Background
Phase III, open-label, randomized, multicenter trial. 80 patients with newly diagnosed advanced-stage (III/IV) extranodal NK/T-cell lymphoma (ENKTL), nasal type. SMILE (dexamethasone/methotrexate/ifosfamide/L-asparaginase/etoposide) is the established reference regimen; DDGP (dexamethasone/cisplatin/gemcitabine/pegaspargase) was designed to improve efficacy with reduced toxicity.
Interventions and follow up
Arm A: DDGP (dexamethasone + cisplatin + gemcitabine + pegaspargase) every 21d × 6 cycles
Arm B: SMILE (dexamethasone + methotrexate + ifosfamide + L-asparaginase + etoposide) every 28d × 6 cycles
Primary endpoint: Progression-free survival
Median follow-up: ~3.5 years
Arm B: SMILE (dexamethasone + methotrexate + ifosfamide + L-asparaginase + etoposide) every 28d × 6 cycles
Primary endpoint: Progression-free survival
Median follow-up: ~3.5 years
Results
ORR: 90% (DDGP) vs 60% (SMILE), P=.002
CR rate: 72.5% vs 37.5%, P<.001
Median PFS: not reached vs 6.8 months, HR 0.42, 95% CI 0.23–0.77, P=.004
3-year OS: 68% vs 41%, HR 0.51, P=.02
CR rate: 72.5% vs 37.5%, P<.001
Median PFS: not reached vs 6.8 months, HR 0.42, 95% CI 0.23–0.77, P=.004
3-year OS: 68% vs 41%, HR 0.51, P=.02
Adverse events
Hematologic: Grade ≥3 leukopenia 62.5% (DDGP) vs 85.0% (SMILE)
Infectious: Grade ≥3 infections 22.5% vs 47.5%
Hepatic: Grade ≥3 hepatotoxicity 7.5% vs 37.5%
Mortality: Treatment-related deaths 2 (DDGP) vs 5 (SMILE)
Infectious: Grade ≥3 infections 22.5% vs 47.5%
Hepatic: Grade ≥3 hepatotoxicity 7.5% vs 37.5%
Mortality: Treatment-related deaths 2 (DDGP) vs 5 (SMILE)
Conclusions
DDGP significantly outperformed SMILE in advanced ENKTL (ORR 90% vs 60%, CR 72.5% vs 37.5%, median PFS not reached vs 6.8 months, 3-year OS 68% vs 41%) with markedly less toxicity, establishing DDGP as a preferred frontline regimen for advanced ENKTL.
Key Limitations
Small single-center Chinese trial (n=80), limiting generalizability. Open-label design with no central response review. Pegaspargase availability and ENKTL epidemiology differ between Asian and Western populations, where the disease is rarer.
Clinical Context
ENKTL frontline therapy is built on asparaginase-containing regimens. DDGP and SMILE are both ESMO-recognized options for advanced disease; this trial supports DDGP as a less toxic alternative. No specific regulatory approval applies as these use generic agents.