Early Treatment Intensification in Advanced-Stage High-Risk Hodgkin Lymphoma (HL) Patients, with a Positive FDG-PET Scan After Two ABVD Courses – First Interim Analysis of the GITIL/FIL HD0607 Clinical Trial

Interim FDG-PET performed after 2 chemotherapy courses (PET-2) is the most powerful predictor of treatment outcome in advanced-stage, ABVD-treated HL (AAHL) patients (pts). Whether early therapy intensification in PET-2 positive HL pts improves overall treatment efficacy for all AAHL pts compared to standard ABVD is still unproven.

In the HD 0607 clinical trial (ClinicalTRial.gov identifier 00795613), AHL (stage IIB-IVB) pts prospectively enrolled by 26 Italian and one Israelian institution are treated with 2 ABVD courses and a PET-2 performed afterwards. PET-2+ pts are randomized to either BEACOPP escalated (Be) plus BEACOPP baseline (Bb) (4+4 courses) or Be+Bb (4+4) and Rituximab (R). PET-2 negative pts are treated with 4 additional ABVD and, upon CR achievement, randomized to either consolidation radiotherapy (Rxt) on the sites of initial bulky disease or no further treatment. Primary endpoint is the efficacy and feasibility of the overall therapeutic strategy. All the non-negative PET-2 (nnPET-2), defined as scans without any residual FDG uptake in any site outside the physiological areas of the tracer concentration, are uploaded in a website for blinded independent central review (BICR) by 6 nuclear medicine experts. Scans are interpreted by visual assessment according to the Deauville 5-point scale (5PS).

Starting from 07/2008 till 07/2012, 497 AHL pts were consecutively enrolled and 446 scanned with PET-2. 189/446 (42%) PET-2scans, judged as nnPET-2 by the local PET center, underwent review: 92 were adjudged as positive (62 score 4, 30 score 5) and 97 as negative (score 1–3). Altogether, of 446 pts scanned with a PET-2, 92 (20%) resulted positive and 354 (80%) negative. Age, sex, stage III-IV, bulky, extranodal sites or IPS class where equally distributed among PET-2 positive and negative pts.(p>.05). The median time from PET uploading in the website to review was 45.38 hours, (1–119). The BICR yielded a binary concordance rate among pair of reviewers “very good”, ranging from 0.77 to 0.83 (Cohen's k coefficient) and a overall concordance rate of 0.77 (Krippendorf's alpha). In 92 PET-2+ pts, 60 showed a single site of residual uptake in mediastinal (48), laterocervical (4), supraclavear (2), abdominal (3), axillary (1) nodes and in lung (2).In 32 there were ≥ 2 sites of persistent FDG uptake. In 38/40 pts with a positive PET-2 and bulky disease at baseline the residual FDG uptake (singe or multifocal) was seen within the bulky lesion. Overall response to treatment could be assessed in a cohort of 263 pts who had been fully restaged after lymphoma treatment. Forty-one (15%) had a positive and 222 (84%) a negative PET-2 scan. The relative dose intensity (RDI) for Be+Bb ± R and ABVD ± RxT treated pts. was 94.7% and 97.8%, respectively. Among 41 PET-2+ pts CR was achieved in 30 (73%), PR in 1 (2%) Progression or Relapse (Pro/Rel) in 8 (19%) and not evaluable (NE) in 2(5%). Among 222 PET-2- pts. CR was achieved in 212 (95.5%), PR in 2 (1%), Pro/Rel in 6 (3%), NE in 1 (0,5%). Treatment efficacy could be assessed in a cohort of 187 pts. with a complete treatment and a minimum follow-up of 12 months from treatment completion: 27 (15%) with a positive PET-2, treated with Be+Bb ± R and 160 (85%) with a negative PET-2, treated with ABVD ± RxT. The median follow-up from diagnosis was 845 days (101–1345). Among 27 PET-2+ pts, CCR (Continuous CR) was recorded in 22 (81%) Pro/Rel in 5 (18%). Three patients died in CR: 2 for septic shock and one for pneumonia. Among 160 PET-2- pts. CCR was recorded in 146 (91%), Pro/Rel in 9 (5%), Lost of FU (in CR) in 5 (3%). The 1-y PFS was 80.5%, 97.3% and 94.7% for PET-2+, PET-2- p, and for the entire population, respectively. Overall, treatment was well tolerated: 512 Adverse effects were reported: WHO grade 0+1: 453, grade 2: 45. Grade 3 were observed in 12 pts: anemia (2), neutropenia (6), pancytopenia (1), sepsis (1), diverticulitis (1), Vomiting (1). Grade 4 in 2 pts: pneumonia and neutropenia.

These preliminary findings suggest that 1) an early switch from ABVD to escalated BEACOPP can be done safely in PET-2 positive pts, with CR achievement in the majority of cases; 2) a centralized online PET scan review system is feasible and allows a real time decision making process, without significant reduction in the RDI administered; 3) 5PS is a reliable interpretation criteria for interim PET scan, with a very good concordance rate among reviewers.

No relevant conflicts of interest to declare.