Malignant pleural mesothelioma (MPM) is a cancer of the pleura with few treatment options and an infaust prognosis. We developed a short-term primary tumor culture model from tumor cells derived... Show moreMalignant pleural mesothelioma (MPM) is a cancer of the pleura with few treatment options and an infaust prognosis. We developed a short-term primary tumor culture model from tumor cells derived from pleural fluid of MPM patients and performed drug screening on these cultures to guide treatment decisions of corresponding patients. We observed a high concordance between in vitro results and clinical outcomes and defined three subgroups responding differently to the anti-cancer drugs tested. Gene expression profiling yielded distinct signatures that segregated these subgroups and demonstrated that the fibroblast growth factor pathway was most prominently involved. Pharmacogenomic profiling revealed a subgroup of immortalized and primary MPM lines that appeared highly sensitive to FGFR inhibition. BAP1 protein loss was associated with enhanced sensitivity to FGFR inhibition. Gene expression analyses revealed an association between BAP1 loss and increased expression of the receptors FGFR1/3 and ligands FGF9/18. BAP1 loss was associated with activation of MAPK signaling. These associations were confirmed in a cohort of MPM patient samples. Furthermore, 34 patients were treated in a clinical trial with nivolumab which demonstrated meaningful clinical efficacy and a manageable safety profile in pretreated patients with mesothelioma. PD-L1 expression did not predict for response in this population. Show less
This thesis focuses on using liposomes in two different treatment strategies; vaccination (or immunotherapy) and delivery of a small molecule, and in two different disease models; cancer and... Show moreThis thesis focuses on using liposomes in two different treatment strategies; vaccination (or immunotherapy) and delivery of a small molecule, and in two different disease models; cancer and atherosclerosis. For each of these treatment strategies, the liposomal formulation was tailored to obtain the desired therapeutic effect. Chapter 2 reviews some of the most important physicochemical properties (size, shape, and rigidity) that determine the immunological effects of liposomes and other nanoparticles. In chapter 3 we present a detailed study on the effect of the rigidity of anionic liposomes, as measured by atomic force microscopy, on antigen-specific regulatory T-cell (Treg) responses. In chapter 4, we show that our optimized anionic liposomes can induce potent antigen-specific Treg responses, and can be used to delay atherosclerosis progression in a mouse model. Chapter 5 also focuses on liposomal treatment of atherosclerosis, but here targeted liposomes were prepared to successfully deliver a small molecule to foam cells in atherosclerotic plaques. In Chapter 6, we used cationic liposomes in combination with an adjuvant for cancer immunotherapy in mice. Finally, we summarize the overall findings in chapter 7 and discuss perspectives of using liposomes for vaccination and targeted drug delivery. Show less
Extensive-stage small-cell lung cancer (ES-SCLC) is an aggressive cancer that remains very hard to treat. The life expectancy of a patient diagnosed with this disease has not changed over the past... Show moreExtensive-stage small-cell lung cancer (ES-SCLC) is an aggressive cancer that remains very hard to treat. The life expectancy of a patient diagnosed with this disease has not changed over the past three decades. Recently, three large clinical studies showed a survival benefit by adding an anti-programmed death (ligand) 1 (PD-(L) 1 antibody to the current chemotherapy regimen. Although significant and important, the benefit seems less than what has been achieved in patients with non-small-cell lung cancer treated with chemoimmunotherapy. A number of hypotheses have been explored to explain this discrepancy. Here, we hypothesise that the current chemotherapy backbone in ES-SCLC does not contain the optimal drugs to trigger immunogenic cell death and therefore does not induce a synergy between chemotherapy and immune checkpoint inhibitor therapy. Thereby, we advocate that doxorubicin treatment instead of etoposide should be reconsidered as standard-of-care (SoC) first-line treatment of SCLC. (c) 2020 Published by Elsevier Ltd. Show less
