Nivolumab for Relapsed/Refractory Classic Hodgkin Lymphoma After Failure of Autologous Hematopoietic Cell Transplantation: Extended Follow-Up of the Multicohort Single-Arm Phase II CheckMate 205 Trial

Checkpoint Inhibitors in Relapsed/Refractory Classical Hodgkin Lymphoma

Even though classical Hodgkin lymphoma is highly curable, the outcome of patients with a refractory or relapsed disease has been disappointing. Multiple lines of therapy are available for patients after their first failure, and most respond to subsequent therapies. However, there is a sizable proportion that remains relapsing/recurrent even after several lines of therapy. The overall prognosis of patients with relapsing and recurrent classical Hodgkin lymphoma (rrcHL) has been very disappointing until recently. Immune checkpoint inhibitors such as the anti-programmed death 1 (PD-1) receptor antibodies have recently been approved to treat relapsed and refractory cHL and have significantly improved the outcome of patients with rrcHL. The approved immune checkpoint inhibitors for relapsed and refractory cHL are nivolumab and pembrolizumab. In the Checkmate 205 study nivolumab demonstrated an objective response rate of 69% with an acceptable safety profile. Similarly, pembrolizumab demonstrated an overall response rate (ORR) of 69% with a complete remission rate (CRR) of 22.4% in the KEYNOTE-087 study in heavily pretreated patients with rrcHL.

Latest advances in the management of classical Hodgkin lymphoma: the era of novel therapies

Hodgkin lymphoma is a highly curable disease. Although most patients achieve complete response following frontline therapy, key unmet clinical needs remain including relapsed/refractory disease, treatment-related morbidity, impaired quality of life and poor outcome in patients older than 60 years. The incorporation of novel therapies, including check point inhibitors and antibody-drug conjugates, into the frontline setting, sequential approaches, and further individualized treatment intensity may address these needs. We summarize the current treatment options for patients with classical Hodgkin lymphoma from frontline therapy to allogeneic hematopoietic stem cell transplantation and describe novel trials in the field.

T-cell-based immunotherapy of acute myeloid leukemia: current concepts and future developments

Acute myeloid leukemia (AML) is a heterogeneous disease linked to a broad spectrum of molecular alterations, and as such, long-term disease control requires multiple therapeutic approaches. Driven largely by an improved understanding and targeting of these molecular aberrations, AML treatment has rapidly evolved over the last 3-5 years. The stellar successes of immunotherapies that harness the power of T cells to treat solid tumors and an improved understanding of the immune systems of patients with hematologic malignancies have led to major efforts to develop immunotherapies for the treatment of patients with AML. Several immunotherapies that harness T cells against AML are in various stages of preclinical and clinical development. These include bispecific and dual antigen receptor-targeting antibodies (targeted to CD33, CD123, CLL-1, and others), chimeric antigen receptor (CAR) T-cell therapies, and T-cell immune checkpoint inhibitors (including those targeting PD-1, PD-L1, CTLA-4, and newer targets such as TIM3 and STING). The current and future directions of these T-cell-based immunotherapies in the treatment landscape of AML are discussed in this review.

Immunotherapy in the treatment of lymphoma

Relapsed or refractory non-Hodgkin’s lymphomas, especially diffuse large B-cell lymphoma as well as relapsed or refractory Hodgkin lymphomas are hard-to-treat diseases. Patients who do not respond to initial therapy or experience relapse are treated with salvage regimens, and if eligible for aggressive therapy, treatment is continued with high-dose chemotherapy and autologous stem cell transplantation. Current therapy options can cure substantial numbers of patients, however for some it is still an uncurable disease. Numerous new drugs and cell therapies are being investigated for the treatment of relapsed or refractory lymphomas. Different types of immunotherapy options have shown promising results, and some have already become the standard of care. Here, we review immunotherapy options for the treatment of lymphoma and discuss the results, positions, practical aspects, and future directions of different drugs and cellular therapies for the treatment of this disease.

Biomodulatory Treatment Regimen, MEPED, Rescues Relapsed and Refractory Classic Hodgkin's Disease

Introduction: Current combined intensive chemotherapy and radiation regimens yield excellent survival rates in advanced classic Hodgkin’s lymphoma (cHL). However, acute toxicity in elderly, comorbid patients can be challenging and long-term survival in refractory patients remains poor.

Patients and Methods: We report on six patients with r/r HL, three patients with long-term follow-up, three newly treated, after biomodulatory therapy. All patients received MEPED (treosulfan 250 mg p.o. daily, everolimus 15 mg p.o. daily to achieve serum trough levels of 15 ng/ml, pioglitazone 45 mg p.o. daily, etoricoxib 60 mg p.o. daily and dexamethasone 0.5 mg p.o. daily). Patients had either received every at that time approved systemic treatment or were ineligible for standard treatment, including immune checkpoint inhibition (ICPi) due to prior demyelinating autoimmune polyneuropathy, myasthenia gravis and previous allogeneic hematopoietic-stem-cell transplant (alloHSCT). Medication was administered continuously from day 1. One patient with relapse after alloHSCT received trofosfamide 50 mg daily instead of treosulfan to avoid risk of increased myelotoxicity. The patients were treated in individual healing attempts outside a clinical trial after institutional review board approval. ¹⁸F-fluoro-2-deoxy-d-glucose positron emission tomography combined with computed tomography scan (FDG-PET/CT) was performed to monitor treatment and follow-up.

Results: In the three newly treated patients, CT scans showed partial remissions after 2–5 months on MEPED treatment. Two patients had achieved PET Deauville score 2 and 3, while the third remained positive at Deauville score 5. One patient achieving PR became eligible for alloHSCT, while the other two patients continued treatment with MEPED. All patients eventually achieved continuous complete remission (cCR), one after consecutive alloHSCT, one after discontinuing MEPED consolidation for >1 year and one on on-going MEPED consolidation, respectively. Only one patient experienced Grade 3 toxicity (bacterial pneumonia) requiring temporary discontinuation of MEPED for 10 days. All three previously published patients received allo HSCT for consolidation and have achieved cCR.

Conclusions: MEPED is well tolerated with low toxicity and highly efficacious in relapsed/refractory cHL, including severely comorbid patients. Due to its immunomodulatory components, MEPED might also have a synergistic potential when combined with ICPi but requires further evaluation within a clinical trial.

Nivolumab in relapsed/refractory Hodgkin lymphoma: towards a new treatment strategy?

Chemo-refractory Hodgkin lymphoma (HL), especially after failure of high-dose therapy and autologous stem cell transplantation (ASCT), has a very poor prognosis. Nivolumab, an anti-PD-1 monoclonal antibody, demonstrated durable responses and manageable toxicity in a significant proportion of HL patients who fail both ASCT and brentuximab vedotin. Although anti-PD-1 treatment is often well tolerated, immune-related adverse events (iAE) were frequently observed. New perspectives could be represented by treatment discontinuation in patients with prolonged response or toxicity with the possibility of a re-treatment at relapse, subsequent chemotherapy or a modification of the dose-intensity or treatment duration. The efficacy of anti-PD-1 re-treatment was demonstrated in several cases and we have successfully managed 1 case with this strategy. With the main aim of avoiding the relapse-related psychophysical stress for the patient with manageable toxicity, we have successfully administered nivolumab every 4 weeks to 3 patients in prolonged complete remission, who presented with iAE during treatment. We believe that nivolumab should not only represent a bridge to allogeneic SCT, but it may play an important role also beyond the approved indication and current standard clinical care.

Immune checkpoint inhibitors in combination with radiotherapy as salvage treatment for relapsed/refractory classical Hodgkin lymphoma: A retrospective analysis in 12 patients

The rate of complete remission (CR) with the anti-PD1 immune checkpoint inhibitors (ICI) nivolumab (N) and pembrolizumab (P) in patients with relapsed/refractory (R/R) classical Hodgkin lymphoma (cHL) is low (20-30%), and the majority of patients eventually relapse. One strategy to improve their outcome is to combine ICI with radiotherapy (ICI-RT), taking advantage of a supposed synergistic effect. We retrospectively collected data of 12 adult patients with R/R cHL treated with ICI-RT delivered during or within 8 weeks from the start or after the end of ICI. Median age at ICI-RT was 37 years, 50% had previously received an autologous stem cell transplantation (SCT) and 92% brentuximab vedotin. RT was given concurrently, before or after ICI in 4, 1 and 7 patients. Median RT dose was 30Gy, for a median duration of 22 days. Median number of ICI administrations was 15. Overall response and CR rate were 100% and 58%. Nine patients received subsequent SCT consolidation (7 allogeneic and 2 autologous). After a median follow-up of 18 months, 92% of patients were in CR. No major concerns about safety were reported. ICI-RT combination appears to be a feasible and highly active bridge treatment to transplant consolidation.

