Treatment of relapsed or refractory classical Hodgkin lymphoma with the anti-PD-1, tislelizumab: results of a phase 2, single-arm, multicenter study

Tislelizumab for Relapsed/Refractory Classical Hodgkin Lymphoma: 3-Year Follow-up and Correlative Biomarker Analysis

PURPOSE

Tislelizumab is an anti-programmed cell death protein 1 (anti-PD-1) monoclonal antibody specifically designed to minimize binding to Fcγ receptors (FcγR).

PATIENTS AND METHODS

Here, we present the extended 3-year follow-up of a phase II study of tislelizumab in 70 patients with relapsed/refractory classical Hodgkin lymphoma (cHL) who failed or were ineligible for autologous stem cell transplantation.

RESULTS

With a median follow-up of 33.8 months, the overall response rate by the independent review committee was 87.1%, and the complete response (CR) rate was 67.1%. Responses were durable as shown by a median duration of response of 31.3 months, and median progression-free survival (PFS) of 31.5 months. The 3-year PFS and overall survival rates were 40.8% and 84.8%, respectively. Treatment-related adverse events (TRAEs) of any grade occurred in 97.1% of patients; the grade ≥3 TRAE rate was low (31.4%), and only 8.6% of patients experienced adverse events leading to treatment discontinuation. Correlative biomarker analysis showed that FcγRΙ-expressing macrophages had no observed impact on either the CR rate or PFS achieved with tislelizumab, which may be potentially related to its engineered Fc region.

CONCLUSIONS

With extended follow-up, tislelizumab yielded long-term benefits and demonstrated a favorable safety profile for patients with relapsed/refractory cHL. This trial was registered at clinicaltrials.gov as NCT03209973.

Revolutionization in Cancer Therapeutics via Targeting Major Immune Checkpoints PD-1, PD-L1 and CTLA-4

Numerous research reports have witnessed dramatic advancements in cancer therapeutic approaches through immunotherapy. Blocking immunological checkpoint pathways (mechanisms employed by malignant cells to disguise themselves as normal human body components) has emerged as a viable strategy for developing anticancer immunity. Through the development of effective immune checkpoint inhibitors (ICIs) in multiple carcinomas, advances in cancer immunity have expedited a major breakthrough in cancer therapy. Blocking a variety of ICIs, such as PD-1 (programmed cell death-1), programmed cell death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) has improved the immune system’s efficacy in combating cancer cells. Recent studies also supported the fact that ICIs combined with other potent antitumor candidates, such as angiogenic agents, could be a solid promising chemopreventive therapeutic approach in improving the effectiveness of immune checkpoint inhibitors. Immune checkpoint blockade has aided antiangiogenesis by lowering vascular endothelial growth factor expression and alleviating hypoxia. Our review summarized recent advances and clinical improvements in immune checkpoint blocking tactics, including combinatorial treatment of immunogenic cell death (ICD) inducers with ICIs, which may aid future researchers in creating more effective cancer-fighting strategies.

Immune Checkpoint Blockade for the Treatment of Hodgkin Lymphoma

Classical Hodgkin lymphoma is biologically different than other lymphomas. The cancer cells only occupy a small amount of the lymph node and evade the immune system by amplification of PD-L1 and PD-L2. Therefore, checkpoint inhibitors are a logical treatment option for Hodgkin lymphoma patients to unlock the immune system. Checkpoint inhibitors have shown high response rates in clinical trials in advanced-stage Hodgkin lymphoma. The two most commonly used checkpoint inhibitors are pembrolizumab and nivolumab, both FDA approved as third-line therapy. There is increasing interest in the use of checkpoint inhibitors with combination chemotherapy or with other targeted agents in the second-line or even frontline setting. In this review, we will highlight the clinical trials that led to approvals of checkpoint inhibitors for Hodgkin lymphoma.

Case Report: Glucocorticoid Effect Observation in a Ureteral Urothelial Cancer Patient With ICI-Associated Myocarditis and Multiple Organ Injuries

Immune checkpoint inhibitor (ICI)-associated immune-related adverse events (irAEs) are becoming important safety issues worthy of attention despite the exciting therapeutic prospects. The growing development of new ICIs also brings new cases of irAEs, raising more challenges to clinicians. Cardiac injury is rare but life-threatening among diverse organ injuries, and effective interventions are critical for patients. Here, we report a novel programmed cell death protein-1 (PD-1) inhibitor tislelizumab-associated severe myocarditis and myositis accompanied by liver and kidney damage in a ureteral urothelial cancer patient, who was firstly treated by cardiologists because of cardiac symptoms. Due to the lack of experience about ICI-associated irAEs, an initial low-dose (0.5 mg/kg/day) and short-term methylprednisolone therapy was used and found to be ineffective and risky to the patient; then, steroid therapy was modulated to a higher dose (1.5 mg/kg/day) with prolonged time course, and improvement of patient symptoms and laboratory markers were observed quickly and persistently. The patient did not show adverse events under this steroid dosage. This case reports a rare tislelizumab-related myocarditis and multiple organ injuries, which provides valuable experience to cardiologists like us. Early recognition of ICI-associated myocarditis and sufficient dosage and time course of glucocorticoid therapy are critical for severe cases. High-quality clinical evidence about the precise diagnosis and therapy in ICI-associated myocarditis and other organ injuries are necessary to guide our clinical works.

Current salvage therapies in Hodgkin lymphoma

Hodgkin lymphoma is a B-cell malignancy with approximately 85-95% complete remission rate following frontline therapy; however, relapsed/refractory disease occurs in roughly 10-30% of patients after treatment. Salvage therapy conventionally relies upon cytotoxic chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation. A considerable number of patients experience relapse after transplantation, and further salvage management has included the use of allogeneic transplantation and radiotherapy. In the past decade, novel therapies including, brentuximab vedotin, PD-1 inhibitors, and the incorporation of PET-imaging into management have changed the paradigm of relapsed/refractory disease care. Novel therapies have been investigated in both single and combination regimens with other novel therapies and traditional chemotherapies. There is promising early work into the utility of CD30.CAR-T cell therapy, AFM13, camidanlumab tesirine, novel PD-1 inhibitors, and JAK1/JAK2 inhibition in management. Herein, we will review current salvage therapies in Hodgkin lymphoma and future directions in relapsed/refractory disease management.

Tumor Flare Reaction in a Classic Hodgkin Lymphoma Patient Treated With Brentuximab Vedotin and Tislelizumab: A Case Report

Background

Tumor flare reaction (TFR) is a clinical syndrome, which is mainly associated with painful and swollen lymph nodes or splenomegaly, slight fever, bone pain, and skin rash during treatment with immune-related drugs, causing difficulty in distinguishing TFR from disease progression. Brentuximab vedotin (BV) and programmed death 1 (PD-1) inhibitor are two ideal drugs used for the treatment of classic Hodgkin lymphoma, but few studies have reported their adverse effects in association with TFR. The efficacy and safety of monotherapy or combination therapy with these drugs needs to be further evaluated. It is essential to determine whether treated patients can develop TFR, thus enabling more accurate diagnosis and treatment.

