Project description:Hodgkin Lymphoma (HL) is a unique disease entity both in its pathology and the young patient population that it primarily affects. Although cure rates are high, survivorship can be linked with significant recent long-term morbidity associated with both chemotherapy and radiotherapy. The most significant advances have been with the use of the anti-CD30-drug conjugated antibody brentuximab vedotin (BV) and inhibitors of program death 1 (PD-1). HL is genetically wired to up-regulate program death ligand 1 (PD-L1) in >95% of cases, creating a state of so-called “T cell exhaustion”, which can be reversed with immune checkpoint-inhibitor blockade. The overall and complete response rates to PD-1 inhibitors in patients with relapsed or refractory HL are 70% and 20%, respectively, with a long median duration of response of ~16 months. In fact, PD-1 inhibitors can benefit a wide spectrum of relapsed HL patients, including some who have “progressive disease” by strict response criteria. We review the biology of HL, with a focus on the immune micro-environment and mechanisms of immune evasion. We also provide the rationale supporting the use of PD-1 inhibitors in HL and highlight some of the challenges of monitoring disease response in patients treated with this immunotherapy.
Project description:Intricate systems of checkpoints such as the programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) axis regulate adaptive immune responses to protect against tissue damage. However, diverse cancers can exploit these pathways to evade or suppress antitumor immunity, leading to tumor progression. Correspondingly, immune checkpoint inhibitors that block PD-1/PD-L1 signaling have shown marked therapeutic efficacy in certain cancers, such as Hodgkin lymphoma. Reed-Sternberg cells, the hallmark cells of Hodgkin lymphoma, commonly overexpress PD-1 ligands, and recent clinical trials have demonstrated impressive response rates with the PD-1 inhibitors nivolumab and pembrolizumab in relapsed or refractory Hodgkin lymphoma, leading to their FDA approval in this setting. Current efforts are underway to improve clinical responses by incorporating PD-1 inhibitors into earlier treatment regimens and identifying therapeutic agents that synergize with PD-1 inhibitors. This review summarizes our understanding of the PD-1/PD-L1 axis in Hodgkin lymphoma, recent clinical studies of anti-PD-1 monotherapy and promising combination immunotherapy in the pipeline.
Project description:Atypical response patterns following immune checkpoint blockade (ICB) in Hodgkin lymphoma (HL) led to the concept of continuation of treatment beyond progression (TBP); however, the longitudinal benefit of this approach is unclear. We therefore performed a retrospective analysis of 64 patients treated with ICB; 20 who received TBP (TBP cohort) and 44 who stopped ICB at initial progression (non-TBP cohort). The TBP cohort received ICB for a median of 4.7 months after initial progression and delayed subsequent treatment by a median of 6.6 months. Despite receiving more prior lines of therapy, the TBP cohort achieved longer progression-free survival with post-ICB treatment (median, 17.5 months vs. 6.1 months, p = .035) and longer time-to-subsequent treatment failure, defined as time from initial ICB progression to failure of subsequent treatment (median, 34.6 months vs. 9.9 months, p = .003). With the limitations of a retrospective study, these results support the clinical benefit of TBP with ICB for selected patients.
Project description: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.
Project description:Cancer cells escape immune recognition by exploiting the programmed cell-death protein 1 (PD-1)/programmed cell-death 1 ligand 1 (PD-L1) immune checkpoint axis. Immune checkpoint inhibitors that target PD-1/PD-L1 unleash the properties of effector T cells that are licensed to kill cancer cells. Immune checkpoint blockade has dramatically changed the treatment landscape of many cancers. Following the cancer paradigm, preliminary results of clinical trials in lymphoma have demonstrated that immune checkpoint inhibitors induce remarkable responses in specific subtypes, most notably classical Hodgkin lymphoma and primary mediastinal B-cell lymphoma, while in other subtypes, the results vary considerably, from promising to disappointing. Lymphomas that respond to immune checkpoint inhibitors tend to exhibit tumor cells that reside in a T-cell-rich immune microenvironment and display constitutive transcriptional upregulation of genes that facilitate innate immune resistance, such as structural variations of the PD-L1 locus, collectively referred to as T-cell-inflamed lymphomas, while those lacking such characteristics are referred to as noninflamed lymphomas. This distinction is not necessarily a sine qua non of response to immune checkpoint inhibitors, but rather a framework to move the field forward with a more rational approach. In this article, we provide insights on our current understanding of the biological mechanisms of immune checkpoint evasion in specific subtypes of B-cell and T-cell non-Hodgkin lymphomas and summarize the clinical experience of using inhibitors that target immune checkpoints in these subtypes. We also discuss the phenomenon of hyperprogression in T-cell lymphomas, related to the use of such inhibitors when T cells themselves are the target cells, and consider future approaches to refine clinical trials with immune checkpoint inhibitors in non-Hodgkin lymphomas.