Background: Mucosal melanoma (MM) is rare and has a poor prognosis. Since 2011, new effective treatments are available for advanced melanoma. It is unclear whether patients with mucosal melanoma... Show moreBackground: Mucosal melanoma (MM) is rare and has a poor prognosis. Since 2011, new effective treatments are available for advanced melanoma. It is unclear whether patients with mucosal melanoma equally benefit from these new treatments compared with patients with cutaneous melanoma (CM).Methods: Patients with advanced MM and CM diagnosed between 2013 and 2017 were included from a nationwide population-based registry the Dutch Melanoma Treatment Registry. Overall survival (OS) was estimated with the Kaplan-Meier method (also for a propensity score-matched cohort). A Cox model was used to analyse the association of possible prognostic factors with OS.Results: In total, 120 patients with MM and 2960 patients with CM were included. Median OS was 8.7 months and 14.5 months, respectively. Patients with MM were older (median age 70 versus 65 years) and more often female (60% versus 41%), compared with CM. In total, 77% and 2% of the MM patients were treated with first-line immunotherapy and targeted therapy, respectively, compared with 49% and 33% of the CM patients. In contrast to CM, OS for MM did not improve for patients diagnosed in 2015-2017, compared with 2013-2014. ECOG performance score >= 1 (HR = 1.99 [1.26-3.15; p = 0.003]) and elevated LDH level (HR = 1.63 [0.96-2.76]; p = 0.069) in MM were associated with worse survival.Conclusions: Within the era of immune and targeted therapies, prognosis for patients with advanced MM has not improved as much as for CM. Collaboration is necessary to enlarge sample size for research to improve immunotherapeutic strategies and identify targetable mutations. (C) 2020 Elsevier Ltd. All rights reserved. Show less
The prognosis of recurrent or metastatic endometrial cancer is poor, with five-year survival of only 10-20 %. First-line therapy consists of either platinum-based chemotherapy or hormonal therapy.... Show moreThe prognosis of recurrent or metastatic endometrial cancer is poor, with five-year survival of only 10-20 %. First-line therapy consists of either platinum-based chemotherapy or hormonal therapy. No standard subsequent-line therapy has been identified. In recent years, significant progress has been made in the knowledge on underlying molecular biology of endometrial cancer and potential targets for therapy have been identified. Targeted therapies as poly (ADP-ribose) polymerase (PARP) inhibitors and immunotherapy as PD-1/PD-L1 checkpoint inhibitors have the potential to be effective against specific subtypes of endometrial cancer. Preclinical studies have shown that combining these agents may result in a synergistic effect. In this review, we focus on the molecular basis of checkpoint inhibition and targeted therapy as PARP inhibition in endometrial cancer and summarize available clinical data, and ongoing and planned clinical trials that investigate these agents as mono- or combination therapies in endometrial cancer and where relevant, other gynecological cancers. Show less
Dou, Y.Y.; Jansen, D.T.S.L.; Bosch, A. van den; Man, R.A. de; Montfoort, N. van; Araman, C.; ... ; Buschow, S.I. 2020
Synthetic long peptide (SLP) vaccination is a promising new treatment strategy for patients with a chronic hepatitis B virus (HBV) infection. We have previously shown that a prototype HBV-core... Show moreSynthetic long peptide (SLP) vaccination is a promising new treatment strategy for patients with a chronic hepatitis B virus (HBV) infection. We have previously shown that a prototype HBV-core protein derived SLP was capable of boosting CD4(+ )and CD8(+) T cell responses in the presence of a TLR2-ligand in chronic HBV patients ex vivo. For optimal efficacy of a therapeutic vaccine in vivo, adjuvants can be conjugated to the SLP to ensure delivery of both the antigen and the co-stimulatory signal to the same antigen-presenting cell (APC). Dendritic cells (DCs) express the receptor for the adjuvant and are optimally equipped to efficiently process and present the SLP-contained epitopes to T cells. Here, we investigated TLR2-ligand conjugation of the prototype HBV-core SLP. Results indicated that TLR2-ligand conjugation reduced cross-presentation efficiency of the SLP-contained epitope by both monocyte-derived and naturally occurring DC subsets. Importantly, cross-presentation was improved after optimization of the conjugate by either shortening the SLP or by placing a valine-citrulline linker between the TLR2-ligand and the long SLP, to facilitate endosomal dissociation of SLP and TLR2-ligand after uptake. HBV-core SLP conjugates also triggered functional patient T cell responses ex vivo. These results provide an import step forward in the design of a therapeutic SLP-based vaccine to cure chronic HBV. Show less
