High-Dose Interleukin-2 (HD IL-2) Therapy Should Be Considered for Treatment of Patients with Melanoma Brain Metastases

Type I interferon response in astrocytes promotes brain metastasis by enhancing monocytic myeloid cell recruitment

Cancer metastasis to the brain is a significant clinical problem. Metastasis is the consequence of favorable interactions between invaded cancer cells and the microenvironment. Here, we demonstrate that cancer-activated astrocytes create a sustained low-level activated type I interferon (IFN) microenvironment in brain metastatic lesions. We further confirm that the IFN response in astrocytes facilitates brain metastasis. Mechanistically, IFN signaling in astrocytes activates C-C Motif Chemokine Ligand 2 (CCL2) production, which further increases the recruitment of monocytic myeloid cells. The correlation between CCL2 and monocytic myeloid cells is confirmed in clinical brain metastasis samples. Lastly, genetically or pharmacologically inhibiting C-C Motif Chemokine Receptor 2 (CCR2) reduces brain metastases. Our study clarifies a pro-metastatic effect of type I IFN in the brain even though IFN response has been considered to have anti-tumor effects. Moreover, this work expands our understandings on the interactions between cancer-activated astrocytes and immune cells in brain metastasis.

Complications associated with immunotherapy for brain metastases

PURPOSE OF REVIEW

Median survival after the diagnosis of brain metastases has historically been on the order of months. With the recent development of immune checkpoint inhibitors, intracranial activity and durable responses have been observed in brain metastases on multiple phase 2 clinical trials, which have primarily been conducted in patients with melanoma. Immune-related adverse events related to checkpoint inhibitor therapy of brain metastasis can present unique challenges for the clinician and underscore the need for a multidisciplinary team in the care of these patients. The goal of this review is to address the current knowledge, limitations of understanding, and future directions in research regarding immune therapy trials and neurologic toxicities based on retrospective, prospective, and case studies.

RECENT FINDINGS

Immune therapy has the potential to exacerbate symptomatic edema and increase the risk of radiation necrosis in previously irradiated lesions. Neurologic toxicities will likely increase in prevalence as more patients with brain metastatic disease are eligible for immune therapy.

SUMMARY

An improved understanding and heightened awareness of the unique neurologic toxicities that impact this patient group is vital for mitigating treatment-related morbidity and mortality.

Blood-brain barrier permeable nano immunoconjugates induce local immune responses for glioma therapy

Brain glioma treatment with checkpoint inhibitor antibodies to cytotoxic T-lymphocyte-associated antigen 4 (a-CTLA-4) and programmed cell death-1 (a-PD-1) was largely unsuccessful due to their inability to cross blood-brain barrier (BBB). Here we describe targeted nanoscale immunoconjugates (NICs) on natural biopolymer scaffold, poly(β-L-malic acid), with covalently attached a-CTLA-4 or a-PD-1 for systemic delivery across the BBB and activation of local brain anti-tumor immune response. NIC treatment of mice bearing intracranial GL261 glioblastoma (GBM) results in an increase of CD8+ T cells, NK cells and macrophages with a decrease of regulatory T cells (Tregs) in the brain tumor area. Survival of GBM-bearing mice treated with NIC combination is significantly longer compared to animals treated with single checkpoint inhibitor-bearing NICs or free a-CTLA-4 and a-PD-1. Our study demonstrates trans-BBB delivery of tumor-targeted polymer-conjugated checkpoint inhibitors as an effective GBM treatment via activation of both systemic and local privileged brain tumor immune response.

High-dose interleukin-2 (HD IL-2) for advanced melanoma: a single center experience from the University of Pittsburgh Cancer Institute

Background

Durable remissions are observed in a fraction of metastatic melanoma patients treated with high-dose interleukin-2 (HD IL-2). Early studies reported overall (OR) and complete response (CR) rates of 16% and 8% respectively. Toxicity limited use to specialized centers with standardized protocols. We report on 243 patients treated at the University of Pittsburgh in a non-intensive care unit (ICU) oncology specialty setting.

Methods

Clinical and radiological data were collected on 243 patients treated between 1992 and 2015. Each HD IL-2 cycle was given over 5 days, cycles were repeated after 9 days and courses (2 cycles) were repeated every 6–9 weeks in patients with stable or responding disease, for up to 3 courses total. Influence of baseline characteristics on outcomes was assessed using Kaplan-Meier estimates and Cox proportional hazards analysis.

