Chemotherapy after PD-1 inhibitors in relapsed/refractory Hodgkin lymphoma: Outcomes and clonal evolution dynamics

Outcome of High-Dose Chemotherapy Followed by Autologous Stem Cell Transplantation in Relapsed/Refractory Hodgkin Lymphoma after Different Numbers of Salvage Regimens

The introduction of novel drugs (PD-1 inhibitors and/or brentuximab vedotin) into salvage regimens has improved the response rate and the outcome of patients with relapsed/refractory Hodgkin lymphoma. However, the impact of new drugs on the outcome has not been adequately investigated so far. We retrospectively analyzed 42 consecutive patients treated at our institution with high-dose chemotherapy/autologous stem cell transplantation after either one standard chemotherapy represented by BEGEV (n = 28) or >1 salvage therapy (ST) comprising novel drugs (n = 14). With a median follow-up of 24 months, the 2-year cumulative incidence of relapse was similar between the two cohorts: 26% for 1 ST and 18% for >1 ST (p = 0.822). Consistently, overall survival and progression-free survival did not differ among the two groups: 3-year overall survival was 91% and 89% (p = 0.731), respectively, and 3-year progression-free survival was 74% and 83% (p = 0.822) for only one and more than one salvage regimens, respectively. Of note, the post-transplant side effects and engraftment rates were similar between the 1 ST and >1 ST cohorts. In conclusion, consolidation with high-dose chemotherapy/autologous stem cell transplantation is a safe and curative option, even for patients achieving disease response after more than one rescue line of therapy.

Nivolumab for relapsed/refractory classical Hodgkin lymphoma: 5-year survival from the pivotal phase 2 CheckMate 205 study

Patients with relapsed/refractory (R/R) classical Hodgkin lymphoma (cHL) for whom autologous hematopoietic cell transplantation (auto-HCT) had failed experienced frequent and durable responses to nivolumab in the phase 2 CheckMate 205 trial. We present updated results (median follow-up, ∼5 years). Patients with R/R cHL who were brentuximab vedotin (BV)-naive (cohort A), received BV after auto-HCT (cohort B), or received BV before and/or after auto-HCT (cohort C) were administered with nivolumab 3 mg/kg IV every 2 weeks until progression or unacceptable toxicity. Patients in cohort C with complete remission (CR) for 1 year could discontinue nivolumab and resume upon relapse. Among 243 patients (cohort A, n = 63; B, n = 80; and C, n = 100), the objective response rate (ORR) was 71.2% (95% confidence interval [CI], 65.1-76.8); the CR rate was 21.4% (95% CI, 16.4-27.1). Median duration of response, CR, and partial remission were 18.2 (95% CI, 14.7-26.1), 30.3, and 13.5 months, respectively. Median progression-free survival was 15.1 months (95% CI, 11.3-18.5). Median overall survival (OS) was not reached; OS at 5 years was 71.4% (95% CI, 64.8-77.1). In cohort C, all 3 patients who discontinued in CR and were subsequently re-treated achieved objective response. No new or unexpected safety signals were identified. This 5-year follow-up of CheckMate 205 demonstrated favorable OS and confirmed efficacy and safety of nivolumab in R/R cHL after auto-HCT failure. Results suggest patients may discontinue treatment after persistent CR and reinitiate upon progression. This trial was registered at www.clinicaltrials.gov as #NCT02181713.

Optimizing Treatment for Relapsed/Refractory Classic Hodgkin Lymphoma in the Era of Immunotherapy

Most patients with classic Hodgkin lymphoma (cHL) are cured with combination chemotherapy, but approximately 10-20% will relapse, and another 5-10% will have primary refractory disease. The treatment landscape of relapsed/refractory (R/R) cHL has evolved significantly over the past decade following the approval of brentuximab vedotin (BV), an anti-CD30 antibody-drug conjugate, and the PD-1 inhibitors nivolumab and pembrolizumab. These agents have significantly expanded options for salvage therapy prior to autologous hematopoietic cell transplantation (AHCT), post-transplant maintenance, and treatment of relapse after AHCT, which have led to improved survival in the modern era. In this review, we highlight our approach to the management of R/R cHL in 2023 with a focus on choosing first salvage therapy, post-transplant maintenance, and treatment of relapse after AHCT. We also discuss the management of older adults and transplant-ineligible patients, who require a separate approach. Finally, we review novel immunotherapy approaches in clinical trials, including combinations of PD-1 inhibitors with other immune-activating agents as well as novel antibody-drug conjugates, bispecific antibodies, and cellular immunotherapies. Ongoing studies assessing biomarkers of response to immunotherapy and dynamic biomarkers such as circulating tumor DNA may further inform treatment decisions and enable a more personalized approach in the future.

