Complete intracranial response to talimogene laherparepvec (T-Vec), pembrolizumab and whole brain radiotherapy in a patient with melanoma brain metastases refractory to dual checkpoint-inhibition

Evaluating the efficacy of combination and single-agent immunotherapies in real-world patterns of disease progression and survival of metastatic melanoma patients

The objective of this study is to describe survival outcomes in patients with metastatic melanoma in a real-world setting receiving combination and single-agent immunotherapy outside the clinical trial context. We conducted a retrospective single-institution study of patients with metastatic melanoma in a real-world setting. Survival was calculated using log-rank test. Contingency tables were analyzed using Fisher's Exact test. CD8 + T-cell densities were measured using quantitative immunofluorescence and analyzed using Mann-Whitney U test. The median overall survival (OS) for 132 patients was 45.3 months. Brain metastasis did not confer a higher risk of death relative to liver and/or bone disease (39.53 versus 30.00 months, respectively; P  = 0.687). Anti-PD-1 monotherapy was the most common first-line treatment, received by 49.2% of patients. There was no significant difference in OS between patients receiving single-agent anti-PD-1 and combination anti-PD-1 plus CTLA-4 (39.4 months versus undefined; P  = 0.643). Patients treated with combination therapy were more likely to be alive without progression at the last follow-up than those who received monotherapy (70.4% versus 49.2%; P  = 0.0408). Median OS was 21.8 months after initiation of second-line therapy after anti-PD-1 monotherapy. CD8+ T-cell densities were higher in patients who achieved disease control on first-line immunotherapy ( P  = 0.013). In a real-world setting, patients with metastatic melanoma have excellent survival rates, and treatment benefit can be achieved even after progression on first-line therapy. Combination immunotherapy may produce more favorable long-term outcomes in a real-world setting. High pretreatment CD8+ T-cell infiltration correlates with immunotherapy efficacy.

The potential of swine pseudorabies virus attenuated vaccine for oncolytic therapy against malignant tumors

BACKGROUND

Oncolytic viruses are now well recognized as potential immunotherapeutic agents against cancer. However, the first FDA-approved oncolytic herpes simplex virus 1 (HSV-1), T-VEC, showed limited benefits in some patients in clinical trials. Thus, the identification of novel oncolytic viruses that can strengthen oncolytic virus therapy is warranted. Here, we identified a live-attenuated swine pseudorabies virus (PRV-LAV) as a promising oncolytic agent with broad-spectrum antitumor activity in vitro and in vivo.

METHODS

PRV cytotoxicity against tumor cells and normal cells was tested in vitro using a CCK8 cell viability assay. A cell kinase inhibitor library was used to screen for key targets that affect the proliferation of PRV-LAV. The potential therapeutic efficacy of PRV-LAV was tested against syngeneic tumors in immunocompetent mice, and against subcutaneous xenografts of human cancer cell lines in nude mice. Cytometry by time of flight (CyTOF) and flow cytometry were used to uncover the immunological mechanism of PRV-LAV treatment in regulating the tumor immune microenvironment.

RESULTS

Through various tumor-specific analyses, we show that PRV-LAV infects cancer cells via the NRP1/EGFR signaling pathway, which is commonly overexpressed in cancer. Further, we show that PRV-LAV kills cancer cells by inducing endoplasmic reticulum (ER) stress. Moreover, PRV-LAV is responsible for reprogramming the tumor microenvironment from immunologically naïve ("cold") to inflamed ("hot"), thereby increasing immune cell infiltration and restoring CD8+ T cell function against cancer. When delivered in combination with immune checkpoint inhibitors (ICIs), the anti-tumor response is augmented, suggestive of synergistic activity.

CONCLUSIONS

PRV-LAV can infect cancer cells via NRP1/EGFR signaling and induce cancer cells apoptosis via ER stress. PRV-LAV treatment also restores CD8+ T cell function against cancer. The combination of PRV-LAV and immune checkpoint inhibitors has a significant synergistic effect. Overall, these findings point to PRV-LAV as a serious potential candidate for the treatment of NRP1/EGFR pathway-associated tumors.