Relapsed and refractory classical Hodgkin lymphoma: could virotherapy help solve the equation?

Classical Hodgkin lymphoma is a neoplastic hematological disease. Standard first-line therapy, including chemotherapy and radiotherapy, is curative in >85% of early-stage patients, with a 5-year survival rate of >95%. However, approximately 15% of patients have hard-to-treat lymphoma with poor outcomes, and new treatment strategies are needed for these young adults. There are several well-documented cases in the medical literature on hematologic cancer remission following natural human viral infections. Therefore, hoping to reproduce these spontaneous tumor regressions, researchers have been investigating various viruses with oncolytic properties. There is a high rationale for using virotherapy in the treatment of Hodgkin lymphoma, in which tumor cells are often infected with the Epstein-Barr virus. Modern viral technologies and current knowledge about the relationship between viruses and cancer could accelerate the discovery of effective viral oncolytic therapies. This article reviews the use of oncolytic viruses as innovative therapies for treating Hodgkin lymphoma.

Camidanlumab tesirine in patients with relapsed or refractory lymphoma: a phase 1, open-label, multicentre, dose-escalation, dose-expansion study

BACKGROUND

Novel approaches are required to improve outcomes in relapsed or refractory classical Hodgkin lymphoma and non-Hodgkin lymphoma. We aimed to evaluate camidanlumab tesirine, an anti-CD25 antibody-drug conjugate, in this patient population.

METHODS

This was a phase 1, dose-escalation (part 1), dose-expansion (part 2), multicentre trial done in 12 hospital sites (seven in the USA and five in the UK). Adults (≥18 years old) with pathologically confirmed relapsed or refractory classical Hodgkin lymphoma or non-Hodgkin lymphoma, an Eastern Cooperative Oncology Group performance status 0-2, who had no therapies available to them with established clinical benefit for their disease stage were enrolled. Camidanlumab tesirine was administered intravenously (3-150 μg/kg) once every 3 weeks. Primary objectives were to assess dose-limiting toxicity, determine maximum tolerated dose and recommended expansion dose(s), and assess safety of camidanlumab tesirine. Safety was assessed in all treated patients; antitumour activity was assessed in patients with one or more valid baseline and post-baseline disease assessment and in those who had disease progression or died after first study-drug dose. This trial was registered with ClinicalTrials.gov, NCT02432235.

FINDINGS

Between Oct 5, 2015, and Jun 30, 2019, 133 patients were enrolled (77 [58%] had classical Hodgkin lymphoma and 56 (42%) had non-Hodgkin lymphoma). Median follow-up was 9·2 months (IQR 4·2-14·3). Eight dose-limiting toxicities were reported in five (6%) of 86 patients who were evaluable; the maximum tolerated dose was not reached. The recommended doses for expansion were 30 μg/kg and 45 μg/kg for patients with classical Hodgkin lymphoma and 80 μg/kg for patients with T-cell non-Hodgkin lymphomas. No recommended doses for expansion were defined for B-cell non-Hodgkin lymphomas. Grade 3 or worse treatment-emergent adverse events (reported by ≥10% of the 133 patients) included increased γ-glutamyltransferase (20 [15%] patients), maculopapular rash (16 [12%]), and anaemia (15 [11%]); 74 (56%) patients had serious treatment-emergent adverse events, most commonly pyrexia (16 [12%]). One (1%) fatal treatment-emergent adverse event and two (2%) deaths outside the reporting period were considered at least possibly study-drug related. Antitumoural activity was seen in classical Hodgkin and non-Hodgkin lymphomas; notably in all patients with classical Hodgkin lymphoma, the overall response was 71% (95% CI 60-81).

INTERPRETATION

These results warrant evaluation of camidanlumab tesirine as a potential treatment option for relapsed or refractory lymphoma, particularly in patients with classical Hodgkin lymphoma.

FUNDING

ADC Therapeutics.

Disease Status at Transplant has a Significant Impact on Outcomes of Autologous Transplantation (ASCT) in Patients with Hodgkin Lymphoma—A Single Center Experience

High dose chemotherapy followed by autologous stem cell transplantation is the treatment of choice for relapsed Hodgkin lymphoma (HL). We analyzed 100 consecutive patients who underwent ASCT at our center between January 1999 and June 2019 for relapsed or refractory disease with a median age of 28 years (range: 9-65). At ASCT, 59 were in complete remission (CR) while 31 achieved partial remission (PR) and 10 had refractory disease (RD). Most had BEAM conditioning with a median infused cell dose of 4.84 × 10⁶ CD 34 cells/kg. Prompt engraftment occurred in 97 patients at a median of 11 days. The day 100 transplant related mortality (TRM) was 5%. At a median of 37 months follow up, 79 patients are alive while 34 have relapsed. The 3-year event free survival (EFS) and overall survival (OS) are 62.3 ± 0.5% and 77.9 ± 4.4% respectively. The 3-year OS for patients in CR, PR and RD were 83.0 ± 5.2%, 78.4 ± 8.1% and 38.9 ± 1.7 respectively [p = 0.007] while the 3-year EFS for CR, PR and RD were 73.1 ± 6.2%, 61.3 ± 9.2% and 25.0 ± 1.5 respectively [p = 0.005]. Only disease status at time of ASCT was found to correlate with both OS and EFS. ASCT for HL is associated with good outcomes and low TRM. Disease status at ASCT impacted both OS and EFS and strategies to improve outcomes in patients with refractory disease needs to be explored.

Case Report: Anlotinib Combined With Sintilimab as Third-Line Treatment in a Metastatic Urothelial Bladder Carcinoma Patient With FGFR3 Mutation

We report on a case of metastatic urothelial bladder carcinoma (mUBC) treated with anlotinib combined with sintilimab. A 69-year-old male was diagnosed with non-muscle invasive bladder cancer (NMIBC). He received transurethral resection of bladder tumor (TURBT) and intravesical gemcitabine chemotherapy. After the patients' cancer progressed to mUBC, cisplatin-based chemotherapy (gemcitabine combined with cisplatin, GC) was performed to this patient as first line therapy for four cycles. However, the disease progressed again within 6 months. Local radiotherapy was performed on the metastatic lesions, and after radiotherapy, the patient received anti-PD-1 antibody (sintilimab 200 mg, q3w)combined with Albumin-bound (Nab)-paclitaxel (100 mg, qw) as the second-line therapy, but the patient's cancer was still observed to be progressing. Molecular characterization confirmed the presence of FGFR3 mutations in the patient. Anlotinib was recommended to this patient. After the patient was fully informed and he was aware of off-label use of the drug, then, Nab-paclitaxel was replaced by anlotinib (10 mg D1-14, q3w) and sintilimab infusions were maintained for every 3 weeks. Partial response (PR) was observed through imaging examinations and stable disease (SD) was observed for more than 11 months; the patient's quality of life also improved. This case suggested that anlotinib combined with sintilimab may be a safe and effective choice in the treatment of mUBC in patients with FGFR3 mutations.

Incidence of Immune-Mediated Pseudoprogression of Lymphoma Treated with Immune Checkpoint Inhibitors: Systematic Review and Meta-Analysis

We evaluated the incidence of pseudoprogression and indeterminate response (IR) in patients with lymphoma treated with immune checkpoint inhibitors (ICIs). A systematic search of PubMed and EMBASE was performed up to 6 February 2021, using the keywords “lymphoma,” “immunotherapy,” and “pseudoprogression.” Random-effects models were used to calculate both pooled incidence of pseudoprogression patients with lymphoma and an IR according to LYRIC criteria, while the Higgins inconsistency index (I2) test and Cochran’s Q test were used for heterogeneity. Eight original articles were included, in which the number of patients ranged from 7 to 243. Among the lymphoma patients with ICIs, the pooled incidence of pseudoprogression was 10% (95% confidence interval [CI]: 0.06–0.17). There was no publication bias in Begg’s test (p = 0.14). Three articles were analyzed to determine the pooled incidence of pseudoprogression in patients with IR according to LYRIC criteria in a subgroup analysis, which was shown to be 19% (95% CI: 0.08–0.40). A significant proportion (10%) of patients with lymphoma treated with ICIs showed pseudoprogression, and 19% of patients with an IR response showed pseudoprogression and a delayed response. Immune-related response criteria such as LYRIC may be used for patients with lymphoma treated with ICIs.