Tackling the dysregulated immune-checkpoints in classical Hodgkin lymphoma: bidirectional regulations between the microenvironment and Hodgkin/Reed-Sternberg cells

Immune evasion is considered one of the modern hallmarks of cancer and is a key element in the pathogenesis of classical Hodgkin Lymphoma (cHL). This haematological cancer achieves effective avoidance of the host's immune system by overexpressing the PD-L1 and PD-L2 proteins on the surface of the neoplastic cells. Subversion of the PD-1/PD-L axis, however, is not the sole contributor to immune evasion in cHL, as the microenvironment nurtured by the Hodgkin/Reed-Sternberg cells is a major player in the creation of a biological niche that sustains their survival and hinders immune recognition. In this review, we will discuss the physiology of the PD-1/PD-L axis and how cHL is able to exploit a plethora of different molecular mechanisms to build an immunosuppressive microenvironment and achieve optimal immune evasion. We will then discuss the success obtained by checkpoint inhibitors (CPI) in treating cHL, both as single agents and as part of combination strategies, analysing the rationale for their combination with traditional chemotherapeutic compounds and the proposed mechanisms of resistance to CPI immunotherapy.

Tumor microenvironment contribution to checkpoint blockade therapy: lessons learned from Hodgkin lymphoma

Classic Hodgkin lymphoma (cHL) is characterized by a tumor microenvironment (TME) containing inflammatory/immune cells. Follicular lymphoma, mediastinal gray zone lymphoma, and diffuse large B-cell lymphomas may show a TME containing inflammatory/immune cells, but the TMEs are quite different. In B-cell lymphomas and cHL, programmed cell death 1 (PD-1)-PD ligand 1 pathway blockade drugs differ in their effectiveness among patients with refractory/relapsed disease. Further research should explore innovative assays that could reveal which molecules influence sensitivity or resistance to therapy in an individual patient.

Chemotherapy postimmunotherapy for recurrent metastatic head and neck squamous cell carcinoma

PURPOSE OF REVIEW

Clinical data on salvage chemotherapy used after checkpoints inhibitors in oncology are reviewed, with a special focus on recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC).

RECENT FINDINGS

Converging evidence is emerging about high response and/or disease control rates associated with salvage chemotherapy after immunotherapy failure in advanced solid tumours. This phenomenon is mainly reported in retrospective studies for "hot tumours" such as R/M HNSCC, melanoma, lung, urothelial or gastric cancers, but also in haematological malignancies. Some physiopathological hypotheses have been raised.

SUMMARY

Several independent series show increased response rates associated with postimmuno chemotherapy when compared with retrospective series in similar settings. Several mechanisms could be involved such as a "carry-over" allowed by a persistence of the checkpoint inhibitor, a modulation of tumour microenvironment components but also an intrinsic immunomodulatory effect of chemotherapy, increased by a specific immunologic state induced by the therapeutic pressure of checkpoint inhibitors. These data establish a rationale for prospectively evaluating the features of postimmunotherapy salvage chemotherapy.

Immune priming with avelumab and rituximab prior to R-CHOP in diffuse large B-cell lymphoma: the phase II AvR-CHOP study

Immune evasion, due to abnormal expression of programmed-death ligands 1 and 2 (PD-L1/PD-L2), predicts poor outcomes with chemoimmunotherapy in diffuse large B-cell lymphoma (DLBCL). Immune checkpoint inhibition (ICI) has limited efficacy at relapse but may sensitise relapsed lymphoma to subsequent chemotherapy. ICI delivery to immunologically intact patients may thus be the optimal use of this therapy. In the phase II AvR-CHOP study, 28 patients with treatment-naive stage II-IV DLBCL received sequential avelumab and rituximab priming ("AvRp;" avelumab 10 mg/kg and rituximab 375 mg/m2 2-weekly for 2 cycles), R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone for 6 cycles) and avelumab consolidation (10 mg/kg 2-weekly for 6 cycles). Grade 3/4 immune-related adverse events occurred in 11%, meeting the primary endpoint of a grade ≥3 irAE rate of <30%. R-CHOP delivery was not compromised but one patient ceased avelumab. Overall response rates (ORR) after AvRp and R-CHOP were 57% (18% CR) and 89% (all CR). High ORR to AvRp was observed in primary mediastinal B-cell lymphoma (67%; 4/6) and molecularly-defined EBV-positive DLBCL (100%; 3/3). Progression during AvRp was associated with chemorefractory disease. Two-year failure-free and overall survival were 82% and 89%. An immune priming strategy with AvRp, R-CHOP and avelumab consolidation shows acceptable toxicity with encouraging efficacy.