Combination therapy with immune checkpoint inhibitors (ICIs); a new frontier

Recently, immune checkpoint inhibitors (ICIs) therapy has become a promising therapeutic strategy with encouraging therapeutic outcomes due to their durable anti-tumor effects. Though, tumor inherent or acquired resistance to ICIs accompanied with treatment-related toxicities hamper their clinical utility. Overall, about 60-70% of patients (e.g., melanoma and lung cancer) who received ICIs show no objective response to intervention. The resistance to ICIs mainly caused by alterations in the tumor microenvironment (TME), which in turn, supports angiogenesis and also blocks immune cell antitumor activities, facilitating tumor cells' evasion from host immunosurveillance. Thereby, it has been supposed and also validated that combination therapy with ICIs and other therapeutic means, ranging from chemoradiotherapy to targeted therapies as well as cancer vaccines, can capably compromise tumor resistance to immune checkpoint blocked therapy. Herein, we have focused on the therapeutic benefits of ICIs as a groundbreaking approach in the context of tumor immunotherapy and also deliver an overview concerning the therapeutic influences of the addition of ICIs to other modalities to circumvent tumor resistance to ICIs.

Emerging systemic delivery strategies of oncolytic viruses: A key step toward cancer immunotherapy

Oncolytic virotherapy (OVT) is a novel type of immunotherapy that induces anti-tumor responses through selective self-replication within cancer cells and oncolytic virus (OV)-mediated immunostimulation. Notably, talimogene laherparepvec (T-Vec) developed by the Amgen company in 2015, is the first FDA-approved OV product to be administered via intratumoral injection and has been the most successful OVT treatment. However, the systemic administration of OVs still faces huge challenges, including in vivo pre-existing neutralizing antibodies and poor targeting delivery efficacy. Recently, state-of-the-art progress has been made in the development of systemic delivery of OVs, which demonstrates a promising step toward broadening the scope of cancer immunotherapy and improving the clinical efficacy of OV delivery. Herein, this review describes the general characteristics of OVs, focusing on the action mechanisms of OVs as well as the advantages and disadvantages of OVT. The emerging multiple systemic administration approaches of OVs are summarized in the past five years. In addition, the combination treatments between OVT and traditional therapies (chemotherapy, thermotherapy, immunotherapy, and radiotherapy, etc.) are highlighted. Last but not least, the future prospects and challenges of OVT are also discussed, with the aim of facilitating medical researchers to extensively apply the OVT in the cancer therapy.

The phosphoinositide 3-kinase inhibitor ZSTK474 increases the susceptibility of osteosarcoma cells to oncolytic vesicular stomatitis virus VSVΔ51 via aggravating endoplasmic reticulum stress

Blockage of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signal pathway is effective to increase the cytotoxic effects of oncolytic virus on cancer cells, but the detailed mechanisms are still largely unknown. Based on this, the present study managed to investigate the anti-tumor effects of PI3K inhibitor ZSTK474 and oncolytic vesicular stomatitis virus VSVΔ51 combination treatments on osteosarcoma (OS) in vitro and in vivo. Specifically, ZSTK474 aggravated the inhibiting effects of VSVΔ51 on osteosarcoma development by triggering endoplasmic reticulum (ER)-stress mediated apoptotic cell death. Mechanistically, either ZSTK474 or VSVΔ51 alone had limited effects on cell viability in osteosarcoma cells, while ZSTK474 and VSVΔ51 combination treatments significantly induced osteosarcoma cell apoptosis. Interestingly, VSVΔ51 increased the expression levels of IRE1α and p-PERK to initiate ER stress in osteosarcoma cells, which were aggravated by co-treating cells with ZSTK474. Next, the promoting effects of ZSTK474-VSVΔ51 combined treatment on osteosarcoma cell death were abrogated by the ER-stress inhibitor 4-phenyl butyric acid (4-PBA), indicating that ZSTK474 enhanced the cytotoxic effects of VSVΔ51 on osteosarcoma cells in an ER-stress dependent manner. Finally, the xenograft tumor-bearing mice models were established, and the results showed that ZSTK474-VSVΔ51 combined treatment synergistically hindered tumorigenesis of osteosarcoma cells in vivo. Taken together, our data suggested that ZSTK474 was a novel agent to enhance the cytotoxic effects of VSVΔ51 on osteosarcoma by aggravating ER-stress, and the present study might provide alternative therapy treatments for osteosarcoma in clinic.

Oncolytic Virotherapy for Melanoma Brain Metastases, a Potential New Treatment Paradigm?

INTRODUCTION

Melanoma brain metastases remain a devastating disease process with poor prognosis. Recently, there has been a surge in studies demonstrating the efficacy of oncolytic virotherapy for brain tumor treatment. Given their specificity and amenability to genetic modification, the authors explore the possible role of oncolytic virotherapy as a potential treatment option for patients with melanoma brain metastases.