Efficacy and safety results from CheckMate 140, a phase 2 study of nivolumab for relapsed/refractory follicular lymphoma

Nivolumab, an anti-programmed death-1 (PD-1) monoclonal antibody, showed promising activity in relapsed or refractory (R/R) follicular lymphoma (FL) in a phase 1 study. We conducted a phase 2 trial to further evaluate its efficacy and safety in patients with R/R FL and to explore biomarkers of response. Patients with R/R FL and at least 2 prior lines of therapy, each containing a CD20 antibody or an alkylating agent, were treated with nivolumab 3 mg/kg every 2 weeks. The primary end point was objective response rate (ORR) assessed by an independent radiologic review committee. Biomarker analyses included gene expression profiling and multiplex immunofluorescence studies of pretreatment tumor samples. A total of 92 patients were treated. After a minimum follow-up of 12 months, ORR was 4% (4 of 92 patients). Median progression-free survival (PFS) was 2.2 months (95% confidence interval [CI], 1.9-3.6 months). Median duration of response was 11 months (95% CI, 8-14 months). Exploratory analyses suggested that responders had significantly higher proportion of CD3+ T cells in the tumor microenvironment than nonresponders, but no significant differences in PD-1 or programmed death-ligand 1 expression were observed. High expression of a set of tumor-associated macrophage genes was associated with reduced PFS (hazard ratio, 3.28; 95% CI, 1.76-6.11; P = .001). The safety profile was consistent with previous reports of nivolumab. In conclusion, nivolumab monotherapy was associated with very limited activity in patients with R/R FL. Better understanding of the immune biology of this disease may facilitate the development of effective checkpoint-based strategies. This trial was registered at www.clinicaltrials.gov as #NCT02038946.

Trends in postrelapse survival in classic Hodgkin lymphoma patients after experiencing therapy failure following auto-HCT

Patients with classic Hodgkin lymphoma (cHL) who relapse after autologous hematopoietic cell transplantation (auto-HCT) historically have had poor outcomes. We hypothesized that, post-auto-HCT relapse, overall survival (PR-OS) has improved in recent years as a result of more widespread use of novel therapies and allogeneic HCT (allo-HCT). We conducted a retrospective study in 4 US academic centers, evaluating 215 patients who underwent auto-HCT from 2005 to 2016 and relapsed thereafter. Patients were divided into 2 cohorts based on timing of auto-HCT, 2005 through 2010 (cohort 1; n = 118) and 2011 to 2016 (cohort 2; n = 97), to compare differences in clinical outcomes. The median age and disease status at auto-HCT were similar in cohorts 1 and 2. The proportions of patients who received brentuximab vedotin (Bv; 55% vs 69%; P = .07), checkpoint inhibitors (CPIs; 3% vs 36%; P ≤ .001), and allogeneic-HCT (22% vs 35%, P = .03) were significantly different between cohorts 1 and 2, respectively. At the 5-year follow-up after auto relapse, 32% and 50% of patients were alive in cohorts 1 and 2, respectively (P = .01). In multivariate analysis for PR-OS, cohort 1 vs 2 (hazard ratio [HR], 2.3; 95% confidence interval [CI], 1.14-4.60; P = .01), age at auto-HCT (HR, 1.48; 95% CI, 1.18-1.87; P ≤ .001), and time to relapse from auto-HCT (HR, 0.59; 95% CI, 0.47-74; P ≤ .0001), retained independent prognostic significance for PR-OS. Our study supports the hypothesis that survival of cHL patients after auto-HCT failure has significantly improved in recent years, most likely because of incorporation of novel therapies and more widespread use of allo-HCT.

Checkpoint inhibition before haploidentical transplantation with posttransplant cyclophosphamide in Hodgkin lymphoma

We report on 59 Hodgkin lymphoma patients undergoing haploidentical stem cell transplantation (SCT; haplo-SCT) with posttransplant cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis, comparing outcomes based on pretransplant exposure to checkpoint inhibitors (CPIs). Considering pretransplant characteristics, the 2 cohorts (CPI = 29 patients vs no-CPI = 30 patients) were similar, except for the number of prior lines of therapy (6 vs 4; P < .001). With a median follow-up of 26 months (range, 7.5-55 months), by univariate analysis, the 100-day cumulative incidence of grade 2-4 acute GVHD was 41% in the CPI group vs 33% in the no-CPI group (P = .456), whereas the 1-year cumulative incidence of moderate to severe chronic GVHD was 7% vs 8%, respectively (P = .673). In the CPI cohort, the 2-year cumulative incidence of relapse appeared lower compared with the no-CPI cohort (0 vs 20%; P = .054). No differences were observed in terms of overall survival (OS), progression-free survival (PFS), and nonrelapse mortality (NRM) (at 2 years, 77% vs 71% [P = .599], 78% vs 53% [P = .066], and 15% vs 21% [P = .578], respectively). By multivariable analysis, CPI before SCT was an independent protective factor for PFS (hazard ratio [HR], 0.32; P = .037). Stable disease (SD)/progressive disease (PD) was an independent negative prognostic factor for both OS and PFS (HR, 14.3; P < .001 and HR, 14.1; P < .001, respectively) . In conclusion, CPI as a bridge to haplo-SCT seems to improve PFS, with no impact on toxicity profile.

Diffuse Large B-Cell Lymphoma: Recognition of Markers for Targeted Therapy

Diffuse large B-cell lymphomas (DLBCL)s, the most common type of Non-Hodgkin’s Lymphoma, constitute a heterogeneous group of disorders including different disease sites, strikingly diverse molecular features and a profound variability in the clinical behavior. Molecular studies and clinical trials have partially revealed the underlying causes for this variability and have made possible the recognition of some molecular variants susceptible of specific therapeutic approaches. The main histogenetic groups include the germinal center, activated B cells, thymic B cells and terminally differentiated B cells, a basic scheme where the large majority of DLBCL cases can be ascribed. The nodal/extranodal origin, specific mutational changes and microenvironment peculiarities provide additional layers of complexity. Here, we summarize the status of the knowledge and make some specific proposals for addressing the future development of targeted therapy for DLBC cases.

KEYNOTE-013 4-year follow-up of pembrolizumab in classical Hodgkin lymphoma after brentuximab vedotin failure

The KEYNOTE-013 study was conducted to evaluate pembrolizumab monotherapy in hematologic malignancies; classical Hodgkin lymphoma (cHL) was an independent expansion cohort. We present long-term results based on >4 years of median follow-up for the cHL cohort. The trial enrolled cHL patients who experienced relapse after, were ineligible for, or declined autologous stem cell transplantation and experienced progression with or did not respond to brentuximab vedotin. Patients received IV pembrolizumab 10 mg/kg every 2 weeks for up to 2 years or until confirmed progression or unacceptable toxicity. Primary end points were safety and complete response (CR) rate by central review. Enrolled patients (N = 31) had received a median of 5 therapies (range, 2 to 15). After a median follow-up of 52.8 months (range, 7.0 to 57.6 months), CR rate was 19%, and median duration of response (DOR) was not reached; 24-month and 36-month DOR rates were both 50% by the Kaplan-Meier method. Median overall survival was not reached; 36-month overall survival was 81%. Six patients (19%) experienced grade 3 treatment-related adverse events (AEs); there were no grade 4 or 5 treatment-related AEs. With long-term follow-up among a heavily pretreated cohort, pembrolizumab had a favorable safety profile; some patients maintained long-term response with pembrolizumab years after end of treatment. This trial was registered at www.clinicaltrials.gov as #NCT01953692.

