Music therapy for supporting informal carers of adults with life-threatening illness pre- and post-bereavement; a mixed-methods systematic review

BACKGROUND

Music therapy interventions with informal carers of individuals with life-threatening illness at pre- and post-bereavement is an increasingly important clinical area. This systematic review is the first to synthesise and critically evaluate the international evidence associated with music therapy with adult informal carers pre- and post-bereavement. Specifically, the objectives were: i) to describe the characteristics and effectiveness of music therapy interventions which aim to improve health-related outcomes for adult informal carers of adults with life-threatening illness (pre- and post-bereavement), and ii) to describe the experience of music therapy for adult informal carers of adults with life-threatening illness (pre- and post-bereavement).

METHODS

Eligibility: adult informal carers of adults at end of life or bereaved; music therapy interventions for improving health-related outcomes; qualitative; mixed-method; and quantitative studies including comparators of any other intervention; published in English from 1998 onwards. Six databases were searched up to July 2022. A JBI mixed-methods systematic review approach was followed throughout, including quality appraisal, data extraction and a convergent segregated approach to synthesis and integration.

RESULTS

A total of 34 studies were included, published between 2003 and 2022. Most were conducted in North America (n = 13), Australia (n = 10), or Europe (n = 8). No studies were conducted in low- and middle-income countries or in the UK. The majority were qualitative (n = 17), followed by quasi-experimental (n = 8), mixed-methods (n = 7) and two RCTs. The majority focused on carers of individuals with dementia (n = 21) or advanced cancer (n = 7). Seventeen studies were purely quantitative or included a quantitative component. During meta-synthesis, findings were aligned to core outcomes for evaluating bereavement interventions in palliative care and previously identified risk factors for complicated grief. Commonly targeted outcomes in quantitative studies included quality of life and mental wellbeing, showing equivocal effectiveness of music therapy with significant and non-significant results. Twenty-two studies either purely qualitative or with a qualitative component underwent meta synthesis and suggested a diverse range of improved pre- and post-bereavement outcomes for informal carers across all core outcomes, and across all risk and protective factors, including psychological, spiritual, emotional, and social outcomes.

CONCLUSIONS

Qualitative studies provide moderate to strong evidence for improved health-related outcomes for adult informal carers of adults with life-threatening illness pre-bereavement. Limited studies including those bereaved negates conclusions for the bereavement phase. Comparisons and explanations for effectiveness across quantitative and qualitative studies are equivocal, with a high risk of bias and small samples in the limited number of quantitative studies, demonstrating a need for high-quality RCTs.

SYSTEMATIC REVIEW PRE-REGISTRATION

PROSPERO [CRD42021244859].

A Potent Kalihinol Analogue Disrupts Apicoplast Function and Vesicular Trafficking in P. falciparum Malaria

Here we report the discovery of MED6-189, a new analogue of the kalihinol family of isocyanoterpene (ICT) natural products. MED6-189 is effective against drug-sensitive and -resistant P. falciparum strains blocking both intraerythrocytic asexual replication and sexual differentiation. This compound was also effective against P. knowlesi and P. cynomolgi. In vivo efficacy studies using a humanized mouse model of malaria confirms strong efficacy of the compound in animals with no apparent hemolytic activity or apparent toxicity. Complementary chemical biology, molecular biology, genomics and cell biological analyses revealed that MED6-189 primarily targets the parasite apicoplast and acts by inhibiting lipid biogenesis and cellular trafficking. Genetic analyses in P. falciparum revealed that a mutation in PfSec13, which encodes a component of the parasite secretory machinery, reduced susceptibility to the drug. The high potency of MED6-189 in vitro and in vivo, its broad range of efficacy, excellent therapeutic profile, and unique mode of action make it an excellent addition to the antimalarial drug pipeline.

On thresholds for controlling negative particle (PM2.5) readings in air quality reporting

Ambient PM2.5 (particles less than 2.5 μm in diameter) is monitored in many countries including Australia. Occasionally PM2.5 instruments may report negative measurements, although in realty the ambient air can never contain negative amounts of particles. Some negative readings are caused by instrument faults or procedural errors, thus can be simply invalidated from air quality reporting. There are occasions, however, when negative readings occur due to other factors including technological or procedural limitations. Treatment of such negative data requires consideration of factors such as measurement uncertainty, instrument noise and risk for significant bias in air quality reporting. There is very limited documentation on handling negative PM2.5 data in the literature. This paper demonstrates how a threshold is determined for controlling negative hourly PM2.5 readings in the New South Wales (NSW) air quality data system. The investigation involved a review of thresholds used in different data systems and an assessment of instrument measurement uncertainties, zero air test data and impacts on key reporting statistics when applying different thresholds to historical datasets. The results show that a threshold of -10.0 μg/m3 appears optimal for controlling negative PM2.5 data in public reporting. This choice is consistent with the measurement uncertainty estimates and the zero air test data statistics calculated for the NSW Air Quality Monitoring Network, and is expected not to have significant impacts on key compliance reporting statistics such as data availability and annual average pollution levels. The analysis can be useful for air quality monitoring in other Australian jurisdictions or wider context.

546 Results from Phase Ib study of tebentafusp (tebe) in combination with durvalumab (durva) and/or tremelimumab (treme) in metastatic cutaneous melanoma (mCM)

Background

Tebe, a T cell receptor fused to an anti-CD3 effector, can redirect T cells to target gp100+ cells and in Ph3, demonstrated overall survival (OS) benefit as monotherapy in metastatic uveal melanoma. In Ph2, any tumor shrinkage (44% of patients) was a better predictor of OS than response rate. In Ph1, Tebe had monotherapy activity in mCM, also a gp100+ tumor, with 1-year OS ~74% in PD-1 naïve mCM. A Ph1 dose escalation of tebe with durva (anti-PD-L1) and/or treme (anti-CTLA4) was conducted in pre-treated mCM [NCT02535078], with nearly all patients having prior PD1-treatment, and where recently reported therapies have 1-yr OS of ~55%.

Methods

Heavily pre-treated HLA-A2+ mCM patients received weekly IV tebe alone (Arm 4) or with increasing doses of durva and/or treme (Arm 1–3) administered IV monthly starting day 15 of each cycle. Primary objective was to identify RP2D of combination therapy. Secondary objectives included adverse events (AE) and efficacy.

Results

112 pts received ≥1 tebe dose. Median age was 59, 77% were ECOG 0, and 37% were BRAFm (of which 71% received prior BRAFi/MEKi). 91% of pts were 2L+, while 74% were 3L+. 103 (92%) received prior PD-1 inhibitor, of which 87% also received prior ipilimumab. 43 pts received tebe + durva (Arm 1), 13 received tebe + treme (Arm 2), 29 received triplet therapy (Arm 3), and 27 received tebe alone (Arm 4). Maximum target doses of tebe (68 mcg) + durva (20 mg/kg) and treme (1 mg/kg) were tolerated. MTD was not formally identified for any arm. Two DLTs occurred: prolonged grade 3 rash (Arm 1) and grade 2 diarrhea leading to treatment delay (Arm 2). Related AEs that were Grade ≥3 or led to discontinuations were: 44%/0% (Arm 1), 23%/0% (Arm2), 38%/7% (Arm3), 26%/4% (Arm 4). There were no treatment-related deaths.In prior PD-1 pts, tumor shrinkage occurred in 36% and 1-yr OS was 68%. Of 51 evaluable PD-1 resistant pts (best response CR/PR/SD to prior PD1), tumor shrinkage occurred in 28% and 1-yr OS was 73% (figure 1). In 35 evaluable PD-1 refractory pts (prior best response PD), tumor shrinkage occurred in 49% and 1-yr OS was 61%. For 38 prior PD-1 pts who received ≥10mg/kg durva, 1-yr OS was 81%.