Case presentation

A 26-year-old female patient, diagnosed with classic Hodgkin lymphoma, had received 2 + 3 cycles of ABVD chemotherapy (a combination of adriamycin, bleomycin, vinblastine, and dacarbazine) and 4 cycles of PD-1 inhibitor (tislelizumab) therapy but exhibited poor efficacy. Subsequently, she was given combination therapy of BV (100 mg) + tislelizumab (200 mg). However, a slight fever, painful and swollen axillary lymph nodes, multiple skin rashes with pruritus, joint pain, and fatigue with poor appetite appeared during the treatment. Ultrasound (US) scans revealed that multiple lymph nodes were significantly enlarged. After treatment with low-dose dexamethasone and cetirizine, the symptoms were alleviated. A biopsy of the left axillary lymph node revealed that lymphoid tissue exhibited proliferative changes, without tumor cell infiltration. These findings were consistent with the clinical and pathological manifestations of TFR.

Conclusion

Combination therapy with BV and PD-1 inhibitor was effective in the treatment of relapsed or refractory classic Hodgkin lymphoma. The results suggest that the combination therapy may cause TFR, and biopsy and also continuous imaging observation are important to determine the disease stage. This approach allows clinicians to decide whether to continue the current treatment plan, and alerts them to the occurrence of excessive activation of the immune system.

Tislelizumab: A Modified Anti-tumor Programmed Death Receptor 1 Antibody

Tislelizumab is an anti-programmed death receptor 1 (PD-1) monoclonal immunoglobulin G 4 antibody developed by BeiGene. The structure of tislelizumab has been modified to maximally inhibit the binding of PD-1 to programmed death ligand 1 (PD-L1) and minimize the binding of tislelizumab to Fcγ receptors. In clinical studies, tislelizumab has shown preliminary anti-tumor effects in various solid tumors, such as Hodgkin's lymphoma, urothelial carcinoma, lung cancer, gastric and esophageal cancer, liver cancer, nasopharyngeal carcinoma, colorectal cancer, and microsatellite instability-high/mismatch repair-deficient tumors. In addition, it also showed new promise in solid tumor treatment in combination with ociperlimab. Due to its satisfactory anti-tumor effects, tislelizumab has received approvals in China for the treatment of classical Hodgkin's lymphoma, urothelial carcinoma, squamous non-small cell lung cancer, non-squamous non-small cell lung cancer, and hepatocellular carcinoma, and it is now under investigation for a new indication in microsatellite instability-high/mismatch repair-deficient tumors. Moreover, it has been granted orphan designations in hepatocellular carcinoma, esophageal cancer, and gastric cancer, including cancer of the gastroesophageal junction, by the US Food and Drug Administration. Tislelizumab has an acceptable safety profile; the most common adverse effects include fatigue, anemia, and decreased neutrophil count, while the most fatal events have been related to respiratory infection or failure, and hepatic injury. Tislelizumab has an economic advantage compared with other well-studied PD-1/PD-L1 inhibitors; thus, the introduction of it could provide clinical oncologists with an effective weapon against tumors and may alleviate the burden of cancer patients.

Anti-Angiogenic Agent Combined with Anti-PD-1 Immunotherapy Showed Activity in Patients With Classical Hodgkin Lymphoma Who Have Failed Immunotherapy: A Retrospective Case Report Study

Background

PD-1/PD-L1 inhibitor immunotherapy has showed impressive activity in various cancers, especially relapsed/refractory (r/r) classical Hodgkin lymphoma (cHL). However, acquired resistance is inevitable for most patients. Sometimes severe side effects also lead to treatment termination. When immunotherapy failed, alternative treatment options are limited. In the past few years, we have used the anti-angiogenic agent apatinib and PD-1 inhibitor camrelizumab to treat cHL patients who failed prior immunotherapy. In this study, we analyzed the data of these patients.

Patients and Methods

Patients with r/r cHL who had failed immunotherapy and subsequently received apatinib-camrelizumab (AC) combination therapy were included in this study. Patient data were collected from medical records and follow-up system. The efficacy and safety of AC therapy were analyzed.

Results

Seven patients who failed immunotherapy were identified in our database, of which five patients acquired immunotherapy resistance and two patients experienced severe side effects. They received a combination of camrelizumab (200 mg every four weeks) and apatinib (425 mg or 250 mg per day). As of the cut-off date, these patients had received a median of 4 cycles (range, 2 - 31) of treatment. Two (2/7) patients achieved complete response, four (4/7) partial response, and one (1/7) stable disease. The median progression-free survival was 10.0 months (range, 2.0 – 27.8). Low-dose apatinib (250 mg) plus camrelizumab was well tolerated and had no unexpected side effects. Besides, no reactive cutaneous capillary endothelial proliferation was observed in AC-treated patients.

Conclusions

Low dose apatinib plus camrelizumab might be a promising treatment option for r/r cHL patients who have failed immunotherapy. This combination treatment is worthy of further investigation in more patients including solid cancer patients who have failed immunotherapy.

How to choose first salvage therapy in Hodgkin lymphoma: traditional chemotherapy vs novel agents

Approximately 10% to 30% of patients with classical Hodgkin lymphoma (cHL) develop relapsed or refractory (R/R) disease. Of those patients, 50% to 60% show long-term progression-free survival after standard salvage chemotherapy followed by high-dose chemotherapy (HDCT) and autologous stem cell transplant (ASCT). In the past decade, novel therapies have been developed, such as the CD30-directed antibody-drug conjugate brentuximab vedotin and immune checkpoint inhibitors, which have greatly extended the treatment possibilities for patients with R/R cHL. Several phase 1/2 clinical trials have shown promising results of these new drugs as monotherapy or in combination with chemotherapy, but unfortunately, very few randomized phase 3 trials have been performed in this setting, making it difficult to give evidence-based recommendations for optimal treatment sequencing. Two important goals for the improvement in the treatment of R/R cHL can be identified: (1) increasing long-term progression-free and overall survival by optimizing risk-adapted treatment and (2) decreasing toxicity in patients with a low risk of relapse of disease by evaluating the need for HDCT/ASCT in these patients. In this review, we discuss treatment options for patients with R/R cHL in different settings: patients with a first relapse, primary refractory disease, and in patients who are ineligible or unfit for ASCT. Results of clinical trials investigating novel therapies or strategies published over the past 5 years are summarized.

