Role of hematopoietic stem cell transplantation in relapsed/refractory hodgkin lymphoma

Brentuximab vedotin compared with other therapies in relapsed/refractory Hodgkin lymphoma post autologous stem cell transplant: median overall survival meta-analysis

OBJECTIVE

This meta-analysis compared the median overall survival (mOS) of brentuximab vedotin reported in the pivotal phase 2 study with published results of other therapies for the treatment of relapsed/refractory (R/R) Hodgkin lymphoma (HL) post autologous stem cell transplant (ASCT).

RESEARCH DESIGN AND METHODS

A systematic literature review identified studies that reported survival outcomes following conventional/experimental therapies in R/R HL patients, with ≥50% having failed ≥1 ASCT. Kaplan-Meier curves were used to reconstruct individual patient level survival data. Patients were grouped by treatment type and reconstructed data were used to estimate the mOS. Censored median regression modeling was used to compare mOS in each group with the mOS in the pivotal brentuximab vedotin trial. All patients in the pivotal trial had undergone ASCT, therefore a sensitivity analysis was conducted among studies with a 100% post-ASCT patient population.

RESULTS

The mOS reported for brentuximab vedotin was 40.5 (95% CI 30.8-NA) compared with 26.4 months (95% CI 23.5-28.5) across all 40 studies identified (n = 2518 excluding the brentuximab vedotin trial) (p < 0.0001). The difference in mOS between brentuximab vedotin and chemotherapy, allogeneic stem cell transplant (allo-SCT), and other therapies, was 17.7 (95% CI 10.6-24.7; p < 0.0001), 12.5 (95% CI 8.2-16.9; p < 0.0001), and 15.2 months (95% CI 4.9-25.5; p = 0.0037), respectively. For the 11 studies reporting a 100% prior-ASCT rate (n = 662 excluding the brentuximab vedotin trial), the mOS was 28.1 months (95% CI 23.9-34.5), and the difference in mOS between brentuximab vedotin, chemotherapy, allo-SCT, and other therapies was 19.0 (95% CI 12.9-25.1; p < 0.0001), 9.4 (p > 0.05), and 6.8 months (95% CI 1.2-12.5; p = 0.0018), respectively.

CONCLUSIONS

While some selection bias may occur when comparing trials with heterogeneous eligibility criteria, in the absence of randomized controlled trial data these results suggest brentuximab vedotin improves long-term survival and is associated with longer mOS in R/R HL post-ASCT compared with other therapies.

Treatment outcome in children and adolescents with relapsed Hodgkin lymphoma--results of the UK HD3 relapse treatment strategy

The purpose of this national retrospective study was to evaluate the outcome in children with relapsed or primary refractory Hodgkin lymphoma [HL] after a primary chemotherapy alone treatment strategy. Between 2000 and 2005, 80 children with relapsed [n = 69] or primary refractory [n = 11] HL were treated on a standardized treatment protocol of 4-6 cycles of EPIC [etoposide, prednisolone, ifosfamide and cisplatin] chemotherapy. Radiotherapy was recommended to all relapsed sites. High dose therapy with stem cell rescue [SCT] was recommended for patients with poor response. The 5-year overall survival [OS] and progression-free survival from relapse was 75·8% [64·8-83·9] and 59·9% [48·3-69·7] respectively. Duration of first remission was strongly associated with OS; risk of death was decreased by 53% [Hazard ratio (HR): 0·47, 95% confidence interval (CI): 0·19-1·18] for those with a time from end of treatment to relapse of 3-12 months (compared to <3 months) and reduced by 80% (HR 0·20, 95% CI: 0·04-0·90) for those >12 months after end of treatment. Other poor prognostic factors included advanced stage disease at relapse and B symptoms at first diagnosis. The most important factor associated with salvage failure was time to relapse. Survival outcome in children with primary refractory HL is poor.

Unrelated and alternative donor allogeneic stem cell transplant in patients with relapsed or refractory Hodgkin lymphoma: a systematic review

Abstract Allogeneic stem cell transplant (allo-SCT) is considered a clinical option for patients with Hodgkin lymphoma (HL) who have experienced at least two chemosensitive relapses. The aim of this systematic review was to determine the benefits and harms of allo-SCT with an unrelated donor (UD) versus related donor (RD) allo-SCT for adult patients with HL. Alternative donor sources such as haploidentical donor cells (Haplo) and umbilical cord blood (UCB) were also included. The available evidence was limited. Ten studies were included in this assessment. Four studies provided sufficient data to compare UD with RD allo-SCT. None of these studies was a randomized controlled trial. Additionally, three non-comparative studies, such as registry analyses, which considered patients with UD transplants were included. The risk of bias in the studies was high. Results on overall and progression-free survival (PFS) showed no consistent tendency in favor of a donor type. Results on therapy-associated mortality and acute (grade II-IV) and chronic graft-versus-host disease were also inconsistent. The study comparing UCB with RD transplants and two non-comparative studies with UCB transplants showed similar results. One of the studies comparing additionally Haplo with RD transplants indicated a benefit in PFS for the Haplo transplant group. In summary, our findings do not indicate a substantial outcome disadvantage of UD and alternative donor sources versus RD allo-SCT for adult patients with advanced HL.

Hematopoietic progenitor cells transplantation for recurrent or refractory Hodgkin's lymphoma

INTRODUCTION

Advanced-stage Hodgkin's lymphoma (HL) has become a curable disease in the majority of patients. Despite this, about 20% of these patients relapsed or are primary refractory to the first-line treatment and high-dose chemotherapy (HDC) and autologous (Auto) hematopoietic progenitor cells transplantation (HPCT) are considered a therapeutic option.

AREAS COVERED

The authors reviewed HDC and HPCT treatment strategies in recurrent or refractory HL patients, with the goal of providing an overview of this approach.

EXPERT OPINION

Patients younger than 60-65 years with relapsed disease or refractory to first-line therapy should receive a second-line chemotherapy, followed by HDC and Auto-HPCT. Progression-free and overall survival results are significantly better when a second remission or a minimal disease status is achieved before Auto-HPCT, and demonstrate that this strategy is able to cure more than half of the advanced HL patients. Myeloablative allogeneic HPCT (Allo-HPCT) has been employed in advanced phases of the disease, but there have been significant concerns due to treatment-related mortality (TRM). The safety of allogeneic transplantation has improved with the use of reduced-intensity allogeneic (RIC-Allo) HPCT strategies. Despite early favorable results, mature results of RIC-Allo available in the literature are consistent in demonstrating a lack of long-term disease control.