PD-1 and LAG-3 Checkpoint Blockade: Potential Avenues for Therapy in B-Cell Lymphoma

The dependence of cancer on an immunotolerant tumor microenvironment (TME) is well established. Immunotherapies that overcome tumor-induced immune suppression have been central to recent advancements in oncology. This is highlighted by the success of agents that interrupt PD-1 mediated immune suppression in a range of cancers. However, while PD-1 blockade has been paradigm-shifting in many malignancies, the majority of cancers show high rates of primary resistance to this approach. This has led to a rapid expansion in therapeutic targeting of other immune checkpoint molecules to provide combination immune checkpoint blockade (ICB), with one such promising approach is blockade of Lymphocyte Activation Gene 3 (LAG-3). Clinically, lymphoproliferative disorders show a wide spectrum of responses to ICB. Specific subtypes including classical Hodgkin lymphoma have demonstrated striking efficacy with anti-PD-1 therapy. Conversely, early trials of ICB have been relatively disappointing in common subtypes of Non-Hodgkin lymphoma. In this review, we describe the TME of common lymphoma subtypes with an emphasis on the role of prominent immune checkpoint molecules PD-1 and LAG3. We will also discuss current clinical evidence for ICB in lymphoma and highlight key areas for further investigation where synergistic dual checkpoint blockade of LAG-3 and PD-1 could be used to overcome ICB resistance.

Safety and Efficacy of Immune Checkpoint Inhibitors in Children and Young Adults with Haematological Malignancies: Review and Future Perspectives

Despite the marked improvement in overall survival rates of paediatric patients with haematological malignancies that has been achieved during the last decades, there is still a pressing need for novel therapeutic approaches for the subset of patients with relapsed or refractory disease. Immune checkpoint inhibitors aim to induce potent anti-tumour immune responses by targeted blockade of inhibitory receptors and have shown great promise in preclinical models and studies in the adult population. However, paediatric malignancies present unique features and so far, experience with these agents remains limited. In the current review we present an overview of efficacy and safety data from case reports, case series and clinical trials employing the use of immune checkpoint inhibitors in children, adolescents and young adults with haematological malignancies. We also discuss new possibilities involving novel targets and combination treatments and provide a summary of the currently registered clinical trials.

Immune imitation of tumor progression after anti-CD19 chimeric antigen receptor T cells treatment in aggressive B-cell lymphoma

We present three patients with aggressive non-Hodgkin's B-cell lymphoma (NHL) who received anti-CD19 chimeric antigen receptor T (CAR T) cells therapy after failure of several lines of chemotherapy that developed pseudo-progression. One-week clinical and radiological findings were consistent with tumor progression. Positron emission tomography-computed tomography (PET-CT) at 1 month post CAR T cells administration was consistent with treatment response. The rapid tumor growth and subsequent resolution are suggestive of tumor pseudo-progression mediated secondary to infiltration and immune activation of CAR T cells. Overall, 56 adult patients with NHL were enrolled in a phase 1b/2 in house clinical study with CD19 CAR T cells. Out of them 22/56 patients progressed as per PET-CT the 1 month post CAR T cells. In 14 patients, signs of progression started 7-10 days after CAR T cells infusion. In 11/14 patients, it was true progression, while in 3 it was pseudo-progression. Additional studies are warranted to describe the extent of this phenomenon and evaluate correlation with the CAR T activity and long-term disease control.

Pediatric classical Hodgkin lymphoma

Over the past century, classical Hodgkin lymphoma (HL) has been transformed from a uniformly fatal disease to one of the most curable cancers. Given the high cure rate, a major focus of classical HL management is reducing the use of radiation therapy (RT) and chemotherapy agents such as procarbazine and doxorubicin to minimize long-term toxicities. In both North America and Europe, an important philosophy in the management of classical HL is to guide the intensity of treatment according to the risk category of the disease. The main factors used for risk classification are tumor stage, bulk of disease, and the presence of B symptoms. Response to chemotherapy is an important factor guiding the utilization of RT in ongoing Children's Oncology Group (COG) and European Network Pediatric Hodgkin Lymphoma (EuroNet-PHL) trials. Both trial groups have transitioned to reduced RT volumes that target the highest risk sites using highly conformal techniques, along with standard or intensified chemotherapy regimens to improve outcomes in higher risk patients. However, given the potential acute toxicities of intensified chemotherapy, immunoregulatory drugs are being investigated in upcoming trials. The purpose of this review is to summarize current approaches to treating pediatric classical HL according to the COG and EuroNet-PHL.

Immuno-oncology for B-cell lymphomas

The goal of cancer immunotherapy is to restore and optimize the immune response against malignant clones through several stages, from recognition of tumor antigens to establishment of long-lived memory cell populations. Boosting the intrinsic anti-tumor immune responses of the patients’ own, several types of “active immunotherapies” have been tried in many types of malignancies, inspired by successful experiences of immune checkpoint inhibition even in Hodgkin lymphoma. However, in B-cell non-Hodgkin lymphomas, clinical usefulness of such “active immunotherapies” is relatively unsatisfactory considering the remarkable advances in “passive immunotherapy,” including CD19-targeting chimeric antigen receptor T-cell therapy. Understanding how tumor cells and immune cells interact and contribute to immune evasion processes in the tumor microenvironment (TME) is an important prerequisite for the successful restoration of anti-tumor immune responses. In this review, a recent understanding of the biology of the immune tumor microenvironment surrounding B-cell non-Hodgkin lymphomas will be introduced. In addition, novel therapeutic approaches targeting the immune microenvironment other than immune checkpoint blockade are discussed.

Immune checkpoint inhibition in classical hodgkin lymphoma

Introduction: Hodgkin lymphoma (HL) accounts for 10% of lymphoma cases every year. HL is often curable by conventional chemotherapy and radiotherapy. However, in case of relapsed or refractory HL (r/r HL) after autologous hematopoietic stem cell transplantation (ASCT), few treatment options are currently available. Blockade of the immune checkpoint receptors, programmed death receptor-1 (PD-1), or cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) expressed on T-cells, and their ligands expressed on tumor-associated antigen-presenting cells (APCs), and Hodgkin and Reed/Sternberg (HRS) cells can remove inhibitory signals from anti-tumor T cells. Checkpoint blockade using monoclonal antibodies could be a potential treatment. Nivolumab and pembrolizumab are approved antibodies for the treatment of r/r HL.Areas covered: This paper provides a comprehensive discussion of checkpoint inhibitors in HL treatment, including the most important clinical trials with mono- or combination therapies as a first or second-line treatment of HL.Expert opinion: Relatively high response rates and an acceptable safety profile of checkpoint inhibitors make them an effective therapy for HL. The combination of checkpoint inhibition with other conventional cancer treatments and identifying the mechanisms responsible for resistance to checkpoint inhibition may improve the efficacy and safety of this immunotherapy, and enhance patient quality of life.

How we incorporate novel agents into the treatment of classic Hodgkin lymphoma

The introduction of targeted immunotherapies specifically, brentuximab vedotin (BV) and programmed death-1 (PD-1) blocking antibodies (nivolumab and pembrolizumab), has reshaped the therapeutic landscape of classic Hodgkin lymphoma (cHL) in the past decade. Targeting specific biologic features of cHL, these novel agents have expanded treatment options for patients with multiply rel/ref cHL and have increasingly been studied at earlier points in a patient's disease course. With the plethora of studies evaluating BV and PD-1 blockade as part of cHL therapy, often in non-randomized, controlled studies, more questions than answers have arisen about how to optimally integrate these drugs into clinical practice. In this article, we use a case-based format to offer practical guidance on how we incorporate BV and anti-PD1 antibodies into the management of cHL and review the data supporting those recommendations.

Novel agents and regimens for hematological malignancies: recent updates from 2020 ASH annual meeting

Antibodies and chimeric antigen receptor-engineered T cells (CAR-T) are increasingly used for cancer immunotherapy. Small molecule inhibitors targeting cellular oncoproteins and enzymes such as BCR-ABL, JAK2, Bruton tyrosine kinase, FLT3, BCL-2, IDH1, IDH2, are biomarker-driven chemotherapy-free agents approved for several major hematological malignancies. LOXO-305, asciminib, "off-the-shelf" universal CAR-T cells and BCMA-directed immunotherapeutics as well as data from clinical trials on many novel agents and regimens were updated at the 2020 American Society of Hematology (ASH) Annual Meeting. Major developments and updates for the therapy of hematological malignancies were delineated at the recent Winter Symposium and New York Oncology Forum from the Chinese American Hematologist and Oncologist Network (CAHON.org). This study summarized the latest updates on novel agents and regimens for hematological malignancies from the 2020 ASH annual meeting.

