Long-term survival and immunological parameters in metastatic melanoma patients who responded to ipilimumab 10 mg/kg within an expanded access programme

Background

Ipilimumab can result in durable clinical responses among patients with advanced melanoma. However, no predictive marker of clinical activity has yet been identified. We provide preliminary data describing the correlation between immunological parameters and response/survival among patients with advanced melanoma who received ipilimumab 10 mg/kg in an expanded access programme.

Methods

Patients received ipilimumab 10 mg/kg every 3 weeks (Q3W) for four doses (induction) and Q12W from week 24 (W24) as maintenance therapy. Tumor assessments were conducted Q12W. Expression of inducible T cell costimulator (ICOS) on CD4⁺ and CD8⁺ T cells was assessed at baseline, W7, W12 and W24, and the ratio between absolute neutrophils (N) and lymphocytes (L) determined at baseline, W4, W7 and W10.

Results

Median overall survival among 27 patients was 9.6 months (95 % CI 3.2–16.1), with 3- and 4-year survival rates of 20.4 %. Five patients survived >4 years. Patients with an increase in the number of circulating ICOS⁺ T cells at W7 were more likely to experience disease control and have improved survival. An N/L ratio below the median at W7 and W10 was also associated with better survival compared with an N/L ratio above the median.

Conclusions

Ipilimumab can induce long-term survival benefits in heavily pretreated patients with metastatic melanoma. Changes in the number of circulating ICOS⁺ T cells or N/L ratio during ipilimumab treatment may represent early markers of response. However, given the limited sample size, further investigation is required.     

Notch-signalling is required for head regeneration and tentacle patterning in Hydra

Local self-activation and long ranging inhibition provide a mechanism for setting up organising regions as signalling centres for the development of structures in the surrounding tissue. The adult hydra hypostome functions as head organiser. After hydra head removal it is newly formed and complete heads can be regenerated. The molecular components of this organising region involve Wnt-signalling and β-catenin. However, it is not known how correct patterning of hypostome and tentacles are achieved in the hydra head and whether other signals in addition to HyWnt3 are needed for re-establishing the new organiser after head removal. Here we show that Notch-signalling is required for re-establishing the organiser during regeneration and that this is due to its role in restricting tentacle activation. Blocking Notch-signalling leads to the formation of irregular head structures characterised by excess tentacle tissue and aberrant expression of genes that mark the tentacle boundaries. This indicates a role for Notch-signalling in defining the tentacle pattern in the hydra head. Moreover, lateral inhibition by HvNotch and its target HyHes are required for head regeneration and without this the formation of the β-catenin/Wnt dependent head organiser is impaired. Work on prebilaterian model organisms has shown that the Wnt-pathway is important for setting up signalling centres for axial patterning in early multicellular animals. Our data suggest that the integration of Wnt-signalling with Notch-Delta activity was also involved in the evolution of defined body plans in animals.     

Inhibition of VEGF-C Modulates Distal Lymphatic Remodeling and Secondary Metastasis

Tumor-associated lymphatics are postulated to provide a transit route for disseminating metastatic cells. This notion is supported by preclinical findings that inhibition of pro-lymphangiogenic signaling during tumor development reduces cell spread to sentinel lymph nodes (SLNs). However, it is unclear how lymphatics downstream of SLNs contribute to metastatic spread into distal organs, or if modulating distal lymph transport impacts disease progression. Utilizing murine models of metastasis, longitudinal in vivo imaging of lymph transport, and function blocking antibodies against two VEGF family members, we provide evidence that distal lymphatics undergo disease course-dependent up-regulation of lymph transport coincidental with structural remodeling. Inhibition of VEGF-C activity with antibodies against VEGF-C or NRP2 prevented these disease-associated changes. Furthermore, utilizing a novel model of adjuvant treatment, we demonstrate that antagonism of VEGF-C or NRP2 decreases post SLN metastasis. These data support a potential therapeutic strategy for inhibiting distant metastatic dissemination via targeting tumor-associated lymphatic remodeling.     

In vitro analysis of the melanoma/endothelium interaction increasing the release of soluble intercellular adhesion molecule 1 by endothelial cells

Melanoma cells constitutively release intercellular adhesion molecule 1 (ICAM-1) as soluble ICAM-1 (sICAM-1), and its levels are elevated in melanoma patients and correlate with disease progression. However, this correlation is not absolute, suggesting that specific characteristics of neoplastic cells and/or ICAM-1-positive non-neoplastic cells may influence the amounts of circulating sICAM-1. In this study, we found a weak correlation (r = 0.55; r ² = 0.3) between sICAM-1 release by 40 metastatic melanomas (36 primary cultures and 4 cell lines), and ICAM-1 expression on neoplastic cells. In addition, melanoma-secreted interleukin-1α (IL-1α) (1/40) but not vascular endothelial growth factor (VEGF) (29/40), significantly (P < 0.05) up-regulated the shedding of sICAM-1 by human umbilical vein endothelial cells (HUVEC). This was completely abolished by IL-1α/β neutralizing antibodies both at the protein and mRNA level. Altogether, our results suggest that (i) the extent of sICAM-1 release is distinctive for individual melanomas and can be independent of ICAM-1 expression; (ii) tumor endothelia may sustain levels of sICAM-1 in selected melanomas; (iii) melanoma-released VEGF does not affect ICAM-1 expression and sICAM-1 release by HUVEC. Melanoma-derived sICAM-1 inhibits cell-mediated cytotoxicity of melanoma cells; therefore, constitutive levels of sICAM-1 release and IL-1α secretion by individual melanomas can differentially influence tumor progression and the clinical effectiveness of cytotoxic-cell-based vaccines. Received: 15 October 1998 / Accepted: 17 February 1999     