Abstract 546 Figure 1

% tumor change from baseline in evaluable patients with known response to prior PD1 exposure

Conclusions

Tebe with anti-PD-L1 and/or anti-CTLA4 had an acceptable safety profile. Tebe + durva demonstrated durable tumor shrinkage and promising 1-yr OS rates in prior-PD1 treated mCM relative to recent reports.

Trial Registration

NCT02535078

Ethics Approval

The institutional review board or independent ethics committee at each center approved the trial. The trial was conducted in accordance with the Declaration of Helsinki and the International Conference on Harmonization Good Clinical Practice guidelines.

950 Final analysis: phase 1b study investigating intratumoral injection of toll-like receptor 9 agonist vidutolimod ± pembrolizumab in patients with PD-1 blockade–refractory melanoma

Background

There are limited therapeutic options for patients with progressive disease (PD) on or after PD-1–blocking antibody therapy. Vidutolimod (CMP-001) is a first-in-class, immunostimulatory virus-like particle containing a CpG-A Toll-like receptor 9 (TLR9) agonist. This phase 1b study evaluated the safety and clinical activity of intratumoral vidutolimod with and without pembrolizumab in patients with refractory melanoma.

Methods

This two-part, open-label, multicenter, phase 1b study (NCT02680184) enrolled adults with histologically confirmed metastatic or unresectable cutaneous melanoma who had stable disease after ≥12 weeks or PD on anti−PD-1 treatment, measurable disease per RECIST v1.1, ECOG PS 0/1, and ≥1 lesion accessible for intratumoral injection. Part 1 evaluated vidutolimod + pembrolizumab and Part 2 evaluated vidutolimod monotherapy. Key objectives included assessment of safety and clinical activity, and exploratory analyses were performed on available tumor biopsies using immunohistochemistry and RNAseq.

Results

At data cutoff (August 17, 2021), 159 patients had enrolled in Part 1 and 40 patients in Part 2. The median age was 64 years in Part 1 (range, 30-90) and 68 years in Part 2 (range, 30-89). Most patients had PD as their last response to prior anti–PD-1 therapy (Part 1, 93.1%; Part 2, 80.0%). Grade 3/4 treatment-related adverse events (TRAEs) occurred in 37.1% of patients treated with vidutolimod + pembrolizumab and in 22.5% of patients treated with vidutolimod monotherapy. No treatment-related deaths occurred. Based on the efficacy data presented in Table 1, vidutolimod polysorbate 20 (PS20) A was selected for further development as this formulation in combination with pembrolizumab had a best objective response rate (ORR; RECIST v1.1) of 23.5%, with a median duration of response (DOR) of 25.2 months. Vidutolimod monotherapy had an ORR of 20.0%, with a median DOR of 5.6 months. Exploratory translational analyses identified association of unique biomarkers with response among patients with T cell–inflamed versus non-T cell–inflamed tumors at baseline.

Abstract 950 Table 1

Safety and clinical activity of vidutolomod ± pembrolizumab

Conclusions

Promising clinical activity was observed with vidutolimod + pembrolizumab and vidutolimod monotherapy in patients with PD-1 blockade–refractory melanoma. A manageable safety profile was observed. The DOR with vidutolimod + pembrolizumab was substantially longer than with vidutolimod monotherapy. Clinical studies to confirm the efficacy of vidutolimod + PD-1 blockade in patients with previously untreated unresectable/metastatic melanoma (phase 2/3, NCT04695977) or PD-1 blockade–refractory melanoma (phase 2, NCT04698187) are ongoing.

Acknowledgements

This work was supported by Checkmate Pharmaceuticals. Medical writing assistance was provided by Steffen Biechele, PhD (ApotheCom, San Francisco, CA, USA), and funded by Checkmate Pharmaceuticals.

Trial Registration

NCT02680184

Ethics Approval

This study was approved by the WCG-WIRB; WIRB approval tracking number: 20152597.

88 Evidence of enhanced immune activation within the tumor microenvironment and the circulation of female patients with high-risk melanoma compared to males

Background

Sex differences in tumor immunity and response to immunotherapy were shown in murine models and descriptive analyses from recent clinical trials. We recently reported that female gender is a favorable prognostic marker for survival benefit following ipilimumab and high dose interferon-alfa (HDI) adjuvant therapy of high-risk melanoma in the ECOG-ACRIN E1609 trial (N=1670). Therefore, we investigated differences in candidate immune biomarkers in the circulation and tumor microenvironment (TME) of female and male patients.

Methods

Gene expression profiling (GEP) was performed on the tumor biopsies of 718 (454 male, 264 female) patients. The primary endpoint was mRNA expression profiling using U133A 2.0 Affymetrix gene chips. Raw microarray data sets were normalized by using the Robust Multi-array Average (RMA) method using Affymetrix Power Tools (APT) as previously published. Multiple probe sets representing the same genes were collapsed by using the probe with maximum gene expression. Gene set enrichment analysis (GSEA) was performed by comparing the female and male tumor samples, and gene sets with FDR q-value <0.1 were deemed as significant. Similarly, peripheral blood (serum and PBMC) samples were tested for soluble (Luminex) and cellular (multicolor flow cytometry) prognostic biomarkers in a subset of patients (N=321; 109 female and 212 male). All patients provided an IRB-approved written informed consent.

Results

Among the subset of patients tested for circulating biomarkers, females were significantly younger than males (P=0.03). Testing PBMCs, the percentages of CD3+ T cells (P=0.04) and CD3+CD4+ helper T cells (P=0.0005) were significantly higher in female patients compared to males. Also, there were trends toward higher levels of proinflammatory cytokines IL1beta (P=0.07) and IL6 (P=0.06) in females. On the other hand, males had significantly higher percentages of monocytes (P=0.03). Further, there were trends toward higher percentages of CD3+/CD4+/CD25hi+/Foxp3+ (P=0.1) and CD3+/CD4+/CD25+/CD127low+ (P=0.1) T-reg in male patients compared to females. Among the cohort of patients (N=718) with tumor GEP data, females were significantly younger than males (P=0.0009). GEP identified pathways and genes related to immune cell infiltration and activation that were significantly enriched in the tumors of females compared to males (table 1).

Abstract 88 Table 1

Immune pathways significantly enriched in tumors of females

Conclusions

Female gender was associated with adjuvant immunotherapeutic benefits and female patients were more likely to have evidence of immune activation within the TME and the circulation, supporting a potentially important role for female related factors in the immune response against melanoma, and these require further investigation.

Acknowledgements

We are grateful to the patients and family members who participated in the E1609 trial and the E1609 trial investigators. This study was conducted by the ECOG-ACRIN Cancer Research Group (Peter J. O’Dwyer, MD and Mitchell D. Schnall, MD, PhD, Group Co-Chairs) and supported by the National Cancer Institute of the National Institutes of Health under the following award numbers: U10CA180794, U10CA180820, U10CA180888, UG1CA233180, UG1CA233184. Biomarkers studies were supported under the following award number: P50CA12197310 (Tarhini and Kirkwood). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Trial Registration

NCT01274338

Ethics Approval

The E1609 study protocol was approved by the institutional review board of each participating institution and conducted in accordance with Good Clinical Practice guidelines as defined by the International Conference on Harmonization. All patients provided an IRB-approved written informed consent.

Consent

Not applicable.

87 Enhanced immunogenicity within the tumor microenvironment and the circulation of high-risk melanoma patients with unknown primary compared to those whose primary melanoma is known

Background

We recently reported data supporting the unknown primary status as a potentially distinct prognostic group among high-risk melanoma patients treated with ipilimumab and high dose interferon-alfa (HDI) in the ECOG-ACRIN E1609 trial (N=1670) with improved RFS and OS outcomes compared to known primary. Therefore, we investigated differences in candidate immune biomarkers in the circulation and tumor microenvironment (TME) of patients with unknown compared to those with known primary melanoma enrolled in this trial that tested adjuvant ipilimumab at 3 and 10 mg/kg versus HDI.

