核医学显像探针在肿瘤PD-L1免疫治疗中的应用

程序化死亡配体-1（PD-L1）靶向免疫治疗被广泛应用于不同类型的癌症中，患者从PD-L1靶向免疫治疗的获益主要依赖于肿瘤组织PD-L1的表达水平。目前临床主要采用穿刺活检等有创手段来评价肿瘤组织PD-L1的表达水平，严重受限于PD-L1表达的时间和空间异质性。核医学探针能够在分子水平上实现对PD-L1的在体无创检测，对于指导患者筛选、预测患者免疫治疗响应具有重要的临床意义。本文综述了靶向PD-L1的核医学分子影像探针，并讨论其在肿瘤PD-L1显像中的应用。     

Bispecific antibody based therapeutics: Strengths and challenges

Monoclonal antibody-based targeted therapy has greatly improved treatment options for patients. However, long-term efficacy of such antibodies is limited by resistance mechanisms. New insights into the mechanisms by which tumors evade immune control have driven innovative therapeutic strategies to eliminate cancer by re-directing immune cells to tumors. Advances in protein engineering technology have generated multiple bispecific antibody (BsAb) formats capable of targeting multiple antigens as a single agent. Approval of two BsAb and three check point blocking mAbs represent a paradigm shift in the use of antibody constructs. Since BsAbs can directly target immune cells to tumors, drug resistance and severe adverse effects are much reduced. The wave of next generation “bispecific or multispecific antibodies” has advanced multiple candidates into ongoing clinical trials. In this review, we focus on preclinical and clinical studies in hematological malignancies as well as discuss reasons for the limited success of BsAbs against solid tumors.     

Closing the gap: Novel therapies in treating acute lymphoblastic leukemia in adolescents and young adults

Acute lymphoblastic leukemia (ALL) is one of the most common cancer diagnoses identified in adolescents and young adults (AYAs). Although most children with ALL are cured of their disease, AYAs have experienced much worse outcomes over time, with event-free survival ranging from 30 to 45%. This survival disparity is likely due to differences in tumor biology, treatment-related toxicities, and nonmedical issues. This review summarizes these differences as well as focusing on the various trials that have demonstrated superior outcomes with pediatric protocols in AYAs with ALL. Even with the widespread use of these protocols, a treatment gap remains, and novel therapies are one way to address this problem. Still, these therapies also have significant toxicities and unique issues that need to be tested further, especially in the AYA population. The development of more AYA-specific trials will be an important way to examine novel therapies and interventions designed to reduce treatment-related toxicities and improve long-term outcomes.     

Pancreatic ductal adenocarcinoma: Emerging therapeutic strategies

The seventh leading cause of cancer-related death globally, pancreatic ductal adenocarcinoma (PDAC) involves the exocrine pancreas and constitutes greater than 90% of all pancreatic cancers. Surgical resection in combination with systemic chemotherapy with or without radiation remains the mainstay of treatment and the only potentially curative treatment option. While there has been improvement in systemic chemotherapy, long-term survival among patients with PDAC remains poor. Improvement in the understanding of tumorigenesis, genetic mutations, the tumor microenvironment (TME), immunotherapies, as well as targeted therapies continued to drive advances in PDAC treatment. We herein review the TME, genetic landscape, as well as various metabolic pathways associated with PDAC tumorigenesis relative to emerging therapies.     

Immune evasion mechanisms and therapeutic strategies in gastric cancer

Gastric cancer (GC) is a malignancy with a high incidence and mortality. The tumor immune microenvironment plays an important role in promoting cancer development and supports GC progression. Accumulating evidence shows that GC cells can exert versatile mechanisms to remodel the tumor immune microenvironment and induce immune evasion. In this review, we systematically summarize the intricate crosstalk between GC cells and immune cells, including tumor-associated macrophages, neutrophils, myeloid-derived suppressor cells, natural killer cells, effector T cells, regulatory T cells, and B cells. We focus on how GC cells alter these immune cells to create an immunosuppressive microenvironment that protects GC cells from immune attack. We conclude by compiling the latest progression of immune checkpoint inhibitor-based immunotherapies, both alone and in combination with conventional therapies. Anti-cytotoxic T-lymphocyte-associated protein 4 and anti-programmed cell death protein 1/programmed death-ligand 1 therapy alone does not provide substantial clinical benefit for GC treatment. However, the combination of immune checkpoint inhibitors with chemotherapy or targeted therapy has promising survival advantages in refractory and advanced GC patients. This review provides a comprehensive understanding of the immune evasion mechanisms of GC, and highlights promising immunotherapeutic strategies.     

The Current Lung Cancer Neoantigen Landscape and Implications for Therapy

All tumors harbor unique mutant peptides, some of which are able to elicit T-cell–mediated immune responses. These are known as neoantigens. Lung cancers bear a heavy mutational burden and hence many potential neoantigens. Neoantigens are increasingly recognized as key mediators of tumor-specific immune activation and have been identified as potential targets for personalized cancer therapies. In this review, we discuss the current data on neoantigens in lung cancer and provide an overview of the recent advances in neoantigen-based immunotherapy. Furthermore, we look ahead to highlight the major opportunities and challenges for the clinical application of neoantigen-based treatment strategies for thoracic and other malignancies.