Vaccimel immunization is associated with enhanced response to treatment with anti-PD-1 monoclonal antibodies in cutaneous melanoma patients - a case reports study

Cancer vaccines are gaining ground as immunotherapy options. We have previously demonstrated in cutaneous melanoma (CM) patients that adjuvant treatment with VACCIMEL, a mixture of four irradiated CM cell lines co-adjuvanted with BCG and GM-CSF, increases the cellular immune response to melanocyte differentiation antigens, cancer-testis antigens and neoantigens, with respect to basal levels. On the other hand, it is also known that treatment with anti-PD-1 monoclonal antibodies (MAbs), acting on pre-existing tumor-reactive lymphocytes, induces clinical responses in CM patients, albeit in a fraction of treated patients. A combination of both treatments would appear therefore desirable. In this paper, we describe CM patients who, having progressed even years after vaccination, were treated with anti-PD-1 MAbs. In 5/5 of such progressor patients, complete responses were obtained which lasted between 3 and 65+ months. Three of the patients remain disease-free and two recurred. One of the patients passed away after a recurrence of brain metastases. We suggest that clonally expanded reactive lymphocytes induced by VACCIMEL partially remain as memory cells, which may be recalled after tumor recurrence and may foster ulterior activity of anti-PD-1 MAbs.

HEV-associated dendritic cells are observed in metastatic tumor-draining lymph nodes of cutaneous melanoma patients with longer distant metastasis-free survival after adjuvant immunotherapy

Introduction

Tissue biomarkers that aid in identifying cutaneous melanoma (CM) patients who will benefit from adjuvant immunotherapy are of crucial interest. Metastatic tumor-draining lymph nodes (mTDLN) are the first encounter site between the metastatic CM cells and an organized immune structure. Therefore, their study may reveal mechanisms that could influence patients´ outcomes.

Methods

Twenty-nine stage-III CM patients enrolled in clinical trials to study the vaccine VACCIMEL were included in this retrospective study. After radical mTDLN dissection, patients were treated with VACCIMEL (n=22) or IFNα-2b (n=6), unless rapid progression (n=1). Distant Metastasis-Free Survival (DMFS) was selected as an end-point. Two cohorts of patients were selected: one with a good outcome (GO) (n=17; median DMFS 130.0 months), and another with a bad outcome (BO) (n=12; median DMFS 8.5 months). We analyzed by immunohistochemistry and immunofluorescence the expression of relevant biomarkers to tumor-cell biology and immune cells and structures in mTDLN, both in the tumor and peritumoral areas.

Results

In BO patients, highly replicating Ki-67+ tumor cells, low tumor HLA-I expression and abundant FoxP3+ lymphocytes were found (p=0.037; p=0.056 and p=0.021). In GO patients, the most favorable biomarkers for prolonged DMFS were the abundance of peri- and intra-tumoral CD11c+ cells (p=0.0002 and p=0.001), peri-tumoral DC-LAMP+ dendritic cells (DCs) (p=0.001), and PNAd+ High Endothelial Venules (HEVs) (p=0.004). Most strikingly, we describe in GO patients a peculiar, heterogeneous structure that we named FAPS (Favoring Antigen-Presenting Structure), a triad composed of DC, HEV and CD62L+ naïve lymphocytes, whose postulated role would be to favor tumor antigen (Ag) priming of incoming naïve lymphocytes. We also found in GO patients a preferential tumor infiltration of CD8+ and CD20+ lymphocytes (p=0.004 and p=0.027), as well as peritumoral CD20+ aggregates, with no CD21+ follicular dendritic cells detected (p=0.023). Heterogeneous infiltration with CD64+CD68-CD163-, CD64+CD68+CD163- and CD64+CD68+CD163+ macrophages were observed in both cohorts.

Discussion

The analysis of mTDLN in GO and BO patients revealed marked differences. This work highlights the importance of analyzing resected mTDLN from CM patients and suggests a correlation between tumor and immune characteristics that may be associated with a spontaneous or vaccine-induced long DMFS. These results should be confirmed in prospective studies.

Early contribution of germline and nevi genetic alterations to a rapidly-progressing cutaneous melanoma patient: a case report

BACKGROUND

Cutaneous melanoma is the skin cancer with the highest mutational burden and metastatic rate. Early genetic alterations and biomarkers of distant progression are a point of interest. In addition to germline-susceptibility loci, almost 30% of melanomas arise from precursor benign nevi lesions, providing a source for malignant transformation.