Methods

Gene expression profiling (GEP) was performed on the tumor biopsies of 718 (102 unknown, 616 known primary) melanoma patients. The primary endpoint was mRNA expression profiling using U133A 2.0 Affymetrix gene chips. Raw microarray data sets were normalized by using the Robust Multi-array Average (RMA) method using Affymetrix Power Tools (APT) as previously published. Multiple probe sets representing the same genes were collapsed by using the probe with maximum gene expression. Gene set enrichment analysis (GSEA) was performed by comparing the unknown and known primary tumor samples, and gene sets with FDR q-value <0.1 were deemed as significant. Similarly, peripheral blood (serum and PBMC) samples were tested for soluble (Luminex) and cellular (multicolor flow cytometry) immune biomarkers in a subset of patients (N=321; 66 unknown and 255 known primary). All patients provided an IRB-approved written informed consent.

Results

Unknown primary melanoma cases represented 12.8% of the total E1609 study population (N=1670) including 11.7% on the ipilimumab arms and 14.7% on the HDI arm. Stratifying by stage, relapse free survival (RFS) (P=0.001) and overall survival (OS) (P=0.009) were significantly better for patients with unknown primary tumor compared to known primary. Including only ipilimumab-treated patients, RFS (P=0.005) and OS (P=0.023) were significantly better in favor of the unknown primary status. Among the cohort of patients with tumor GEP data (N=718), GEP identified pathways and genes related to autoimmunity, inflammation, immune cell infiltration and immune activation that were significantly enriched in the unknown primary tumors compared to known primaries (table 1). Among the subset of patients tested for circulating biomarkers, patients with unknown primary melanoma had significantly higher circulating levels of IL-2R than those with known primary (P=0.04).

Abstract 87 Table 1

Immune pathways enriched in unknown primary melanoma

Conclusions

Unknown primary high-risk melanoma patients had significantly better prognosis and evidence of significantly enhanced immune activation within the TME and the circulation, supporting the designation of unknown primary melanoma as a distinct prognostic marker in patients with high-risk melanoma.

Acknowledgements

We are grateful to the patients and family members who participated in the E1609 trial and the E1609 trial investigators. This study was conducted by the ECOG-ACRIN Cancer Research Group (Peter J. O’Dwyer, MD and Mitchell D. Schnall, MD, PhD, Group Co-Chairs) and supported by the National Cancer Institute of the National Institutes of Health under the following award numbers: U10CA180794, U10CA180820, U10CA180888, UG1CA233180, UG1CA233184. Biomarkers studies were supported under the following award number: P50CA12197310 (Tarhini and Kirkwood). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Trial Registration

NCT01274338

Ethics Approval

The E1609 study protocol was approved by the institutional review board of each participating institution and conducted in accordance with Good Clinical Practice guidelines as defined by the International Conference on Harmonization. All patients provided an IRB-approved written informed consent.

Consent

Not applicable.

Urinary nitrate concentration as a marker for kidney transplant rejection

BACKGROUND

Early identification and treatment of kidney transplant rejection episodes is vital to limit loss of function and prolong the life of the transplanted kidney and recipient. Current practice depends on detecting a creatinine rise. A biomarker to diagnose transplant rejection at an earlier time point than current practice, or to inform earlier decision making to biopsy, could be transformative. It has previously been shown that urinary nitrate concentration is elevated in renal transplant rejection. Nitrate is a nitric oxide (NO) oxidation product. Transplant rejection upregulates NO synthesis via inducible nitric oxide synthase leading to elevations in urinary nitrate concentration. We have recently validated a urinary nitrate concentration assay which could provide results in a clinically relevant timeframe. Our aim was to determine whether urinary nitrate concentration is a useful tool to predict renal transplant rejection in the context of contemporary clinical practice.

METHODS

We conducted a prospective observational study, recruiting renal transplant participants over an 18-month period. We made no alterations to the patients' clinical care including medications, immunosuppression, diet and frequency of visits. We collected urine samples from every clinical attendance. We assessed the urinary nitrate to creatinine ratio (uNCR) between patient groups: routine attendances, biopsy proven rejection, biopsy proven no rejection and other call backs. uNCR was examined over time for those with biopsy proven transplant rejection. These four groups were compared using an ANOVA test.

RESULTS

A total of 2656 samples were collected. uNCR during biopsy proven rejection, n = 15 (median 49 μmol/mmol, IQR 23-61) was not significantly different from that of routine samples, n = 164 (median 55 μmol/mmol, IQR 37-82) (p = 0.55), or biopsy proven no rejection, n = 12 (median 39 μmol/mmol, IQR 21-89) (P = 0.77). Overall uNCR was highly variable with no diagnostic threshold for kidney transplant rejection. Furthermore, within-patient uNCR was highly variable over time, and thus it was not possible to produce individualised patient thresholds to identify rejection. The total taking Tacrolimus was 204 patients, with no statistical difference between the uNCR of all those on Tacrolimus, against those not, p = 0.18.

CONCLUSION

The urinary nitrate to creatinine ratio is not a useful biomarker for renal transplant rejection.

Abstract A04: Analysis of molecular and immune features that correlate with serum lactate dehydrogenase (LDH) levels in patients (pts) with metastatic melanoma

Background: Elevated serum LDH is a poor prognostic factor in pts with MM. It is currently unknown if serum LDH levels correlate with molecular or immune differences in tumors, including LDH expression. We analyzed resected melanoma metastases to identify features that correlate with serum LDH elevation.

Methods: Metastases with serum LDH levels measured within 30 days of surgery were included in the study: (1) a TMA of resected stage IV metastases from MD Anderson (MDACC) (n=207); (2) resected stage IV metastases from MDACC with previously acquired RNA-sequencing (RNA-seq) and CD8+ immunohistochemistry (IHC) data (n=24); (3) publicly available data for regional metastases from the melanoma TCGA (n=104) from MDACC and the Melanoma Institute of Australia. IHC was performed for LDHA, LDHB, PTEN, PD-L1, MITF, and Ki67 on the stage IV TMA, and publicly available data for DNA, RNA, and proteins for the TCGA samples were downloaded. Data were analyzed to identify features that differed between tumors with elevated and normal serum LDH levels. TCGA and stage IV tumors expressing the 25% highest and lowest LDHA and LDHB by RNA-seq were also compared.

Results: IHC of the stage IV TMA identified no significant associations with serum LDH levels, including tumor LDHA (p=0.69) and LDHB (p=0.93) expression. Serum LDH was elevated in 33.3% of stage IV metastases with RNA-seq data and 21.6 % of TCGA regional metastases, which by Ensemble of Gene Set Enrichment Analyses (EGSEA) correlated with decreased expression of interferon alpha (q=8.26 × 10−14 and q=2.31 × 10−14), interferon gamma (q=9.46 × 10−14 and q=2.34 × 10−19), and inflammatory response (q= 1.26 × 10−20 and q=4.17 × 10−28) gene sets. Fewer (p=0.0464) CD8+ T cells were detected in stage IV tumors from pts with elevated serum LDH. Comparison of stage IV and TCGA tumors with high vs. low LDHA and LDHB mRNA expression levels did not correlate with serum LDH status, but significant enrichment of oxidative phosphorylation (q=6.32 × 10−21 and q=5.69 × 10−19), pyruvate metabolism (q= 7.90 × 10−16 and q=1.78 × 10−14), and citrate cycle (q= 1.51 × 10−06 and q=5.44 × 10−06) gene sets were detected in LDHA-high tumors. Increased LDHB expression correlated with enrichment of citrate cycle (q= 4.04 × 10−16 and q= 1.68 × 10−14), pyruvate metabolism (q= 2.34 × 10−11 and q=1.50 × 10−10), and glycolysis (q= 2.92 × 10−9 and q=1.55 × 10−8) gene sets.

Conclusions: Elevated serum LDH levels correlated with decreased expression of immune response genes, but not LDHA or LDHB expression, in melanoma regional and distant metastases. Elevated serum LDH also correlated with decreased CD8+ T cell infiltrates by IHC. LDHA and LDHB expression levels in regional metastases correlated with distinct metabolic pathways, but not serum LDH levels.

