Trial Information

A Prospective Study of Intensified Conditioning Regimen With High-Dose-Etoposide for Allogeneic Hematopoietic Stem Cell Transplantation for Adult Acute Lymphoblastic Leukemia in China

In the first decade of the new millennium, multiple studies have begun to change our
thinking about the treatment of adults with acute lymphoblastic leukemia (ALL). In pediatric
patients cure rates in the range of 80% to 90% are now attainable. While adult patients with
ALL now have a 90% complete remission (CR) with modern chemotherapy, most patients will
relapse, and leukemia-free survival with 3 to 7 years of follow-up in large series is only
in the range of 30% to 40%. The poor outcome of chemotherapy in adults with ALL as compared
to children relates to multiple factors, including poor tolerance of intensive courses of
chemotherapy and a higher incidence of poor prognostic subtypes of ALL such as Philadelphia
chromosome-positive ALL and a lower incidence of favorable subtypes such as the t (12; 21).

Evolving paradigms in the treatment of adult ALL include the application of intense
pediatric regimens to the treatment of adolescents and young adults (AYA) and the
optimization of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the cure
of patients. Adult regimens are typically less intense than pediatric regimens. The Cancer
and Leukemia Group B (CALGB) and the Children's Cancer Group (CCG) first asked whether AYA
between the ages of 16 and 20 fared differently whether they were treated on pediatric
protocols. The results of this study demonstrated that although the complete remission rates
were identical for the AYAs treated on the CALGB and CCG trials, the AYAs had a 63%
event-free survival (EFS) and 67% OS at 7 years on the CCG trials compared with 34% and 46%,
respectively, on the CALGB trials. These results have prompted new studies where pediatric
ALL regimens have been adapted to the treatment of younger adults. With short follow-up,
GRAALL-2003 reports suggest EFS and OS outcomes in the range of 60%. This improved outcome
was more pronounced in the standard-risk patients with a donor who had an OS at 5 years of
69%. On the same time, our previous researches have confirmed the effect and safety of
FA-intensified conditioning regimen on relapse and refractary leukemia.

Based on mentioned above, we speculate that VP-16-intensified conditioning regimen could
improve the outcome for adult ALL. The potential mechanism will be attributed to reduce MRD
and promote GVL effect via providing enough time-window for immuno-reconstitution by
high-dose preparative regimen.