A multicenter study of gemcitabine-containing regimen in relapsed or refractory Hodgkin's lymphoma patients

Brentuximab vedotin in relapsed/refractory Hodgkin lymphoma post-autologous transplant: meta-analysis versus historical data

OBJECTIVE

This meta-analysis evaluated the antitumor activity of brentuximab vedotin versus historical values in patients with relapsed/refractory Hodgkin lymphoma post-autologous stem cell transplantation (ASCT).

METHODS

A systematic literature review identified studies (1993-February 2013) reporting complete remission (CR) rates in patients with relapsed/refractory Hodgkin lymphoma post-ASCT. Publications reporting CR rates, identified through interrogation of multiple electronic databases and manual searches (with search terms used to capture 'relapsed', 'refractory', 'HL', and 'ASCT'), were included if they reported: ≥20 relapsed/refractory Hodgkin lymphoma patients, where ≥80% were aged ≥12 years and ≥50% had failed prior ASCT. Overall CR rate was determined using a random-effect model, and compared with that reported for brentuximab vedotin in a pivotal phase 2 trial (SG035-0003).

MAIN OUTCOME MEASURES

Across 17 evaluable studies of historical or experimental agents (n = 812), the estimated overall CR rate was 11.1% (95% confidence interval [CI] 7.0, 17.6; range, 0-38.5%) versus 33.3% (95% CI 25.3, 43.9) for brentuximab vedotin (p < 0.0001). In sensitivity analyses, the estimated overall CR rates for historical/experimental agents were 13.6% (95% CI 8.7, 21.4) when only HL trials that reported a CR rate of >0% were included (13 studies; n = 696; p = 0.0009 vs. brentuximab vedotin), and 9.0% (95% CI 4.9, 16.6) when only HL trials were included where CR definition was reported and was measured using the same criteria as in the SG035-0003 study (12 studies; n = 562; p = 0.0001 vs. brentuximab vedotin).

CONCLUSIONS

Indirect comparisons against a heterogeneous historical sample population naturally limit our ability to draw comparisons, yet the results from this quantitative meta-analysis suggest that the antitumor activity of brentuximab vedotin may exceed that of other therapies used to treat patients with relapsed/refractory Hodgkin lymphoma post-ASCT.

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.

Gemcitabine and oxaliplatinum: an effective regimen in patients with refractory and relapsing Hodgkin lymphoma

Background

Most Hodgkin lymphomas (HL) can be cured with current strategies. However, one-third of the cases do not respond or relapse and need salvage regimens. We report the results of a retrospective study using the gemcitabine and oxaliplatinum (GemOx) regimen.

Methods

Patients who relapsed or failed to achieve complete response were eligible and received GemOx salvage therapy. To avoid selection bias and thus to overcome the retrospective nature of the study, all treated patients were included from the pharmacy database.

Results

Between 2003–2013, 24 HL patients – relapsing (number [n]=12) or refractory (n=12) – were included, receiving a total of 26 induction treatments with GemOx. Mean previous regimens were 2.38 (42% relapsing after autologous transplantation). Median follow-up was 37 months, and 71% responded (38% of patients achieved complete response). The factors related to better progression-free survival were: B symptoms; response to GemOx; and consolidation with stem cell transplantation. Grades 1 and 2 neurological toxicity was present in 17% of patients. Hematological toxicity was common, with grades 3 and 4 neutropenia (25%) and thrombocytopenia (34%) observed. Progression-free survival was better in patients consolidated with stem cell transplantation. The peripheral blood stem cell collection after GemOx was successful for all candidates.

Conclusion

1) The GemOx regimen is effective in relapsed or refractory HL with manageable toxicity. 2) No mobilization failures were observed. 3) Consolidation after response is needed. 4) Its efficacy and favorable toxicity profile might make multiple administrations possible in several recurrences in HL.

Changing therapeutic landscape--the last decade

Undoubtedly the most important event in the previous decade in lymphoma treatment was the establishment of immunotherapy as a prime modality. Addition of rituximab improves survival in almost every group of patients with CD20+ tumors. This has led to the appearance of a number of "me too" monoclonal antibodies (MoAbs) as well as MoAbs directed against other antigens whose usefulness remains to be proven during the next decade. We have also seen the raise and, probably unwarranted, fall of radioimmunotherapy. Conventional radiotherapy is losing ground. Regarding chemotherapy, the success of attempts to supplant R-CHOP-21 for front-line treatment of DLBCL with more dose-dense or dose-intense regimens remains doubtful and this issue is still unresolved. Bendamustine appeared as possibly the most effective cytotoxic agent for treatment of indolent lymphomas, while treatment of HL is becoming more tailored to prognostic features. This decade has also seen the advent of targeted drugs for lymphoma treatment. Their real impact will become known in the years to come. Finally, we may hope that advances in understanding the biology of lymphomas, made in the last decade, will help resolve remaining critical issues, treatment of T-NHLs and high-risk DLBCLs, being probably the most prominent.

The Role of Allogeneic Stem Cell Transplantation in Relapsed/Refractory Hodgkin's Lymphoma Patients

Despite the favorable prognosis of most patients with Hodgkin's Lymphoma (HL), 15-20% of patients remain refractory to chemoradiotherapy, and 20-40% experience relapses following autologous stem cell transplantation (SCT) being used as salvage approach in this situation. Long-term survival of only 20% was reported for patients who failed this option. As some authors suggested the presence of a graft versus HL effect, allogeneic SCT was introduced as a further option. Myeloablative strategies were reported to be able to achieve cure in some younger patients, but high nonrelapse mortality remains a problem. Reduced intensity conditioning, in turn, was found to be associated with high posttransplant relapse rates. As there is currently no standard in the management of HL patients who failed autologous SCT, we here review the literature on allogeneic stem cell transplantation in HL patients with a special focus on the outcomes and risk factors being reported in the largest studies.