In cancer treatment, nanomedicines may be employed in an attempt to improve the tumor localization of antineoplastic drugs e.g. immunotherapeutic agents either through passive or active targeting,... Show moreIn cancer treatment, nanomedicines may be employed in an attempt to improve the tumor localization of antineoplastic drugs e.g. immunotherapeutic agents either through passive or active targeting, thereby potentially enhancing therapeutic effect and reducing undesired off-target effects. However, a large number of administrated nanocarriers often fail to reach the tumor area. In the present study, we show that photodynamic therapy (PDT) enhances the tumor accumulation of systemically administered lipid-PEG layer coated poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NP). Intravital microscopy and histological analysis of the tumor area reveal that the tumor vasculature was disrupted after PDT, disturbing blood flow and coinciding with entrapment of nanocarriers in the tumor area. We observed that the nanoparticles accumulating after treatment do not confine to specific locations within the tumor, but rather localize to various cells present throughout the tumor area. Finally, we show by flow cytometry that NP accumulation occurred mostly in immune cells of the myeloid lineage present in the tumor microenvironment (TME) as well as in tumor cells, albeit to a lower extent. These data expose opportunities for combination treatments of clinical PDT with NP-based immunotherapy to modulate the TME and improve antitumor immune responses. Show less
Immunotherapy has obtained a secure place in the treatment of metastatic non-small cell lung cancer (NSCLC) and has made a great impact on prognosis of responders. Unfortunately, not all NSCLC... Show moreImmunotherapy has obtained a secure place in the treatment of metastatic non-small cell lung cancer (NSCLC) and has made a great impact on prognosis of responders. Unfortunately, not all NSCLC patients derive benefit from this treatment. Several immune escape mechanisms have been postulated, explaining failure of tumor immune attack. A better understanding of these mechanisms helps us to seek treatment strategies to overcome resistance to immunotherapy. Radiotherapy has immunomodulatory qualities capable of enhancing the anticancer immune response by tackling a number of these tumor escape mechanisms. In this review, we focus on mechanisms of off-target effects of radiotherapy, the so-called abscopal effect, by describing the current role of immune checkpoint inhibitors (ICIs) in NSCLC, the possible reasons for its failures and evidence on how radiotherapy may be able to counteract these mechanisms. An oversight of pre-clinical and clinical data supporting augmentation of abscopal events by radiotherapy when combined with ICIs is presented. As much remains unclear regarding optimal dose, fractionation, target volume or timing of radiation therapy, future research will need to focus on implementing data from pre-clinical and translational findings in the development of new clinical trials in order to help optimizing the potential of the combination of immunotherapy with radiotherapy. Show less
The immune system is quite remarkable having both the ability to tolerate innocuous and self-antigens while possessing a robust capacity to recognize and eradicate infectious pathogens and foreign... Show moreThe immune system is quite remarkable having both the ability to tolerate innocuous and self-antigens while possessing a robust capacity to recognize and eradicate infectious pathogens and foreign entities. The genetics that encode this delicate balancing act include multiple genes and specialized cell types. Over the past several years, whole exome and whole genome sequencing has uncovered the genetics driving many human immune-mediated diseases including monogenic disorders and hematological malignancies. With the advent of genome editing technologies, the ability to correct genetic immune defects in autologous cells holds great promise for a number of conditions. Since assessment of novel therapeutic strategies have been difficult in mice, in recent years, immunodeficient mice capable of engrafting human cells and tissue have been developed and utilized for a variety of research applications. In this review, we discuss immune-humanized mice as a research tool to study human immunobiology and genetic immune disorders in vivo and the promise of future applications. Show less
MHC class I antigen-presentation plays a pivotal role in anti-tumor immunity. High surface expression of MHC-I molecules is generally correlated with high CD8 T cell infiltrate and improved overall... Show moreMHC class I antigen-presentation plays a pivotal role in anti-tumor immunity. High surface expression of MHC-I molecules is generally correlated with high CD8 T cell infiltrate and improved overall survival in many cancers. In contrast, partial or complete loss of MHC-I surface expression is associated with reduced survival and primary-resistance to immunotherapy in cancers. Expression of additional molecules in the tumor microenvironment (TME), such as PD-L1 and HLA-E, further shape immune responses. The presence of immune cells and the expression of immune-related genes together determine the ‘immune landscape’ of cancers, while the local production of interferons strongly impacts this environment. Although MHC-I and PD-L1 are both regulated by the IFN pathway, an in-depth study on immune escape of NSCLC showed that the expression of co-inhibitory markers and the loss of MHC-I expression are two independent mechanisms of immune evasion. This classifies tumors into different “types” depending on their MHC-I and PD-L1 expression. The differential expression of MHC-I and PD-L1 suggests that immune-escape of cancer cells occurs through a multitude of distinct “hard-wired” and “soft-wired” modifications and knowing which of the mechanisms underlie immune escape determines which immunotherapeutic strategy has the most potential for clinical success. Show less