Citation Format: Fernando Cintra Lopes Carapet, Grant Fischer, Aron Joon, Huiqin Chen, Lauren Haydu, Sandra Lee, Melissa Saul, Savi Appana, John Thompson, Graham Mann, Jennifer McQuade, Alexander Lazar, Michael Tetzlaff, John Kirkwood, Richard Scolyer, Georgina Long, Michael Davies. Analysis of molecular and immune features that correlate with serum lactate dehydrogenase (LDH) levels in patients (pts) with metastatic melanoma [abstract]. In: Proceedings of the AACR Special Conference on Melanoma: From Biology to Target; 2019 Jan 15-18; Houston, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(19 Suppl):Abstract nr A04.

Abstract IA02: Next targets for immune checkpoint blockade in melanoma

Multiple mechanisms of melanoma-induced immune escape contribute to the failure of T-cell responses to control tumor growth in humans. Many inhibitory pathways play a critical role in impeding T-cell responses to tumor antigens (TAs), including PD-1, the T-cell immunoglobulin and mucin-domain containing-protein 3 (Tim-3), and the T-cell immunoreceptor with Ig and ITIM domains (TIGIT). These inhibitory receptors (IRs) are upregulated by TA-specific CD8+T cells in the tumor microenvironment (TME) while their respective ligands are expressed by antigen-presenting cells (APCs) and tumor cells. Circulating TA-specific CD8+ T cells and CD8+ tumor-infiltrating lymphocytes (TILs) that coexpress PD-1, TIGIT and Tim-3 exhibit different levels of T-cell dysfunction. Dysfunctional/exhausted CD8+ TILs are not totally inert and can exhibit cytolytic functions but are likely kept in check by multiple inhibitory pathways that can be targeted by immune checkpoint blockade. TIGIT is an attractive target for the next-generation immune checkpoint blockade for several reasons. First, it is highly expressed by the majority of CD8+ TILs together with PD-1. Second, the TIGIT ligands, CD155/PVR, and CD112, are highly expressed in the TME by melanoma cells and APCs. Third, dual PD-1/TIGIT blockade augments the expansion and function of human TA-specific CD8+ T cells in vitro and promotes tumor rejection in animal models. Fourth, TIGIT also acts in Tregs and NK cells to regulate antitumor immune responses. CD8+ TILs in melanoma and other solid tumors downregulate the costimulatory molecule DNAM-1/CD226, which competes with TIGIT for binding to the same ligands CD155 and CD112. Therefore, in addition to the TIGIT-mediated T-cell intrinsic inhibitory effects, the downregulation of CD226 expression by CD8+TILs in the TME also contributes to impede T-cell responses to melanoma. Collectively, our findings provide the rationale for dual PD-1/TIGIT blockade together with therapeutic strategies to counteract CD226 downregulation in the TME to improve the clinical benefits of single PD-1 blockade in patients with melanoma and other solid tumors.

Citation Format: Joe-Marc Chauvin, Mignane Ka, Ornella Pagliano, Julien Foucade, Carmine Menna, Diwakar Davar, John Kirkwood, Vijay Kuchroo, Ana Anderson, Alan Korman, Hassane Zarour. Next targets for immune checkpoint blockade in melanoma [abstract]. In: Proceedings of the AACR Special Conference on Melanoma: From Biology to Target; 2019 Jan 15-18; Houston, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(19 Suppl):Abstract nr IA02.

P1612CAN THE URINARY NITRATE TO CREATININE RATIO BE USED AS A MARKER FOR KIDNEY TRANSPLANT REJECTION?

Background and Aims

Early identification and treatment of kidney transplant rejection episodes is vital to limit loss of function and prolong the life of the transplanted kidney and recipient. Current practice depends on detecting a creatinine rise. A biomarker to diagnose transplant rejection, either at an earlier time point, or to inform earlier decision making to biopsy, could be transformative. Urinary nitrate concentration is elevated in renal transplant rejection. Nitrate is a nitric oxide (NO) oxidation product. Transplant rejection upregulates NO synthesis via inducible nitric oxide synthase leading to elevations in urinary nitrate concentration. Historically, assays for measurement of inorganic nitrate in biological fluids have been too time consuming to be useful in a clinical setting. We have recently validated a urinary nitrate concentration assay which could provide results in a clinically relevant timeframe. Our aim was to determine whether urinary nitrate concentration is a useful tool to predict renal transplant rejection in the context of contemporary clinical practice.

Method

We conducted a prospective observational study, recruiting renal transplant participants over an 18 month period. We made no alterations to the patients’ clinical care including medications, immunosuppression, diet and frequency of visits. We collected urine samples from every clinical attendance including routine attendances, unscheduled attendances for acute clinical indications, and on the day of attendance for biopsy, for those who underwent biopsy. We measured the urinary nitrate to creatinine ratio (uNCR) between patient groups including routine attendances, biopsy proven rejection and biopsy proven “no rejection”. uNCR was examined over time for those with transplant rejection. Groups were compared using a 2 tail t-test of unequal variance, for statistical significance.

Results

A total of 2656 samples were collected. uNCR during biopsy proven rejection, median 49 µmol/mmol, IQR 23-61, was not significantly different from that of routine samples, median 55 µmol/mmol, IQR 37-82 (p=0.56), or biopsy proven “no rejection”, median 39 µmol/mmol, IQR 21-89, (P=0.77). Overall uNCR was highly variable; median 52 µmol/mmol, IQR 31-81, with no diagnostic threshold for kidney transplant rejection. Furthermore, within-patient uNCR was highly variable over time, and thus it was not possible to produce individualised patient thresholds to identify rejection.

Conclusion

The urinary nitrate to creatinine ratio is not a useful biomarker for renal transplant rejection.

Low-cost sensors as an alternative for long-term air quality monitoring

Low-cost air quality sensors are increasingly being used in many applications; however, many of their performance characteristics have not been adequately investigated. This study was conducted over a period of 13 months using low-cost air quality monitors, each comprising two low-cost sensors, which were subjected to a wide range of pollution sources and concentrations, relative humidity and temperature at four locations in Australia and China. The aim of the study was to establish the performance characteristics of the two low-cost sensors (a Plantower PMS1003 for PM_2.5 and an Alphasense CO-B4 for carbon monoxide, CO) and the KOALA monitor as a whole under various conditions. Parameters evaluated included the inter-variability between individual monitors, the accuracy of monitors in comparison with the reference instruments, the effect of temperature and RH on the performance of the monitors, the responses of the PM_2.5 sensors to different types of aerosols, and the long-term stability of the PM_2.5 and CO sensors. The monitors showed high inter-correlations (r > 0.91) for both PM_2.5 and CO measurements. The monitor performance varied with location, with moderate to good correlations with reference instruments for PM_2.5 (0.44< R² < 0.91) and CO (0.37< R² < 0.90). The monitors performed well at relative humidity < 75% and high temperature conditions; however, two monitors in Beijing failed at low temperatures, probably due to electronic board failure. The PM_2.5 sensor was less sensitive to marine aerosols and fresh vehicle emissions than to mixed urban background emissions, aged traffic emissions and industrial emissions. The long-term stability of the PM_2.5 and CO sensors was good, while CO relative errors were affected by both high and low temperatures. Overall, the KOALA monitors performed well in the environments in which they were operated and provided a valuable contribution to long-term air quality monitoring within the elucidated limitations.

O85 Durable responses in anti-PD-1 refractory melanoma following intratumoral injection of a toll-like receptor 9 (TLR9) agonist, CMP-001, in combination with pembrolizumab

Background

Intratumoral (IT) injection of CMP-001, a CpG-A TLR9 agonist packaged within a virus-like particle, is designed to activate tumor-associated plasmacytoid dendritic cells, inducing an interferon-rich tumor microenvironment and anti-tumor CD8+ T cell responses.