Older patients with Hodgkin Lymphoma: Walking the tightrope of efficacy and toxicity

Since its initial description, classical Hodgkin lymphoma (cHL) portends a greatly improved prognosis and the goal of treatment in most patients is cure with minimisation of toxicity from treatment. Outcomes in older patients (>60 years old) lag behind those of their younger counterparts however, and cure remains achievable mostly for those who can tolerate full doses of conventional chemotherapy. This review addresses the difference in biology between younger and older patients with cHL and examines the impact of frailty and comorbidities on outcomes. The toxicities of conventional chemotherapy in anthracycline-fit and -unfit patients are examined, with a particular focus on pulmonary toxicity associated with bleomycin in older patients. New advances are discussed, including the possibility of using more targeted therapies such as the anti-CD30 antibody brentuximab vedotin (BV) and checkpoint inhibitors as a method of reducing dependency on conventional chemotherapy for those less well able to tolerate it. Treatment of older patients with cHL remains an area of unmet need in hematological research, and efforts to rectify this knowledge gap should continue.

Advances in the treatment of Hodgkin lymphoma: Current and future approaches

Hodgkin lymphoma (HL) is a rare type of lymphoma with unique histologic, immunophenotypic, and clinical features. It represents approximately one-tenth of lymphomas diagnosed in the United States and consists of two subtypes: classical Hodgkin's lymphoma (cHL), which accounts for majority of HL cases, and nodular lymphocyte predominant Hodgkin lymphoma represent approximately 5% of Hodgkin lymphoma cases. From this point, we will be focusing on cHL in this review. In general, it is considered a highly curable disease with first-line chemotherapy with or without the addition of radiotherapy. However, there are patients with disease that relapses or fails to respond to frontline regimens and the standard treatment modality for chemo sensitive cHL is high dose chemotherapy followed by autologous hematopoietic stem cell transplant (AHSCT). In recent years, targeted immunotherapy has revolutionized the treatment of cHL while many novel agents are being explored in addition to chimeric antigen receptor (CAR) T-cell therapy which is also being investigated in clinical trials as a potential treatment option.

Anti-PD1 Consolidation in Patients with Hodgkin Lymphoma at High Risk of Relapse after Autologous Stem Cell Transplantation: A Multicenter Real-Life Study

(1) Background: Consolidation therapy is an emerging strategy for patients with relapsed/refractory (RR) Hodgkin Lymphoma (HL) at high risk of failing salvage autologous stem cell transplantation (ASCT). (2) Objectives: To assess the safety and effectiveness of PD1-blockade consolidation for these high-risk patients. (3) Design: Multi-center retrospective analysis. (4) Methods: We identified 26 patients given anti-PD1 consolidation, from June 2016 to May 2020. (5) Results: Patients displayed the following risk factors: refractory disease (69%), relapse < 12 months from upfront therapy (15%), ≥2 lines of salvage therapy (73%), extranodal disease (65%). Nineteen patients (73%) had ≥3 of these factors. In addition, 16 patients (61%) also displayed PET-positive (Deauville ≥ 4) disease before ASCT. Treatment-related adverse events (TRAEs), never graded > 3, occurred in 12 patients (46.15%) and mainly included skin rashes (41.7%), transaminitis (33.3%), and thyroid hypofunction (25%). Patients completed a median of 13 courses (range 6−30). At a median follow-up of 25.8 months post-ASCT, the median progression-free (PFS) was 42.6 months, with a 2-year PFS and overall survival rates of 79% and 87%, respectively. (6) Conclusions: Post-ASCT consolidation with anti-PD1 is feasible and effective. Further studies are warranted to define the optimal treatment length and patients’ subsets more likely to benefit from this approach.