Evading immune eradication is a prerequisite for neoplastic progression and one of the hallmarks of cancer. Here, we review the different immune escape strategies of lymphoma and classify them into ...two main mechanisms. First, lymphoma cells may "hide" to become invisible to the immune system. This can be achieved by losing or downregulating MHC and/or molecules involved in antigen presentation (including antigen processing machinery and adhesion molecules), thereby preventing their recognition by the immune system. Second, lymphoma cells may "defend" themselves to become resistant to immune eradication. This can be achieved in several ways: by becoming resistant to apoptosis, by expressing inhibitory ligands that deactivate immune cells and/or by inducing an immunosuppressive (humoral and cellular) microenvironment. These immune escape mechanisms may have therapeutic implications. Their identification may be used to guide "personalized immunotherapy" for lymphoma.
Although chimeric antigen receptor T cells demonstrated remarkable efficacy in patients with chemo-resistant hematologic malignancies, a significant portion still resist or relapse. This immune ...evasion may be due to CAR T cells dysfunction, a hostile tumor microenvironment, or resistant cancer cells. Here, we review the intrinsic resistance mechanisms of cancer cells to CAR T cell therapy and potential strategies to circumvent them.
Patients with relapsed or refractory mantle-cell lymphoma who have disease progression during or after the receipt of Bruton's tyrosine kinase (BTK) inhibitor therapy have a poor prognosis. KTE-X19, ...an anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, may have benefit in patients with relapsed or refractory mantle-cell lymphoma.
In a multicenter, phase 2 trial, we evaluated KTE-X19 in patients with relapsed or refractory mantle-cell lymphoma. Patients had disease that had relapsed or was refractory after the receipt of up to five previous therapies; all patients had to have received BTK inhibitor therapy previously. Patients underwent leukapheresis and optional bridging therapy, followed by conditioning chemotherapy and a single infusion of KTE-X19 at a dose of 2×10
CAR T cells per kilogram of body weight. The primary end point was the percentage of patients with an objective response (complete or partial response) as assessed by an independent radiologic review committee according to the Lugano classification. Per the protocol, the primary efficacy analysis was to be conducted after 60 patients had been treated and followed for 7 months.
A total of 74 patients were enrolled. KTE-X19 was manufactured for 71 patients and administered to 68. The primary efficacy analysis showed that 93% (95% confidence interval CI, 84 to 98) of the 60 patients in the primary efficacy analysis had an objective response; 67% (95% CI, 53 to 78) had a complete response. In an intention-to-treat analysis involving all 74 patients, 85% had an objective response; 59% had a complete response. At a median follow-up of 12.3 months (range, 7.0 to 32.3), 57% of the 60 patients in the primary efficacy analysis were in remission. At 12 months, the estimated progression-free survival and overall survival were 61% and 83%, respectively. Common adverse events of grade 3 or higher were cytopenias (in 94% of the patients) and infections (in 32%). Grade 3 or higher cytokine release syndrome and neurologic events occurred in 15% and 31% of patients, respectively; none were fatal. Two grade 5 infectious adverse events occurred.
KTE-X19 induced durable remissions in a majority of patients with relapsed or refractory mantle-cell lymphoma. The therapy led to serious and life-threatening toxic effects that were consistent with those reported with other CAR T-cell therapies. (Funded by Kite, a Gilead company; ZUMA-2 ClinicalTrials.gov number, NCT02601313.).
Chimeric antigen receptor (CAR)-modified T cells and BiTEs are both immunotherapies which redirect T cell specificity against a tumor-specific antigen through the use of antibody fragments. They ...demonstrated remarkable efficacy in B cell hematologic malignancies, thus paving the way for their development in solid tumors. Nonetheless, the use of such new drugs to treat solid tumors is not straightforward. So far, the results from early phase clinical trials are not as impressive as expected but many improvements are under way. In this review we present an overview of the clinical development of CAR-T cells and BiTEs targeting the main antigens expressed by solid tumors. We emphasize the most frequent hurdles encountered by either CAR-T cells or BiTEs, or both, and summarize the strategies that have been proposed to overcome these obstacles.
