Treatment of adolescents and young adults with acute lymphoblastic leukemia by a pediatric-inspired therapy

The study investigated whether a pediatric (designed for children) therapy for acute lymphoblastic leukemia (ALL) can treat adolescents and young adults (AYA) with standard-risk (SR) ALL. The main finding was that a full pediatric therapy could effectively treat such patients.

There are major differences between therapies designed for children and AYAs with ALL. Recently, full pediatric treatments improved survival among young adults with ALL. Another study showed that outcomes between adolescents and young adults with ALL were not different when treated in a pediatric way. However, cancer was not assessed by analyzing minimal residual disease (MRD) in this study. MRD refers to the number of leukemic cells left in patients’ blood after therapy. The effects of a full pediatric therapy on MRD among AYAs with SR-ALL are still unknown.

This clinical trial was conducted on 89 AYAs with SR-ALL. 38 of them were adolescents (aged 15-18 years) and 51 were young adults (aged 19-30 years). No patient had Philadelphia-chromosome (Ph), a genetic abnormality associated with leukemia.

After 14 days of initial pediatric therapy, 21 patients (24%) showed a slower treatment response with higher MRD levels. 20 patients switched to a high-risk (HR) treatment method and 16 of them achieved a complete response (CR). CR refers to the absence of all clinical symptoms of cancer. 66 patients who showed standard response to initial therapy, experienced CR. Overall, CR was achieved in 95% of patients.

Relapse was seen in 35% of patients after 5 years. 13% of adolescents and 52% of young adults faced relapse. Overall, 74% of patients were estimated to survive in 5 years. Survival rate was 87% in adolescents and 63% in young adults at 5 years. Relapse and survival rates were similar among patients undergoing regular therapy and switching to the HR method. The number of severe infections was low in all patients.

The authors concluded that AYAs with SR-ALL and no Ph-chromosome could be effectively and safely treated by a full pediatric ALL therapy. The authors also suggested that treatment outcomes were better in adolescents than in young adults treated with this regimen.

This study included patients with the SR form of ALL only. It also excluded patients who had Ph-chromosome. Further studies are needed.