Cancer immunotherapy: Challenges and limitations

Although cancer immunotherapy has taken center stage in mainstream oncology inducing complete and long-lasting tumor regression, only a subset of patients receiving treatment respond and others relapse after an initial response. Different tumor types respond differently, and even in cancer types that respond (hot tumors), we still observe tumors that are unresponsive (cold tumors), suggesting the presence of resistance. Hence, the development of intrinsic or acquired resistance is a big challenge for the cancer immunotherapy field. Resistance to immunotherapy, including checkpoint inhibitors, CAR-T cell therapy, oncolytic viruses, and recombinant cytokines arises due to cancer cells employing several mechanisms to evade immunosurveillance.

Advances in CD30- and PD-1-targeted therapies for relapsed or refractory Hodgkin lymphoma

The current standard approach for relapsed or refractory (R/R) Hodgkin lymphoma (HL) is salvage chemotherapy, followed by autologous stem cell transplantation (ASCT). However, this therapeutic regimen is successful in only half of patients with relapsed or refractory classical HL. In addition, some patients with R/R HL are ineligible for ASCT. To improve survival time and quality of life and decrease the acute and long-term toxicities of therapy, many schemes for the treatment of R/R HL have emerged. Recently, the use of targeted therapy and immunotherapy represents an important advance in the treatment of R/R HL. The CD30 antibody drug conjugate brentuximab vedotin (BV) and programmed death-1 (PD-1) receptor checkpoint inhibitors nivolumab and pembrolizumab are effective and well-tolerated treatments for R/R HL patients, broadening treatment options for these patients. BV and anti-PD-1 antibodies can be used as monotherapy or combined with other chemotherapy regimens for rescue treatment, consolidation treatment and second-line treatment of R/R HL. In this article, we review current pathobiology knowledge of R/R HL and summarize recent advances in therapy schemes.

Camrelizumab for relapsed or refractory classical Hodgkin lymphoma: Extended follow-up of the multicenter, single-arm, Phase 2 study

Camrelizumab (a humanized high-affinity IgG4 mAb against programmed death-l) showed potent antitumor activity, well tolerance and controllable safety in patients with relapsed or refractory classical Hodgkin lymphoma (r/r cHL), based on the primary analysis of a Phase 2 study. Here, we present the extended follow-up outcomes. Seventy-five patients who had failed to achieve a remission or experienced progression after autologous stem cell transplantation or had received at least two lines of systemic chemotherapies were enrolled to receive camrelizumab 200 mg every 2 weeks. With a median follow-up of 36.2 months (range, 7.2-38.1), objective response rate per independent central review was 76.0% (95% confidence interval [CI], 64.7-85.1). Among the 57 responders, 31 (54.4%) had ongoing responses. Median duration of response was 31.7 months (95% CI, 16.7-not reached). Median progression-free survival was 22.5 months (95% CI, 14.7-not reached). Thirty-six-month overall survival rate was 82.7% (95% CI, 72.0-89.5). Reactive capillary endothelial proliferation (RCEP) occurred in 97.3% of patients (73/75), but all RCEP were Grade 1 or 2 in severity and 67.1% of these patients (49/73) achieved complete resolution. Occurrence of new RCEP lesions was rare (8/42 [19.0%] at 12 months; 2/32 [6.3%] at 24 months). No treatment-related deaths occurred, and no new toxicities were reported. With extended follow-up, camrelizumab monotherapy continues to provide a robust and durable response, long survival and manageable safety in r/r cHL patients.

Combination of PD-1 inhibitor with GVD (gemcitabine, vinorelbine, liposomal doxorubicin) versus GVD regimen as second-line therapy for relapsed/refractory classical Hodgkin lymphoma

Patients with classical Hodgkin lymphoma (cHL) who do not achieve complete remission (CR) after second-line chemotherapy have poor clinical outcomes. Besides, conventional salvage chemotherapy regimens have an unsatisfactory CR rate. The present retrospective study reports the efficacy and toxicity of the GVD (gemcitabine, vinorelbine, liposomal doxorubicin) regimen with or without programmed cell death 1 (PD-1) inhibitor for patients with cHL who failed first-line treatment. A total of 103 patients with cHL (GVD+PD-1 group, n = 27; GVD group, n = 76) with response assessment based on positron emission tomography were included. The GVD+PD-1 group tended to have a higher CR rate than GVD group (85·2% vs. 65·8%, P = 0·057) and had a better event-free survival (EFS) (P = 0·034). Subgroup analysis showed that patients with low-risk second-line International Prognostic Score might benefit from the addition of PD-1 inhibitor (GVD+PD-1 vs. GVD, 100·0% vs. 64·7%, P = 0·028) and had better EFS than GVD alone (P = 0·016). Further analysis demonstrated that PD-1 consolidation therapy might provide an EFS benefit (P = 0·007). The toxicity of the GVD+PD-1 regimen was comparable to the GVD regimen, except for higher rates of hypothyroidism and autoimmune pneumonitis, which were manageable. In conclusion, combining a PD-1 inhibitor with a GVD regimen could be a potentially effective second-line therapy for patients with cHL.

Reverted exhaustion phenotype of circulating lymphocytes as immune correlate of anti-PD1 first-line treatment in Hodgkin lymphoma

While classical Hodgkin lymphoma (HL) is highly susceptible to anti-programmed death protein 1 (PD1) antibodies, the exact modes of action remain controversial. To elucidate the circulating lymphocyte phenotype and systemic effects during anti-PD1 1st-line HL treatment we applied multicolor flow cytometry, FluoroSpot and NanoString to sequential samples of 81 HL patients from the NIVAHL trial (NCT03004833) compared to healthy controls. HL patients showed a decreased CD4 T-cell fraction, a higher percentage of effector-memory T cells and higher expression of activation markers at baseline. Strikingly, and in contrast to solid cancers, expression for 10 out of 16 analyzed co-inhibitory molecules on T cells (e.g., PD1, LAG3, Tim3) was higher in HL. Overall, we observed a sustained decrease of the exhausted T-cell phenotype during anti-PD1 treatment. FluoroSpot of 42.3% of patients revealed T-cell responses against ≥1 of five analyzed tumor-associated antigens. Importantly, these responses were more frequently observed in samples from patients with early excellent response to anti-PD1 therapy. In summary, an initially exhausted lymphocyte phenotype rapidly reverted during anti-PD1 1st-line treatment. The frequently observed IFN-y responses against shared tumor-associated antigens indicate T-cell-mediated cytotoxicity and could represent an important resource for immune monitoring and cellular therapy of HL.