CASE PRESENTATION

Patient#009 developed a cutaneous melanoma over a nevus, followed by progression to regional and distant metastases in months, unresponsive to targeted therapy. To search for the genetic contribution to this rapid progression, a longitudinal analysis was performed through WES of germline, nevi, primary tumor, and a metastatic lymph node. Differential SNP/INDEL and CNV gene alterations, with functional impact on key pathways and cancer hallmarks in each step of evolution, were discerned. Tumor-associated nevus was, for the first time, split into two sections, distant and adjacent to the primary tumor, to study its heterogeneity. Shared SNP alterations, with stable allele fraction from germline to metastasis were detected, mainly affecting DNA repair genes and promoting genome instability. Early somatic alterations, shared by nevi and primary and metastatic tumors, included BRAF^V600E and focal copy-loss of several genes, acquiring additional cancer hallmarks. Phylogenetic analyses revealed that these common somatic alterations would provide a "bridge", allowing progression from a benign to a malignant state. Distant and adjacent nevi were rich in alterations, presenting differential SNP and CNV alterations. Upon tumor transformation, a marked increase in CNV over SNP alterations was determined. Both the number of SNP and CNV-affected genes, including known driver genes, increased throughout progression, although TMB levels remained lower than expected for melanoma. Typical alterations in BRAF^V600E tumors related to intrinsic resistance to targeted therapy were found, including BRAF amplification and loss of PTEN, CDKN2A/B, and TP53 surveillance genes. Finally, numerous metastatic alterations were detected, further promoting tumor progression.

CONCLUSIONS

In this patient, longitudinal WES analysis revealed a sequential and cumulative pattern of genetic alterations, where germline and nevi somatic events contributed early to its rapid clinical progression. In this case report, we found tumor-associated nevi as genetically heterogeneous precursor entities, in which potential prognostic biomarkers should be studied prospectively.

An Update of Cutaneous Melanoma Patients Treated in Adjuvancy With the Allogeneic Melanoma Vaccine VACCIMEL and Presentation of a Selected Case Report With In-Transit Metastases

The CSF-470 vaccine (VACCIMEL) plus BCG and GM-CSF as adjuvants has been assayed in cutaneous melanoma patients. In the adjuvant randomized Phase II study CASVAC-0401, vaccinated patients had longer distant metastasis-free survival (DMFS) than those treated with IFNα2b. Five years after locking the data, an actualization was performed. The benefit in DMFS was maintained in the vaccinated group versus the IFNα2b-treated group (p = 0.035), with a median DMFS of 96 months for VACCIMEL and 13 months for IFNα2b. The favorable risk-benefit ratio was maintained. DMFS was also analyzed as a single cohort in all the IIB, IIC, and III patients (n = 30) who had been treated with VACCIMEL. The median DMFS was 169 months, and at 48 months follow-up, it was 71.4%, which was not statistically different from DMFS of previously published results obtained in adjuvancy with ipilimumab, pembrolizumab, nivolumab, or dabrafenib/trametinib. The possible toxicity of combining VACCIMEL with anti-immune checkpoint inhibitors (ICKi) was analyzed, especially since VACCIMEL was co-adjuvated with BCG in every vaccination. A patient with in-transit metastases was studied to produce a proof of concept. During treatment with VACCIMEL, the patient developed T-cell clones reactive towards tumor-associated antigens. Three years after ending the VACCIMEL study, the patient progressed and was treated with ICKi. During ICKi treatment, the patient did not reveal any toxicity due to previous BCG treatment. When she recurred after a 4-year treatment with nivolumab, a biopsy was obtained and immunohistochemistry and RNA-seq were performed. The tumor maintained expression of tumor-associated antigens and HLA-I and immune infiltration, with immunoreactive and immunosuppressive features. VACCIMEL plus BCG and GM-CSF is an effective treatment in adjuvancy for stages IIB, IIC, and III cutaneous melanoma patients, and it is compatible with subsequent treatments with ICKi.

Evaluation of T-Cell Responses Against Shared Melanoma Associated Antigens and Predicted Neoantigens in Cutaneous Melanoma Patients Treated With the CSF-470 Allogeneic Cell Vaccine Plus BCG and GM-CSF

The CSF-470 vaccine consists of lethally-irradiated allogeneic cells derived from four cutaneous melanoma cell lines administered plus BCG and GM-CSF as adjuvants. In an adjuvant phase II study vs. IFN-α2b, the vaccine significantly prolonged the distant metastasis-free survival (DMFS) of stages IIB-IIC-III melanoma patients with evidence of the induction of immune responses against vaccine cells. Purpose: The aim of this study was to analyze the antigens against which the immune response was induced, as well as the T-helper profile and lytic ability of immune cells after CSF-470 treatment. Methods: HLA-restricted peptides from tumor-associated antigens (TAAs) were selected from TANTIGEN database for 13 evaluable vaccinated patients. In addition, for patient #006 (pt#006), tumor somatic variants were identified by NGS and candidate neoAgs were selected by predicted HLA binding affinity and similarity between wild type (wt) and mutant peptides. The patient's PBMC reactivity against selected peptides was detected by IFNγ-ELISPOT. T-helper transcriptional profile was determined by quantifying GATA-3, T-bet, and FOXP3 mRNA by RT-PCR, and intracellular cytokines were analyzed by flow cytometry. Autologous tumor cell lysis by PBMC was assessed in an in vitro calcein release assay. Results: Vaccinated patient's PBMC reactivity against selected TAAs derived peptides showed a progressive increase in the number of IFNγ-producing cells throughout the 2-yr vaccination protocol. ELISPOT response correlated with delayed type hypersensitivity (DTH) reaction to CSF-470 vaccine cells. Early upregulation of GATA-3 and Foxp3 mRNA, as well as an increase in CD4+IL4+cells, was associated with a low DMFS. Also, IFNγ response against 9/73 predicted neoAgs was evidenced in the case of pt#006; 7/9 emerged after vaccination. We verified in pt# 006 that post-vaccination PBMC boosted in vitro with the vaccine lysate were able to lyse autologous tumor cells. Conclusions: A progressive increase in the immune response against TAAs expressed in the vaccine and in the patient's tumor was induced by CSF-470 vaccination. In pt#006, we demonstrated immune recognition of patient's specific neoAgs, which emerged after vaccination. These results suggest that an initial response against shared TAAs could further stimulate an immune response against autologous tumor neoAgs.

