Abstract P037

PET-Adapted EACODD-14 Regimen in Early Unfavorable and Advanced Stages of Classical Hodgkin Lymphoma: Efficacy and Survival in the Multicenter HL-Russia-1 Study

Background: Optimal first-line treatment for classical Hodgkin lymphoma (cHL) requires balancing efficacy and toxicity. The intensive EACODD-14 regimen (a modification of EA(50)COPP-14 substituting procarbazine/prednisone with dacarbazine/dexamethasone) demonstrated high efficacy and manageable toxicity in single-center trials. HL-Russia-1 evaluates PET-adapted approach in a real-world multicenter setting across Russia.

Aims: To assess the real-world effectiveness, PET-response dynamics, and survival outcomes of the PET-adapted EACODD-14 in patients (pts) with early stages unfavorable prognosis (ESUP) and advanced stages (AS) of cHL.

Methods: HL-Russia-1 (NCT04638790) is a prospective multicenter study. ESUP received 2 cycles of EACODD-14; PET-2-negative pts proceeded to 2 cycles of AVD, while PET-positive pts received 2-4 additional cycles of EACODD-14. AS pts received 6 cycles of EACODD-14. Consolidation involved-site radiotherapy (ISRT) was indicated for bulky disease, residual masses ≥2.5 cm, or PET-positive residual lesions. Primary neutropenia prophylaxis with pegG-CSF was recommended. Survival was analyzed using the Kaplan-Meier method.

Results: Between Nov 2020 and Apr 2026, 13 centers enrolled 349 pts. We analyzed 283 pts with ESUP and AS treated with EACODD-14.

Baseline: Median age was 30 years (18 – 64), 59.3% male. AS 64.1%, ESUP 26.6%. Pts with ESFP received ABVD and were excluded. IPS >2 for AS: 33.1%.

PET Response: PET-2 evaluable in 243 pts (85.9%); complete metabolic response (CMR, DS 1-3) in 64.7%. PET-4 and PET-6 CMR rates were 74.3% and 88.9%.

Radiotherapy: RT performed in 36.3% of pts; omitted in 44.6% of ESUP and 71.5% of AS pts with CMR and residual masses <2.5 cm.

Efficacy & Survival: EOT remission rate 93.5%. With a median follow-up of 9.4 months (range 1-58.2), the estimated 2-year progression-free survival (PFS) for the entire EACODD-14 cohort is 90.3% (95% CI: 84.6% - 93.9%). For ESUP, 2-year PFS is 95.0% (95% CI: 84.9% - 98.4%), and for AS, it is 88.2% (95% CI:80.6% - 92.9%). Overall survival is 100%. Treatment failures occurred in 18 pts.

Conclusion: Updated HL-Russia-1 confirms that PET-adapted EACODD-14 is highly effective and feasible in a real-world multicenter setting. High early metabolic response rates allow safe radiotherapy omission in a significant proportion of pts, minimizing long-term toxicity without compromising PFS. This platform demonstrates robust outcomes across federal and regional centers.