[Show abstract][Hide abstract] ABSTRACT: Despite advances in combinatorial chemotherapy regimens and the advent of intraperitoneal chemotherapy administration, current therapeutic options for ovarian cancer patients are inadequate. Immunotherapy offers a novel and promising therapeutic strategy for treating ovarian tumors. Following the demonstration of the immunogenicity of ovarian tumors, multiple immunotherapeutic modalities have been developed. Antibody-based therapies, immune checkpoint blockade, cancer vaccines, and chimeric antigen receptor-modified T cells have demonstrated preclinical success and entered clinical testing. In this review, we discuss these promising immunotherapeutic approaches and emphasize the importance of combinatorial treatment strategies and biomarker discovery.
[Show abstract][Hide abstract] ABSTRACT: We describe 47 patients with lymphoma and failed prior autologous hematopoietic cell transplantation (HCT) who received TLI-ATG (anti-thymocyte globulin) conditioning followed by allogeneic HCT. Thirty-two patients had non-Hodgkin lymphoma (NHL; diffuse large B-cell lymphoma (n=19), T-cell NHL (n=6), mantle cell lymphoma (n=4) or other B-cell subtypes (n=3)), and 15 had Hodgkin lymphoma. The median follow-up was 4.9 (range, 2.1-11.9) years. The cumulative incidence of grade II-IV acute GvHD at day +100 was 12%, and the cumulative incidence of extensive chronic GvHD at 1 year was 36%. The 3-year cumulative incidences of overall survival (OS), PFS and non-relapse mortality (NRM) were 81%, 44% and 7%, respectively. Fifteen patients died (relapse, n=10; NRM, n=5). Among the 25 patients with relapse after allogeneic HCT, 11 (44%) achieved durable (>1 year) CRs following donor lymphocyte infusion or chemoradiotherapy. The majority of surviving patients (75%; n=24) were able to discontinue all immunosuppression. For patients with relapsed lymphoma after autologous HCT, allogeneic HCT using TLI-ATG conditioning is a well-tolerated, predominantly outpatient therapy with low NRM (7% at 3 years), a low incidence of GvHD, durable disease control and excellent OS (81% at 3 years).Bone Marrow Transplantation advance online publication, 6 July 2015; doi:10.1038/bmt.2015.149.
Bone marrow transplantation 07/2015; DOI:10.1038/bmt.2015.149 · 3.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The 29th annual meeting of the Society for Immunotherapy of Cancer (SITC) was held November 7-9, 2014 in National Harbor, MD and was organized by Dr. Arthur A. Hurwitz (National Cancer Institute), Dr. Kim A. Margolin (Stanford University), Dr. Daniel E. Speiser (Ludwig Center for Cancer Research, University of Lausanne) and Dr. Walter J. Urba (Earle A. Chiles Research Institute, Providence Cancer Center). This meeting included over 1,600 registered participants from 28 separate countries, making it the largest SITC meeting held to date. It highlighted significant worldwide progress in the development and application of cancer immunology to the practice of clinical oncology, including advances in diagnosis, prognosis and therapy, utilizing several immunological pathways and mechanisms for a variety of oncologic conditions. Presentations and posters demonstrated that many concepts that had been pursued preclinically in the past are now being translated into clinical practice, with clear benefits for patients.
[Show abstract][Hide abstract] ABSTRACT: Monoclonal antibodies can block cellular interactions that negatively regulate T-cell immune responses, such as CD80/CTLA-4 and PD-1/PD1-L, amplifying preexisting immunity and thereby evoking antitumor immune responses. Ibrutinib, an approved therapy for B-cell malignancies, is a covalent inhibitor of BTK, a member of the B-cell receptor (BCR) signaling pathway, which is critical to the survival of malignant B cells. Interestingly this drug also inhibits ITK, an essential enzyme in Th2 T cells and by doing so it can shift the balance between Th1 and Th2 T cells and potentially enhance antitumor immune responses. Here we report that the combination of anti-PD-L1 antibody and ibrutinib suppresses tumor growth in mouse models of lymphoma that are intrinsically insensitive to ibrutinib. The combined effect of these two agents was also documented for models of solid tumors, such as triple negative breast cancer and colon cancer. The enhanced therapeutic activity of PD-L1 blockade by ibrutinib was accompanied by enhanced antitumor T-cell immune responses. These preclinical results suggest that the combination of PD1/PD1-L blockade and ibrutinib should be tested in the clinic for the therapy not only of lymphoma but also in other hematologic malignancies and solid tumors that do not even express BTK.
Proceedings of the National Academy of Sciences 02/2015; 112(9). DOI:10.1073/pnas.1500712112 · 9.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An expanding panel of monoclonal antibodies (mAbs) that specifically target malignant cells or intercept trophic factors delivered by the tumor stroma is now available for cancer therapy. These mAbs can exert direct antiproliferative/cytotoxic effects as they inhibit pro-survival signal transduction cascades or activate lethal receptors at the plasma membrane of cancer cells, they can opsonize neoplastic cells to initiate a tumor-targeting immune response, or they can be harnessed to specifically deliver toxins or radionuclides to transformed cells. As an indication of the success of this immunotherapeutic paradigm, international regulatory agencies approve new tumor-targeting mAbs for use in cancer patients every year. Moreover, the list of indications for previously licensed molecules is frequently expanded to other neoplastic disorders as the results of large, randomized clinical trials become available. Here, we discuss recent advances in the preclinical and clinical development of tumor-targeting mAbs for oncological indications.
