-transplant cyclophosphamide (PTCy) graft-versus-host disease (GVHD) prevention strategy. Trial participants' one-year overall survival rates exceeded 80% across all match levels, on par with those from fully matched donors.

Historically, blood stem cell transplants required an exact donor-patient match of eight human leukocyte antigen (HLA) markers, which are immune system receptors on cell surfaces used to assess donor-recipient compatibility and prevent life-threatening GVHD. These new results highlight patient outcomes for those who received donor cells with fewer matching HLA markers (4/8–6/8), alongside those with more closely matched donors (7/8), suggesting that physicians can safely select donors from a substantially broader pool, increasing access for patients from non-European ancestries who historically may not have found a fully matched donor.

"For many patients, particularly those with ethnically diverse ancestries, not having a fully matched donor used to mean they were ineligible for transplant, limiting their options and potentially a second chance at life," said Steven Devine, MD, chief medical officer, NMDPSM, and senior scientific director, CIBMTR® (Center for International Blood and Marrow Transplant Research®). "These findings are promising signals regarding what a donor search can mean for patients, bringing us one step closer to a future where virtually every patient needing a transplant can find a suitable donor through international registries."

Historically, patients from ethnically diverse ancestries had much lower chances of finding a fully matched unrelated donor—as low as 29% for Black or African American patients and 48% for Latino and Hispanic patients versus 79% for non-Hispanic White patients. Prior modeling studies included in the paper suggest that inclusion of 6/8 MMUDs could increase donor availability to near-universal levels for all patients regardless of ancestry.

A 'Donor for All': Research widens access to transplant for more patients