Project description:Glioblastoma multiforme (GBM) is the most common primary brain cancer. Even with aggressive combination therapy, the median life expectancy for patients with GBM remains approximately 14 months. In order to improve the outcomes of patients with GBM, the development of newer treatments is critical. The concept of using the immune system as a therapeutic option has been suggested for several decades; by harnessing the body's adaptive immune mechanisms, immunotherapy could provide a durable and targeted treatment against cancer. However, many cancers, including GBM, have developed mechanisms that protect tumor cells from being recognized and eliminated by the immune system. For new immunotherapeutic regimens to be successful, overcoming immunosuppression via immune checkpoint signaling should be taken into consideration.
Project description: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.
Project description:IntroductionPreclinical studies have demonstrated the ability of radiation therapy (RT) to augment immune response and tumor control by immune checkpoint inhibitors (ICI). However, numerous clinical trials combining RT and ICI have yielded relatively disappointing results. To improve understanding of optimal use of these therapies, we assessed systemic immune effects of prior RT in patients receiving ICI.Methods and materialsPre- and post-ICI blood samples were collected from patients enrolled in a prospective immunotherapy biospecimen protocol. Mutiplex panels of 40 cytokines and 120 autoantibodies (Ab) were analyzed. We identified differences in these parameters according to receipt, timing, and type of prior RT. We calculated P values using the Pearson product-moment correlation coefficient and false discovery rate (FDR) using the Benjamini-Hochberg Procedure.ResultsAmong 277 total patients, 69 (25%) received RT in the 6 months prior to ICI initiation. Among RT-treated patients, 23 (33%) received stereotactic RT, and 33 (48%) received curative intent RT. There was no significant difference in demographics or type of immunotherapy between patients according to prior RT exposure. Baseline complement C8 Ab and MIP-1d/CCL15 were significantly higher among patients with prior RT. For MIP-1d/CCL15, only prior stereotactic RT was associated with significant differences.ConclusionsPrior RT is associated with few changes in systemic immune parameters in patients receiving ICI. The underlying mechanisms and optimal approach to harnessing the potential synergy of RT and ICI require further prospective clinical investigation.
Project description:Options for patients with relapsed or refractory (R/R) classical Hodgkin lymphoma (cHL) after brentuximab vedotin (Bv) and autologous stem cell transplantation (ASCT) are limited. Immune checkpoint inhibitors (ICI) are active in this population but rarely induce complete response (CR). Ten patients with R/R cHL after ASCT and Bv received pembrolizumab (n = 8) or nivolumab (n = 2). Five had been previously exposed to 5-azacitidine on a phase 1 study. Among nine evaluable patients, seven (78%) achieved CR, one partial response, and one reduction of tumor burden. All five patients who had received 5-azacitidine prior to ICI achieved CR, while only two of four who did not receive prior 5-azacitidine achieved CR. At a median follow-up of 9.9 months [0.5-14.3], eight patients are alive and five are still receiving treatment. We documented an unprecedented CR rate after ICI in patients with R/R cHL. We hypothesize that hypomethylating agents might have an immune priming effect and enhance the efficacy of ICI.
Project description:Radiation therapy plays a key role in the management of intracranial metastatic disease. Historically, systemic therapy was able to address extracranial disease but not cross the blood-brain barrier and radiation therapy and surgery were the only mechanisms to treat intracranial metastases. There are now several examples of contemporary systemic therapies with central nervous system efficacy in some patients. With such improvements in systemic therapies, patients are living longer and the optimal management of brain metastases is becoming an increasingly important clinical priority. However, the role of radiation therapy remains critical in treating brain metastases. The concurrent use of new systemic therapies with radiation brings about novel and significant questions regarding potential synergy between these therapies in the brain in regard to both oncologic efficacy and toxicity. One important systemic therapy to consider is immune checkpoint inhibitors. These drugs are now at the forefront of management of many malignancies and have changed the landscape of treatment for many common cancers, particularly those with a predilection for brain metastases. In this review we will examine the existing data on the efficacy and toxicity of concurrent radiation therapy and immunotherapy for brain metastases and explore potential mechanisms underlying the published clinical observations.