Chinese Learning Anxiety on Foreign Students

<p>The purpose of this study is to investigate the level of anxiety in learning Chinese, discover the dominant factors of anxiety in learning Chinese language and analyze differences in Chinese language anxiety based on gender, year of study and HSK in foreign students in Wuhan, China. The research method used was quantitative using a survey approach. There are 250 foreign students as the samples, consisting of 108 male and 142 female students. The data collection technique used is questionnaire called CLAS (Chinese Learning Anxiety Survey) adapted from FLCAS (Foreign Language Classroom Anxiety Survey). The data were analyzed using SPSS with descriptive statistical techniques and Multivariate Analysis. The results showed that Chinese language anxiety among foreign students is on a moderate level, with communication anxiety as the most dominant aspect. The male and female students have the same anxiety level in learning Chinese. The foreign students who had longer duration of learning Chinese and had higher HSK tend to have lower level of anxiety in learning Chinese. This showed that years of study and HSK were two factors that determine the high or low level of anxiety in learning Chinese for foreign students.</p>

Immunization With the CSF-470 Vaccine Plus BCG and rhGM-CSF Induced in a Cutaneous Melanoma Patient a TCRβ Repertoire Found at Vaccination Site and Tumor Infiltrating Lymphocytes That Persisted in Blood

The CSF-470 cellular vaccine plus BCG and rhGM-CSF increased distant metastases-free survival in cutaneous melanoma patients stages IIB-IIC-III relative to medium dose IFN-α2b (CASVAC-0401 study). Patient-045 developed a mature vaccination site (VAC-SITE) and a regional cutaneous metastasis (C-MTS), which were excised during the protocol, remaining disease-free 36 months from vaccination start. CDR3-TCRβ repertoire sequencing in PBMC and tissue samples, along with skin-DTH score and IFN-γ ELISPOT assay, were performed to analyze the T-cell immune response dynamics throughout the immunization protocol. Histopathological analysis of the VAC-SITE revealed a highly-inflamed granulomatous structure encircled by CD11c+ nested-clusters, brisk CD8+ and scarce FOXP3+, lymphocytes with numerous Langhans multinucleated-giant-cells and macrophages. A large tumor-regression area fulfilled the C-MTS with brisk lymphocyte infiltration, mainly composed of CD8+PD1+ T-cells, CD20+ B-cells, and scarce FOXP3+ cells. Increasing DTH score and IFN-γ ELISPOT assay signal against the CSF-470 vaccine-lysate was evidenced throughout immunization. TCRβ repertoire analysis revealed for the first time the presence of common clonotypes between a VAC-SITE and a C-MTS; most of them persisted in blood by the end of the immunization protocol. In vitro boost with vaccine-lysate revealed the expansion of persistent clones that infiltrated the VAC-SITE and/or the C-MTS; other persistent clones expanded in the patient's blood as well. We propose that expansion of such persistent clonotypes might derive from two different although complementary mechanisms: the proliferation of specific clones as well as the expansion of redundant clones, which increased the number of nucleotide rearrangements per clonotype, suggesting a functional antigenic selection. In this patient, immunization with the CSF-470 vaccine plus BCG and rhGM-CSF induced a T-cell repertoire at the VAC-SITE that was able to infiltrate an emerging C-MTS, which resulted in the expansion of a T-cell repertoire that persisted in blood by the end of the 2-year treatment.

Changes in the TCRβ Repertoire and Tumor Immune Signature From a Cutaneous Melanoma Patient Immunized With the CSF-470 Vaccine: A Case Report

