Final Analysis of a Prospective Multicenter Phase II Trial of the Lymphoma Study Association (LYSA) Using Prednisone, Vinblastine, Doxorubicin and Bendamustine (PVAB) Regimen in First Line Therapy for Patients over 60 Years with Advanced-Stage Classical Hodgkin Lymphoma

Introduction: Older classical Hodgkin lymphoma (cHL) patients are characterized by a significant reduced survival as compared to younger patients. In relapsed and refractory HL, prospective and retrospective studies showed that bendamustine monotherapy provided interesting efficacy with 30% of complete response with an acceptable toxicity profile. We developed the PVAB (Prednisone, Vinblastine, Doxorubicin, Bendamustine) regimen in first line therapy to improve prognosis of older HL with advanced stage.

Methods: In this prospective phase II, we recruited newly diagnosed classical HL patients age of 61 years or older with an advanced stage (Ann Arbor stage III, IV, IIB with risk factors). Inclusion criteria were: ECOG performance status 0-2; adequate cardio-pulmonary function with LVEF ≥ 50%; adequate renal function with creatinine clearance ≥ 40 mL/min; HIV negative; For patients aged 70 years old and more, a Mini Nutritional Assessment (MNA) ≥ 17. Treatment consisted of 6 cycles of prednisone (40mg/m ² D1-5), vinblastine (6mg/m ², D1), doxorubicin (40mg/m ², D1) and bendamustine (120mg/m ², D1) every 21 days. The primary endpoint was the complete metabolic response (CMR) rate according to local review after 6 cycles of study treatment or at premature treatment discontinuation according to Lugano Classification. We presented the final analysis of the study with a median follow-up of 42 months (range, 0.5-63.8), with prognostic analyses for progression free survival (PFS) measured from the date of inclusion to the date of progression, relapse or death from any cause. Prognostic factors included baseline clinical and biological characteristics, geriatric assessments and 18F-FDG PET/CT metabolic parameters especially baseline total metabolic tumor volume (TMTV). Optimal thresholds for some parameters were calculated using X-Tile approach.

Results: Between July 2015 and July 2018, 89 patients were included in 34 LYSA centers. The median age was 68 years (range, 61-88) with 35 patients ≥70 years old (39%). The main histological subtype was nodular sclerosis cHL (n=56, 63%) with 26 EBV associated cases (LMP1 staining). Ann Arbor stages were as follows: II (n=3, 3%), III (n=30, 34%), IV (n=56, 63%). B symptoms were present in 57% of patients; 70 patients (80%) had IPS≥3. The median of CIRS-G score was 3 (range, 0-12). Seventy-eight patients (88%) completed the 6 cycles of PVAB. Update results for toxicity showed that 28 patients (32%) presented at least one serious adverse event (SAE) in particular infections (n=13, 15%), blood (n=11, 12%) and cardiac disorders (n=4, 4.5%). The CMR rate according to local review corresponding to the primary endpoint of the study was 77.5% (95%CI, 67-86) with 69 patients in CMR. After central review of 79 available PET/CT images, the CMR rate was 78.5%. Thirty-one patients relapsed or progressed (35%). The 4-year PFS rate was 50% (95%CI, 39-61). For the 69 patients achieving CMR, the 4-year disease free survival (DFS) rate was 62.8% (95%CI, 49-74). Twenty-four patients (27%) died: 11 cHL (46%), 4 treatment toxicity (17%), 6 second cancers (25%), 3 other causes after treatment (infection, cardiac insufficiency, pulmonary embolism, 12%). The 4-year overall survival rate was 69% (95%CI, 57-79). In univariate analysis, altered ECOG PS, Ann Arbor stage IV, bulky disease (>7cm), B-symptoms, extra-nodal involvement (>1), bone or medullar involvement, liver involvement, albumin (≤30g/l), hemoglobin level (<10.5g/dl), lymphocyte count (<0.8 G/L), leucocyte count (≥12G/L), CD4+ lymphocyte count (<0.41G/L), B2 microglobuline level (3 mg/l), CRP level (>88mg/l), TMTV (>450ml) and number of medications non-related to HL (>5) were associated with PFS. In multivariate analysis, liver involvement (HR: 3.79; 95%CI,1.71-8.43; P=0.001), lymphopenia (HR: 3.04; 95%CI,1.54-6.01; P=0.001), CRP (HR: 3.37; 95%CI, 1.69-6.69; P=0.0005) and co-medications (HR: 2.85; 95%CI,1.44-5.66; P=0.003) were independently associated with PFS.

Conclusions: PVAB regimen provided high CMR (77.5%) with acceptable toxicity for advanced stage cHL patient over 60 years. The 4-year PFS and OS rates were 50% and 69% respectively, these survival endpoints were influenced by not related-lymphoma events. Prognostic analyses showed that specific involved site (liver), biological parameters (lymphocyte count and CRP) and patient's comorbidity (co-medications) influenced independently PFS.