Phase II trial of GVDexa (gemcitabine, vinorelbine and dexamethasone) regimen in relapsed/refractory Hodgkin's lymphoma

Background: Gemcitabine, vinorelbine and liposomal doxorubicin (GVD) is an effective regimen in relapsed/refractory Hodgkin's lymphoma (RRHL). Conventional second-line chemotherapy is still required as the cost of immunotherapy and antibody-drug conjugates are prohibitive to Indian patients. We report the results of a phase II, open-label, single-arm, single centre interventional study in RRHL where dexamethasone replaced liposomal doxorubicin. Methods: Adult patients (≥18 years) with RRHL at first or second relapse were included. GVDex was delivered as outpatient once in 3 weeks (Gemcitabine 1000 mg/m2 IV over 30 min on D1,8;Vinblastine 25 mg/m2 IV fast infusion on D1,8;Dexamethasone 40 mg PO D1-4) for two cycles followed by interim PET CT assessment by Cheson's criteria and Deauville scoring. The primary endpoint was the objective response rate (ORR = complete response + partial response). The sample size was calculated using Fleming's 2-stage model (α error: 0.05 and power: 0.8). Twenty patients were required in the first stage. If there were ≥16 responses, the null hypothesis would be rejected and the study stopped. Results: Between May 2016, and December 2020, 26 patients with RRHL were screened, and 20 were enrolled: primary resistant HL-8 patients (40%) and relapsed HL-12 patients (60%). The median age was 35 years (range:20-52). Six patients (30%) presented with limited stage and 14 patients (70%) with advanced stage HL at relapse. GVdex was delivered as a first salvage regimen in 18 patients (90%) and second in 2 patients. After 2 cycles of GVDex, 16 (80%) had responded [partial response: 12 (60%);complete response: 4 (20%)]. Median number of cycles of GVDex: 3 (range: 1-4). Five patients (25%) required dose reductions due to chemotherapy-related toxicities. The median duration of objective response was 13.4 months. Eleven patients (55%) underwent highdose chemotherapy supported by autologous stem cell rescue. After a median follow-up of 25 months (95% CI: 5.9-44.5), the median progression-free survival (PFS) was 24.7 months, and the median overall survival (OS) has not been reached. The estimated 2-year PFS was 44%, and the 2-year OS was 79%. The most common treatment-related adverse events were anemia (100%), neutropenia (70%, 14/20) and fatigue (70%, 14/20). Grade 3 or 4 treatment-related AEs occurred in 14 patients (70%). Grade ≥3 neutropenia occurred in 9 patients (45%) and febrile neutropenia in 3 patients (15%). Serious adverse events were reported in 3 patients (15%). One patient developed Ficat and Arlet classification stage III avascular necrosis of the femoral head. One patient died due to suspected COVID-19 pneumonia (non-neutropenic fever) before cycle 2 of chemotherapy. Conclusions: GVDex it is an effective salvage regimen with acceptable toxicity in patients with RRHL.