The allogeneic therapeutic vaccine CSF-470 has demonstrated a significant benefit over medium-dose IFNα2b in the distant metastasis-free survival for stages IIB-IIC-III cutaneous melanoma patients in a randomized phase II/III clinical trial (CASVAC-0401, NCT01729663). At the end of the 2-year CSF-470 immunization protocol, patient #006 developed several lung and one subcutaneous melanoma metastases; this later was excised. In this report, we analyzed the changes throughout vaccination of immune populations in blood and in the tumor tissue, with special focus on the T-cell repertoire. Immunohistochemistry revealed a marked increase in CD8+, CD4+, and CD20+ lymphocytes infiltrating the metastasis relative to the primary tumor. Lymphocytes were firmly attached to dying-tumor cells containing Granzyme-B granules. Whole-exon sequencing assessment indicated a moderate-to-high tumor mutational burden, with BRAFV600E as the main oncogenic driver. Mutational signature presented large numbers of mutations at dipyrimidines, typical of melanoma. Relevant tumor and immune-related genes from the subcutaneous metastasis were addressed by RNA-Seq analysis, revealing expression of typical melanoma antigens and proliferative tumor-related genes. Stimulatory and inhibitory immune transcripts were detected as well as evidence of active T-cell effector function. Peripheral blood monitoring revealed an increase in CD4+ and CD8+ cells by the end of the immunization protocol. By CDR3-T-cell receptor β (TCRβ) sequencing, generation of new clones and an increase in oligoclonality was observed in the peripheral T-cells immune repertoire throughout immunization. A shift, with the expansion of selected preexisting and newly arising clones with reduction of others, was detected in blood. In tumor-infiltrating lymphocytes, prevalent clones (50%) were both new and preexisting that were expanded in blood following CSF-470 immunization. These clones persisted in time, since 2 years after completing the immunization, 51% of the clones present in the metastasis were still detected in blood. This is the first report of the modulation of the TCRβ repertoire from a melanoma patient immunized with the CSF-470 vaccine. After immunization, the changes observed in peripheral immune populations as well as in the tumor compartment suggest that the vaccine can induce an antitumor adaptive immune repertoire that can reach tumor lesions and persists in blood for at least 2 years.

Immunomodulatory Monoclonal Antibodies in Combined Immunotherapy Trials for Cutaneous Melanoma

In the last few years, there has been a twist in cancer treatment toward immunotherapy thanks to the impressive results seen in advanced patients from several tumor pathologies. Cutaneous melanoma is a highly mutated and immunogenic tumor that has been a test field for the development of immunotherapy. However, there is still a way on the road to achieving complete and long-lasting responses in most patients. It is desirable that immunotherapeutic strategies induce diverse immune reactivity specific to tumor antigens, including the so-called neoantigens, as well as the blockade of immunosuppressive mechanisms. In this review, we will go through the role of promising monoclonal antibodies in cancer immunotherapy with immunomodulatory function, especially blocking of the inhibitory immune checkpoints CTLA-4 and PD-1, in combination with different immunotherapeutic strategies such as vaccines. We will discuss the rational basis for these combinatorial approaches as well as different schemes currently under study for cutaneous melanoma in the clinical trials arena. In this way, the combination of "push and release" immunomodulatory therapies can contribute to achieving a more robust and durable antitumor immune response in patients.

Phase II Study of Adjuvant Immunotherapy with the CSF-470 Vaccine Plus Bacillus Calmette-Guerin Plus Recombinant Human Granulocyte Macrophage-Colony Stimulating Factor vs Medium-Dose Interferon Alpha 2B in Stages IIB, IIC, and III Cutaneous Melanoma Patients: A Single Institution, Randomized Study

The irradiated, allogeneic, cellular CSF-470 vaccine plus Bacillus Calmette–Guerin (BCG) and recombinant human granulocyte macrophage-colony stimulating factor (rhGM-CSF) is being tested against medium-dose IFN-α2b in stages IIB–III cutaneous melanoma (CM) patients (pts) after surgery in an open, randomized, Phase II/III study. We present the results of the Phase II part of the ongoing CASVAC-0401 study (ClinicalTrials.gov: NCT01729663). Thirty-one pts were randomized to the CSF-470 vaccine (n = 20) or to the IFN-α2b arm (n = 11). During the 2-year treatment, immunized pts should receive 13 vaccinations. On day 1 of each visit, 1.6 × 10⁷ irradiated CSF-470 cells plus 10⁶ colony-forming units BCG plus 100 µg rhGM-CSF were administered intradermally, followed on days 2–4 by 100 µg rhGM-CSF. IFN-α2b pts should receive 10 million units (MU)/day/5 days a week for 4 weeks; then 5 MU thrice weekly for 23 months. Toxicity and quality of life (QOL) were evaluated at each visit. With a mean and a maximum follow-up of 39.4 and 83 months, respectively, a significant benefit in the distant metastasis-free survival (DMFS) for CSF-470 was observed (p = 0.022). Immune monitoring showed an increase in antitumoral cellular and humoral response in vaccinated pts. CSF-470 was well tolerated; 20/20 pts presented grades 1–2 dermic reactions at the vaccination site; 3/20 pts presented grade 3 allergic reactions. Other adverse events (AEs) were grade 1. Pts in the IFN-α2b arm presented grades 2–3 hematological (7/11), hepatic (2/11), and cardiac (1/11) toxicity; AEs in 9/11 pts forced treatment interruptions. QOL was significantly superior in the vaccine arm (p < 0.0001). Our results suggest that CSF-470 vaccine plus BCG plus GM-CSF can significantly prolong, with lower toxicity, the DMFS of high-risk CM pts with respect to medium-dose IFN-α2b. The continuation of a Phase III part of the CASVAC-0401 study is encouraged.