9p24.1 alterations and programmed cell death 1 ligand 1 expression in early stage unfavourable classical Hodgkin lymphoma: an analysis from the German Hodgkin Study Group NIVAHL trial

High programmed cell death 1 ligand 1 (PD-L1) protein expression and copy number alterations (CNAs) of the corresponding genomic locus 9p24.1 in Hodgkin- and Reed-Sternberg cells (HRSC) have been shown to be associated with favourable response to anti-PD-1 checkpoint inhibition in relapsed/refractory (r/r) classical Hodgkin lymphoma (cHL). In the present study, we investigated baseline 9p24.1 status as well as PD-L1 and major histocompatibility complex (MHC) class I and II protein expression in 82 biopsies from patients with early stage unfavourable cHL treated with anti-PD-1-based first-line treatment in the German Hodgkin Study Group (GHSG) NIVAHL trial (ClinicalTrials.gov Identifier: NCT03004833). All evaluated specimens showed 9p24.1 CNA in HRSC to some extent, but with high intratumoral heterogeneity and an overall smaller range of alterations than reported in advanced-stage or r/r cHL. All but two cases (97%) showed PD-L1 expression by the tumour cells in variable amounts. While MHC-I was rarely expressed in >50% of HRSC, MHC-II expression in >50% of HRSC was found more frequently. No obvious impact of 9p24.1 CNA or PD-L1 and MHC-I/II expression on early response to the highly effective anti-PD-1-based NIVAHL first-line treatment was observed. Further studies evaluating an expanded panel of potential biomarkers are needed to optimally stratify anti-PD-1 first-line cHL treatment.

Toxicity of Immune-Checkpoint Inhibitors in Hematological Malignancies

Immune checkpoint inhibitors (ICIs), especially those targeting the programmed-death 1 (PD-1) receptor and its ligands, have become indispensable agents in solid tumor anti-cancer therapy. Concerning hematological malignancies, only nivolumab and pembrolizumab have been approved for the treatment of relapsed and refractory classical Hodgkin lymphoma and primary mediastinal large B cell lymphoma to date. Nevertheless, clinical research in this field is very active. The mechanism of action of ICIs is based on unblocking the hindered immune system to recognize and eliminate cancer cells, but that also has its costs in the form of ICI-specific immune related adverse events (irAEs), which can affect any organ system and can even be lethal. In this article, we have reviewed all prospective blood cancer clinical trials investigating ICIs (both monotherapy and combination therapy) with available toxicity data with the purpose of determining the incidence of irAEs in this specific setting and to offer a brief insight into their management, as the use of immune checkpoint blockade is not so frequent in hemato-oncology.

Efficacy and safety of GLS-010 (zimberelimab) in patients with relapsed or refractory classical Hodgkin lymphoma: A multicenter, single-arm, phase II study

BACKGROUND

GLS-010 (zimberelimab) is a novel, fully human, anti-programmed death-1 monoclonal antibody that shows promising efficacy and safety in advanced solid tumors. This trial aimed to evaluate the efficacy and safety of GLS-010 (zimberelimab) in Chinese patients with relapsed or refractory classical Hodgkin lymphoma (r/r-cHL).

METHODS

This phase II, single-arm, open-label, multicenter clinical trial was conducted at 24 centers in China and enrolled patients with r/r-cHL after two or more lines of therapy. The patients were administered intravenous GLS-010 (zimberelimab) (240 mg, once every 2 weeks) until progression, death, unacceptable toxicity, or consent withdrawal. The primary end-point was the objective response rate assessed by an independent radiology review committee (IRC). This study was registered (NCT03655483).

RESULTS

Eighty-five patients were enrolled between August 2018 and August 2019. The median follow-up was 15.8 months. Seventy-seven patients (90.6%; 95% confidence interval [CI] 82.3-95.9) had an IRC-assessed objective response. The complete response rate was 32.9% (n = 28). The 12-month progression-free survival and overall survival rates were 78% (95% CI 67.5-85.6) and 99% (95% CI 91.9-99.8), respectively. Treatment-related adverse events (TRAEs) were observed in 92.9% of participants. Grade III or IV TRAEs occurred in 24 (28.2%) of the 85 participants. The most common grade III or IV TRAEs were abnormal hepatic function (5.9%), hyperuricemia (4.7%), decreased neutrophil count (3.5%), and increased weight (3.5%). Only one grade V AE, gastrointestinal infection, occurred.

CONCLUSIONS

GLS-010 (zimberelimab) appears to be effective and safe for the treatment of Chinese patients with r/r-cHL. Long-term follow-up is required to confirm these clinical benefits.

Synchronizing the use of allogeneic hematopoietic cell transplantation in checkpoint blockade therapy for Hodgkin lymphoma

INTRODUCTION

The use of checkpoint blockade therapy (CBT) has shown impressive results for the treatment of relapsed/refractory Hodgkin lymphoma (cHL). The impact of CBT depends on the reversal of an exhausted T-cell immune phenotype and a consequential increase in the immunological, anti-tumor effect derived from a patient's adaptive immunity. As most patients with classical Hodgkin lymphoma will relapse during or after this treatment, clinicians often provide consolidation with allogeneic hematopoietic cell transplantation (alloHCT) in fit patients. However, the mechanisms responsible for CBT efficacy can also be those that increase the risk of immunological complications after alloHCT.

AREAS COVERED

We carried out in-depth research on the current medical literature to report and discuss the mechanism of action of CBT within a cHL setting; clinical results of CBT in cHL setting pre-alloHCT and post-alloHCT; interactions between CBT and alloHCT; and further clinical considerations.

EXPERT OPINION

Checkpoint blockade therapy is an effective strategy for relapsed/refractory cHL. Its use is associated with higher immunological toxicities when administered before or after alloHCT. Whenever alloHCT is planned, clinicians should follow international recommendations such as using post-transplant cyclophosphamide GVHD prophylaxis.

Targeting the tumor microenvironment in B-cell lymphoma: challenges and opportunities

B-cell lymphoma is a group of hematological malignancies with high clinical and biological heterogeneity. The pathogenesis of B-cell lymphoma involves a complex interaction between tumor cells and the tumor microenvironment (TME), which is composed of stromal cells and extracellular matrix. Although the roles of the TME have not been fully elucidated, accumulating evidence implies that TME is closely relevant to the origination, invasion and metastasis of B-cell lymphoma. Explorations of the TME provide distinctive insights for cancer therapy. Here, we epitomize the recent advances of TME in B-cell lymphoma and discuss its function in tumor progression and immune escape. In addition, the potential clinical value of targeting TME in B-cell lymphoma is highlighted, which is expected to pave the way for novel therapeutic strategies.

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.