Immunity reloaded: Deconstruction of the PD-1 axis in B cell lymphomas

Over the past decade therapies targeting the PD-1 axis with monoclonal antibodies to reinstate host immune function have revolutionized the clinical management of some cancers but have had minimal impact on others. This dichotomy is exemplified by B cell lymphomas. Whilst striking results are observed in classical Hodgkin Lymphoma (cHL) and Primary Mediastinal B Cell Lymphoma (PMBL), responses in other B cell lymphomas are infrequent. Even with cHL and PMBL, responses are not always durable and adverse effects can result in treatment discontinuation. A more nuanced approach to manipulate the PD-1 axis is required before the full benefits of PD-1 axis blockade can be realised. In this review, we provide an outline of PD-1 axis biology, including the range of cellular expression, the molecular mechanisms underlying regulation and the impacts of downstream signalling. These may permit the development of alternate strategies to PD-1 axis blockade to enhance the therapeutic efficacy in B cell lymphomas.

Response Efficacy of PD-1 and PD-L1 Inhibitors in Clinical Trials: A Systematic Review and Meta-Analysis

Background

Immune checkpoint inhibitors targeting the PD-1/PD-L1 pathway have demonstrated promise in treating a variety of advanced cancers; however, little is known regarding their efficacy under various clinical situations, including different cancer types, treatment lines, drug combinations, and therapeutic regimens.

Methods

Published articles and conference abstracts (in English) in PubMed, Embase, the Cochrane Central Register, and Web of Science were searched up to February 10, 2020. The data were analyzed by the meta-analysis program in Stata.

Results

A total of 16,400 patients from 91 clinical trials were included in this meta-analysis. PD-1/PD-L1 inhibitors had a mean ORR of 19.56% (95% CI: 15.09–24.03), a median TTR of 2.05 months (m) (95%CI: 1.85–2.26), and a median DOR of 10.65 m (95%CI: 7.78–13.52). First-line treatment had a higher ORR (36.57% vs. 13.18%) but a shorter DOR (9.00 m vs. 13.42 m) compared to the second-line or subsequent treatment. Immunotherapy combined with chemotherapy (I+C) (46.81% [95%CI: 36.02–57.60]) had a statistically significant higher ORR compared to immunotherapy (I) (17.75% [95%CI: 14.47–21.03]) or immunotherapy combined with immunotherapy (I+O) (12.25% [95%CI: 1.56–22.94]), while I+C (8.09 m [95%CI: 6.86–9.32]) appeared to reduce the DOR compared to I (12.39 m [95%CI: 7.60–17.18]). PD-1 inhibitors were associated with better ORR (21.65% vs. 17.60%) and DOR (11.26 m vs. 10.03 m) compared to PD-L1 inhibitors. There were no significant differences in TTR under different situations.

Conclusions

PD-1/PD-L1 inhibitors were promising immunotherapeutic agents to achieve satisfactory response efficacies with different cancer types, treatment lines, drug combinations, and therapeutic regimens. This comprehensive summary of the response efficacy of PD-1/PD-L1 inhibitors serves as a reference for clinicians to make evidence-based decisions.

Pembrolizumab in Patients With Metastatic Breast Cancer With High Tumor Mutational Burden: Results From the Targeted Agent and Profiling Utilization Registry (TAPUR) Study

PURPOSE

The TAPUR Study is a phase II basket trial that aims to identify signals of antitumor activity of commercially available targeted agents in patients with advanced cancers harboring genomic alterations known to be drug targets. Results in a cohort of patients with metastatic breast cancer (mBC) with high tumor mutational burden (HTMB) treated with pembrolizumab are reported.

METHODS

Patients with advanced mBC received standard doses of either 2 mg/kg or 200 mg infusions of pembrolizumab every 3 weeks. Simon's two-stage design was used with a primary study end point of disease control (DC) defined as objective response or stable disease of at least 16 weeks duration. If two or more patients in stage I achieved DC, the cohort would enroll 18 additional patients in stage II. Secondary end points include progression-free survival (PFS), overall survival, and safety.

RESULTS

Twenty-eight patients were enrolled from October 2016 to July 2018. All patients' tumors had HTMB ranging from 9 to 37 mutations/megabase. DC and objective response were noted in 37% (95% CI, 21 to 50) and 21% of patients (95% CI, 8 to 41), respectively. Median PFS was 10.6 weeks (95% CI, 7.7 to 21.1); median overall survival was 30.6 weeks (95% CI, 18.3 to 103.3). No relationship was observed between PFS and tumor mutational burden. Five patients experienced ≥ 1 serious adverse event or grade 3 adverse event at least possibly related to pembrolizumab consistent with the product label.

CONCLUSION

Pembrolizumab monotherapy has antitumor activity in heavily pretreated patients with mBC characterized by HTMB. Our findings support the recent US Food and Drug Administration approval of pembrolizumab for treatment of patients with unresectable or metastatic solid tumors with HTMB without alternative treatment options.

Tumor and microenvironment response but no cytotoxic T-cell activation in classic Hodgkin lymphoma treated with anti-PD1

Classic Hodgkin lymphoma (cHL) is the cancer type most susceptible to antibodies targeting programmed cell death protein 1 (PD1) and is characterized by scarce Hodgkin and Reed-Sternberg cells (HRSCs), perpetuating a unique tumor microenvironment (TME). Although anti-PD1 effects appear to be largely mediated by cytotoxic CD8+ T cells in solid tumors, HRSCs frequently lack major histocompatibility complex expression, and the mechanism of anti-PD1 efficacy in cHL is unclear. Rapid clinical responses and high interim complete response rates to anti-PD1 based first-line treatment were recently reported for patients with early-stage unfavorable cHL treated in the German Hodgkin Study Group phase 2 NIVAHL trial. To investigate the mechanisms underlying this very early response to anti-PD1 treatment, we analyzed paired biopsies and blood samples obtained from NIVAHL patients before and during the first days of nivolumab first-line cHL therapy. Mirroring the rapid clinical response, HRSCs had disappeared from the tissue within days after the first nivolumab application. The TME already shows a reduction in type 1 regulatory T cells and PD-L1+ tumor-associated macrophages at this early time point of treatment. Interestingly, a cytotoxic immune response and a clonal T-cell expansion were not observed in the tumors or peripheral blood. These early changes in the TME were distinct from alterations found in a separate set of cHL biopsies at relapse during anti-PD1 therapy. We identify a unique very early histologic response pattern to anti-PD1 therapy in cHL that is suggestive of withdrawal of prosurvival factors, rather than induction of an adaptive antitumor immune response, as the main mechanism of action.

Improved clinical outcome in a randomized phase II study of anti-PD-1 camrelizumab plus decitabine in relapsed/refractory Hodgkin lymphoma

Background

Programmed death-1 (PD-1) blockade monotherapy induced durable remission in a subset of patients with relapsed/refractory classical Hodgkin lymphoma (cHL). We asked whether the anti-PD-1 agent, camrelizumab, combined with the DNA demethylating agent, decitabine, improves progression-free survival (PFS) in patients with relapsed/refractory cHL over camrelizumab alone.

Methods

This extended follow-up of an ongoing randomized phase II trial analyzed PFS among patients enrolled from January 2017 through July 2018. Sixty-one patients with relapsed/refractory cHL who were clinically naïve to PD-1 blockade and had received ≥2 previous therapies were randomized 1:2 to receive either camrelizumab (200 mg) monotherapy or camrelizumab (200 mg, day 8) combined with decitabine (10 mg/day, days 1–5) every 3 weeks.

Results

With a median follow-up of 34.5 months, complete remission was 79% (95% CI 63% to 90%) in the decitabine-plus-camrelizumab group versus 32% (95% CI 13% to 57%) in the camrelizumab group (p=0.001). Median duration of response was not reached in the decitabine-plus-camrelizumab group, with an estimated 63% (95% CI 46% to 75%) of patients maintaining a response at 24 months. Median PFS with decitabine-plus-camrelizumab therapy was 35.0 months (95% CI not reached) and 15.5 months (95% CI 8.4 to 22.7 months) with camrelizumab monotherapy (HR, 0.46; 95% CI 0.21 to 1.01; p=0.02). Female gender, lower tumor burden, and fewer previous therapies were favorable prognostic factors for durable remission with camrelizumab monotherapy. The PFS benefits of decitabine-plus-camrelizumab versus camrelizumab were observed in most subgroups, especially in patients with relative larger tumor burdens and those treated with ≥3 prior therapies. After decitabine-plus-camrelizumab treatment, the percentage increase of circulating peripheral central memory T-cells correlated with both improved clinical response and PFS, suggesting a putative biomarker of decitabine-plus-camrelizumab therapy for cHL.

