Outcomes Among Classical Hodgkin Lymphoma Patients After an Interim PET Scan: A Real-World Experience.

INTRODUCTION: The utility of dose escalation after positive positron emission tomography following 2 cycles of ABVD (PET2) for Hodgkin Lymphoma (HL) remains controversial. We describe the United States real-world practice patterns for PET2 positive patients. PATIENTS AND METHODS: Data was collected from 15 sites on PET2 positive HL patients after receiving frontline treatment between January, 2015 and June, 2019. Descriptive analyses between those with therapy change and those continuing initial therapy were assessed. RESULTS: A total of 129 patients were identified; 111 (86%) were treated with ABVD therapy and 18 (14%) with an alternate regimen. At PET2 assessment, 74.4% (96/129) had Deauville score (DS) 4 and 25.6% (33/129) had DS 5. Of the 66 limited stage (LS) patients with PET2 DS score of 4/5, 77.3% (51/66) continued initial therapy and 22.7% (15/66) changed to escalated therapy. The 12-month progression-free survival (PFS) for DS 4/5 LS patients was 67.0% (95% CI; 54.9-81.7) for patients without escalation compared with 51.4% (95% CI; 30.8-85.8) for those who escalated. Of the 63 DS 4/5 patients with advanced stage (AS) disease, 76.2% (48/63) continued initial therapy and 23.8% (15/63) changed to escalated therapy. The 12-month PFS for DS 4/5 AS patients was 38.3% (95% CI: 26.3%-55.7%) for patients without escalation compared with 57.1% (95% CI: 36.3-89.9) for those with escalation. CONCLUSION: A minority of PET2 positive HL patients undergo therapy escalation and outcomes remain overall suboptimal. Improved prognostics markers and better therapeutics are required to improve outcomes for high-risk PET2 positive HL patients.