Results

Two hundred forty-three patients received 692 cycles (5270 doses) between 1992 and 2015. Two hundred thirty-seven patients were evaluable for response: OR rate 18.1% with CR rate 8.0%. Median overall survival (OS) 9.6 months in the entire cohort but 64.9 months in responders. Median number of cycles delivered was 2,and median number of doses per cycle was 8. Toxicity was consistent with prior reports. HD IL-2 required ICU transfers in 11 patients and 1 death was attributed to HD IL-2. Pre-treatment lactate dehydrogenase (LDH) levels correlated significantly with progression-free survival [1-2× upper limit normal (ULN) HR 1.95; >2× ULN HR 2.32] and overall survival (1-2× ULN HR 1.67; >2× ULN 2.49). Response to HD IL-2 and site of metastatic disease also correlated significantly with progression-free and overall survival.

Conclusions

In this large series of patients spanning more than two decades, OR/CR rates with HD IL-2 were 18.1%/8.0% respectively. Toxicity data was consistent with prior reports. Pre-treatment LDH values and site(s) of metastatic disease may be useful markers to select patients at greater likelihood of benefit to HD IL-2 therapy.

Electronic supplementary material

The online version of this article (10.1186/s40425-017-0279-5) contains supplementary material, which is available to authorized users.

History and current state of immunotherapy in glioma and brain metastasis

Malignant brain tumors such as glioblastoma (GBM) and brain metastasis have poor prognosis despite conventional therapies. Successful use of vaccines and checkpoint inhibitors in systemic malignancy has increased the hope that immune therapies could improve survival in patients with brain tumors. Manipulating the immune system to fight malignancy has a long history of both modest breakthroughs and pitfalls that should be considered when applying the current immunotherapy approaches to patients with brain tumors. Therapeutic vaccine trials for GBM date back to the mid 1900s and have taken many forms; from irradiated tumor lysate to cell transfer therapies and peptide vaccines. These therapies were generally well tolerated without significant autoimmune toxicity, however also did not demonstrate significant clinical benefit. In contrast, the newer checkpoint inhibitors have demonstrated durable benefit in some metastatic malignancies, accompanied by significant autoimmune toxicity. While this toxicity was not unexpected, it exceeded what was predicted from pre-clinical studies and in many ways was similar to the prior trials of immunostimulants. This review will discuss the history of these studies and demonstrate that the future use of immune therapy for brain tumors will likely need a personalized approach that balances autoimmune toxicity with the opportunity for significant survival benefit.

Challenges in the delivery of therapies to melanoma brain metastases

Brain metastases are a major cause of morbidity and mortality in patients with advanced melanoma. Recent approval of several molecularly-targeted agents and biologics has brought hope to patients with this previously untreatable disease. However, patients with symptomatic melanoma brain metastases have often been excluded from pivotal clinical trials. This may be in part attributed to the fact that several of the approved small molecule molecularly-targeted agents are substrates for active efflux at the blood-brain barrier, limiting their effective delivery to brain metastases. We believe that successful treatment of melanoma brain metastases will depend on the ability of these agents to traverse the blood-brain barrier and reach micrometastases that are often not clinically detectable. Moreover, overcoming the emergence of a unique pattern of resistance, possibly through adequate delivery of combination targeted therapies in brain metastases will be important in achieving a durable response. These concepts, and the current challenges in the delivery of new treatments to melanoma brain metastases, are discussed in this review.

Melanoma Brain Metastasis: Mechanisms, Models, and Medicine

The development of brain metastases in patients with advanced stage melanoma is common, but the molecular mechanisms responsible for their development are poorly understood. Melanoma brain metastases cause significant morbidity and mortality and confer a poor prognosis; traditional therapies including whole brain radiation, stereotactic radiotherapy, or chemotherapy yield only modest increases in overall survival (OS) for these patients. While recently approved therapies have significantly improved OS in melanoma patients, only a small number of studies have investigated their efficacy in patients with brain metastases. Preliminary data suggest that some responses have been observed in intracranial lesions, which has sparked new clinical trials designed to evaluate the efficacy in melanoma patients with brain metastases. Simultaneously, recent advances in our understanding of the mechanisms of melanoma cell dissemination to the brain have revealed novel and potentially therapeutic targets. In this review, we provide an overview of newly discovered mechanisms of melanoma spread to the brain, discuss preclinical models that are being used to further our understanding of this deadly disease and provide an update of the current clinical trials for melanoma patients with brain metastases.