Methods

CMP-001-001 is an ongoing Phase 1b trial evaluating the safety and efficacy of CMP-001 in combination with pembrolizumab (Part 1; N = 144) or alone (Part 2; N = 23) in patients with advanced melanoma resistant to prior anti-PD-1 therapy (Tables 1). CMP-001 is administered IT into accessible lesion(s) either with, or without on-site saline dilution (table 1), and response assessed by RECIST v1.1. Monotherapy patients who progress can be rolled over onto combination therapy and continue on study. Baseline and on-therapy serum is analyzed for cytokines, and immunohistochemistry and RNA-Seq are performed on available tumor biopsies.

Abstract O85 Table 1

Advanced anti-PD-1 Refractory melanoma patient population by treatment allocation

Results

Adverse events (AEs) attributed to CMP-001 in combination with pembrolizumab or as monotherapy consisted predominately of transient low-Grade flu-like symptoms and injection site reactions: Grade 3+ related AEs were reported in 33% of patients treated with combination therapy and 22% of patients with monotherapy.

The Objective Response Rate (ORR) with undiluted CMP-001 in combination with pembrolizumab was 24% (18/75; 95% confidence interval: 15%-35% (table 1); on-site dilution of CMP-001 was associated with a substantial decrease in ORR to 12% (7/61; 95% confidence interval: 5%-22% (table 1). Three additional patients had a delayed partial response after an initial period of disease progression. Anti-tumor response was comparable between injected and uninjected lesions. The median duration of response to combination therapy has not been reached. The ORR to CMP-001 monotherapy was 22% (5/23; 95% confidence interval: 7%-44% (table 1); time from last anti-PD-1 therapy before CMP-001 was 1.5 to >20 months in responders; 3 of the patients responding to CMP-001 monotherapy achieved PR at the first evaluation, but progressed by the second evaluation.

Serum and tumor biopsy translational studies in the patients receiving combination therapy supported the proposed mechanism of TLR9 activation and identified a possible association between induction of serum CXCL10 and response.

Conclusions

IT CMP-001 alone and in combination with pembrolizumab appears well tolerated, can reverse resistance to anti-PD-1 therapy, and can produce deep and durable clinical responses in patients with advanced melanoma.

Ethics Approval

CMP-001-001 was centrally approved by the WCG-WIRB, WIRB approval tracking number 20152597.

IL-6, IL-8 drive LAG3/PD1 immune suppression on effector and naïve, peripheral blood CD8+ T cells in cancer patients

Cancer patients off therapy and with normal white blood cell counts are often at greater risk for infections, immune dysregulation, progressive disease or reactivation of viral infections. However, the exact mechanism of this systemic immunosuppression in cancer patients is not fully understood. We hypothesize that cancer patients may have systemic immune suppression via cytokine-driven IR expression in all CD8+ T cells subsets, including naïve cells.

PBL were obtained from healthy donors and treatment-naïve NSCLC, HNSCC, and melanoma patients. IR (i.e. LAG3, PD1, CTLA4, etc) expression was assessed on CD8+ T cells, CD4+ T cells, and regulatory T cells. Plasma cytokine concentrations were compared by Luminex. Autologous micro-stimulation assays were performed on peripheral CD8+ or CD4+ T cells with antigen presenting cells plus or minus IR blockade.

CD8+ T cells, including naive CD8+ T cells, from cancer patient PBL contain elevated total LAG3 expression which correlated with worse state, worse survival, and elevated expression of other IRs. Further, CD8+ T cells from these patients had decreased proliferation, which was rescued with the addition of anti-LAG3 or anti-PD1. Plasma from these patients had significantly elevated levels of cytokines that can signal via STAT3 (i.e. IL-6, IL-8), which were independently found to increase total IR expression in healthy donor, naïve CD8+ T cells.

Patients with cancer have systemic elevations IL-6 and IL-8 leading to increased IR expression in naïve, peripheral CD8+ T cells making them poised for exhaustion even before TCR binding. These findings suggest that cytokine combined with IR blockade may play a role in reversing PD1 blockade resistance.

Unconventional Approaches to Modulating the Immunogenicity of Tumor Cells

For several years, it has been known that histone deacetylase inhibitors have the potential to alter the immunogenicity of tumor cells exposed to checkpoint inhibitory immunotherapy antibodies. HDAC inhibitors can rapidly reduce expression of PD-L1 and increase expression of MHCA in various tumor types that subsequently facilitate the antitumor actions of checkpoint inhibitors. Recently, we have discovered that drug combinations which cause a rapid and intense autophagosome formation also can modulate the expression of HDAC proteins that control tumor cell immunogenicity via their regulation of PD-L1 and MHCA. These drug combinations, in particular those using the irreversible ERBB1/2/4 inhibitor neratinib, can result in parallel in the internalization of growth factor receptors as well as fellow-traveler proteins such as mutant K-RAS and mutant N-RAS into autophagosomes. The drug-induced autophagosomes contain HDAC proteins/signaling proteins whose expression is subsequently reduced by lysosomal degradation processes. These findings argue that cancer therapies which strongly promote autophagosome formation and autophagic flux may facilitate the subsequent use of additional antitumor modalities using checkpoint inhibitor antibodies.

[Neratinib + Valproate] exposure permanently reduces ERBB1 and RAS expression in 4T1 mammary tumors and enhances M1 macrophage infiltration

The irreversible ERBB1/2/4 inhibitor neratinib has been shown in vitro to rapidly reduce the expression of ERBB1/2/4 and RAS proteins via autophagic/lysosomal degradation. We have recently demonstrated that neratinib and valproate interact to suppress the growth of 4T1 mammary tumors but had not defined whether the [neratinib + valproate] drug combination, in a mouse, had altered the biology of the 4T1 cells. Exposure of 4T1 mammary tumors to [neratinib + valproate] for three days resulted, two weeks later, in tumors that expressed less ERBB1, K-RAS, N-RAS, indoleamine-pyrrole 2,3-dioxygenase (IDO-1), ornithine decarboxylase (ODC) and had increased Class I MHCA expression. Tumors previously exposed to [neratinib + valproate] grew more slowly than those exposed to vehicle control and contained more CD8+ cells and activated NK cells. M1 but not M2 macrophage infiltration was significantly enhanced by the drug combination. In vitro exposure of 4T1 tumor cells to [neratinib + valproate] variably reduced the expression of histone deacetylases 1-11. In vivo, prior exposure of tumors to [neratinib + valproate] permanently reduced the expression of HDACs 1-3, 6 and 10. Combined knock down of HDACs 1/2/3 or of 3/10 rapidly reduced the expression IDO-1, and ODC and increased the expression of MHCA. H&E staining of normal tissues at animal nadir revealed no obvious cyto-architectural differences between control and drug-treated animals. We conclude that [neratinib + valproate] evolves 4T1 tumors to grow more slowly and to be more sensitive to checkpoint immunotherapy antibodies.

The levels of mutant K-RAS and mutant N-RAS are rapidly reduced in a Beclin1 / ATG5 -dependent fashion by the irreversible ERBB1/2/4 inhibitor neratinib

The FDA approved irreversible inhibitor of ERBB1/2/4, neratinib, was recently shown to rapidly down-regulate the expression of ERBB1/2/4 as well as the levels of c-MET and mutant K-RAS via autophagic degradation. In the present studies, in a dose-dependent fashion, neratinib reduced the expression levels of mutant K-RAS or of mutant N-RAS, which was augmented in an additive to greater than additive fashion by the HDAC inhibitors sodium valproate and AR42. Neratinib could reduce PDGFRα levels in GBM cells, that was enhanced by sodium valproate. Knock down of Beclin1 or of ATG5 prevented neratinib and neratinib combined with sodium valproate / AR42 from reducing the expression of mutant N-RAS in established PDX and fresh PDX models of ovarian cancer and melanoma, respectively. Neratinib and the drug combinations caused the co-localization of mutant RAS proteins and ERBB2 with Beclin1 and cathepsin B. The drug combination activated the AMP-dependent protein kinase that was causal in enhancing HMG Co A reductase phosphorylation. Collectively, our data reinforce the concept that the irreversible ERBB1/2/4 inhibitor neratinib has the potential for use in the treatment of tumors expressing mutant RAS proteins.