Abstract 4897: First evidence of changes in the TCRâ repertoire from a cutaneous melanoma patient immunized with the CSF-470 vaccine

Introduction: A breakthrough of immunotherapy for cancer treatment has emerged, with promising results in several tumors. We have developed the allogeneic vaccine CSF-470, composed of lethally-irradiated human Cutaneous Melanoma (CM) cell lines plus BCG and GM-CSF, currently tested in a Phase II-III study in adjuvancy (NCT01729663). The aim of this work was to analyze the TCRâ repertoire in multiples samples obtained through CSF-470 vaccination from a CM patient who developed a cutaneous metastasis (Mts) at the end of the 2-year immunization protocol.

Methods: DNA from PBMC at 0, 12 and 24 months (PRE-PBMC, POST-1, POST-3) from protocol start, and from Mts-TIL (Tumor Infiltrating Lymphocytes) was obtained. TCRâ sequence and further analysis was performed with the IMMUNOSEQ platform. Patterns were defined for clone tracking: 1, present at PRE, increases during immunization; 2, absent at PRE, increases during immunization; 3, present at PRE, absent following immunization; 4, present at PRE, decreases during immunization; 5, detected only at 24 months (POST-3); 6, absent at PBMC, present in Mts-TIL.

Results: PBMC TCRâ repertoire analysis revealed an increase in clonality (2.3X) and total frequency of TOP100 clones through CSF-470 immunization. PBMC clones tracking analysis (with frequency ≥0.01%) revealed prevalence of Pattern-1 clones (54%) and Pattern-5 clones (30%). Regarding Mts-TIL, clones were distributed in Pattern-1 (23%), Pattern-3 (5%), Pattern-5 (16%), and Pattern-6 (53%). However, when analyzing TOP100 Mts-TIL clones, 60% of them corresponded to Pattern-1, 19% to Pattern-5 and only 12% to Pattern-6. Databases search revealed the presence in PBMC of shared TCRâ sequences previously reported in association to M.bovis infection. Also, some clones found in Mts-TILs matched to previously identified in other CM metastases.

Conclusions: This is the first report of the TCRâ repertoire from a CM patient immunized with CSF-470 vaccine. The main observations regarding TCRâ repertoire analysis were: 1- Vaccination induced expansion of selected pre-immunization TCR clones, which might recognize dominant Ags either from patient′s tumor or vaccine. 2- TCR clones arising after immunization might recognize dominant Ags from vaccine or derived by epitope spreading from the patient′s tumor. 3- More than 50% of total clones were exclusively present in Mts-TIL, suggesting local activation. However, most frequent Mts-TIL clones included those that were expanded exclusively by CSF-470 vaccination. 4- TCRâ repertoire comparison also allowed detection of some clones already reported in TIL from CM Mts and in memory repertoire against M.Bovis, possibly accounting BCG adjuvancy.

Finally, changes observed in the TCRâ repertoire from this patient, driven by the CSF-470 vaccine, suggest an anti-tumor immune response taking place both in the periphery and the local compartment.

Citation Format: Mariana Aris, María Marcela Barrio, José Mordoh. First evidence of changes in the TCRâ repertoire from a cutaneous melanoma patient immunized with the CSF-470 vaccine. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4897.

Abstract A37: Immunization of cutaneous melanoma patients with the allogeneic cell vaccine CSF-470 enhances immune infiltration of metastatic lesions and would favor subsequent response to Vemurafenib

Therapeutic cancer vaccines are aimed at promoting tumor-specific immunity with long-term memory. We have developed the CSF-470 therapeutic vaccine, a mini-allograft of four irradiated allogeneic cutaneous melanoma cell lines, combined with BCG and rhGM-CSF as adjuvants; that is currently being assayed in adjuvancy against medium-dose IFN-alfa2b in the CASVAC-0401 phase II/III clinical trial (ClinicalTrials.gov identifier: NCT01729663). An update to September 2014 reveals that after inclusion of 31 patients, a significant benefit in the distant metastasis-free survival for the CSF-470 arm is obtained (p=0.034). Of the 20 patients assigned to the CSF-470 arm, with a mean follow-up of 26 months, six patients developed distant metastases, of whom two died, and fourteen patients are distant metastases-free (70%). Five patients of the vaccine arm were treated with Vemurafenib after progression; two of them achieved complete remission and two of them partial remission (&gt;50%); only one developed severe dermatitis. Before Vemurafenib treatment, metastases biopsies from only three patients could be obtained; two of them later achieved complete responses. In this work, we present the analysis of the peripheral blood and in situ immune populations during CSF-470 immunization in the two patients that achieved complete responses with Vemurafenib treatment.

To attain this task, histopathological characterization of tumor biopsies, along with immune populations determined by immunohistochemistry, was performed by microscopy and image analysis. Peripheral blood mononucleated cells were obtained from patients at different times during CSF-470 immunization and immune populations were assessed by flow cytometry.

