Background
Phase 3, open-label, 2×2 factorial RCT (GHSG HD10). N=1,190 patients with untreated early-stage favorable classical Hodgkin lymphoma (stage IA/IIA, no bulky disease, ESR <50 without B symptoms or <30 with B symptoms, ≤3 lymph node areas). Randomized to four arms comparing 2 vs 4 cycles of ABVD and 20 Gy vs 30 Gy involved-field radiotherapy (IF-RT).
Interventions and follow up
Arm A: 2×ABVD + 20 Gy IF-RT (least intensive arm)
Arm B: 4×ABVD + 30 Gy IF-RT (most intensive arm; two intermediate arms also included in 2×2 factorial design)
Primary endpoint: Freedom from treatment failure (FFTF)
Median follow-up: 79 months (primary); 10 years (Sasse et al, JCO 2017)
Arm B: 4×ABVD + 30 Gy IF-RT (most intensive arm; two intermediate arms also included in 2×2 factorial design)
Primary endpoint: Freedom from treatment failure (FFTF)
Median follow-up: 79 months (primary); 10 years (Sasse et al, JCO 2017)
Results
5-yr FFTF (all arms): 91–93% — no significant difference across any arm
10-yr PFS (2-cycle vs 4-cycle): 87% vs 87%, HR 1.0 (95% CI 0.6–1.5) — noninferior
10-yr PFS (20 Gy vs 30 Gy): 86% vs 87% — noninferior
10-yr OS: 94% both groups, HR 0.9 (95% CI 0.5–1.6)
10-yr PFS (2-cycle vs 4-cycle): 87% vs 87%, HR 1.0 (95% CI 0.6–1.5) — noninferior
10-yr PFS (20 Gy vs 30 Gy): 86% vs 87% — noninferior
10-yr OS: 94% both groups, HR 0.9 (95% CI 0.5–1.6)
Adverse events
Late effects: Numerically fewer secondary malignancies and cardiac events in less intensive arms at 10-year follow-up, though not statistically significant
Acute toxicity/mortality: No significant differences in grade ≥3 acute toxicity across arms; treatment-related mortality <1% in all arms
Acute toxicity/mortality: No significant differences in grade ≥3 acute toxicity across arms; treatment-related mortality <1% in all arms
Conclusions
Two cycles of ABVD plus 20 Gy IF-RT was noninferior to four cycles plus 30 Gy for FFTF and OS, establishing the minimally intensive regimen as the international standard of care for early-stage favorable cHL. Ten-year follow-up confirmed durable disease-control equivalence.
Key Limitations
FFTF is a surrogate endpoint that does not capture differential late treatment-related mortality between arms. IF-RT fields (larger than modern INRT/ISRT) overestimate the late-effect risk of current RT approaches. PET staging was not used, so a subset with occult advanced disease may have been included. The GHSG favorable-risk definition (ESR thresholds) differs from other guideline criteria. No PET-adapted de-escalation arm was tested, leaving open whether PET-negative patients can safely omit RT entirely.
Clinical Context
HD10 remains the foundational trial for early-stage favorable cHL worldwide, incorporated into ESMO guidelines as the basis for 2×ABVD + 20 Gy as the minimum effective regimen. Subsequent RAPID and H10 trials showed RT omission in PET-negative patients fails noninferiority criteria, confirming RT remains essential after 2-cycle ABVD. Modern protocols substitute INRT or ISRT for IF-RT to reduce late toxicity while maintaining efficacy.
References