[Show abstract][Hide abstract] ABSTRACT: The development of human cancer is a multistep process characterized by the accumulation of genetic and epigenetic alterations that drive or reflect tumour progression. These changes distinguish cancer cells from their normal counterparts, allowing tumours to be recognized as foreign by the immune system. However, tumours are rarely rejected spontaneously, reflecting their ability to maintain an immunosuppressive microenvironment. Programmed death-ligand 1 (PD-L1; also called B7-H1 or CD274), which is expressed on many cancer and immune cells, plays an important part in blocking the 'cancer immunity cycle' by binding programmed death-1 (PD-1) and B7.1 (CD80), both of which are negative regulators of T-lymphocyte activation. Binding of PD-L1 to its receptors suppresses T-cell migration, proliferation and secretion of cytotoxic mediators, and restricts tumour cell killing. The PD-L1-PD-1 axis protects the host from overactive T-effector cells not only in cancer but also during microbial infections. Blocking PD-L1 should therefore enhance anticancer immunity, but little is known about predictive factors of efficacy. This study was designed to evaluate the safety, activity and biomarkers of PD-L1 inhibition using the engineered humanized antibody MPDL3280A. Here we show that across multiple cancer types, responses (as evaluated by Response Evaluation Criteria in Solid Tumours, version 1.1) were observed in patients with tumours expressing high levels of PD-L1, especially when PD-L1 was expressed by tumour-infiltrating immune cells. Furthermore, responses were associated with T-helper type 1 (TH1) gene expression, CTLA4 expression and the absence of fractalkine (CX3CL1) in baseline tumour specimens. Together, these data suggest that MPDL3280A is most effective in patients in which pre-existing immunity is suppressed by PD-L1, and is re-invigorated on antibody treatment.
[Show abstract][Hide abstract] ABSTRACT: Blockade of the immune checkpoint programmed death receptor ligand-1 (PD-L1)/PD-1 pathway has well-established clinical activity across many tumor types. PD-L1 protein expression by immunohistochemistry (IHC) is emerging as a predictive biomarker of response to these therapies. Here, we examine PD-L1 expression in a thymic epithelial tumor (TET) tissue microarray (TMA).
The TMA contained 69 TETs and 17 thymic controls, with each case represented by triplicate cores. The TMA was stained with rabbit monoclonal antibody (clone 15, Sino Biological) to human PD-L1. PD-L1 staining was scored based on intensity as follows: 0=none, 1=equivocal/uninterpretable, 2=weak, and 3=intermediate-strong. Those cases with all cores scoring 3 in the epithelial component were categorized as PD-L1 and the remaining as PD-L1.
D-L1 scores were more frequent in TETs than controls (68.1% vs. 17.6%, p=0.0036). PD-L1 scores and histology were significantly correlated, with higher intensity staining in WHO B2/B3/C TETs. Only 14.8% of TETs had PD-L1 staining of associated lymphocytes. In an adjusted analysis (age/gender), PD-L1 TETs had a significantly worse overall survival (HR 5.40, 95% CI 1.13-25.89, p=0.035) and a trend for worse event-free survival (HR 2.94, 95% CI 0.94-9.24, p=0.064).
PD-L1 expression was present in all cases of TETs within the epithelial component but only in a minority in the lymphocytic component. TETs stained more intensely for PD-L1 than controls, and PD-L1 TETs were associated with more aggressive histology and worse prognosis. This study lends rationale to a clinical trial with anti-PD1/PD-L1 therapy in this rare tumor type.
Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer 11/2014; 10(3). DOI:10.1097/JTO.0000000000000429 · 5.28 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Preclinical models have been developed and applied to predict the clinical efficacy of immune checkpoint antibodies. Now these models can be used to dissect the mechanisms by which such immunotherapeutic antibodies work and to build the rationale for combining immune checkpoint-targeting antibodies with potential synergistic activity in cancer patients.
[Show abstract][Hide abstract] ABSTRACT: Oncolytic virotherapy is safe and clinically active in solid tumors, however its efficacy in hematologic malignancies as well as in combination with checkpoint inhibitors and radiation is unexplored. To simulate advanced lymphoma, A20 cells were injected subcutaneously on bilateral flanks of BALB/c mice and treatment initiated on day 17 to only the right flank tumor with local irradiation (Irr), intratu-moral (i.t.) vaccinia virus (VACV) and i.t. anti-CTLA-4 antibody.
Our findings are the first to demonstrate the potential of combination immunotherapy with oncolytic viruses and checkpoint inhibitors in hematologic malignancies. The antitumor activity is attributed to the induction of an effective and specific immune response. This finding is corroborated by the significant infiltration with mature activated NK cells, followed by CD8+ T cells, in both treated and untreated tumors. Importantly, the tumor-specific CD8+ T cells showing a memory phenotype (CD44hi) suggest the effective induction of a potent immune memory response. Effective targeting of distant metastases after intratumoral administration is also an important finding with significant clinical implications. This novel combination immunotherapy with oncolytic viruses and checkpoint inhibitors following local tumor irradiation is now being translated to a Phase I proof-of-concept clinical trial in non-Hodgkin’s lymphoma.