Patient #006 entered the CASVAC-0401 study after a primary and lymph node tumor resection. By the end of CSF-470 immunization, she developed simultaneously subcutaneous and lung metastases. Following a 3-month cycle of Vemurafenib 960mg bid, patient #006 achieved complete remission of lung tumor nodules. Analysis of immune response evolution during protocol revealed a marked increase in in situ immune infiltration at the cutaneous metastasis relative to the primary tumor, especially in CD8+, CD4+ and CD20+ cells. Several dying tumor cells could be distinguished in the cutaneous metastasis, with attached and surrounding CD8+, CD4+ and CD45Ro+ T lymphocytes and CD68+ cells; and with Granzyme B vesicles and DNA strand breaks. Patient #005 developed sequential in transit metastases; CD8+, CD4+ and CD20+ lymphocyte infiltration increased in situ in biopsies following CSF-470 immunization. Vemurafenib treatment allowed achieving a complete response characterized by brisk infiltration of CD68+ macrophages, CD11c+ dendritic cells, CD8+ and CD4+ lymphocytes. In both patients, analysis of peripheral immune populations revealed an increment of NK cells detected after 6-months treatment, followed by an increase in CD4+ and CD8+ cells by the end of the protocol (2 years). Also, serum reactivity to CSF-470 cutaneous melanoma cells increased during vaccination.

We suggest that previous immunization of melanoma patients with CSF-470 vaccine increases tumor immune infiltration and subsequent response to Vemurafenib. These encouraging results may open new options for combined therapies in cutaneous melanoma.

Citation Format: Mariana Aris, María Betina Pampena, Estrella M. Levy, Alicia I. Bravo, Florencia P. Madorsky-Rowdo, Ana Mordoh, Julio Kaplan, Antonela Baron, Mariela Urrutia, Paula A. Blanco, María Marcela Barrio, José Mordoh. Immunization of cutaneous melanoma patients with the allogeneic cell vaccine CSF-470 enhances immune infiltration of metastatic lesions and would favor subsequent response to Vemurafenib. [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy: A New Chapter; December 1-4, 2014; Orlando, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2015;3(10 Suppl):Abstract nr A37.

Abstract CT118: A randomized phase II study of the CSF-470 therapeutic vaccine plus BCG plus rhGM-CSF versus IFN-α2b in cutaneous melanoma patients stages IIB, IIC and III

Adjuvant treatment of high-risk cutaneous melanoma (CM) patients (pts) is still an unsolved issue, since the cost-benefit ratio of high-dose IFN-α2b is under discussion. The CSF-470 therapeutic vaccine, a mini-allograft of four lethally-irradiated allogeneic CM cell lines, with BCG and rhGM-CSF as adjuvants, is currently being tested in post-surgical adjuvancy vs medium-dose IFN-2b in stage IIB-III CM pts (phase II/III trial CASVAC-0401, NCT01729663).We present here the results of the phase II part of the study. A total of 31 pts (stage IIC = 2; stage III: 29) were enrolled: 20 pts were randomized to receive CSF-470 vaccine and 11 pts to IFN-α2b. Pts assigned to the vaccine arm received i.d. 1.6×107 CSF-470 irradiated cells plus 106cfu BCG and 100μg rhGM-CSF (first day); 100 μg rhGM-CSF/day/3days were injected consecutively i.d. at the vaccination site. During the two-year treatment, pts in the vaccine arm received a total of 13 vaccinations. Pts assigned to the IFN-α2b arm received 10 MU/day/5 days a week for 4 weeks; then 5 MU 3/week for 23 months. Imaging studies were performed to follow the clinical evolution of the disease. Analysis of blood chemistry and differential white blood cell counts were performed to monitor systemic toxicity. Immune monitoring was performed at baseline and at 6, 12 and 24 months from protocol start. Also, pts were evaluated by Quality of Life Questionnaires (QOL) along the study. After including 20 pts who received a total of 176 vaccinations, we conclude that: CSF-470 vaccine was well tolerated; the main toxicity was a grade 2 reaction at the injection site; 3/20 pts presented grade 3 allergic reactions that were easily handled with anti-histamines and corticosteroids. Pts in the IFN-α2b arm presented grade 2-3 hematologic toxicity; 9 pts developed adverse events that forced treatment discontinuation provisionally or permanently. With a mean follow-up of 28 months and a maximum follow-up of 67 months, a significant benefit in the distant metastasis-free survival (DMFS) for CSF-470 was observed: 14/20 pts (70%) immunized with CSF-470 vaccine and only 4/11 pts (36.4%) in the IFN-α2b arm remain without distant metastases (p = 0.032). No

significant differences in OS were yet observed. QOL was significantly superior for CSF-470 vaccine as compared to IFN-α2b treatment (p&lt;0.0002). DMF pts developed a significantly higher DTH reaction after the 7th and 12th vaccine as compared to progressing pts. These results demonstrate a clear superiority of CSF-470 vaccine plus BCG plus GM-CSF vs IFN-α2b in the adjuvant setting in pts with high-risk CM.