PD-1 blockade is an effective therapy in relapsed/refractory (R/R) classical Hodgkin Lymphoma (cHL) who have relapsed after or are ineligible for autologous hematopoietic cell transplantation (HCT). ...Although single-agent anti-PD-1 monoclonal antibodies (mAb's) are associated with high response rates and durable remissions, available results to date suggest that a large majority of patients will eventually progress on therapy. Many of these patients are potential candidates for allogeneic HCT (allo-HCT) after receiving anti-PD-1 mAb's, and allo-HCT remains for now the only treatment with demonstrated curative potential in this setting. However, initial reports suggested that allo-HCT in this setting may be associated with increased risk of early transplant-related toxicity, likely driven by lingering effects of PD-1 blockade. Furthermore, many patients with R/R cHL who undergo allo-HCT will relapse after transplantation, most often with limited treatment options. Here again, PD-1 blockade appears to yield high response rates, but with an increased risk of attendant immune toxicity. Many questions remain regarding the use of PD-1 blockade before or after allo-HCT, especially in relation to the feasibility, outcome, optimal timing, and method of allo-HCT after PD-1 blockade. Despite the scarcity of prospective data, these questions are unavoidable and must be tackled by clinicians in the routine care of patients with advanced cHL. We provide consensus recommendations of a working group based on available data and experience, in an effort to help guide treatment decisions until more definitive data are obtained.
Mantle-cell lymphoma is generally incurable. Despite high rates of complete response after initial immunochemotherapy followed by autologous stem-cell transplantation, patients have relapses. We ...investigated whether rituximab maintenance therapy at a dose of 375 mg per square meter of body-surface area administered every 2 months for 3 years after transplantation would prolong the duration of response.
In a phase 3 trial involving 299 patients who were younger than 66 years of age at diagnosis, we randomly assigned 240 patients to receive rituximab maintenance therapy or to undergo observation after autologous stem-cell transplantation (120 patients per group); 59 patients did not undergo randomization. The primary end point was event-free survival (with an event defined as disease progression, relapse, death, allergy to rituximab, or severe infection) after transplantation among patients who underwent randomization.
After four courses of immunochemotherapy induction (rituximab, dexamethasone, cytarabine, and a platinum derivative R-DHAP), the overall response rate was 89%, and the complete response rate 77%. Transplantation was performed in 257 patients. The median follow-up from randomization after transplantation was 50.2 months (range, 46.4 to 54.2). Starting from randomization, the rate of event-free survival at 4 years was 79% (95% confidence interval CI, 70 to 86) in the rituximab group versus 61% (95% CI, 51 to 70) in the observation group (P=0.001). The rate of progression-free survival at 4 years was 83% (95% CI, 73 to 88) in the rituximab group versus 64% (95% CI, 55 to 73) in the observation group (P<0.001). The rate of overall survival was 89% (95% CI, 81 to 94) in the rituximab group versus 80% (95% CI, 72 to 88) in the observation group (P=0.04). According to a Cox regression unadjusted analysis, the rate of overall survival at 4 years was higher in the rituximab group than in the observation group (hazard ratio for death, 0.50; 95% CI, 0.26 to 0.99; P=0.04).
Rituximab maintenance therapy after transplantation prolonged event-free survival, progression-free survival, and overall survival among patients with mantle-cell lymphoma who were younger than 66 years of age at diagnosis. (Funded by Roche and Amgen; LyMa ClinicalTrials.gov number, NCT00921414 .).
