Brentuximab vedotin prior to allogeneic stem cell transplantation increases survival in chemorefractory Hodgkin's lymphoma patients

A real-world analysis of PD1 blockade from the Rete Ematologica Pugliese (REP) in patients with relapse/refractory Hodgkin's lymphoma

Checkpoint inhibitors have significantly changed the prognosis of patients with relapsing refractory classical Hodgkin's lymphoma (cHL), demonstrating excellent results in heavily pretreated patients. However, there is still limited data on the real-world experience with PD-1 inhibitors in cHL. Within the context of the Apulian hematological network (Rete Ematologica Pugliese, REP), we performed a retrospective, multicenter analysis of 66 patients with relapsing refractory cHL who had received PD-1 inhibitors in the non-trial setting. Forty-three patients (65%) were treated with nivolumab and 23 (35%) with pembrolizumab. Thirty-one (47%) and 8 (12%) patients underwent autologous or allogeneic stem cell transplantation prior to checkpoint inhibitor therapy, respectively. The median number of lines of treatment attempted prior to PD-1 inhibitor therapy was 4 (range, 3 to 7). All patients had received brentuximab vedotin prior to checkpoint inhibitor therapy. The overall response rate to PD-1 inhibitors therapy was 70% (47% complete remission (CR) and 23% partial remission (PR)). Twenty-four immune-related adverse events (19 (80%) grades 1-2; 5 (20%) grades 3-4) were documented (4 gastrointestinal, 4 hepatic, 6 fever, 4 hematological, 3 dermatological, 3 allergic rhinitis). Toxicity resolved in all patients, and there were no deaths attributed to checkpoint inhibitor therapy. After a median follow-up of 26 months (range 3-72 months), 54 patients (82%) are alive, and 12 (18%) died. The cause of death was attributed to disease progression in 9 patients and sepsis in 3 patients. After PD-1 inhibitor therapy, 22 patients (33%) relapsed or progressed. The overall survival and progression-free survival at 5 years were 65% and 54%, respectively. This study confirms the efficacy and tolerability of PD-1 inhibitor therapy in relapsed refractory cHL in a real-world setting, demonstrating similar clinical outcomes and toxicity profiles compared to clinical studies.

Novel antibodies which have an impact on immune status after allogeneic hematopoietic cell transplantation

INTRODUCTION

In the field of hematological malignancy, we often have the opportunity to use antibodies such as immune checkpoint inhibitors that can alter a patient's immune status before or after allo-HCT. The appropriate use of these novel agents is highly necessary to optimize disease control and reduce the risk of complications associated with adverse allo-immune reactions.

AREAS COVERED

Clinical data on several monoclonal antibodies targeting programmed cell death 1 (PD-1) (nivolumab or pembrolizumab), C-C chemokine receptor 4 (CCR4) (mogamulizumab), CD30 (brentuximab vedotin), or cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) (ipilimumab) are reviewed, with a focus on the incidence and severity of graft-versus-host disease (GVHD).

EXPERT OPINION

While previous studies demonstrated a favorable prognosis in patients who received nivolumab prior to transplantation, the pretransplant use of nivolumab increases the incidence of GVHD, partly due to the expansion and activation of preexisting T cells. Mogamulizumab also has a significant impact on GVHD, caused by persistent depletion of regulatory T cells with CCR4 positivity. Regarding brentuximab vedotin, phase 1 trials have demonstrated considerable efficacy for steroid-refractory acute or chronic GVHD. In the future, sophisticated methods will be needed to determine the impact of each agent on immune status after allo-HCT.

Real-world outcomes of autologous and allogeneic hematopoietic stem cell transplantation for relapsed/refractory Hodgkin lymphoma in the era of novel therapies: a Canadian perspective

BACKGROUND

Despite high cure rates with frontline therapy for Hodgkin lymphoma (HL), about 30% of patients will relapse or have primary refractory disease (R/r). Autologous hematopoietic stem cell transplantation (AHSCT) is the standard of care for R/r disease and alloHSCT is a curative option for patients in second relapse. Novel agents are being incorporated for the treatment of R/r HL, such that the optimal timing of transplant is currently being challenged. Additionally, because access to these new agents varies amongst transplant centers, we sought to offer a Canadian perspective to the treatment of R/r HL and demonstrate the utility and effectiveness of both AHSCT and alloHSCT for the treatment of R/r HL.

METHODS

This single-center retrospective study examined outcomes in 89 consecutive patients with R/r HL treated with AHSCT between January 2007 and December 2019. A total of 17 patients underwent alloHSCT either as a tandem auto-allo approach or as salvage therapy.

RESULTS

With a median follow-up of 5.0 years, the estimated 5-year PFS and OS for patients undergoing AHSCT were 57.5% (95% CI 45.2-68.0) and 81.3% (95% CI 70.0-88.8), respectively. Corresponding figures for patients who underwent alloHSCT were 76.5% (95% CI 48.8-90.4) and 82.4% (95% CI 54.7-93.9). NRM at 100 days and 5 years was 0% and 9.4% post AHSCT and 0% and 5.9% post alloHSCT. Cumulative incidence (CI) of acute GVHD at day +100 was 35.3% (95% CI 17.7 - 62.3) and CI of chronic GVHD at 1 year was 23.5% (95% CI 6.9 - 45.8).

CONCLUSIONS

AHSCT and alloHSCT can both provide robust and prolonged disease control and new agents should be used as a bridge to improve the curative potential of these definitive cellular therapies.

Relapsing/refractory HL after autotransplantation: which treatment?

For advanced-stage Hodgkin lymphoma (HL), front-line chemotherapy, alone or in combination with radiotherapy, leads to 5-year progression-free survival (PFS) rates and freedom-from-treatment failure (FFTF) rates of 70-85%, regardless of the chemotherapy regimen applied. Patients with HL experiencing disease progression during or within 3 months of front-line therapy (primary refractory) and patients whose disease relapses after a complete response have a second chance of treatment. The standard of care for relapsed or refractory HL is second-line chemotherapy followed by autologous stem cell transplantation (ASCT), which can induce long-term remission in approximately 40-50% of patients. However, HL recurrence occurs in about 50% of patients after ASCT, usually within the first year, and represents a significant therapeutic challenge. Allogeneic transplantation from HLA-matched donors represents the standard of care for patients with HL relapsing after- or refractory to ASCT.

Antibody-drug conjugates in clinical trials for lymphoid malignancies and multiple myeloma

Antibody-drug conjugates (ADC) represent a distinct family of chemoimmunotherapy agents. ADCs are composed of monoclonal antibodies conjugated to cytotoxic payloads via specialized chemical linkers. ADCs therefore combine the immune therapy with targeted chemotherapy. Due to the distinct biomarkers associated with lymphocytes and plasma cells, ADCs have emerged as a promising treatment option for lymphoid malignancies and multiple myeloma. Several ADCs have been approved for clinical applications: brentuximab vedotin, inotuzumab ozogamicin, moxetumomab pasudotox, and polatuzumab vedotin. More novel ADCs are under clinical development. In this article, we summarized the general principles for ADC design, and updated novel ADCs under various stages of clinical trials for lymphoid malignancies and multiple myeloma.