Conclusions

Decitabine-plus-camrelizumab results in longer PFS compared with camrelizumab alone in patients with relapsed/refractory cHL.

Trial registration numbers

NCT02961101 and NCT03250962.

A phase 1b study of AFM13 in combination with pembrolizumab in patients with relapsed or refractory Hodgkin lymphoma

In relapsed/refractory Hodgkin lymphoma (R/R HL), immunotherapies such as the anti-programmed death-1 inhibitor pembrolizumab have demonstrated efficacy as monotherapy and are playing an increasingly prominent role in treatment. The CD30/CD16A-bispecific antibody AFM13 is an innate immune cell engager, a first-in-class, tetravalent antibody, designed to create a bridge between CD30 on HL cells and the CD16A receptor on natural killer cells and macrophages, to induce tumor cell killing. Early studies of AFM13 have demonstrated signs of efficacy as monotherapy for patients with R/R HL and the combination of AFM13 with pembrolizumab represents a rational new treatment modality. Here, we describe a phase 1b, dose-escalation study to assess the safety and preliminary efficacy of AFM13 in combination with pembrolizumab in patients with R/R HL. The primary objective was estimating the maximum tolerated dose; the secondary objectives were to assess safety, tolerability, antitumor efficacy, pharmacokinetics, and pharmacodynamics. In this heavily pretreated patient population, treatment with the combination of AFM13 and pembrolizumab was generally well tolerated, with similar safety profiles compared to the known profiles of each agent alone. The combination of AFM13 with pembrolizumab demonstrated an objective response rate of 88% at the highest treatment dose, with an 83% overall response rate for the overall population. Pharmacokinetic assessment of AFM13 in the combination setting revealed a half-life of up to 20.6 hours. This proof-of-concept study holds promise as a novel immunotherapy combination worthy of further investigation. This phase 1b study was registered at www.clinicaltrials.gov as NCT02665650.

A Durable Response after the Discontinuation of Nivolumab in an Advanced Gastric Cancer Patient

A durable response after the discontinuation of immune checkpoint-inhibitor therapy has previously been reported in several cancers. We herein describe a patient with gastric cancer who maintained a durable response after the discontinuation of nivolumab. A 65-year-old man was treated with nivolumab as a sixth-line therapy for recurrent gastric cancer. After four cycles of nivolumab therapy, he showed a partial response. But the treatment was discontinued when two immune-related adverse events occurred after six cycles. Disease regression was sustained for approximately 2 years, without the re-administration of nivolumab. The characteristics leading to such responses are unclear, and further studies are warranted in this regard.

Immune checkpoint inhibitors in the treatment of cancer

BACKGROUND

Immunotherapy drugs, known as immune checkpoint inhibitors (ICIs), work by blocking checkpoint proteins from binding with their partner proteins. The two main pathways that are specifically targeted in clinical practice are cytotoxic T-lymphocyte antigen-4 (CTLA-4) and programmed cell death protein 1 (PD-1) that showed potent immune-modulatory effects through their function as negative regulators of T cell activation.

METHODS

In view of the rapid and extensive development of this research field, we conducted a comprehensive review of the literature and update on the use of CTLA-4, PD-1 and PD-L1 targeted therapy in the treatment of several types of cancer including melanoma, non-small-cell lung carcinoma, breast cancer, hepatocellular carcinoma, hodgkin lymphoma, cervical cancer, head and neck squamous cell carcinoma.

RESULTS

Based on the last updated list released on March 2019, seven ICIs are approved by the FDA including ipilimumab, pembrolizumab, nivolumab, atezolizumab, avelumab, durvalumab, and cemiplimab.

CONCLUSION

This review also highlighted the most common adverse effects caused by ICIs and which affect people in different ways.

Engaging the Innate and Adaptive Antitumor Immune Response in Lymphoma

Immunotherapy has emerged as a powerful therapeutic strategy for many malignancies, including lymphoma. As in solid tumors, early clinical trials have revealed that immunotherapy is not equally efficacious across all lymphoma subtypes. For example, immune checkpoint inhibition has a higher overall response rate and leads to more durable outcomes in Hodgkin lymphomas compared to non-Hodgkin lymphomas. These observations, combined with a growing understanding of tumor biology, have implicated the tumor microenvironment as a major determinant of treatment response and prognosis. Interactions between lymphoma cells and their microenvironment facilitate several mechanisms that impair the antitumor immune response, including loss of major histocompatibility complexes, expression of immunosuppressive ligands, secretion of immunosuppressive cytokines, and the recruitment, expansion, and skewing of suppressive cell populations. Accordingly, treatments to overcome these barriers are being rapidly developed and translated into clinical trials. This review will discuss the mechanisms of immune evasion, current avenues for optimizing the antitumor immune response, clinical successes and failures of lymphoma immunotherapy, and outstanding hurdles that remain to be addressed.

Autologous stem cell transplantation after anti-PD-1 therapy for multiply relapsed or refractory Hodgkin lymphoma

Autologous stem cell transplantation (ASCT) can be curative for patients with relapsed/refractory Hodgkin lymphoma (HL). Based on studies suggesting that anti-PD-1 monoclonal antibodies (mAbs) can sensitize patients to subsequent chemotherapy, we hypothesized that anti-PD-1 therapy before ASCT would result in acceptable outcomes among high-risk patients who progressed on or responded insufficiently to ≥1 salvage regimen, including chemorefractory patients who are traditionally considered poor ASCT candidates. We retrospectively identified 78 HL patients who underwent ASCT after receiving an anti-PD-1 mAb (alone or in combination) as third-line or later therapy across 22 centers. Chemorefractory disease was common, including 42 patients (54%) refractory to ≥2 consecutive systemic therapies immediately before anti-PD-1 treatment. Fifty-eight (74%) patients underwent ASCT after anti-PD-1 treatment, while 20 patients (26%) received additional therapy after PD-1 blockade and before ASCT. Patients received a median of 4 systemic therapies (range, 3-7) before ASCT, and 31 patients (41%) had a positive pre-ASCT positron emission tomography (PET) result. After a median post-ASCT follow-up of 19.6 months, the 18-month progression-free survival (PFS) and overall survival were 81% (95% CI, 69-89) and 96% (95% confidence interval [CI], 87-99), respectively. Favorable outcomes were observed for patients who were refractory to 2 consecutive therapies immediately before PD-1 blockade (18-month PFS, 78%), had a positive pre-ASCT PET (18-month PFS, 75%), or received ≥4 systemic therapies before ASCT (18-month PFS, 73%), while PD-1 nonresponders had inferior outcomes (18-month PFS, 51%). In this high-risk cohort, ASCT after anti-PD-1 therapy was associated with excellent outcomes, even among heavily pretreated, previously chemorefractory patients.

Novel Therapies in the Treatment of Hodgkin Lymphoma

OPINION STATEMENT

Patients with Hodgkin lymphoma (HL) can achieve excellent response and survival rates following frontline combination chemo- and radiation therapy. However, about 10-15% of patients will experience disease relapse which is associated with poor outcomes. Recent breakthroughs in understanding the mechanisms of oncogenicity and interactions within the tumor microenvironment have resulted in development of novel drugs for treatment of patients with HL. Utilizing this information, treatment of newly diagnosed and relapsed HL has become a rapidly evolving field with multiple clinical trials evaluating novel treatment approaches incorporating targeted immunotherapy. In the frontline setting, the use of novel drugs may allow for de-escalation of therapy to avoid long-term complications associated with bleomycin and consolidation radiation therapy. Patients with early-stage, non-bulky disease are candidates for omitting radiation therapy using treatment combinations that include upfront use of brentuximab vedotin or nivolumab. In patients with advanced disease, the addition of brentuximab vedotin to a chemotherapy backbone is currently the standard of care in our practice, particularly in patients with a contraindication for receiving bleomycin. Future investigations in patients with advanced-stage HL will focus on establishing a new standard of care by comparing brentuximab vedotin and nivolumab in combination with chemotherapy (BV-AVD vs. N-AVD) and decreasing the risk of relapse by exploring consolidation therapy in patients with high-risk disease. In patients who have relapsed or are refractory to first-line therapy, salvage treatment has incorporated brentuximab vedotin or PD-1 checkpoint inhibitors to improve response rates of cytotoxic chemotherapy thereby improving the probability of a successful stem cell transplant. Post-transplant consolidation with brentuximab is currently standard of care in patients with high-risk disease. Patients who relapse following autologous stem cell transplant now have an expanded armamentarium of chemo- and immunotherapy options. However, the challenge is to determine the sequence of therapy after prior brentuximab or checkpoint inhibitor exposure.