A Novel Cross-Disciplinary Multi-Institute Approach to Translational Cancer Research: Lessons Learned from Pennsylvania Cancer Alliance Bioinformatics Consortium (PCABC)

Background

The Pennsylvania Cancer Alliance Bioinformatics Consortium (PCABC, http://www.pcabc.upmc.edu ) is one of the first major project-based initiatives stemming from the Pennsylvania Cancer Alliance that was funded for four years by the Department of Health of the Commonwealth of Pennsylvania. The objective of this was to initiate a prototype biorepository and bioinformatics infrastructure with a robust data warehouse by developing a statewide data model (1) for bioinformatics and a repository of serum and tissue samples; (2) a data model for biomarker data storage; and (3) a public access website for disseminating research results and bioinformatics tools. The members of the Consortium cooperate closely, exploring the opportunity for sharing clinical, genomic and other bioinformatics data on patient samples in oncology, for the purpose of developing collaborative research programs across cancer research institutions in Pennsylvania. The Consortium's intention was to establish a virtual repository of many clinical specimens residing in various centers across the state, in order to make them available for research. One of our primary goals was to facilitate the identification of cancer-specific biomarkers and encourage collaborative research efforts among the participating centers.

Methods

The PCABC has developed unique partnerships so that every region of the state can effectively contribute and participate. It includes over 80 individuals from 14 organizations, and plans to expand to partners outside the State. This has created a network of researchers, clinicians, bioinformaticians, cancer registrars, program directors, and executives from academic and community health systems, as well as external corporate partners - all working together to accomplish a common mission. The various sub-committees have developed a common IRB protocol template, common data elements for standardizing data collections for three organ sites, intellectual property/tech transfer agreements, and material transfer agreements that have been approved by each of the member institutions. This was the foundational work that has led to the development of a centralized data warehouse that has met each of the institutions’ IRB/HIPAA standards.

Results

Currently, this “virtual biorepository” has over 58,000 annotated samples from 11,467 cancer patients available for research purposes. The clinical annotation of tissue samples is either done manually over the internet or semi-automated batch modes through mapping of local data elements with PCABC common data elements. The database currently holds information on 7188 cases (associated with 9278 specimens and 46,666 annotated blocks and blood samples) of prostate cancer, 2736 cases (associated with 3796 specimens and 9336 annotated blocks and blood samples) of breast cancer and 1543 cases (including 1334 specimens and 2671 annotated blocks and blood samples) of melanoma. These numbers continue to grow, and plans to integrate new tumor sites are in progress. Furthermore, the group has also developed a central web-based tool that allows investigators to share their translational (genomics/proteomics) experiment data on research evaluating potential biomarkers via a central location on the Consortium's web site.

Conclusions

The technological achievements and the statewide informatics infrastructure that have been established by the Consortium will enable robust and efficient studies of biomarkers and their relevance to the clinical course of cancer.

Abstract 2730: Association of TERT promoter mutations with telomerase expression in melanoma

Telomerase reverse transcriptase (TERT) promoter mutations occur at a high frequency in melanoma, but the functional consequences of these mutations in melanoma remain to be clarified. In a large study of melanoma samples by The Cancer Genome Atlas network, mRNA expression analysis using RNA sequencing data showed that only TERT promoter mutations at C228T were associated with high TERT expression levels. The effect of hotspot C250 or C242T/C243T tandem mutations on telomerase expression has not yet been determined. To assess telomerase expression levels in melanomas harboring C250 or C242T/C243T mutations, we used real-time quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) in a sample set of pediatric melanocytic tumors for which the methylation status and the mutational profile of the TERT promoter were known. We previously showed that in a subset of melanoma, TERT expression is mediated epigenetically by promoter hypermethylation rather than by promoter point mutations. Formalin-fixed paraffin-embedded (FFPE) tissues from 10 metastatic melanomas, of which 8 harbored a hotspot TERT promoter mutation (5 C250T; 2 C228; 1 C242T/C243T) and 2 carried a hypermethylated wild-type TERT promoter were examined. For controls, 9 atypical Spitz tumors with a wild-type unmethylated TERT promoter were also studied. Total RNA was isolated from FFPE tumor tissues and converted to cDNA. TERT expression levels were determined by RT-qPCR by using the TaqMan® Gene Expression Assay and normalized with GAPDH as the endogenous control. In the atypical Spitz tumor samples, TERT mRNA expression was undetectable or negligible. In contrast, TERT expression in all melanoma samples was elevated, ranging from 3- to 71-fold (median, 25-fold) when compared to an atypical Spitz tumor as a reference. Our data support that in melanoma, TERT promoter hotspot C250 and C242T/C243T mutations, similar to C228T mutations, correlate with TERT overexpression and that C250 and C242T/C243T mutations likely contribute biologically to tumorigenesis in melanoma.

Citation Format: Seungjae Lee, Patricia Opresko, Alberto Pappo, John Kirkwood, Armita Bahrami. Association of TERT promoter mutations with telomerase expression in melanoma. [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 2730.

Abstract 4302: Long term monitoring of circulating regulatory T cells (Treg), myeloid derived suppressor cella (MDSC) and type I effector T cells in melanoma patients treated with neoadjuvant ipilimumab

Background: Patients with regionally advanced melanoma were treated with neoadjuvant ipilimumab in a previously reported study (Tarhini. PLOS One 2014) where significant changes in circulating Treg, MDSC and peptide specific type I CD4+ and CD8+ T cells were observed early on-treatment (6 weeks) that correlated with clinical outcome.

Methods: Patients were treated with ipilimumab (10 mg/kg IV every 3 weeks x 2 doses) bracketing surgery. Blood (serum / peripheral blood mononuclear cells) specimens were collected at baseline and during treatment for up to 9 months. We conducted longer term monitoring in patients with available specimens at 3 (n = 28), 6 (n = 22) and 9 (n = 13) months utilizing multicolor flow cytometry. We compared the frequencies of circulating suppressive Treg and MDSC on-study to baseline levels, as well as frequencies of CD4+ and CD8+ T cells specific to shared tumor-associated antigens (Gp-100, MART-1, NY-ESO-1) utilizing overlapping peptide libraries (15-mer peptides overlapping by 4). The prognostic value of cell frequencies in relation to the probability of the event of progression at 9 months was tested.

Results: Baseline levels of Treg (CD4+/CD25hi+/CD39+) were significantly associated with 9 months progression free survival (PFS) (p = 0.04). A significant increase in Treg (CD4+CD25hi+Foxp3+ and CD4+/CD25hi+/CD39+) frequencies reported previously at 6 weeks after initiation of ipilimumab appears to have reversed starting 3 months as no significant changes were seen at this or any of the later time points compared to baseline. However, in monitoring the time dependent change over time in circulating Treg there was a trend towards an association with PFS (p = 0.09). Unlike what we had observed and reported at 6 weeks, no significant decrease in MDSC levels was seen at 3 months or later time points compared to baseline. We detected evidence of spontaneous in vivo cross presentation resulting in type I (interferon-γ producing), fully activated (CD69+) CD4+ and CD8+ antigen-specific T-cell immunity against cancer-testis (NY-ESO-1) as well as melanocytic lineage (MART-1, gp100) antigens in the absence of therapeutic vaccination. These responses were significantly potentiated at 6 weeks and persisted at 3, 6 and 9 months following the initiation of ipilimumab.