METHODS

A comprehensive literature review including both preclinical and clinical evidence of oncolytic virotherapy for the treatment of melanoma brain metastasis was performed.

RESULTS

Oncolytic virotherapy, specifically T-VEC (Imlygic™), was approved for the treatment of melanoma in 2015. Recent clinical trials demonstrate promising anti-tumor changes in patients who have received T-VEC; however, there is little evidence for its use in metastatic brain disease based on the existing literature. To date, only two single cases utilizing virotherapy in patients with metastatic brain melanoma have been reported, specifically in patients with treatment refractory disease. Currently, there is not sufficient data to support the use of T-VEC or other viruses for intracranial metastatic melanoma. In developing a virotherapy treatment paradigm for melanoma brain metastases, several factors must be considered, including route of administration, need to bypass the blood-brain barrier, viral tumor infectivity, and risk of adverse events.

CONCLUSIONS

Evidence for oncolytic virotherapy treatment of melanoma is limited primarily to T-VEC, with a noticeable paucity of data in the literature with respect to brain tumor metastasis. Given the promising findings of virotherapy for other brain tumor types, oncolytic virotherapy has great potential to offer benefits to patients afflicted with melanoma brain metastases and warrants further investigation.

Remodeling of the tumor microenvironment using an engineered oncolytic vaccinia virus improves PD-L1 inhibition outcomes

Immune checkpoint inhibitor (ICI) immunotherapies have vastly improved therapeutic outcomes for patients with certain cancer types, but these responses only manifest in a small percentage of all cancer patients. The goal of the present study was to improve checkpoint therapy efficacy by utilizing an engineered vaccinia virus to improve the trafficking of lymphocytes to the tumor, given that such lymphocyte trafficking is positively correlated with patient checkpoint inhibitor response rates. We developed an oncolytic vaccinia virus (OVV) platform expressing manganese superoxide dismutase (MnSOD) for use as both a monotherapy and together with anti-PD-L1. Intratumoral OVV-MnSOD injection in immunocompetent mice resulted in inflammation within poorly immunogenic tumors, thereby facilitating marked tumor regression. OVV-MnSOD administration together with anti-PD-L1 further improved antitumor therapy outcomes in models in which these monotherapy approaches were ineffective. Overall, our results emphasize the value of further studying these therapeutic approaches in patients with minimally or non-inflammatory tumors.

Successful administration of sequential TVEC and pembrolizumab followed by Temozolomide in immunotherapy refractory intracranial metastatic melanoma with acquired B2M mutation

Despite the substantial advances in the management of metastatic melanoma with the introduction of immune checkpoint inhibitors (ICI), many patients develop disease progression during treatment with immunotherapy. This has been suggested to be mediated by several mechanisms that contribute to acquired resistance to ICI, one of which is acquired beta-2 microgloubulin (B2M) mutation. Talimogene laherparepvec (TVEC) is a genetically modified oncolytic virus that can enhance antitumor immunity. Temozolomide (TMZ) is an oral alkylating agent that has been suggested to augment anti-tumor immune response. The clinical significance of TVEC and TMZ in metastatic melanoma patients who are refractory to immunotherapy is unknown. We report a case of a patient with immunotherapy refractory intracranial metastatic melanoma after initial response to ICI who had acquired B2M mutation. The patient received TVEC and pembrolizumab followed by TMZ. The patient maintained durable response of her visceral and intracranial disease for 19 months and ongoing. More research is essential to delineate whether TVEC or TMZ has efficacy in immunotherapy refractory metastatic melanoma with acquired B2M mutation.

Nanomaterials for Diagnosis and Treatment of Brain Cancer: Recent Updates

Brain tumors, especially glioblastoma, remain the most aggressive form of all the cancers because of inefficient diagnosis and profiling. Nanostructures, such as metallic nanostructures, silica nano-vehicles, quantum dots, lipid nanoparticles (NPs) and polymeric NPs, with high specificity have made it possible to permeate the blood–brain barrier (BBB). NPs possess optical, magnetic and photodynamic properties that can be exploited by surface modification, bio composition, contrast agents’ encapsulation and coating by tumor-derived cells. Hence, nanotechnology has brought on a revolution in the field of diagnosis and imaging of brain tumors and cancers. Recently, nanomaterials with biomimetic functions have been introduced to efficiently cross the BBB to be engulfed by deep skin tumors and cancer malignancies for imaging. The review focuses on nanotechnology-based diagnostic and imaging approaches for exploration in brain tumors and cancers. Moreover, the review also summarizes a few strategies to image glioblastoma and cancers by multimodal functional nanocomposites for more precise and accurate clinical diagnosis. Their unique physicochemical attributes, including nanoscale sizes, larger surface area, explicit structural features and ability to encapsulate diverse molecules on their surface, render nanostructured materials as excellent nano-vehicles to cross the blood–brain barrier and convey drug molecules to their target region. This review sheds light on the current progress of various kinds of nanomaterials, such as liposomes, nano-micelles, dendrimers, carbon nanotubes, carbon dots and NPs (gold, silver and zinc oxide NPs), for efficient drug delivery in the treatment and diagnosis of brain cancer.