Comparisons of Underlying Mechanisms, Clinical Efficacy and Safety Between Anti-PD-1 and Anti-PD-L1 Immunotherapy: The State-of-the-Art Review and Future Perspectives

Over the past decade, diverse PD-1/PD-L1 blockades have demonstrated significant clinical benefit in across a wide range of tumor and cancer types. With the increasing number of PD-1/PD-L1 blockades available in the market, differences between the clinical performance of each of them started to be reported. Here, we provide a comprehensive historical and biological perspective regarding the underlying mechanism and clinical performance of PD-1/PD-L1 blockades, with an emphasis on the comparisons of their clinical efficacy and safety. The real-world evidence indicated that PD-1 blockade may be more effective than the PD-L1, though no significant differences were found as regards to their safety profiles. Future head-to-head studies are warranted for direct comparison between them. Finally, we summarize the yet to be elucidated questions and future promise of anti-PD-1/PD-L1 immunotherapy, including a need to explore novel biomarkers, novel combinatorial strategies, and their clinical use on chronic infection.

Clinical Strategy for the Diagnosis and Treatment of Immune Checkpoint Inhibitor-Associated Myocarditis: A Narrative Review

Importance

In the last decade, immune checkpoint inhibitors (ICIs) have been approved for the treatment of many cancer types. Immune checkpoint inhibitor-associated myocarditis has emerged as a significant and potentially fatal adverse effect. Recognizing, diagnosing, and treating ICI-associated myocarditis poses new challenges for the practicing clinician. Here, the current literature on ICI-associated myocarditis is reviewed.

Observations

Clinical presentation and cardiac pathological findings are highly variable in patients with ICI-associated myocarditis. Although endomyocardial biopsy is the criterion standard diagnostic test, a combination of clinical suspicion, cardiac biomarkers (specifically troponin), and cardiac imaging, in addition to biopsy, is often needed to support the diagnosis. Importantly, the combination of a cytotoxic T-lymphocyte-associated protein 4 inhibitor with a programmed cell death protein 1 or programmed death-ligand 1 inhibitor increases the risk of developing ICI-associated myocarditis.

Conclusion and Relevance

This review aims to provide a standardized diagnostic and therapeutic approach for patients with suspected ICI-associated myocarditis. A complete history of recent cancer treatments and physical examination in combination with cardiac biomarkers, cardiac imaging, and endomyocardial biopsy represent a pragmatic diagnostic approach for most cases of ICI-associated myocarditis. The addition of novel biomarkers or imaging modalities is an area of active research and should be evaluated in larger cohorts.

Reprogramming the anti-tumor immune response via CRISPR genetic and epigenetic editing

Precise clustered regularly interspaced short palindromic repeats (CRISPR)-mediated genetic and epigenetic manipulation of the immune response has become a promising immunotherapeutic approach toward combating tumorigenesis and tumor progression. CRISPR-based immunologic reprograming in cancer therapy comprises the locus-specific enhancement of host immunity, the improvement of tumor immunogenicity, and the suppression of tumor immunoevasion. To date, the ex vivo re-engineering of immune cells directed to inhibit the expression of immune checkpoints or to express synthetic immune receptors (chimeric antigen receptor therapy) has shown success in some settings, such as in the treatment of melanoma, lymphoma, liver, and lung cancer. However, advancements in nuclease-deactivated CRISPR-associated nuclease-9 (dCas9)-mediated transcriptional activation or repression and Cas13-directed gene suppression present novel avenues for the development of tumor immunotherapies. In this review, the basis for development, mechanism of action, and outcomes from recently published Cas9-based clinical trial (genetic editing) and dCas9/Cas13-based pre-clinical (epigenetic editing) data are discussed. Lastly, we review cancer immunotherapy-specific considerations and barriers surrounding use of these approaches in the clinic.

Tislelizumab in Chinese patients with advanced solid tumors: an open-label, non-comparative, phase 1/2 study

BACKGROUND

Tislelizumab is an investigational, humanized, IgG4 monoclonal antibody with high affinity and binding specificity for programmed cell death-1 (PD-1) that was engineered to minimize binding to FcγR on macrophages in order to abrogate antibody-dependent phagocytosis, a mechanism of T-cell clearance and potential resistance to anti-PD-1 therapy.

METHODS

The purpose of this phase 1/2, open-label, non-comparative study was to examine the safety, tolerability, and antitumor activity of tislelizumab in adult (≥18 years) Chinese patients with histologically or cytologically confirmed advanced solid tumors with measurable disease. The phase 1 portion of the study consisted of a dose-verification study and a pharmacokinetic (PK) substudy; phase 2 was an indication-expansion study including 11 solid tumor cohorts. Patients previously treated with therapies targeting PD-1 or its ligand, programmed cell death ligand-1 were excluded. During dose-verification, dose-limiting toxicities (DLTs) were monitored; safety and tolerability were examined and the previously determined recommended phase 2 dose (RP2D) was verified. The primary endpoint of phase 2 was investigator-assessed objective response rate per Response Evaluation Criteria in Solid Tumors V.1.1.

RESULTS

As of December 1, 2018, 300 patients were treated with tislelizumab 200 mg intravenously once every 3 weeks (Q3W). Median duration of follow-up was 8.1 months (range 0.2-21.9). No DLTs were reported during the phase 1 dose-verification study and the RP2D was confirmed to be 200 mg intravenously Q3W. Most treatment-related adverse events (62%) were grade 1 or 2, with the most common being anemia (n=70; 23%) and increased aspartate aminotransferase (n=67; 22%). Of the 251 efficacy evaluable patients, 45 (18%) achieved a confirmed clinical response, including one patient from the PK substudy who achieved a complete response. Median duration of response was not reached for all except the nasopharyngeal carcinoma cohort (8.3 months). Antitumor responses were observed in multiple tumor types.

CONCLUSIONS

Tislelizumab was generally well tolerated among Chinese patients. Antitumor activity was observed in patients with multiple solid tumors.

TRIAL REGISTRATION NUMBER

CTR20160872.

Immunotherapy and Gene Therapy for Oncoviruses Infections: A Review

Immunotherapy has been shown to be highly effective in some types of cancer caused by viruses. Gene therapy involves insertion or modification of a therapeutic gene, to correct for inappropriate gene products that cause/may cause diseases. Both these types of therapy have been used as alternative ways to avoid cancers caused by oncoviruses. In this review, we summarize recent studies on immunotherapy and gene therapy including the topics of oncolytic immunotherapy, immune checkpoint inhibitors, gene replacement, antisense oligonucleotides, RNA interference, clustered regularly interspaced short palindromic repeats Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based gene editing, transcription activator-like effector nucleases (TALENs) and custom treatment for Epstein-Barr virus, human T-lymphotropic virus 1, hepatitis B virus, human papillomavirus, hepatitis C virus, herpesvirus associated with Kaposi's sarcoma, Merkel cell polyomavirus, and cytomegalovirus.

Case Report: Clinical Responses to Tislelizumab as a First-Line Therapy for Primary Hepatocellular Carcinoma With B-Cell Indolent Lymphoma

Background

As an emerging therapy with a promising efficacy, immunotherapy has been widely used in the treatment of solid tumors and hematologic malignancies. This clinical study compares the efficacy of tislelizumab, a domestic immune checkpoint inhibitor (ICI), to that of sorafenib when used as a first-line therapeutic option in hepatocellular carcinoma (HCC), and the concurrence of HCC and non-Hodgkin's lymphoma (NHL) is rare, especially in the treatment of ICIs.

