The ACCESS trial shows that stem cell transplants no longer require a perfect donor match. Using post-transplant cyclophosphamide (PTCy), patients with mismatched unrelated donors achieved a 74.2% two-year survival rate without higher risks of chronic graft-versus-host disease or relapse. Even 7/8, 6/8, or 5/8 matches can now be effective.
This approach has greatly expanded access to treatment. More than half of participants were from diverse ethnic backgrounds, addressing a major gap since minority patients often struggle to find full matches. The trial also included socially and financially vulnerable patients and showed transplants are safe even for those over age 70.
Current research aims to reduce side effects like infections and organ complications. Trials such as OPTIMIZE are testing lower doses of PTCy, while ACCELERATE is exploring drug combinations. Overall, this strategy is making life-saving transplants available to many more patients.