Epithelial Ovarian Cancer and the Immune System: Biology, Interactions, Challenges and Potential Advances for Immunotherapy

Recent advances in the understanding of immune function and the interactions with tumour cells have led to the development of various cancer immunotherapies and strategies for specific cancer types. However, despite some stunning successes with some malignancies such as melanomas and lung cancer, most patients receive little or no benefit from immunotherapy, which has been attributed to the tumour microenvironment and immune evasion. Although the US Food and Drug Administration have approved immunotherapies for some cancers, to date, only the anti-angiogenic antibody bevacizumab is approved for the treatment of epithelial ovarian cancer. Immunotherapeutic strategies for ovarian cancer are still under development and being tested in numerous clinical trials. A detailed understanding of the interactions between cancer and the immune system is vital for optimisation of immunotherapies either alone or when combined with chemotherapy and other therapies. This article, in two main parts, provides an overview of: (1) components of the normal immune system and current knowledge regarding tumour immunology, biology and their interactions; (2) strategies, and targets, together with challenges and potential innovative approaches for cancer immunotherapy, with attention given to epithelial ovarian cancer.

Overhauling CAR T Cells to Improve Efficacy, Safety and Cost

Gene therapy is now surpassing 30 years of clinical experience and in that time a variety of approaches has been applied for the treatment of a wide range of pathologies. While the promise of gene therapy was over-stated in the 1990’s, the following decades were met with polar extremes between demonstrable success and devastating setbacks. Currently, the field of gene therapy is enjoying the rewards of overcoming the hurdles that come with turning new ideas into safe and reliable treatments, including for cancer. Among these modalities, the modification of T cells with chimeric antigen receptors (CAR-T cells) has met with clear success and holds great promise for the future treatment of cancer. We detail a series of considerations for the improvement of the CAR-T cell approach, including the design of the CAR, routes of gene transfer, introduction of CARs in natural killer and other cell types, combining the CAR approach with checkpoint blockade or oncolytic viruses, improving pre-clinical models as well as means for reducing cost and, thus, making this technology more widely available. While CAR-T cells serve as a prime example of translating novel ideas into effective treatments, certainly the lessons learned will serve to accelerate the current and future development of gene therapy drugs.

From threat to cure: understanding of virus-induced cell death leads to highly immunogenic oncolytic influenza viruses

Oncolytic viruses constitute an emerging strategy in immunomodulatory cancer treatment. The first oncolytic virus, Talimogene laherparepvec (T-VEC), based on herpes simplex virus 1 (HSV-1), was approved by the Food and Drug Administration (FDA) and European Medicines Agency (EMA) in 2015. The field of oncolytic virotherapy is still in its beginnings, since many promising viruses remain only superficially explored. Influenza A virus causes a highly immunogenic acute infection but never leads to a chronic disease. While oncolytic influenza A viruses are in preclinical development, they have not made the transition into clinical practice yet. Recent insights into different types of cell death caused by influenza A virus infection illuminate novel possibilities of enhancing its therapeutic effect. Genetic engineering and experience in influenza A virus vaccine development allow safe application of the virus in patients. In this review we give a summary of efforts undertaken to develop oncolytic influenza A viruses. We discuss strategies for targeting viral replication to cancerous lesions and arming them with immunogenic transgenes. We furthermore describe which modes of cell death are induced by influenza A virus infection and how these insights may be utilized to optimize influenza A virus-based oncolytic virus design.

Combination treatments with immunotherapy in brain metastases patients

Immune checkpoint inhibitors (ICI) have revolutionized the treatment of many advanced cancers. However, in most pivotal trials, patients with brain metastases (BM) were either excluded, or only selected patients were allowed. Therefore, there are still some concerns about the safety/efficacy ratio of ICI in patients with BM. In this special report we will provide an overview on the biological rationale for using ICI in the treatment of BM, the reported BM-related outcomes of clinical trials with a focus on ICI plus chemotherapy and ICI plus ICI combinations. Last, we will provide future challenges with this strategy, as well as directions for future research.