Case presentation

A 61-year-old patient presenting with primary HCC and indolent B-cell lymphoma had a partial clinical response to tislelizumab for his primary HCC. Besides, we described a phenomenon of pseudo-progression and delayed diagnosis of his lymphoma during a long course of treatment.

Conclusion

Tislelizumab, an immunotherapeutic option with a favorable efficacy and toxicity, can be used to manage double primary tumors. However, studies should aim to elucidate the probable mechanisms of this therapy. Pseudo-progression and separation remission make the treatment of double primary tumors even more challenging, which calls for additional caution in patients undergoing immunotherapy to avoid misdiagnosis and, therefore, begin early appropriate interventions.

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.

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.

Attitudes and Practices of Immune Checkpoint Inhibitors in Chinese Patients With Cancer: A National Cross-Sectional Survey

Immune-checkpoint inhibitors (ICIs) are revolutionizing the field of immuno-oncology. Side effects and tumor microenvironment currently represent the most significant obstacles to using ICIs. In this study, we conducted an extensive cross-sectional survey to investigate the concept and practices regarding the use of ICIs in cancer patients in China. The results provide real-world data on the adverse events (AEs) of ICIs and the factors influencing the use of ICIs. This survey was developed by the Expert Committee on Immuno-Oncology of the Chinese Society of Clinical Oncology (CSCO-IO) and the Expert Committee on Patient Education of the Chinese Society of Clinical Oncology (CSCO-PE). The surveys were distributed using a web-based platform between November 29, 2019 and December 21, 2019. A total of 1,575 patients were included. High costs (43.9%), uncertainty about drug efficacy (41.2%), and no reimbursement from medical insurance (32.4%) were the factors that prevented the patients from using ICIs. The patients were most concerned about the onset time or effective duration of ICIs (40.3%), followed by the indications of ICIs and pre-use evaluation (33.4%). Moreover, 9.0, 57.1, 21.0, and 12.9% of the patients reported tumor disappearance, tumor volume reduction, no change in tumor volume, and increased tumor volume. Among the patients who received ICIs, 65.7% reported immune-related AEs (irAEs); 96.1% reported mild-to-moderate irAEs. Cancer patients in China had a preliminary understanding of ICIs. Yet, the number of patients treated with ICIs was small.

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.

Checkpoint Inhibition Therapy in Transplant-Ineligible Relapsed or Refractory Classic Hodgkin Lymphoma

The checkpoint inhibitors nivolumab and pembrolizumab are principal treatment options for relapsed or refractory classic Hodgkin lymphoma. In patients who decline autologous stem-cell transplantation or who are unsuited for high-dose chemotherapy and subsequent autologous stem-cell transplantation because of comorbidities, the use of checkpoint inhibitors may improve overall survival and have a manageable side effect profile. This clinical review provides an evidence-based summary to guide practicing oncologists in the use of checkpoint inhibitors in relapsed or refractory classic Hodgkin lymphoma and includes checkpoint inhibitor efficacy and adverse effect profiles. We highlight the use of checkpoint inhibitors in the management of relapsed or refractory classic Hodgkin lymphoma in patients who are ineligible for an autologous stem-cell transplant with the goal of improving disease control while limiting adverse events.

The interplay of interleukin-17A and breast cancer tumor microenvironment as a novel immunotherapeutic approach to increase tumor immunogenicity

Based on its known role in mediating tumor progression and the correlation with poor response to chemotherapy, we hypothesized that blocking interleukin-17A (IL-17A) by anti-IL-17 monoclonal antibodies might have the ability to suppress programmed death-ligand-1 (PD-L1) and to modulate the expression and function of myeloid-derived suppressor cells (MDSCs) in BC microenvironment. We also compared the apoptotic activity of anti-IL-17 with those acquired from our previous work on monoclonal antibodies against IL-6. The influence of anti-IL-17 was investigated in two doses on localized freshly resected tissues from 50 patients with BC. Results revealed increased IL-17A in BC tumor tissues versus surrounding tissues. Additionally, PD-L1 expression was inhibited in cultures treated with both doses of anti-IL-17. Frequencies of MDSCs were reduced in those cultures with anti-IL-17 with reduced suppressive activity. The induced apoptosis in the tumor cells was significantly increased. Anti-IL-17 antibodies effect was related to late stages, vascular metastasis, and hormonal status. Results of the current work suggest a promising role for anti-IL-17 monoclonal antibodies in enhancement of anti-tumor immunological activity in BC, potentially involving suppression of immune checkpoint PD-L1 and MDSCs inhibition with a marked response in aggressive disease.

Predicting Responses to Checkpoint Inhibitors in Lymphoma: Are We Up to the Standards of Solid Tumors?

Treatment of cancer has transformed with the introduction of checkpoint inhibitors. However, the majority of solid tumor patients do not respond to checkpoint blockade. In contrast, the response rate to programmed cell death 1 (PD-1) blockade in relapsed/refractory classical Hodgkin lymphoma (cHL) is 65% to 84% which is the highest among all cancers. Currently, checkpoint inhibitors are only approved for cHL and primary mediastinal B-cell lymphoma as the responses to single-agent checkpoint blockade in other hematologic malignancies is disappointingly low. Various established biomarkers such as programmed cell death 1 ligand 1 (PD-L1) protein surface expression, mismatch repair (MMR) status, and tumor mutational burden (TMB) are routinely used in clinical decision-making in solid tumors. In this review, we will explore these biomarkers in the context of hematologic malignancies. We review characteristic 9p24.1 structural alteration in cHL and primary mediastinal B-cell lymphoma (PMBCL) as a basis for response to PD-1 inhibition, as well as the role of antigen presentation pathways. We also explore the reported frequencies of MMR deficiency in various hematologic malignancies and investigate TMB as a predictive marker.

Tislelizumab: First Approval

Tislelizumab (^®;; Tileilizhu Dankang Zhusheye) is an anti-human programmed death receptor-1 (PD-1) monoclonal IgG4 antibody that is being developed by BeiGene as an immunotherapeutic, anti-neoplastic drug. Tislelizumab has been investigated in haematological cancers and advanced solid tumours, leading to its approval in December 2019 in China for patients with relapsed or refractory classical Hodgkin's lymphoma after at least second-line chemotherapy. This article summarises the major milestones in the development of tislelizumab for this first approval for classical Hodgkin's lymphoma, and its potential upcoming approvals in other indications.

