San Francisco, CA—Early results of the large, prospective Intergroup C10403 trial demonstrate that a high-intensity pediatric-inspired regimen improves event-free survival (EFS) and overall survival (OS) in adolescent and young adults with acute lymphoblastic leukemia (ALL). Many smaller studies have shown that adolescent and young adults have improved outcomes on pediatric regimens, but this is the first large data set to validate this practice.
The 2-year EFS was 66% and the 2-year OS was 79%.
“These results are a major improvement compared with 34% and 39%, respectively, in historical controls. This is a clear opportunity to improve care in adolescent and young adults with ALL,” said lead investigator Wendy Stock, MD, University of Chicago Medical Center, Chicago, IL.
The study showed that the presence of a BCR-Abl1–like signature and aberrant CRLF2 expression were associated with worse EFS and OS rates and are considered factors for increased risk in this patient population. Patients without these clinical features had excellent EFS and OS, Dr Stock told listeners at ASH 2014.
The Intergroup C10403 trial was undertaken by cooperative groups in North America to evaluate treatment with a pediatric intensive regimen delivered by hematologists/oncologists treating adult patients. Dr Stock presented the main results of the trial. Additional analysis of adherence and outcomes based on psychosocial factors will be presented in the future.
A total of 296 adolescent and young adults (median age, 25 years) with ALL were treated between 2007 and 2013. Overall, 75% of the patients had B-precursor ALL and 24% had T-precursor ALL. In addition, 31% of the patients were obese, with body mass index >30 kg/m2, and 7% were morbidly obese.
The backbone of the pediatric inspired regimen included intensified glucocorticoid, vincristine, and asparaginase and more maintenance therapy. The regimen included induction, consolidation, interim maintenance, delayed intensification, and prolonged maintenance (2 years for girls and 3 years for boys).
The EFS rate was similar among the treatment groups, regardless of the age-group or a precursor B- or T lineage. The OS was significantly worse in the obese patients, and significantly improved in patients with undetectable minimal residual disease.
Dr Stock and colleagues will propose a successor US Intergroup trial that should begin in 2015. The plans include the use of the molecular signature of the disease to stratify patients and to add a novel antibody or a targeted kinase inhibitor to eradicate any minimal residual disease and improve outcomes.
“This is a phenomenal achievement,” said Yoav Messinger, MD, Pediatric Oncologist at Children’s Hospital and Clinics of Minnesota, Minneapolis, chair of the session where these data were presented. “We have been waiting for a long time for these data, which put what we already know into a formalized protocol on a large-scale basis.”