Nivolumab for Heavily Pretreated Relapsed/Refractory Hodgkin Lymphoma: Real-Life Experience in Spain (Spanish Group of Lymphoma and Bone Marrow Transplantation, GELTAMO)

Background: Nivolumab, an immune checkpoint inhibitor, has been tested in patients with classical Hodgkin lymphoma (cHL) who failed standard treatment options and has demonstrated remarkable activity with acceptable safety profile in clinical trials. After the impressive results of nivolumab phase I study, a significant number of patients were granted early access to nivolumab through a Name Patient Program (NPP) or compassionate use in Spain. Demonstrating that results of nivolumab use in real-life are similar to those in clinical trials is of major clinical relevance.

Objective: The aim of this retrospective study was to analyze the efficacy and safety profile of nivolumab for the treatment of relapsed/refractory (RR) cHL in a real-life context.

Methods: We retrospectively collected data from 34 GELTAMO centers. Eligible patients included RR cHL patients treated with at least one cycle of nivolumab. The primary end-point was to describe the overall response rate (ORR). Secondary objectives were to assess the complete response rate (CR), safety of nivolumab, and clinical outcomes (overall survival [OS], and progression free survival [PFS]).

Results: Between September 2015 and May 2018, 74 patients with RR cHL received nivolumab monotherapy dosed at 3mg/kg once every 2 weeks (97%). The median age was 38 years (range 17-78). Patients have received a median of 4 (1-15) prior therapy lines; all but 2 were previously treated with brentuximab vedotin (97%), and 38 (51%) of them underwent a hematopoietic stem cell transplantation (HSCT) (n=33 autologous, autoHSCT, and n=5 allogeneic, alloHCST). Median number of nivolumab cycles was 8 (1-65). Ten (14%) patients are still on treatment. Reasons for nivolumab discontinuation were disease progression in 23/64 (36%), referral to HSCT in 27/64 (42%), adverse events (AE) in 8/64 (13%), patient or physician's decision in 5/64 (8%), and unknown in 1/64 (1%). Treatment related AE were reported in 42/69 (61%). Half of them (21, 30%) were probably immune related AE: grade 1-2, 67% (cutaneous n=5, hepatitis n=3, hypothyroidism n=3, gastrointestinal n=3, suprarenal insufficiency n=1); grade 3-4, 24% (pneumonitis n=2, hepatitis n=1, encephalitis n=1, hypothyroidism n=1); grade 5, 3% (pneumonitis n=1, Stevens-Johnson syndrome + hepatitis + nephritis n=1). ORR was 58% (CR 21/72 patients, partial response [PR] 21/72). Stable disease (SD) was achieved in 9 patients (13%). After an initial response (4 PR and 3 SD), 7 patients developed lymphoma progression. A total of 40 (54%) patients finally underwent HSCT, 4 autoHSCT and 36 alloHCST. AlloHSCT was performed after a median of 63 days (41-115) and 8 patients received prior salvage therapy. Complications after alloHSCT consisted of non-infectious fever requiring steroid treatment in 13 (36%), acute graft-versus-host disease in 19 (53%) (2 of them grade 3-4, 1 death), hepatic venocclusive disease in 2 (6%, 1 death), and non-infectious pulmonary complications in 2 (6%). Five (14%) patients died due to transplant complications. At the last follow-up, all autoHSCT patients and 23/36 alloHSCT were in CR. The 2-year OS for the whole series (n=74) was 54% (median not reached). After a median follow-up of survivors patients of 12.5 months (1-31), 29 (39%) were alive in CR.

Conclusions: Our real-life experience confirms the efficacy of nivolumab in very heavily pretreated cHL patients with an ORR of 58%. The safety profile of our cohort is comparable with that previously reported in clinical trials with manageable side effects and low treatment related mortality. In our study the percentage of patients who bridged to transplantation was significantly higher to that previously reported indicating this preference for Spanish physicians. AlloHSCT post-nivolumab showed encouraging results and toxicity seemed comparable to that previously described with other treatment regimens.

Authors thank Bristol Myers Squibb for its support in this study.