Ipilimumab experience in heavily pretreated patients with melanoma in an expanded access program at the University Hospital of Siena (Italy)

Aim of study

To evaluate the feasibility of ipilimumab treatment for metastatic melanoma outside the boundaries of clinical trials, in a setting similar to that of daily practice.

Methods

Ipilimumab was available upon physician request in the Expanded Access Programme for patients with life-threatening, unresectable stage III/IV melanoma who failed or did not tolerate previous treatments and for whom no therapeutic option was available. Induction treatment with ipilimumab 10?mg/kg was administered intravenously every 3?weeks, for a total of 4 doses, with maintenance doses every 12?weeks based on physicians?? discretion and clinical judgment. Tumors were assessed at baseline, Week 12, and every 12?weeks thereafter per mWHO response criteria, and clinical response was scored as complete response (CR), partial response (PR), stable disease (SD), or progressive disease. Durable disease control (DC) was defined as SD at least 24?weeks from the first dose, CR, or PR.

Results

Disease control rate at 24 and 60?weeks was 29.6% and 15%, respectively. Median overall survival at a median follow-up of 8.5?months was 9?months. The 1- and 2-year survival rates were 34.8% and 23.5%, respectively. Changes in lymphocyte count slope and absolute number during ipilimumab treatment appear to correlate with clinical response and survival, respectively. Adverse events were predominantly immune related, manageable, and generally reversible. One patient died from pancytopenia, considered possibly treatment related.

Conclusion

Ipilimumab was a feasible treatment for malignant melanoma in heavily pretreated, progressing patients. A sizeable proportion of patients experienced durable DC, including benefits to long-term survival.     

Phenotypic and functional changes of human melanoma xenografts induced by DNA hypomethylation: immunotherapeutic implications

Emerging in vitro evidence points to an immunomodulatory activity of DNA hypomethylating drugs in human malignancies. We investigated the potential of 5-aza-2'-deoxycytidine (5-AZA-CdR) to modulate the expression of cancer testis antigens (CTA) and of HLA class I antigens by melanoma xenografts, and the resulting modifications in immunogenicity of neoplastic cells. Three primary cultures of melanoma cells, selected for immune phenotype and growth rate, were grafted into BALB/c nu/nu mice that were injected intraperitoneally with different dose- and time-schedules of 5-AZA-CdR. Molecular analyses demonstrated a de novo long-lasting expression of the CTA MAGE-1, -2, -3, -4, -10, GAGE 1-6, NY-ESO-1, and the upregulation of MAGE-1, MAGE-3, and NY-ESO-1 levels in melanoma xenografts from 5-AZA-CdR-treated mice. Serological and biochemical analyses identified a de novo expression of NY-ESO-1 protein and a concomitant and persistent upregulation of HLA class I antigens and of HLA-A1 and -A2 alleles. Immunization of BALB/c mice with 5-AZA-CdR-treated melanoma cells generated high titer circulating anti-NY-ESO-1 antibodies. Altogether, the data obtained identify an immunomodulatory activity of 5-AZA-CdR in vivo and strongly suggest for its clinical use to design novel strategies of CTA-based chemo-immunotherapy for melanoma patients.     

Therapeutic efficacy of ipilimumab,an anti-CTLA-4 monoclonal antibody,in patients with metastatic melanoma unresponsive to prior systemic treatments: clinical and immunological evidence from three patient cases

The management of unresectable metastatic melanoma is a major clinical challenge because of the lack of reliably effective systemic therapies. Blocking cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) has recently been proposed as a strategy to enhance cell-mediated immune responses to cancer, and clinical trials have demonstrated that anti-CTLA-4 therapy can produce durable outcomes with different response patterns than cytotoxic chemotherapy. We enrolled eight out of 155 patients with advanced melanoma in a multicentre phase II trial that evaluated the activity and tolerability of ipilimumab, a fully human, anti-CTLA-4 monoclonal antibody (; NCT00289627; CA184-008). Here we report our experience with three of these patients, who experienced progressive disease after a variety of previous therapies, including prior immunotherapies, and who achieved good outcomes with ipilimumab. One patient had a partial response ongoing at 17+ months on ipilimumab despite failure with four prior therapies, and the other two patients showed durable stable disease, both still ongoing at 17+ and 20+ months, respectively. The patient achieving a partial response experienced no side effects while receiving ipilimumab. The other two patients developed immune-related adverse events (irAEs) including rash (one case; grade 2) and diarrhoea (both cases; grades 1 and 2, respectively); the histopathology of colon biopsy samples from both was suggestive of colitis, with an abundant CD8+ T-cell infiltrate. Nausea, vomiting and acute pancreatitis were also observed in one patient. In addition, immunohistochemical findings of a dense CD8+, TIA1+ and granzyme B+ lymphoid infiltrate within a biopsied lesion provide indirect evidence of functional T-cell activation induced by treatment. These case reports highlight the potential for anti-CTLA-4-based therapy in previously treated patients with advanced melanoma. Moreover, because the patterns of response to ipilimumab differ from chemotherapy, we need to understand how and when patients may respond to treatment so that appropriate clinical decisions can be made.     