The two branches of our highly advanced immune system work closely together to detect and eliminate pathological threats. The first line of defense is provided by the innate immune system via... Show moreThe two branches of our highly advanced immune system work closely together to detect and eliminate pathological threats. The first line of defense is provided by the innate immune system via detection of pathogenic or tumor cell fragments. Adaptive immune cells, on the other hand, recognize pathogens or malignant cells more specifically by scanning peptides, small protein fragments, presented by MHC molecules on other cells in our body. Specialized white blood cells (cytotoxic or killer T cells) can distinguish self- from non-self-peptides and directly eliminate cells that display signs of infection or mutation.The work described in this dissertation highlights how adaptive immunity can be used to our advantage, either from a therapeutic or diagnostic perspective. Immunotherapies that induce or promote anti-tumor or anti-viral responses have proven efficacious against infection and cancer. One strategy described is the development of chemically-modified epitopes as peptide vaccines, but small-molecule chemical drugs are also playing an increasing role in the field of cancer immunotherapy.In addition, monitoring of immune status and response to treatment, as well as mapping of epitopes, can aid diagnosis and design of treatment plans. The second part describes a novel method and application to visualize and monitor cytotoxic T cells. Show less
Smit, H.J.M.; Aerts, J.; Heuvel, M. van den; Hiltermann, T.J.N.; Bahce, I.; Smit, E.F.; ... ; NVALT Immunotherapy Register 2020
Objective: Phase III studies of checkpoint inhibitors changed the therapeutic landscape for lung cancer. In 2015 the Dutch Society of Chest Physicians (NVALT) introduced a national immunotherapy... Show moreObjective: Phase III studies of checkpoint inhibitors changed the therapeutic landscape for lung cancer. In 2015 the Dutch Society of Chest Physicians (NVALT) introduced a national immunotherapy registry for patients with lung cancer; quality standards for hospitals were implemented. At population level we studied clinical benefit in daily practice and in patients who are underrepresented in phase III trials.Materials and Methods: From the initial introduction of checkpoint inhibitors in the Netherlands patients were centrally registered. Educational programs and quality control were provided under supervision of NVALT. The largest immunotherapy providing hospitals were compared to hospitals who provided less checkpoint inhibitors as marker of experience. Patients characteristics, treatment and side effects, response rate and survival were studied.Results: A total of 2676 patients were registered, 2302 with follow up data were evaluated. Between October 2015 and December 2017 a gradual increase from 12 to 30 qualified hospitals showed no major toxicity differences. Toxicity led to a hospital admission rate of 9.1 with an average duration of 10.4 days.Overall tumor response was 21.8 % and median overall survival 12.6 months. Overall survival was not significantly different for patients aged >= 75 years, those having brain metastases or selected auto-immune diseases before start checkpoint inhibitors compared to younger patients or those without, respectively. Survival outcomes were worse in patients with PS 2+, non-smokers, and patients who received any palliative radiotherapy (HR 2.1, 95 % CI 1.7-2.7; 1.3, 95 % CI 1.0-1.6 and 1.2, 95 % CI 1.1-1.4, respectively).Conclusions: Changes in the therapeutic landscape did not lead to major differences in quality of care between hospitals. Elderly patients, those with brain metastases or selected auto-immune disease underrepresented in clinical trials did not do worse on checkpoint inhibitors, except for those with PS 2+. Show less