Plasma soluble PD-L1 and STAT3 predict the prognosis in diffuse large B cell lymphoma patients

Purpose: Diffuse large B cell lymphoma (DLBCL) is one of the most common B cell lymphomas, which displays heterogeneous pathologies. Programmed cell death 1/ programmed cell death ligand 1 (PD-1/PD-L1) plays an essential role in immunosuppression in multiple malignancies. Signal transducer and activator of transcription 3 (STAT3)-positive patients also have an independently inferior clinical outcome. However, there are no reports on the effect of plasma soluble PD-L1 (sPD-L1) combined with plasma STAT3 on the prognosis of DLBCL. In this study, we investigate the relationships between plasma sPD-L1 combined with STAT3 and clinical prognosis of DLBCL.

Methods: Levels of plasma sPD-L1 and STAT3 were quantified using ELISA in eighty-seven DLBCL patients. Multiplexed immunofluorescence staining was performed to visualize the expression of PD-L1 in twenty-nine matched FFPE specimens from all patients.

Results: The survival analysis revealed that the progression-free survival (PFS) and overall survival (OS) in high sPD-L1 level group were poorer than that in low sPD-L1 level group (PFS, P < 0.001; OS, P < 0.001). Similarly, the PFS and OS in high STAT3 level group were also poorer than that in low STAT3 level group. Multivariate cox regression analysis showed that both high sPD-L1 and high STAT3 levels were the independent prognostic factors negatively affecting survival. In addition, patients with DLBCL having high levels of both sPD-L1 and STAT3 had a worse outcome than those patients having any one high or low levels of both (P < 0.001).

Conclusions: We therefore revealed that high levels of plasma sPD-L1 and STAT3 are associated with inferior outcome for DLBCL patients, suggesting that combined measurement of their levels in plasma may be a promising prognostic strategy for DLBCL patients.

Landscape of immune checkpoint inhibitor-related adverse events in Chinese population

This study aimed to describe the landscape of Immune checkpoint inhibitors (ICIs)-related adverse events (AEs) in a predominantly Chinese cohort. We searched electronic datasets including PubMed, Web of Science and Embase to identify and recruit relevant trials up to September 2, 2019. Clinical trials focusing on ICIs in Chinese patients or a predominantly Chinese population were included. Incidences of treatment-related AEs (TRAEs) and immune-related AEs (irAEs) were pooled and compared. In total, we recruited 13 trials consisting of 1063 patients, with 922 (86.7%) receiving ICI monotherapy and 141 (13.3%) receiving combination of ICI with chemotherapy or anti-angiogenesis. The pooled incidence of any grade TRAEs, grade 1–2, grade 3–5 TRAEs, any grade irAEs, grade 1–2 irAEs and grade 3–5 irAEs in all 1063 patients were 84.1%, 63.3%, 20.9%, 43.3%, 40.0% and 3.0%, respectively. Moreover, 4.3% (44/1018) of patients experienced treatment discontinuation and only 8 (0.8%) patients experienced treatment-related death. Compared to ICI monotherapy, combination significantly increased grade 3–5 TRAEs (46.1% vs. 17.0%, P < 0.001) and grade 3–5 irAEs (7.1% vs. 2.0%, P = 0.015). By comparing the toxicity profiles between different ICIs, we found some drug-specific AEs such as reactive capillary haemangiomas for camrelizumab (58.6%), hyperglycemia for toripalimab (55.6%) and pyrexia for tislelizumab (54.3%). Additionally, nivolumab has the lowest incidence of any grade (64.1%) and grade 3–5 (11.8%) TRAEs. ICI-related AEs were generally mild and tolerable for a predominantly Chinese cohort. However, we should pay attention to the combination of ICI with chemotherapy as it could increase grade 3–5 TRAEs and irAEs.

Resistance to PD-1/PD-L1 blockade cancer immunotherapy: mechanisms, predictive factors, and future perspectives

PD-1/PD-L1 blockade therapy is a promising cancer treatment strategy, which has revolutionized the treatment landscape of malignancies. Over the last decade, PD-1/PD-L1 blockade therapy has been trialed in a broad range of malignancies and achieved clinical success. Despite the potentially cure-like survival benefit, only a minority of patients are estimated to experience a positive response to PD-1/PD-L1 blockade therapy, and the primary or acquired resistance might eventually lead to cancer progression in patients with clinical responses. Accordingly, the resistance to PD-1/PD-L1 blockade remains a significant challenge hindering its further application. To overcome the limitation in therapy resistance, substantial effort has been made to improve or develop novel anti-PD-1/PD-L1 based immunotherapy strategies with better clinical response and reduced immune-mediated toxicity. In this review, we provide an overview on the resistance to PD-1/PD-L1 blockade and briefly introduce the mechanisms underlying therapy resistance. Moreover, we summarize potential predictive factors for the resistance to PD-1/PD-L1 blockade. Furthermore, we give an insight into the possible solutions to improve efficacy and clinical response. In the following research, combined efforts of basic researchers and clinicians are required to address the limitation of therapy resistance.

A peripheral immune signature of responsiveness to PD-1 blockade in patients with classical Hodgkin lymphoma

PD-1 blockade is highly effective in classical Hodgkin lymphomas (cHLs), which exhibit frequent copy-number gains of CD274 (PD-L1) and PDC1LG2 (PD-L2) on chromosome 9p24.1. However, in this largely MHC-class-I-negative tumor, the mechanism of action of anti-PD-1 therapy remains undefined. We utilized the complementary approaches of T cell receptor (TCR) sequencing and cytometry by time-of-flight analysis to obtain a peripheral immune signature of responsiveness to PD-1 blockade in 56 patients treated in the CheckMate 205 phase II clinical trial (NCT02181738). Anti-PD-1 therapy was most effective in patients with a diverse baseline TCR repertoire and an associated expansion of singleton clones during treatment. CD4⁺, but not CD8⁺, TCR diversity significantly increased during therapy, most strikingly in patients who had achieved complete responses. Additionally, patients who responded to therapy had an increased abundance of activated natural killer cells and a newly identified CD3^-CD68⁺CD4⁺GrB⁺ subset. These studies highlight the roles of recently expanded, clonally diverse CD4⁺ T cells and innate effectors in the efficacy of PD-1 blockade in cHL.

Hodgkin lymphoma: A 2020 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Hodgkin lymphoma (HL) is an uncommon B-cell lymphoid malignancy affecting 8480 new patients annually and representing approximately 10% of all lymphomas in the United States.

DIAGNOSIS

Hodgkin lymphoma is composed of two distinct disease entities: classical HL and nodular lymphocyte predominant HL. Nodular sclerosis, mixed cellularity, lymphocyte depletion, and lymphocyte-rich HL are subgroups of classical HL.

RISK STRATIFICATION

An accurate assessment of the stage of disease in patients with HL is critical for the selection of the appropriate therapy. Prognostic models that identify patients at low or high risk for recurrence, as well as the response to therapy as determined by positron emission tomography (PET) scan, are used to optimize therapy.