Immunotherapy of Brain Cancer

The brain has long been considered an immune-privileged site precluding potent immune responses. Nevertheless, because of the failure of conventional anti-cancer treatments to achieve sustained control of intracranial neoplasms, immunotherapy has been considered as a promising strategy for decades. However, several efforts aimed at exploiting the immune system as a therapeutic weapon were largely unsuccessful. The situation only changed with the introduction of the checkpoint inhibitors, which target immune cell receptors that interfere with the activation of immune effector cells. Following the observation of striking effects of drugs that target CTLA-4 or PD-1 against melanoma and other tumor entities, it was recognized that these drugs may also be active against metastatic tumor lesions in the brain. Their therapeutic activity against primary brain tumors is currently being investigated within clinical trials. In parallel, other immunotherapeutics such as peptide vaccines are at an advanced stage of clinical development. Further immunotherapeutic strategies currently under investigation comprise adoptive immune cell transfer as well as inhibitors of metabolic pathways involved in the local immunosuppression frequently found in brain tumors. Thus, the ongoing implementation of immunotherapeutic concepts into clinical routine may represent a powerful addition to the therapeutic arsenal against various brain tumors.

A novel modulation of structural and functional changes of mouse bone marrow derived dendritic cells (BMDCs) by interleukin-2(IL-2)

IL-2 is a pleiotropic cytokine produced by T cell after antigen activation of T cell and it is so called T cell growth factor. A large number of documents suggest that Il-2 plays pivotal roles in the immune response and now Il-2 is an approved drug being used for various kinds of diseases such as cancer and dermatitis. (1) The aim of present exploration was to look at effect of IL-2 on structural, phenotypic and functional maturation of murine BMDCs. The structural and phenotypic maturation of BMDCs under influence of IL-2 were evaluated by light microscope and flow cytometry (FCM). The functional maturation of BMDCs was confirmed by cytochemistry assay, FITC-dextran, acid phosphatase (ACP) activity, bio-assay and enzyme linked immunosorbent assay (ELISA).We elucidated that IL-2 up-regulated the expression of key surface markers such as: CD80, CD83, CD86, CD40 and MHC II molecules on BMDCs, down-regulated phagocytosis activity, induced more production of IL-12 and TNF-α secreted by BMDCs. Therefore it can be concluded that IL-2 effectively enhance the maturation of BMDCs. Our results provide direct evidence to support IL-2 would be used as a potent adjuvant in preparation of DC-based vaccines, as well as an immune remedy for cancer situation.

Malignant melanoma of the lung: case series

Extracutaneous locations of primary malignant melanoma are rare. In the respiratory system most melanomas present as metastatic tumors. For the diagnosis of primary lung melanoma, strict histopathological and clinical criteria should be met. In this paper we present three cases of malignant melanoma which showed in the respiratory system. The first 2 case studies present primary lung melanomas, while the last one shows late lung metastasis of tumor originated from vaginal mucosa. The treatment of choice for localized disease as well as single metastasis is surgical excision.

[Systemic treatment of melanoma brain metastases]

Melanomas have a high rate of brain metastases. Both the functional prognosis and the overall survival are poor in these patients. Until now, surgery and radiotherapy represented the two main modalities of treatment. Nevertheless, due to the improvement in the management of the extracerebral melanoma, the systemic treatment may be an option in patients with brain metastases. Immunotherapy with anti-CTLA4 (cytotoxic T-lymphocyte-associated protein 4) - ipilimumab - or BRAF (serine/threonine-protein kinase B-raf) inhibitors - vemurafenib, dabrafenib - has shown efficacy in the management of brain metastases in a- or pauci-symptomatic patients. Studies are ongoing with anti-PD1 (programmed cell death 1) and combinations of targeted therapies associating anti-RAF (raf proto-oncogene, serine/threonine kinase) and anti-MEK (mitogen-activated protein kinase kinase).

Targeting brain metastases in patients with melanoma

Patients with brain metastases from malignant melanoma historically have a very poor outcome. Surgery and radiotherapy can be used, but for the majority of patients the disease will progress quickly. In the recent past, patients with brain metastases derived only minimal benefit from cytotoxic chemotherapy. Novel therapies that have been shown to be superior to chemotherapy in metastatic melanoma have made their way in clinic and data regarding their use in patients with treated or untreated brain metastases are encouraging. In this paper we describe the use of vemurafenib, dabrafenib, and ipilimumab in patients with melanoma disseminated to the brain in addition to other treatments currently in development.