Allogeneic hematopoietic cell transplantation (allo-HCT) is indicated for patients with relapsed or refractory Hodgkin lymphoma (HL). Although long-term disease control can be achieved, relapse is ...still frequent. The programmed cell death protein 1 (PD-1) pathway-blocking antibody nivolumab has shown substantial therapeutic activity and an acceptable safety profile in patients with relapsed or refractory HL who did not receive allo-HCT. However, PD-1 blocking strategy can increase the risk of graft-versus-host disease (GVHD) in murine models. We retrospectively assessed the efficacy and toxicity of nivolumab as a single agent in 20 HL patients relapsing after allo-HCT. GVHD occurred in 6 patients (30%) after nivolumab initiation. All 6 patients had prior history of acute GVHD. The patients with nivolumab-induced GVHD were managed by standard treatment for acute GVHD. Two patients died as a result of GVHD, 1 of progressive disease and 1 of complications related to a second allo-HCT. Overall response rate was 95%. At a median follow-up of 370 days, the 1-year progression-free survival rate was 58.2% (95% CI, 33.1%-76.7%) and the overall survival rate was 78.7% (95% CI, 52.4%-91.5%). Among 13 patients still in response, 6 received a single dose of nivolumab and 7 remain on nivolumab. Compared with standard options for this indication, our results show that nivolumab is effective with an acceptable safety profile.
•PD-1 blockade with nivolumab provides durable disease control after allo-HCT.•PD-1 blockade with nivolumab after allo-HCT is associated with 30% acute GVHD.
Patients with relapsed/refractory Hodgkin lymphoma (R/R HL) experience high response rates upon anti-PD1 therapy. In these patients, there is limited data about the optimal duration of treatment and ...the risk of relapse after anti-PD1 discontinuation. We have previously reported the outcome of 11 patients with R/R HL who discontinued anti-PD1 therapy after achieving a complete response (CR) upon nivolumab1 . These patients experienced favorable outcome as only 2 of them had relapsed after a median follow-up of 21.2 months from discontinuation. Despite the low relapse rate observed in that study, physicians may be worried about the possibility to further rescue these heavily pre-treated patients in case of relapse after anti-PD1 discontinuation. Notably, it is still unknown whether these patients will remain sensitive to a 2nd course of anti-PD1.
Treatment of relapsed/refractory (R/R) primary CNS lymphoma (PCNSL) is poorly defined, because randomized trials and large studies are lacking. The aim of this study was to analyze the ...characteristics, management, and outcome of R/R PCNSL patients after first-line therapy in a nationwide cohort.
We analyzed R/R PCNSL patients following first-line treatment who had been prospectively registered in the database of the French network for oculocerebral lymphoma (LOC) between 2011 and 2014.
Among 563 PCNSL patients treated with first-line therapy, we identified 256 with relapsed (n = 93, 16.5%) or refractory (n = 163, 29.0%) disease. Patients who were asymptomatic at relapse/progression (25.5%), mostly diagnosed on routine follow-up neuroimaging, tended to have a better outcome. Patients who received salvage therapy followed by consolidation (mostly intensive chemotherapy plus autologous hematopoietic stem cell transplantation ICT + AHSCT) experienced prolonged survival compared with those who did not receive salvage or consolidation therapy. Independent prognostic factors at first relapse/progression were: KPS ≥ 70 vs KPS < 70), sensitivity to first-line therapy (relapsed vs refractory disease), duration of first remission (progression-free survival PFS ≥1 y vs <1 y), and management at relapse/progression (palliative care vs salvage therapy). Patients who relapsed early after first-line therapy (ie, PFS < 1 y) had a poor outcome, comparable to that of refractory patients. Conversely, patients experiencing late relapses (PFS ≥ 1 y) and/or undergoing consolidation with ICT + AHSCT experienced prolonged survival.
About a third of PCNSL patients are primary refractory to first line treatment. We identified several independent prognostic factors that can guide the management of R/R PCNSL patients.
T-cell specificity can be redirected against tumor antigens either ex vivo using engineered chimeric antigen receptor (CAR) T-cells or in vivo by bridging natural T-cells and tumor cells with ...bispecific T-cell engager (TCE) antibodies. Currently, four CAR T-cells have been approved by the FDA for the treatment of B-cell lymphomas, including diffuse large B cell lymphomas (DLBCL), mantle cell lymphoma (MCL), and follicular lymphoma (FL). No TCE have yet been approved for the treatment of B-cell lymphomas. However, at least four of them are in clinical development and show promising activity. Here, we review the most recent advances of CAR T-cells and TCE in the treatment of B-cell lymphomas.
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