RISK-ADAPTED THERAPY

Initial therapy for HL patients is based on the histology of the disease, the anatomical stage and the presence of poor prognostic features. Patients with early stage disease are typically treated with combined modality strategies utilizing abbreviated courses of combination chemotherapy, followed by involved-field radiation therapy. Patients with advanced stage disease receive a longer course of chemotherapy, often without radiation therapy. However, newer agents including brentuximab vedotin and anti-PD-1 antibodies are now being incorporated into frontline therapy.

MANAGEMENT OF RELAPSED/REFRACTORY DISEASE

High-dose chemotherapy (HDCT) followed by an autologous stem cell transplant (ASCT) is the standard of care for most patients who relapse following initial therapy. For patients who fail HDCT with ASCT, brentuximab vedotin, PD-1 blockade, non-myeloablative allogeneic transplant or participation in a clinical trial should be considered.

Immune and Cell Therapy in Non-Hodgkin Lymphoma

The promise of immunotherapy has shone brightly for decades in hematologic malignancies and specifically in non-Hodgkin lymphoma. The last decade has witnessed the emergence of completely novel forms of immunotherapy, including immune checkpoint blockade, bispecific antibodies, and chimeric antigen receptor T cells. These treatments have shown phenomenal, and in some cases possibly curative, successes in various relapsed/refractory lymphomas. This review summarizes the most notable successes and promising findings as well as some of the attendant failures. These treatments will doubtlessly transform the treatment paradigms across many lymphoma subtypes. Yet, only if we can better understand their mechanisms of action, toxicity, and resistance will be able to maximize their therapeutic benefit.

Immune checkpoint inhibitors in malignant lymphoma: Advances and perspectives

Classical Hodgkin lymphoma (cHL) has been identified with universal genetic alterations of chromosome 9p24.1, which contains PD-L1/PD-L2 genes. The amplification of 9p24.1 is associated with the increased expression of PD-L1 and PD-L2 on RS cells, which promotes their immune evasion, and subsequently makes cHL sensitive to PD-1 blockade. Several PD-1 inhibitors have shown significant efficacies with overall response rate (ORR) of 70%-90% in relapse/refractory (r/r) cHL and have acquired the approvals for this indication. Recently, more and more studies are conducted to investigate PD-1 blockade in earlier disease course and in combination with neo-agents or chemotherapy. Unlike cHL, non-Hodgkin lymphoma (NHL) consists of numerous subtypes harboring highly biological heterogeneity. Only a few subtypes have been shown to have genetic alteration of9p24.1 including primary mediastinal B cell lymphoma (PMBL), gray zone lymphoma (GZL) with features intermediate between diffuse large B cell lymphoma (DLBCL) and cHL, primary central nervous system lymphoma (PCNSL) and primary testicular lymphoma (PTL). Epstein-Barr virus (EBV)-associated lymphomas have a virally mediated overexpression of PD-L1, also making them sensitive to PD-1 blockade. Therefore, PD-1 inhibitors are less effective in most r/r NHL than in r/r cHL. Further understanding of the biological features of NHL and immune checkpoint inhibitors (ICPi) combined therapy is the research focus in the future. In this review, we outlined the recent progress of ICPi in lymphoma originating from clinical studies.

Looking for the Optimal PD-1/PD-L1 Inhibitor in Cancer Treatment: A Comparison in Basic Structure, Function, and Clinical Practice

Programmed cell death protein-1/ligand 1 (PD-1/L1) targeted immune checkpoint inhibitors have become the focus of tumor treatment due to their promising efficacy. Currently, several PD-1/PD-L1 inhibitors have been approved for clinical practice with several more in clinical trials. Notably, based on available trial data, the selection of different PD-1/PD-L1 inhibitors in the therapeutic application and the corresponding efficacy varies. Widespread attention then is increasingly raised to the clinical comparability of different PD-1/PD-L1 inhibitors. The comparison of the inhibitors could not only help clinicians make in-depth understanding of them, but also further facilitate the selection of the optimal inhibitor for patients in treatment as well as for future clinical research and the development of new related drugs. As we all know, molecular structure could determine molecular function, which further affects their application. Therefore, in this review, we aim to comprehensively compare the structural basis, molecular biological functions, and clinical practice of different PD-1/PD-L1 inhibitors.

Next-generation immuno-oncology agents: current momentum shifts in cancer immunotherapy

Cancer immunotherapy has reached a critical point, now that immune checkpoint inhibitors and two CAR-T products have received market approval in treating 16 types of cancers and 1 tissue-agnostic cancer indication. Accompanying these advances, the 2018 Nobel Prize was awarded for the discovery of immune checkpoint pathways, which has led to the revolution of anti-cancer treatments. However, expanding the indications of immuno-oncology agents and overcoming treatment resistance face mounting challenges. Although combination immunotherapy is an obvious strategy to pursue, the fact that there have been more failures than successes in this effort has served as a wake-up call, placing emphasis on the importance of building a solid scientific foundation for the development of next-generation immuno-oncology (IO) agents. The 2019 China Cancer Immunotherapy Workshop was held to discuss the current challenges and opportunities in IO. At this conference, emerging concepts and strategies for IO development were proposed, focusing squarely on correcting the immunological defects in the tumor microenvironment. New targets such as Siglec-15 and new directions including neoantigens, cancer vaccines, oncolytic viruses, and cytokines were reviewed. Emerging immunotherapies were discussed in the areas of overcoming primary and secondary resistance to existing immune checkpoint inhibitors, activating effector cells, and targeting immunosuppressive mechanisms in the tumor microenvironment. In this article, we highlight old and new waves of IO therapy development, and provide perspectives on the latest momentum shifts in cancer immunotherapy.

Checkpoint inhibition therapy as possible frontline therapy for Hodgkin lymphoma

Classic Hodgkin lymphoma (cHL) is a unique lymphoid malignancy with an immunosuppressed tumor microenvironment. Increased PD-L1 expression on the malignant Hodgkin Reed Sternberg (HRS) cells due to genetic amplification at chromosome 9p24.1 is likely one of the primary mechanisms for this unique biology. For this reason, immune checkpoint inhibitors targeting PD-1/PD-L1 interaction have proven to be uniquely successful in relapsed/refractory cHL. While the response rates are in the 70-80% range and are often durable, most patients still relapse. Combination strategies with conventional chemotherapy, novel drugs such as antibody-drug conjugates (ADCs), and other immune therapies are ongoing. Many unanswered questions about checkpoint inhibitors remain, such as defining the best modality for evaluation of response, confirming a strategy of modifying therapy based on the response, validating response endpoints specific to immune therapies and, identifying predictive biomarkers for response. As we evaluate the use of checkpoint inhibitors in the frontline setting for cHL, we need a critical approach to evaluate the benefits and challenges that ensue.