Citation Format: José Mordoh, María Betina Pampena, Mariana Aris, Paula Blanco, Alicia I. Bravo, Juan Manuel O'Connor, Julio Kaplan, Franco Ramello, Estrella M. Levy, María M. Barrio. A randomized phase II study of the CSF-470 therapeutic vaccine plus BCG plus rhGM-CSF versus IFN-α2b in cutaneous melanoma patients stages IIB, IIC and III. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT118. doi:10.1158/1538-7445.AM2015-CT118

Inoculation site from a cutaneous melanoma patient treated with an allogeneic therapeutic vaccine: a case report

We have developed a therapeutic vaccine consisting of a mixture of lethally-irradiated allogeneic cutaneous melanoma cell lines with BCG and GM-CSF as adjuvants. The CSF-470 vaccine is currently being assayed in a Phase II-III trial against medium-dose IFN-α2b. All vaccinated patients immunized intradermally developed large edematous erythema reactions, which then transformed into subcutaneous nodules active for several months. However, vaccine injection sites were not routinely biopsied. We describe the case of a female patient, previously classified as stage III, but who, due to the simultaneous discovery of bone metastases only received one vaccination was withdrawn from the study, and continued her treatment elsewhere. This patient developed a post-vaccination nodule which was surgically removed 7 weeks later, and allowed to analyze the reactivity and immune profiling of the inoculation site. An inflammatory reaction with zones of fibrosis, high irrigation, and brisk lymphoid infiltration, primarily composed of CD8(+) and CD20(+) lymphocytes, was observed. There were no remaining BCG bacilli, and scarce CD4(+) and Foxp3(+) T cells were determined. MART-1 Ag was found throughout the vaccination site. CD11c(+) Ag presenting cells were either dispersed or forming dense nests. Some CD11c(+) cells proliferated; most of them contained intracellular MART-1 Ag, and some interacted with CD8(+) lymphocytes. These observations suggest a potent, long-lasting local inflammatory response with recruitment of Ag-presenting cells that incorporate melanoma Ags, probably leading to Ag presentation to naïve T cells.

Combining immunotherapy with oncogene-targeted therapy: a new road for melanoma treatment

Cutaneous melanoma arises from the malignant transformation of skin melanocytes; its incidence and mortality have been increasing steadily over the last 50 years, now representing 3% of total tumors. Once melanoma metastasizes, prognosis is somber and therapeutic options are limited. However, the discovery of prevalent BRAF mutations in at least 50% of melanoma tumors led to development of BRAF-inhibitors, and other drugs targeting the MAPK pathway including MEK-inhibitors, are changing this reality. These recently approved treatments for metastatic melanoma have made a significant impact on patient survival; though the results are shadowed by the appearance of drug-resistance. Combination therapies provide a rational strategy to potentiate efficacy and potentially overcome resistance. Undoubtedly, the last decade has also born a renaissance of immunotherapy, and encouraging advances in metastatic melanoma treatment are illuminating the road. Immune checkpoint blockades, such as CTLA-4 antagonist-antibodies, and multiple cancer vaccines are now invaluable arms of anti-tumor therapy. Recent work has brought to light the delicate relationship between tumor biology and the immune system. Host immunity contributes to the anti-tumor activity of oncogene-targeted inhibitors within a complex network of cytokines and chemokines. Therefore, combining immunotherapy with oncogene-targeted drugs may be the key to melanoma control. Here, we review ongoing clinical studies of combination therapies using both oncogene inhibitors and immunotherapeutic strategies in melanoma patients. We will revisit the preclinical evidence that tested sequential and concurrent schemes in suitable animal models and formed the basis for the current trials. Finally, we will discuss potential future directions of the field.

Chemokine receptor-specific antibodies in cancer immunotherapy: achievements and challenges

The 1990s brought a burst of information regarding the structure, expression pattern, and role in leukocyte migration and adhesion of chemokines and their receptors. At that time, the FDA approved the first therapeutic antibodies for cancer treatment. A few years later, it was reported that the chemokine receptors CXCR4 and CCR7 were involved on directing metastases to liver, lung, bone marrow, or lymph nodes, and the over-expression of CCR4, CCR6, and CCR9 by certain tumors. The possibility of inhibiting the interaction of chemokine receptors present on the surface of tumor cells with their ligands emerged as a new therapeutic approach. Therefore, many research groups and companies began to develop small molecule antagonists and specific antibodies, aiming to neutralize signaling from these receptors. Despite great expectations, so far, only one anti-chemokine receptor antibody has been approved for its clinical use, mogamulizumab, an anti-CCR4 antibody, granted in Japan to treat refractory adult T-cell leukemia and lymphoma. Here, we review the main achievements obtained with anti-chemokine receptor antibodies for cancer immunotherapy, including discovery and clinical studies, proposed mechanisms of action, and therapeutic applications.