Colorectal cancer can be categorized into two major molecular subtypes according to the status of their DNA proofreading and repair machinery. The DNA repair status of tumor cells plays a major... Show moreColorectal cancer can be categorized into two major molecular subtypes according to the status of their DNA proofreading and repair machinery. The DNA repair status of tumor cells plays a major role in shaping the immune landscape of tumors and in determining the clinical response of colorectal cancer patients to immune checkpoint blockade therapies. Colorectal cancers that develop in a context of DNA mismatch repair or polymerase proofreading deficiency are generally conspicuously infiltrated by effector memory T cells and are associated with an improved clinical prognosis relative to their replication repair-proficient counterpart. While mismatch repair-deficient colorectal cancers, and most likely POLE and POLD1-mutated cancers, are amenable to immune checkpoint blockade therapies, the promise of immunotherapy still remains unfulfilled for for the majority of colorectal cancer patients. This review focusses on the role of the immune system in the tumorigenesis and clinical behavior of colorectal cancer. Furthermore, we discuss how latest advances in the fields of genomics and oncoimmunology may pave the way to broaden the scope of immunotherapy for this disease. Show less
In the clinic, several forms of immunotherapy are combined with the standard treatments, including chemotherapy. Translational studies trying to understand the different outcomes in patients have... Show moreIn the clinic, several forms of immunotherapy are combined with the standard treatments, including chemotherapy. Translational studies trying to understand the different outcomes in patients have led to new questions and hypotheses. The studies described in this thesis are to answer some of these questions. We revealed the immunostimulatory effect of the chemotherapy agent; cisplatin. Next, we studied the mechanism of relapse following immunotherapy with HPV16 SLP vaccination in mice. We demonstrated that unsuccessful immunotherapy results in immune editing and secondary resistance. To overcome this, the combination therapies are required. Moreover, we showed the importance of IL-6 producing by tumors in dampening anti-tumor response. To induce a long-term sustained effector T cell response, we examined the potency of mouse cytomegalovirus as a viral vector-based vaccine. We demonstrated that the demarcated thresholds of vaccine-specific T cells correlate to tumor protection. Recognizing the fact that at each phase of the antitumor immune response a different type of help might have to be provided to obtain maximal therapeutic efficacy, the correct timing of various types of chemotherapeutic agents or immune modulators when used in combination is discussed. Finally, we discussed the general aspects and relevance of the studies mentioned in this thesis. Show less
Kortekaas, K.E.; Santegoets, S.J.; Abdulrahman, Z.; Ham, V.J. van; Tol, M. van der; Ehsan, I.; ... ; Burg, S.H. van der 2019
Malignant melanoma is an aggressive cancer associated with a poor prognosis in patients with metastatic disease. As in many other cancers, the incidence of melanoma rises with age; and combined... Show moreMalignant melanoma is an aggressive cancer associated with a poor prognosis in patients with metastatic disease. As in many other cancers, the incidence of melanoma rises with age; and combined with the longer life expectancy, this led to an increasing prevalence of melanoma in the older population. Recently, immune checkpoint inhibitors significantly improved the treatment of melanoma given their efficacy and tolerability profile. Two major classes of agents include the anti-cytotoxic T lymphocyte-associated protein 4 (CFLA-4) inhibitors, such as ipilimumab, and the anti-programmed death-ligand 1 (PD-1) inhibitors, such as nivolumab and pembrolizumab. Treatment of metastatic disease with immune checkpoint inhibitors demonstrated improved efficacy and better safety profiles compared to cytotoxic drugs and appears to be an attractive treatment option. Nevertheless, there is a need for tools designed to better predict which older patients will benefit from its use and who will experience toxicities related to the treatment. Current data do not show a major increase in toxicity rates in older patients. However, patients above 75 are often under-represented and those who are included are not representative of the general population of older patients, thereby also stressing the need for real-life data. Ongoing research is aiming at maximizing the potential treatment efficacy and developing novel immune-targeting modalities. Future studies should include older patients and assess geriatric domains in these older patients to better guide decision-making. This review discusses published clinical trials and where known, the efficacy and toxicity in older patients. Moreover, the clinical implications and future perspectives are discussed, with current recommendations for older patients, management of toxicities, and a proposal for an initial approach to the treatment of older patients with metastatic melanoma. (C) 2018 Elsevier Ltd. All rights reserved. Show less