Conclusions: Neoadjuvant ipilimumab significantly modulates the levels of cellular mediators of immune suppression (Treg and MDSC) early on-treatment with less significant changes seen on long term follow up. Significant potentiation of the type I effector T cell response is seen early and persists on long term monitoring. These biomarkers warrant further investigation in relation to the mechanism of action of ipilimumab and for their potential prognostic and therapeutic predictive value. (Supported by NIH award P50CA121973 and BMS)

Citation Format: Janet Retseck, Amanda Gillespie-Twardy, Alexis Nasr, Hui-Min Lin, Yan Lin, John Kirkwood, Lisa H. Butterfield, Haris Zahoor, Cindy Sander, Ahmad A. Tarhini. Long term monitoring of circulating regulatory T cells (Treg), myeloid derived suppressor cella (MDSC) and type I effector T cells in melanoma patients treated with neoadjuvant ipilimumab. [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 4302. doi:10.1158/1538-7445.AM2015-4302

Consensus nomenclature for CD8+ T cell phenotypes in cancer

Whereas preclinical investigations and clinical studies have established that CD8⁺ T cells can profoundly affect cancer progression, the underlying mechanisms are still elusive. Challenging the prevalent view that the beneficial effect of CD8⁺ T cells in cancer is solely attributable to their cytotoxic activity, several reports have indicated that the ability of CD8⁺ T cells to promote tumor regression is dependent on their cytokine secretion profile and their ability to self-renew. Evidence has also shown that the tumor microenvironment can disarm CD8⁺ T cell immunity, leading to the emergence of dysfunctional CD8⁺ T cells. The existence of different types of CD8⁺ T cells in cancer calls for a more precise definition of the CD8⁺ T cell immune phenotypes in cancer and the abandonment of the generic terms "pro-tumor" and "antitumor." Based on recent studies investigating the functions of CD8⁺ T cells in cancer, we here propose some guidelines to precisely define the functional states of CD8⁺ T cells in cancer.

Atypical Spitzoid neoplasms: a review of potential markers of biological behavior including sentinel node biopsy

Atypical cutaneous melanocytic lesions, including those with Spitzoid features, can be difficult to categorize as benign or malignant. This can lead to suboptimal management, with potential adverse patient outcomes. Recent studies have enhanced knowledge of the molecular and genetic biology of these lesions and, combined with clinicopathological findings, is further defining their biological spectrum, classification, and behavior. Sentinel node biopsy provides important prognostic information in patients with cutaneous melanoma, but its role in the management of melanocytic lesions of uncertain malignant potential (MELTUMP) is controversial. This paper examines the role of molecular testing and sentinel node biopsy in MELTUMPs, particularly atypical Spitzoid tumors.

Dasatinib promotes an expanded and therapeutically-superior T cell repertoire in response to vaccination against melanoma (VAC12P.1014)

Dasatinib (DAS) is a potent inhibitor of the BCR-ABL, SRC, c-KIT, PDGFR and ephrin tyrosine kinases that has demonstrated only modest clinical efficacy in patients with melanoma. Given reports suggesting that DAS enhances T cell infiltration into the tumor microenvironment (TME), we analyzed whether therapy employing the combination of DAS plus specific active vaccination (VAC) would promote superior anti-melanoma efficacy in mice bearing s.c. M05 (B16.OVA) melanomas. We observed that a 7-day course of orally-administered DAS (0.1 mg/day) combined with VAC against the OVA (257-264) peptide epitope resulted in extended overall survival versus either single modality. Immunotherapeutic benefits associated with the DAS + VAC protocol included reduced levels of suppressor cell (MDSC and Treg) populations in the TME, enhanced production of CXCR3 ligand chemokines in the tumor stroma, recruitment of Type-1, vaccine-induced CXCR3+CD8+ tumor-infiltrating lymphocytes (TIL) and IL12p70+CD11c+ dendritic cells (DC) into the TME, and profound “spreading” in the repertoire of tumor-associated antigens recognized by CD8+ TIL. These results have fueled the development of UPCI 12-048 (NCT01876212), a randomized phase II pilot clinical trial of type I-polarized autologous DC vaccines incorporating tumor blood vessel antigen-derived peptides in combination with DAS that is currently enrolling HLA-A2+ patients with metastatic melanoma.

PD-1 and Tim-3 regulate the expansion of vaccine-induced tumor antigen-specific CD8+ T cells in patients with advanced melanoma (VAC3P.944)

Although melanoma vaccines stimulate tumor antigen (TA)-specific CD8+ T cells, objective clinical responses are rarely observed. To investigate this discrepancy, we have evaluated vaccine-induced CD8+ T cells for frequency, function and expression of the inhibitory receptors PD-1 and Tim-3 in patients with metastatic melanoma immunized with incomplete Freund’s adjuvant, CpG-oligodeoxynucleotide, and the HLA-A2-restricted analog peptide NY-ESO-1 157-165V either alone, or in combination with the pan-DR epitope NY-ESO-1 119-143. Both vaccines stimulated rapid TA-specific CD8+ T cell responses detected ex vivo, however, TA-specific CD8+ T cells produced more IFN-γ and exhibited higher lytic function upon immunization with MHC class I and class II epitopes. Notably, the vast majority of vaccine-induced CD8+ T cells upregulated PD-1 whereas a minority also upregulated Tim-3 and the levels of PD-1 and Tim-3 expression by vaccine-induced CD8+ T cells at the time of vaccine administration inversely correlated with their expansion in vivo. PD-1 and Tim-3 blockades further enhanced the expansion and cytokine production of vaccine-induced CD8+ T cells in vitro. Collectively, our findings support the use of PD-1 and Tim-3 blockades in addition to cancer vaccines to stimulate potent antitumor T cell responses and increase the likelihood of clinical responses in patients with advanced melanoma.

Tim-3 is expressed by a majority of NK cells at periphery but not at tumor site in patients with advanced melanoma (TUM2P.919)

Tim-3 is a type I glycoprotein expressed by innate and adaptive immune cells. Tim-3 is an inhibitory receptor expressed by dysfunctional tumor antigen-specific CD8+ T cells of patients with advanced melanoma at periphery and in the tumor microenvironment. Tim-3 is also constitutively expressed by functional and mature NK cells in healthy donors (HD). The expression of Tim-3 on NK cells isolated from melanoma patients (MP) and its role in regulating NK functions have not been evaluated yet. To this end, we have investigated Tim-3 expression by NK cells in PBMCs isolated from HD and MP. In sharp contrast with HD, Tim-3 is upregulated by CD56bright as compared to CD56dim NK cells in PBMCs of MP. Upon stimulation with IL-12 and IL-18, NK cells in HD and MP upregulated Tim-3 expression and Tim-3high NK cells produced more IFN-γ than Tim-3neg, suggesting they are more functional. IFN-γ production increased upon NK stimulation with cytokines and Tim-3 ligand Galectin-9 and did not decrease upon Tim-3 blockade. In contrast to circulating NK cells, tumor-infiltrating NK cells (TINKs) are CD56dim in their large majority (&gt; 98%), and exhibit lower levels of Tim-3 expression. Collectively, our data show that Tim-3 is expressed by a majority of functional circulating NK cells in HD and MP but only a minority of TINK cells, suggesting that TINK may be less functional than their peripheral counterpart.

Blood mRNA expression profiling predicts survival in patients treated with tremelimumab

PURPOSE

Tremelimumab (ticilimumab, Pfizer), is a monoclonal antibody (mAb) targeting cytotoxic T lymphocyte-associated antigen-4 (CTLA-4). Ipilimumab (Yervoy, BMS), another anti-CTLA-4 antibody, is approved by the U.S. Federal Drug Administration (FDA). Biomarkers are needed to identify the subset of patients who will achieve tumor control with CTLA-4 blockade.

EXPERIMENTAL DESIGN

Pretreatment peripheral blood samples from 218 patients with melanoma who were refractory to prior therapy and receiving tremelimumab in a multicenter phase II study were measured for 169 mRNA transcripts using reverse transcription polymerase chain reaction (RT-PCR). A two-class latent model yielded a risk score based on four genes that were highly predictive of survival (P < 0.001). This signature was validated in an independent population of 260 treatment-naïve patients with melanoma enrolled in a multicenter phase III study of tremelimumab.