Use of checkpoint inhibitors in patients with lymphoid malignancies receiving allogeneic cell transplantation: a review

Monoclonal antibodies against checkpoint receptors or its ligands have demonstrated high response rates and durable remissions in patients with relapsed Hodgkin lymphoma (HL) and other lymphoid malignancies. However, most patients will eventually progress on therapy and may benefit from further treatments including allogenic hematopoietic cell transplantation (allo-HCT). Furthermore, the use of checkpoint inhibitors (CPI) has emerged as a treatment option for patients relapsing after allo-HCT. The immune effects of the checkpoint blockade leading to a T-cell activation have raised some concerns on the safety of these therapies used either before or after allo-HCT, due to the potential risk of graft-versus-host disease (GVHD). Furthermore, CPI might also induce other immune toxicities, that can affect almost any organ, as a result of the dysregulation on the immune system balance. This review aims to focus on the evidence behind the use of CPI in patients with lymphoma who undergo allo-HCT. We summarize the clinical data generated to date about the use of CPI in HL and other lymphoid malignancies, the mechanisms of checkpoint inhibition in the context of allo-HCT as well as the clinical and biological observations of different GVHD prophylaxis in this setting. Furthermore, we discuss the evidence from retrospective series and early clinical trials on the feasibility and safety of the use of CPI in patients who relapsed after allo-HCT.

Early Evaluation of Immunotherapy Response in Lymphoma Patients by 18F-FDG PET/CT: A Literature Overview

Immunotherapy is a promising therapeutic strategy both for solid and hematologic tumors, such as in Hodgkin (HL) and non-Hodgkin lymphoma (NHL). In particular, immune-checkpoint inhibitors, such as nivolumab and pembrolizumab, are increasingly used for the treatment of refractory/relapsed HL. At the same time, evidence of chimeric antigen receptor (CAR)-T-cell immunotherapy efficacy mostly in NHL is growing. In this setting, the challenge is to identify an appropriate imaging method to evaluate immunotherapy response. The role of 18F-Fluorodeoxyglucose (18F-FDG) positron-emission tomography/computed tomography (PET/CT), especially in early evaluation, is under investigation in order to guide therapeutic strategies, taking into account the possible atypical responses (hyperprogression and pseudoprogression) and immune-related adverse events that could appear on PET images. Herein, we aimed to present a critical overview about the role of 18F-FDG PET/CT in evaluating treatment response to immunotherapy in lymphoma patients.

Pembrolizumab versus brentuximab vedotin in relapsed or refractory classical Hodgkin lymphoma (KEYNOTE-204): an interim analysis of a multicentre, randomised, open-label, phase 3 study

BACKGROUND

PD-1 blockade via pembrolizumab monotherapy has shown antitumour activity and toxicity in patients with relapsed or refractory classical Hodgkin lymphoma. Here, we present interim analyses from the KEYNOTE-204 study evaluating pembrolizumab versus brentuximab vedotin for relapsed or refractory classical Hodgkin lymphoma.

METHODS

In this randomised, open-label, phase 3 study, patients aged 18 years or older with relapsed or refractory classical Hodgkin lymphoma with measurable disease and an Eastern Cooperative Oncology Group performance status of 0 or 1 who were ineligible for or had relapsed after autologous haematopoietic stem-cell transplantation (HSCT) were enrolled at 78 hospitals and cancer centres in 20 countries and territories. Patients were randomly assigned (1:1) with an interactive voice response system to pembrolizumab 200 mg intravenously every 3 weeks or brentuximab vedotin 1·8 mg/kg intravenously every 3 weeks. Randomisation was stratified by previous autologous HSCT and status after front-line therapy. Results from the second interim analysis are presented here, with a database cutoff of Jan 16, 2020. The dual primary endpoints assessed in the intention-to-treat population were progression-free survival as assessed by blinded independent central review, and overall survival (not analysed at this interim analysis). Safety was assessed in all patients who received at least one dose of the study drug. This study is registered with ClinicalTrials.gov, NCT02684292. Recruitment for this trial is closed.

FINDINGS

Between July 8, 2016, and July 13, 2018, 151 patients were randomly assigned to pembrolizumab and 153 to brentuximab vedotin. After a median time from randomisation to data cutoff of 25·7 months (IQR 23·4-33·0), median progression-free survival was 13·2 months (95% CI 10·9-19·4) for pembrolizumab versus 8·3 months (5·7-8·8) for brentuximab vedotin (hazard ratio 0·65 [95% CI 0·48-0·88]; p=0·0027). The most common grade 3-5 treatment-related adverse events were pneumonitis (six [4%] of 148 patients in the pembrolizumab group vs one [1%] of 152 patients in the brentuximab vedotin group), neutropenia (three [2%] vs 11 [7%]), decreased neutrophil count (one [1%] vs seven [5%]), and peripheral neuropathy (one [1%] vs five [3%]). Serious treatment-related adverse events occurred in 24 (16%) of 148 patients receiving pembrolizumab and 16 (11%) of 152 patients receiving brentuximab vedotin. One treatment-related death due to pneumonia occurred in the pembrolizumab group.

INTERPRETATION

Pembrolizumab showed statistically significant and clinically meaningful improvement in progression-free survival compared with brentuximab vedotin, with safety consistent with previous reports. These data support pembrolizumab as the preferred treatment option for patients with relapsed or refractory classical Hodgkin lymphoma who have relapsed post-autologous HSCT or are ineligible for autologous HSCT.

FUNDING

Merck Sharp & Dohme Corp (a subsidiary of Merck & Co, Inc, Kenilworth, NJ, USA).

Spatial signatures identify immune escape via PD-1 as a defining feature of T-cell/histiocyte-rich large B-cell lymphoma

T-cell/histiocyte-rich large B-cell lymphoma (TCRLBCL) is an aggressive variant of diffuse large B-cell lymphoma (DLBCL) characterized by rare malignant B cells within a robust but ineffective immune cell infiltrate. The mechanistic basis of immune escape in TCRLBCL is poorly defined and not targeted therapeutically. We performed a genetic and quantitative spatial analysis of the PD-1/PD-L1 pathway in a multi-institutional cohort of TCRLBCLs and found that malignant B cells harbored PD-L1/PD-L2 copy gain or amplification in 64% of cases, which was associated with increased PD-L1 expression (P = .0111). By directed and unsupervised spatial analyses of multiparametric cell phenotypic data within the tumor microenvironment, we found that TCRLBCL is characterized by tumor-immune "neighborhoods" in which malignant B cells are surrounded by exceptionally high numbers of PD-L1-expressing TAMs and PD-1+ T cells. Furthermore, unbiased clustering of spatially resolved immune signatures distinguished TCRLBCL from related subtypes of B-cell lymphoma, including classic Hodgkin lymphoma (cHL) and DLBCL-NOS. Finally, we observed clinical responses to PD-1 blockade in 3 of 5 patients with relapsed/refractory TCRLBCL who were enrolled in clinical trials for refractory hematologic malignancies (NCT03316573; NCT01953692), including 2 complete responses and 1 partial response. Taken together, these data implicate PD-1 signaling as an immune escape pathway in TCRLBCL and also support the potential utility of spatially resolved immune signatures to aid the diagnostic classification and immunotherapeutic prioritization of diverse tumor types.

Immunosuppressive Cell Subsets and Factors in Myeloid Leukemias

Simple Summary

Effector immune system cells have the ability to kill tumor cells. However, as a cancer (such as leukemia) develops, it inhibits and evades the effector immune response. Such a state of immunosuppression can be driven by several factors – receptors, soluble cytokines, as well as by suppressive immune cells. In this review, we describe factors and cells that constitute immunosuppressive microenvironment of myeloid leukemias. We characterize factors of direct leukemic origin, such as inhibitory receptors, enzymes and extracellular vesicles. Furthermore, we describe suppressive immune cells, such as myeloid derived suppressor cells and regulatory T cells. Finally, we sum up changes in these drivers of immune evasion in myeloid leukemias during therapy.

