Phase III Study of VCAP-AMP-VECP vs. Biweekly CHOP in Aggressive Adult T-Cell Leukemia-Lymphoma (ATLL): Japan Clinical Oncology Group Study, JCOG9801.

Background: In our study for non-Hodgkin lymphoma (NHL) in 1980’s (JCOG8701), human T-lymphotropic virus type-1- associated ATLL was the poorest prognostic subtype in NHL. The complete response (CR) rate was 42%, the median survival time (MST) was 8 months, and the 4-yr overall survival (OS) was 12% (

Methods: Previously untreated patients (pts) with aggressive ATLL, acute-, lymphoma- or unfavorable chronic-type, were randomized either to receive 6 courses of VCAP-AMP-VECP every 4 weeks (arm A) or 8 courses of biweekly-CHOP (arm B) with minimization method balancing performance status and institution. Both regimens were supported with G-CSF and intrathecal prophylaxis using cytarabine, methotrexate and prednisolone. Eligibility included preserved organ functions and aged 15–69 years. Primary endpoint was OS to be compared by log-rank test. Assuming 60 eligible pts in each arm, the study had 0.8 power to detect a 15% difference in 3-year OS at 0.05 one-sided alpha.

Results: 118 pts (57 in arm A, 61 in arm B) were randomized between 07/98 and 10/03. Median follow-up time in all randomized pts was 11.0 months at 12/04. 72 % of the pts responded, with 23 pts achieving CR (40%) and 18 achieving partial response (PR; 32%) in arm A. The RR was 66%, with 15 pts achieving CR (25%) and 25 achieving PR (41%) in arm B. The median progression-free survival (PFS) time and PFS at one-year in arm A were 7.0 months and 28.1%, respectively, whereas 5.4 months and 16.2% in arm B. The MST and OS at 3 years in arm A were 12.7 months and 23.6%, respectively, whereas 10.9 months and 12.7% in arm B. Log-rank p-value for primary end point, OS, was 0.085. After adjustment of patients’ characteristics at registration by Cox regression, the p value became 0.029 because of unbalanced prognostic factors such as bulky lesion. In arm A vs. arm B, %G4 neutropenia, %G4 thrombocytopenia and %G4 infection were 98% vs. 83%, 74% vs. 17% and 7% vs. 3%, respectively. Three toxic deaths were reported in arm A.

Conclusions: These results demonstrate that VCAP-AMP-VECP yields longer OS time than biweekly-CHOP but with higher toxicity profiles that are acceptable, and suggest that the former regimen should be the standard therapy for aggressive ATLL.