Development of a novel methodology for cryopreservation of melanoma cells applied to CSF470 therapeutic vaccine

CSF470 vaccine is a mixture of four lethally irradiated melanoma cell lines, administered with BCG and GM-CSF, which is currently being tested in a Phase II/III Clinical trial in stage II/III melanoma patients. To prepare vaccine doses, irradiated melanoma cell lines are frozen using dimethyl sulfoxide (Me(2)SO) and stored in liquid nitrogen (liqN(2)). Prior to inoculation, doses must be thawed, washed to remove Me(2)SO and suspended for clinical administration. Avoiding the use of Me(2)SO and storage in liqN(2) would allow future freeze-drying of CSF470 vaccine to facilitate pharmaceutical production and distribution. We worked on the development of an alternative cryopreservation methodology while keeping the vaccine's biological and immunogenic properties. We tested different freezing media containing trehalose suitable to remain as excipients in a freeze-dried product, to cryopreserve melanoma cells either before or after gamma irradiation. Melanoma cells incorporated trehalose after 5 h incubation at 37°C by fluid-phase endocytosis, reaching an intracellular concentration that varied between 70-140 mM depending on the cell line. Optimal freezing conditions were 0.2 M trehalose and 30 mg/ml human serum albumin, at -84°C. Vaccine doses could be frozen in trehalose at -84°C for at least four months keeping their cellular integrity, antigen expression and apoptosis/necrosis profile after gamma-irradiation as compared to Me(2)SO control. Non-irradiated melanoma cell lines also showed comparable proliferative capacity after both cryopreservation procedures. Trehalose-freezing medium allowed us to cryopreserve melanoma cells, either alive or after gamma irradiation, at -84°C avoiding the use of Me(2)SO and liqN(2) storage. These cryopreservation conditions could be suitable for future freeze-drying of CSF470 vaccine.

Combined metallothioneins and p53 proteins expression as a prognostic marker in patients with Dukes stage B and C colorectal cancer

Our study aimed to evaluate metallothionein and p53 expression in colorectal cancer and to correlate their combined expression with selected clinical and pathologic variables of the disease, to define their prognostic significance. Colorectal cancer specimens from 99 patients were retrospectively analyzed by immunohistochemistry for metallothionein and p53 expression. Survival curves were generated according to the Kaplan-Meier method, and univariate survival distributions were compared with the use of the log-rank test. Multivariate models were computed using Cox proportional hazards regression. This research was approved by the institutional review boards of all centers. Tumors showing concomitant high metallothionein expression and negative p53 (metallothionein(H)/p53(-)) were significantly inversely related to depth of invasion, frequency of nodal metastasis, and Dukes stage (P < .01). In univariate analysis, patients with metallothionein(H)/p53(-) phenotype showed a better overall survival (hazard ratio [HR], 2.83; P < .05) and disease-free survival (HR, 2.03; P < .05). In multivariate analysis, considering staging, metallothionein, and metallothionein + p53 variables, in 83 patients with Dukes stages B and C, metallothionein(H)/p53(-) combination was the sole factor showing an independent prognostic value for overall survival (HR, 3.88; P < .1) and disease-free survival (HR, 2.56; P < .1). In conclusion, the combined analysis of metallothionein and p53 may enhance the prognostic power of each individual marker by predicting the progression of the disease and contributing to a better identification of patients at low risk for mortality, especially for those with Dukes stage B and C colorectal cancer.

Metallothionein expression in colorectal cancer: relevance of different isoforms for tumor progression and patient survival

Metallothioneins are a family of small, cysteine-rich proteins with many functions. Immunohistochemical evaluation of all metallothionein 1 + 2 isoforms in colorectal tumors has demonstrated an important down-regulation compared with normal tissue, although its prognostic significance is unclear. Moreover, the contribution of individual isoforms to overall metallothionein down-regulation is not known. To address these important issues, we analyzed the messenger RNA expression levels of all functional metallothionein 1 + 2 isoforms by quantitative reverse transcription polymerase chain reaction in 22 pairs of normal and tumor-microdissected epithelia and correlated these to the overall immunohistochemical protein expression. Our results showed that 5 isoforms (MT1G, 1E, 1F, 1H, and 1M) were lost during the transition from normal mucosa to tumor, whereas MT1X and MT2A were less down-regulated, and their expression was correlated with overall protein positivity. Second, we showed that MT1G hypermethylation occurred in cell lines and in 29% of tumor samples, whereas histone deacetylase inhibitors are able to induce most isoforms. Furthermore, we analyzed by immunohistochemistry 107 normal mucosae, 25 adenomas, 81 carcinomas, and 19 lymph node metastases to evaluate metallothionein expression during different stages of cancer development and to assess its relationship to patient survival. A lower immunohistochemical expression was associated with poorer survival, although it was not an independent predictor. Overall, this study identifies for the first time the relevant metallothionein isoforms for colorectal cancer progression, supports the concept that their loss is associated with worse prognosis, and suggests 2 mechanisms for epigenetic repression of metallothionein expression in colorectal tumors.

Using magnostrictive metal as a pump for biomedical application

A new theory of pumping fluids, including blood, has been developed using magnetostrictive technology. This new pump uses the magnetostrictive material known as Terfenol-DTM. A magnetic field is imposed on the Terfenol in periodic pulses causing it to expand and then relax to its original state. The expansion and relaxation of the terfenol cause a smooth, continuous flow of fluid. This pump is currently being built and will be tested as a left ventricular assist device, totally implantable artificial heart, or both.