Combining Oncolytic Viruses With Cancer Immunotherapy: Establishing a New Generation of Cancer Treatment

The recent successes of tumor immunotherapy approaches, such as immune checkpoint blockade (ICB) and chimeric antigen receptor T cell (CAR-T) therapy, have revolutionized cancer treatment, improving efficacy and extending treatment to a larger proportion of cancer patients. However, due to high heterogeneity of cancer, poor tumor cell targeting, and the immunosuppressive status of the tumor microenvironment (TME), combinatorial agents are required to obtain more effective and consistent therapeutic responses in a wide range of cancers. Oncolytic viruses (OVs) are able to selectively replicate in and destroy tumor cells and subsequently induce systematic anti-tumor immune responses. Thus, they are ideal for combining with cancer immunotherapy. In this review, we discuss the current understanding of OVs, as well as the latest preclinical and clinical progress of combining OVs with cancer immunotherapies, including ICB, CAR-T therapy, bispecific T cell engagers (BiTEs), and cancer vaccines. Moreover, we consider future directions for applying OVs to personalized cancer immunotherapies, which could potentially launch a new generation of cancer treatments.

Radiotherapy as a Backbone for Novel Concepts in Cancer Immunotherapy

Radiation-induced immunogenic cell death has been described to contribute to the efficacy of external beam radiotherapy in local treatment of solid tumors. It is well established that radiation therapy can induce immunogenic cell death in cancer cells under certain conditions. Initial clinical studies combining radiotherapy with immunotherapies suggest a synergistic potential of this approach. Improving our understanding of how radiation reconditions the tumor immune microenvironment should pave the way for designing rational and robust combinations with immunotherapeutic drugs that enhance both local and systemic anti-cancer immune effects. In this review, we summarize irradiation-induced types of immunogenic cell death and their effects on the tumor microenvironment. We discuss preclinical insights on mechanisms and benefits of combining radiotherapy with immunotherapy, focusing on immune checkpoint inhibitors. In addition, we elaborate how these observations were translated into clinical studies and which parameters may be optimized to achieve best results in future clinical trials.

Therapeutic vaccination immunomodulation: forming the basis of all cancer immunotherapy

Recent immunotherapy advances have convincingly demonstrated complete tumour removal with long-term survival. These impressive clinical responses have rekindled enthusiasm towards immunotherapy and tumour antigen vaccination providing 'cures' for melanoma and other cancers. However, many patients still do not benefit; sometimes harmed by severe autoimmune toxicity. Checkpoint inhibitors (anti-CTLA4; anti-PD-1) and interleukin-2 (IL-2) are 'pure immune drivers' of pre-existing immune responses and can induce either desirable effector-stimulatory or undesirable inhibitory-regulatory responses. Why some patients respond well, while others do not, is presently unknown, but might be related to the cellular populations being 'driven' at the time of dosing, dictating the resulting immune response. Vaccination is in-vivo immunotherapy requiring an active host response. Vaccination for cancer treatment has been skeptically viewed, arising partially from difficulty demonstrating clear, consistent clinical responses. However, this article puts forward accumulating evidence that 'vaccination' immunomodulation constitutes the fundamental, central, intrinsic property associated with antigen exposure not only from exogenous antigen (allogeneic or autologous) administration, but also from endogenous release of tumour antigen (autologous) from in-vivo tumour-cell damage and lysis. Many 'standard' cancer therapies (chemotherapy, radiotherapy etc.) create waves of tumour-cell damage, lysis and antigen release, thus constituting 'in-vivo vaccination' events. In essence, whenever tumour cells are killed, antigen release can provide in-vivo repeated vaccination events. Effective anti-tumour immune responses require antigen release/supply; immune recognition, and immune responsiveness. With better appreciation of endogenous vaccination and immunomodulation, more refined approaches can be engineered with prospect of higher success rates from cancer therapy, including complete responses and better survival rates.