Abstract

Both chronic myeloid leukemia and acute myeloid leukemia evade the immune response during their development and disease progression. As myeloid leukemia cells modify their bone marrow microenvironment, they lead to dysfunction of cytotoxic cells, such as CD8+ T cells or NK cells, simultaneously promoting development of immunosuppressive regulatory T cells and suppressive myeloid cells. This facilitates disease progression, spreading of leukemic blasts outside the bone marrow niche and therapy resistance. The following review focuses on main immunosuppressive features of myeloid leukemias. Firstly, factors derived directly from leukemic cells – inhibitory receptors, soluble factors and extracellular vesicles, are described. Further, we outline function, properties and origin of main immunosuppressive cells - regulatory T cells, myeloid derived suppressor cells and macrophages. Finally, we analyze interplay between recovery of effector immunity and therapeutic modalities, such as tyrosine kinase inhibitors and chemotherapy.

Hodgkin Lymphoma-Review on Pathogenesis, Diagnosis, Current and Future Treatment Approaches for Adult Patients

Hodgkin lymphoma (HL) is a rare malignancy accounting for roughly 15% of all lymphomas and mostly affecting young patients. A second peak is seen in patients above 60 years of age. The history of HL treatment represents a remarkable success story in which HL has turned from an incurable disease to a neoplasm with an excellent prognosis. First-line treatment with stage-adapted treatment consisting of chemotherapy and/or radiotherapy results in cure rates of approximately 80%. Second-line treatment mostly consists of intensive salvage chemotherapy followed by high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT). Novel approaches such as antibody drug conjugates and immunomodulatory drugs have shown impressive results in clinical trials in refractory and relapsed HL and are now increasingly implemented in earlier treatment lines. This review gives a comprehensive overview on HL addressing epidemiology, pathophysiology and current treatment options as well as recent developments and perspectives.

Repeated courses of escalating doses of Nivolumab in refractory Hodgkin lymphoma with recurrent relapses post allografting: A safe and effective treatment approach

For patients with Hodgkin Lymphoma (HL) who experience relapse post allogeneic stem cell transplantation, limited treatment options exist, and the ultimate outcome is poor. Recently, the programmed cell death protein-1 (PD-1) inhibitors have shown remarkable efficacy in patients with refractory/relapsed HL, also demonstrating an acceptable safety profile. However, due to effects on T-cell activity, the use of PD-1 inhibitors post allografting may potentially increase the risk of treatment-emergent graft versus host disease. We herein report the clinical course of a patient who experienced multiple relapses of HL post allogeneic stem cell transplantation. He failed several treatment modalities but he responded to escalating doses of the PD-1 inhibitor nivolumab, given at two different treatment time points, also demonstrating minimal and easily manageable toxicity.

Efficacy of Decitabine plus Anti-PD-1 Camrelizumab in Patients with Hodgkin Lymphoma Who Progressed or Relapsed after PD-1 Blockade Monotherapy

PURPOSE

Programmed death-1 (PD-1) blockade monotherapy is effective in relapsed/refractory classical Hodgkin lymphoma (cHL), but a subset of patients is recalcitrant to PD-1 inhibitors and only a minority of patients achieves durable remission. Effective treatment regimens for those with relapsed/progressive cHL after single-agent anti-PD-1 are urgently needed. Anti-PD-1 combination with the DNA-demethylating agent decitabine showed positive preliminary results in our test cohort patients who were resistant to anti-PD-1. Here, we assess the efficacy of decitabine plus anti-PD-1 therapy in an expansion cohort and after longer follow-up.

PATIENTS AND METHODS

We present the response and progression-free survival rates from patients with relapsed/refractory cHL who relapsed/progressed after prior anti-PD-1 monotherapy, and who received decitabine (10 mg/day, days 1-5) plus the anti-PD-1 camrelizumab (200 mg, day 8), every 3 weeks in a phase II trial (ClinicalTrials.gov: NCT02961101 and NCT03250962).

RESULTS

Overall, 51 patients (test cohort: 25, expansion cohort: 26) were treated and 50 evaluated for efficacy. The objective response rate was 52% [nine complete responses (CR); 36%] in the test cohort, and 68% (six CRs; 24%) in the expansion cohort. Median progression-free survival with decitabine plus camrelizumab was 20.0 and 21.6 months, respectively, which was significantly longer than that achieved with prior anti-PD-1 monotherapy. Durable response was observed in an estimated 78% of patients who achieved CR at 24 months. After decitabine plus camrelizumab, the ratio increase of circulating peripheral central memory T cells directly correlated with both clinical response and progression-free survival.

CONCLUSIONS

Decitabine plus camrelizumab is associated with high response rates and long-term benefits in patients with relapsed/refractory cHL who failed PD-1 inhibitors.

High efficacy of BGD (bendamustine, gemcitabine, and dexamethasone) in relapsed/refractory Hodgkin Lymphoma

The optimal salvage therapy in relapsed/refractory Hodgkin lymphoma (R/R HL) has not been defined so far. The goal of this multicenter retrospective study was to evaluate efficacy and safety of BGD (bendamustine, gemcitabine, dexamethasone) as a second or subsequent line of therapy in classical R/R HL. We have evaluated 92 consecutive R/R HL patients treated with BGD. Median age was 34.5 (19-82) years. Fifty-eight patients (63%) had received 2 or more lines of chemotherapy, 32 patients (34.8%) radiotherapy, and 21 patients (22.8%) an autologous hematopoietic stem cell transplantation (autoHCT). Forty-four patients (47.8%) were resistant to first line of chemotherapy. BGD therapy consisted of bendamustine 90 mg/m² on days 1 and 2, gemcitabine 800 mg/m² on days 1 and 4, dexamethasone 40 mg on days 1-4. Median number of BGD cycles was 4 (2-7). The following adverse events ≥ 3 grade were noted: neutropenia (22.8%), thrombocytopenia (20.7%), anemia (15.2%), infections (10.9%), AST/ALT increase (2.2%), and skin rush (1.1%). After BGD therapy, 51 (55.4%) patients achieved complete remission, 23 (25%)-partial response, 7 (7.6%)-stable disease, and 11 (12%) patients experienced progression disease. AutoHCT was conducted in 42 (45.7%) patients after BGD therapy, and allogeneic HCT (alloHCT) in 16 (17.4%) patients. Median progression-free survival was 21 months. BGD is a highly effective, well-tolerated salvage regimen for patients with R/R HL, providing an excellent bridge to auto- or alloHCT.

Future directions in Hodgkin lymphoma: checkpoint inhibitors and beyond

Classic Hodgkin lymphoma (cHL) is curable with chemotherapy but relapses occur in approximately 30% of cases. Novel agents, including brentuximb vedotin (BV) and programmed cell death-1 (PD-1) inhibitors, alone or in combination with chemotherapy, have encouraging activity in newly diagnosed and relapsed/refractory cHL, confirming that the use of agents that target tumor cells or the tumor microenvironment are promising strategies to improve patient outcomes. The field of immunotherapy in cHL is now moving toward combinations of PD-1 inhibitors with other immunological agents such as cytotoxic T- lymphocyte associated protein-4 (CTLA-4) inhibitors, newer PD-1 inhibitors such as sintilimab, tislelizumab, avelumab and camrelizumab, bispecific antibodies such as AFM-13, cellular therapies using CD30 chimeric antigen T-cells (CD30.CART) and anti-CD25 antibody-drug conjugates such as camidanlumab tesirine (cami-T). Here we review early phase studies evaluating these approaches in the treatment of cHL.

Anti-PD-1 and Anti-PD-L1 Monoclonal Antibodies in People Living with HIV and Cancer

PURPOSE OF REVIEW

Immune checkpoint inhibitors targeting the programmed cell death-1 (PD-1) pathway are a class of anti-cancer immunotherapy agents changing treatment paradigms of many cancers that occur at higher rates in people living with HIV (PLWH) than in the general population. However, PLWH have been excluded from most of the initial clinical trials with these agents.

RECENT FINDINGS

Two recent prospective studies of anti-PD-1 agents, along with observational studies and a meta-analysis, have demonstrated acceptable safety in PLWH. Preliminary evidence indicates activity in a range of tumors and across CD4⁺ T cell counts. Safety and preliminary activity data suggest monoclonal antibodies targeting PD-1 or its ligand, PD-L1, are generally appropriate for PLWH and cancers for which there are FDA-approved indications. Ongoing and future trials of anti-PD-1 and anti-PD-L1 therapy alone or in combination for HIV-associated cancers may further improve outcomes for this underserved population.