Epigenetic drugs as pleiotropic agents in cancer treatment: biomolecular aspects and clinical applications

In the last three decades huge efforts have been made to characterize genetic defects responsible for cancer development and progression, leading to the comprehensive identification of distinct cellular pathways affected by the alteration of specific genes. Despite the undoubtable role of genetic mechanisms in triggering neoplastic cell transformation, epigenetic modifications (i.e., heritable changes of gene expression that do not derive from alterations of the nucleotide sequence of DNA) are rapidly emerging as frequent alterations that often occur in the early phases of tumorigenesis and that play an important role in tumor development and progression. Epigenetic alterations, such as modifications in DNA methylation patterns and post-translational modifications of histone tails, behave extremely different from genetic modifications, being readily revertable by "epigenetic drugs" such as inhibitors of DNA methyl transferases and inhibitors of histone deacetylases. Since epigenetic alterations in cancer cells affect virtually all cellular pathways that have been associated to tumorigenesis, it is not surprising that epigenetic drugs display pleiotropic activities, being able to concomitantly restore the defective expression of genes involved in cell cycle control, apoptosis, cell signaling, tumor cell invasion and metastasis, angiogenesis and immune recognition. Prompted by this emerging clinical relevance of epigenetic drugs, this review will focus on the large amount of available data, deriving both from in vitro experimentations and in vivo pre-clinical and clinical studies, which clearly indicate epigenetic drugs as effective modifiers of cancer phenotype and as positive regulators of tumor cell biology with a relevant therapeutic potential in cancer patients.     

Epigenetically regulated clonal heritability of CTA expression profiles in human melanoma

The intratumoral heterogeneity of cancer testis antigens (CTA) expression, which is driven by promoter methylation status, may hamper the effectiveness of CTA‐directed vaccination of melanoma patients. Thus, we investigated whether the intratumoral heterogeneity of CTA expression is inherited at cellular level, or evolves throughout cellular replication, leading to a phenotypically unstable tumor cell population with reduced immunogenicity and/or able to escape immune control. Utilizing a previously characterized ex vivo clonal model of intratumoral heterogeneity of CTA expression in melanoma, Mel 313 MAGE‐A3‐low clone 5 (clone 5^M3‐low) and MAGE‐A3‐high clone 14 (clone 14^M3‐high) were sub‐cloned and analyzed for CTA profile. Molecular assays demonstrated that levels of MAGE‐A3 expression were highly conserved among generated sub‐clones, as compared to parental clones. A similar behavior was identified for an extensive panel of other CTA investigated. Inherited levels of MAGE‐A3 expression correlated with the extent of promoter methylation among clone 5^M3‐low and clone 14^M3‐high sub‐clones analyzed. Treatment of clone 5^M3‐low with a DNA hypomethylating agent (DHA) resulted in an up‐regulated expression of MAGE‐A3, which was inherited at single cell level, being still detectable at day 60 in its sub‐clones. Bisulfite sequencing demonstrated that also MAGE‐A3 promoter methylation status was inherited among sub‐clones generated from DHA‐treated clone 5^M3‐low and strictly correlated with MAGE‐A3 expression levels in investigated sub‐clones. Similar results were obtained for additional CTA studied. Altogether our findings demonstrate that constitutive and DHA‐modified CTA profiles of melanoma cells are clonally inherited throughout cellular replications, thus providing relevant insights to improve the effectiveness of CTA‐based immunotherapy. J. Cell. Physiol. 223: 352–358, 2010. © 2010 Wiley‐Liss, Inc.     

Isolation of Human Hepatocytes by a Two-step Collagenase Perfusion Procedure

The liver, an organ with an exceptional regeneration capacity, carries out a wide range of functions, such as detoxification, metabolism and homeostasis. As such, hepatocytes are an important model for a large variety of research questions. In particular, the use of human hepatocytes is especially important in the fields of pharmacokinetics, toxicology, liver regeneration and translational research. Thus, this method presents a modified version of a two-step collagenase perfusion procedure to isolate hepatocytes as described by Seglen ¹.Previously, hepatocytes have been isolated by mechanical methods. However, enzymatic methods have been shown to be superior as hepatocytes retain their structural integrity and function after isolation. This method presented here adapts the method designed previously for rat livers to human liver pieces and results in a large yield of hepatocytes with a viability of 77±10%. The main difference in this procedure is the process of cannulization of the blood vessels. Further, the method described here can also be applied to livers from other species with comparable liver or blood vessel sizes.