Response to the Rechallenge With Talimogene Laherparepvec (T-VEC) After Ipilimumab/Nivolumab Treatment in Patient With Cutaneous Malignant Melanoma Who Initially Had a Progression on T-VEC With Pembrolizumab

Talimogene laherparepvec (T-VEC) is approved for unresected stage III-IV malignant melanoma. T-VEC has a direct cytotoxic effect and enhances the antitumor immunity of host cells. Immune checkpoints inhibitors also enhance the immunity of host cells by increasing the recruitment of antigen-presenting cells or activation and restoration of T-cell functions. Both type of therapies can potentiate the effect of the other therapy. We are reporting a case of T-VEC rechallenge who initially progressed on T-VEC with pembrolizumab but then responded to T-VEC rechallenge after intervening ipilimumab/nivolumab. An 83-year-old man developed a subungual lesion of the left thumb and found to have AJCC V. 7 stage IIIb melanoma. Few months later, he developed axillary lymphadenopathy and multiple subcutaneous nodules (AJCC V. 7 stage IIIc). The patient was started on intralesional rose Bengal and pembrolizumab. After 4 cycles of pembrolizumab with rose Bengal, a positron-emission tomography/computerized tomography scan showed the progression of disease. He was started on T-VEC intralesional injections with concurrent pembrolizumab, however, after 3 T-VEC injections and 2 more cycles of pembrolizumab, there was the progression of disease. Subsequently, ipilimumab/nivolumab was started and patient responded partially. Ipilimumab/nivolumab was held due to toxicity. Eight weeks from the last dose of ipilimumab/nivolumab, he experienced locoregional progression and was rechallenged with T-VEC monotherapy. The patient showed a significant response after second T-VEC injection and continued to show response 6 months since rechallenge. After, initial progression on T-VEC with pembrolizumab, intervening immune checkpoints inhibitors may favorably modify the antitumor immunity and potentiate antitumor effect of T-VEC rechallenge.

Radiotherapy for Melanoma: More than DNA Damage

Despite its reputation as a radioresistant tumour, there is evidence to support a role for radiotherapy in patients with melanoma and we summarise current clinical practice. Melanoma is a highly immunogenic tumour and in this era of immunotherapy, there is renewed interest in the potential of irradiation, not only as an adjuvant and palliative treatment, but also as an immune stimulant. It has long been known that radiation causes not only DNA strand breaks, apoptosis, and necrosis, but also immunogenic modulation and cell death through the induction of dendritic cells, cell adhesion molecules, death receptors, and tumour-associated antigens, effectively transforming the tumour into an individualised vaccine. This immune response can be enhanced by the application of clinical hyperthermia as evidenced by randomised trial data in patients with melanoma. The large fraction sizes used in cranial radiosurgery and stereotactic body radiotherapy are more immunogenic than conventional fractionation, which provides additional radiobiological justification for these techniques in this disease entity. Given the immune priming effect of radiotherapy, there is a strong but complex biological rationale and an increasing body of evidence for synergy in combination with immune checkpoint inhibitors, which are now first-line therapy in patients with recurrent or metastatic melanoma. There is great potential to increase local control and abscopal effects by combining radiotherapy with both immunotherapy and hyperthermia, and a combination of all three modalities is suggested as the next important trial in this refractory disease.

State of clinical research of radiotherapy/chemoradiotherapy and immune checkpoint inhibitor therapy combinations in solid tumours-a German radiation oncology survey

Combinations of immune checkpoint inhibitors (ICIs) with radiotherapy and/or chemoradiotherapy are currently under investigation in many cancer types and clinical settings. In this survey, we solicited members of the German Radiation Oncology Society and young DEGRO (working group of DEGRO e.V.) to review the current status of research in this field and underline critical issues such as oncological benefit, treatment toxicity and obstacles in clinical research. The responses represent 14 different departments of radiation oncology at German university hospitals. Respondents of the same department were analysed for congruence. Sixty-one percent of all respondents perform radiotherapy/chemoradiotherapy and ICI therapy combination studies at their institutions and participate in multicentre studies. Combinations were investigated mainly in head and neck tumours (95%), lung cancer (57%), malignant melanoma (48%) and tumours of the upper gastrointestinal tract (9%). Combination of chemoradiotherapy with checkpoint inhibitors was only tested in head and neck cancers (52%), non-small-cell lung cancer (NSCLC) (8.70%) and malignant melanoma (4%). A combination of radiotherapy/chemoradiotherapy with ICIs is assumed to be effective or very effective by >85% of all respondents. The treatment of intracranial metastatic disease by this combination is assumed to be very effective by most respondents (61%). The present survey shows great acceptance of new combined modality treatment paradigm. ICIs with radiotherapy and/or chemoradiotherapy are under investigation at >75% of all participating centres. Head and neck tumours, NSCLC and malignant melanoma are the most frequently tested cancer types.