SPIRIT

Background

Phase II, single-arm, multicenter study. 34 patients with newly diagnosed advanced-stage extranodal NK/T-cell lymphoma (ENKTL). ENKTL tumors express high PD-L1 (EBV-driven), providing biologic rationale for PD-1 blockade combined with asparaginase-based chemotherapy.

Interventions and follow up

Regimen: Sintilimab 200 mg IV day 1 + gemcitabine 1000 mg/m² IV days 1, 8 + oxaliplatin 130 mg/m² IV day 1 + pegaspargase 2500 IU/m² IM day 1, q21d × 6 cycles; then maintenance sintilimab q3w up to 2 years or progression
Primary endpoint: Overall response rate
Median follow-up: ~36 months

Results

ORR (primary): 100% (CR + PR in all 34 patients)
CR rate: 85.3%
2-year PFS: 64.0%
3-year OS: 76.4%
EBV DNA clearance: 100% at end of treatment

Adverse events

Hematologic: Grade ≥3 neutropenia 50%; grade ≥3 thrombocytopenia 20.6%; grade ≥3 anemia 8.8%
Immune-mediated: Hypothyroidism any grade 20.6%; grade ≥3 immune events uncommon; no grade ≥3 CRS
Mortality: No treatment-related deaths

Conclusions

Sintilimab + P-GEMOX achieved 100% ORR and 85.3% CR in newly diagnosed advanced ENKTL, with 2-year PFS 64% and 3-year OS 76%, among the most impressive published response rates in this disease and establishing PD-1 inhibitor integration as a key frontline strategy.

Key Limitations

Small single-arm Phase II without randomized comparator; ENKTL is exceptionally sensitive to asparaginase-based regimens, so the incremental benefit of sintilimab cannot be determined. Conducted in China; sintilimab is not FDA/EMA approved.

Clinical Context

SPIRIT supports PD-1 inhibitor combinations as a promising frontline approach in ENKTL, capitalizing on EBV-driven high PD-L1 expression. No PD-1 inhibitor is currently FDA or EMA approved for ENKTL; ESMO recommends asparaginase-based chemotherapy frontline, with clinical trial enrollment strongly preferred for immunotherapy integration.

References