RESULTS

Median follow-up was 297 days for the training population and 386 days for the test population. Expression levels of the 169 genes were closely correlated across the two populations (r = 0.9939). A four-gene model, including cathepsin D (CTSD), phopholipase A2 group VII (PLA2G7), thioredoxin reductase 1 (TXNRD1), and interleukin 1 receptor-associated kinase 3 (IRAK3), predicted survival in the test population (P = 0.001 by log-rank test). This four-gene model added to the predictive value of clinical predictors (P < 0.0001).

CONCLUSIONS

Expression levels of CTSD, PLA2G7, TXNRD1, and IRAK3 in peripheral blood are predictive of survival in patients with melanoma treated with tremelimumab. Blood mRNA signatures should be further explored to define patient subsets likely to benefit from immunotherapy.

Pathologic and gene expression features of metastatic melanomas to the brain

BACKGROUND

The prognosis of metastatic melanomas to the brain (MBM) is variable with prolonged survival in a subset. It is unclear whether MBM differ from extracranial metastases (EcM) and primary melanomas (PrM).

METHODS

To study the biology of MBM, histopathologic analysis of tumor blocks from patients' craniotomy samples and whole-genome expression profiling (WGEP) with confirmatory immunohistochemistry were performed.

RESULTS

High mononuclear infiltrate and low intratumoral hemorrhage were associated with prolonged overall survival (OS). Pathway analysis of WGEP data from 29 such craniotomy tumor blocks demonstrated that several immune-related BioCarta gene sets were associated with prolonged OS. WGEP analysis of MBM in comparison with same-patient EcM and PrM showed that MBM and EcM were similar, but both differ significantly from PrM. Immunohistochemical analysis revealed that peritumoral CD3⁺ and CD8⁺ cells were associated with prolonged OS.

CONCLUSIONS

MBMs are more similar to EcM compared with PrM. Immune infiltrate is a favorable prognostic factor for MBM.

Dasatinib is an effective adjuvant to therapeutic vaccination against melanoma (P4269)

Dasatinib (DAS) is an FDA-approved inhibitor of receptor tyrosine kinases (RTKs) (i.e., EphA2 and PDGFRβ) involved in vasculature development/maintenance of solid cancers such as melanoma. Administration of DAS transiently normalizes tumor blood vessels and reduces lesional interstitial pressure, hypoxia, and acidosis (which typically impede the efficacy of standard of care therapies). We hypothesized that DAS-induced vascular changes would lead to improved recruitment of therapeutic effector T cells, particularly after specific vaccination. As a model system, C57BL/6 mice bearing established day 7 subcutaneous B16 melanomas were vaccinated (weekly x 2; VAC) with a tumor-specific DC-based vaccine +/- DAS (i.p. daily for days 7-13). We confirmed that DAS reconditioned tumor blood vessels based on a disruption of hypoxia (reduced expression of HIF-1α/HIF-2α and cancer stem cell markers) and pericyte/endothelial cell architecture. Interestingly, DAS also abrogated systemic frequencies of the MDSC/Treg cell immunosuppressor cell populations. Combination VAC + DAS therapy provided superior anti-tumor protection versus either monotherapy, which correlated with the enhanced trafficking of antigen-specific CD8+ T effectors into tumor lesions. Overall, these results support the clinical translation of this combination immunotherapy for the treatment of melanoma.

Abstract 21: Survival prognostic significance of TNFRII, TGFa, TIMP1 & CRP in high-risk melanoma patients

Background:

The E1694 trial tested the GM2-KLH-QS21 (GMK) vaccine versus high dose interferon-alpha2b as adjuvant therapy for patients with operable high-risk stage IIB/III melanoma in relation to relapse-free survival (RFS) and overall survival (OS). Multiplex analysis of candidate serum analytes utilizing banked specimens from patients participating in this trial was evaluated to develop biomarkers of prognostic or therapeutic predictive value.

Methods:

The Aushon Multiplex Platform was used to simultaneously quantitate the serum levels of 115 candidate analytes selected based on previous data. Univariate proportional hazard (PH) model was used to assess the association between each marker and OS or RFS. The Benjamini and Hochberg's method was used to adjust for multiple testing. Baseline serum samples from 40 patients treated with the GMK vaccine were analyzed. The least absolute shrinkage and selection operator proportional hazard regression (LASSOPH) was used to select markers that are most informative for RFS and OS. We then fit the regular PH models using the markers selected by the LASSOPH. The survival ROC analysis was used to evaluate the ability of the models to predict 1 year RFS and 5 year OS. Leave-one-out cross validations (LOOCVs) were used to avoid over fitting.

Results:

A panel of four markers, Tumor Necrosis Factor alpha Receptor II (TNFRII), Transforming Growth Factor alpha (TGFa), Tissue Inhibitor of Metalloproteinases 1 (TIMP1), and C-reactive protein (CRP), at baseline was found to be most informative to OS after GMK vaccine treatment (high serum levels correlate with worse prognosis). The dichotomized risk score based on the four markers can separate the OS curves well (log rank test p-value=0.0005). When using the 4 marker PH model to predict the 5 year OS, we achieved an AUC of 89% (cross validated AUC=72%). High baseline TNFRII was also identified as the most informative marker of worse RFS after GMK vaccine. The RFS of patients with high (above median) baseline TNFRII was significantly lower than that of patients with low (below median) baseline TNFRII (log rank test p-value=0.01).

Conclusions:

Our modeling analysis yielded a panel of four serum biomarkers that is significantly prognostic of survival in patients with high-risk melanoma and warrants further investigation.

Citation Format: Ahmad A. Tarhini, Yan Lin, William A. LaFramboise, Sandra Lee, John Kirkwood. Survival prognostic significance of TNFRII, TGFa, TIMP1 & CRP in high-risk melanoma patients. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 21. doi:10.1158/1538-7445.AM2013-21

Linear accelerator based stereotactic radiosurgery for melanoma brain metastases

PURPOSE

Melanoma is one of the most common malignancies to metastasize to the brain. Many patients with this disease will succumb to central nervous system (CNS) disease, highlighting the importance of effective local treatment of brain metastases for both palliation and survival of the disease. Our objective was to evaluate the outcomes associated with stereotactic radiosurgery (SRS) in the treatment of melanoma brain metastases.

MATERIALS AND METHODS

We retrospectively reviewed 54 patients with a total of 103 tumors treated with SRS. Twenty patients had prior surgical resection and nine patients underwent prior whole brain radiation therapy (WBRT). 71% of patients had active extracranial disease at the time of SRS. Median number of tumors treated with SRS was 1(range: 1-6) with median radiosurgery tumor volume 2.1 cm 3 (range: 0.05-59.7 cm 3 ). The median dose delivered to the 80% isodose line was 24 Gy in a single fraction.

RESULTS

The median follow-up from SRS was five months (range:1-30 months). Sixty-five percent of patients had a follow-up MRI available for review. Actuarial local control at six months and 12 months was 87 and 68%, respectively. Eighty-one percent of patients developed new distant brain metastases at a median time of two months. The six-month and 12-month actuarial overall survival rates were 50 and 25%, respectively. The only significant predictor of overall survival was surgical resection prior to SRS. Post-SRS bleeding occurred in 18% of patients and at a median interval of 1.5 months. There was only one episode of radiation necrosis with no other treatment-related toxicity.

CONCLUSION

SRS for brain metastases from melanoma is safe and achieves acceptable local control.

The upregulation of the inhibitory receptors BTLA and PD-1 defines a novel subset of dysfunctional tumor antigen-specific CD8+ T cells (127.19)

Cytotoxic T cells present at the periphery or at tumor sites recognize tumor epitopes presented by melanoma cells but fail to induce tumor rejection in melanoma patients. Inhibitory receptors including PD-1 and Tim-3 expressed by spontaneous CD8+ T cells directed against the cancer-germline antigen NY-ESO-1 play a role in promoting tumor-induced T cell dysfunction. In the present study, we show that BTLA is upregulated on spontaneous NY-ESO-1-specific CD8+ T cells and that BTLA-expressing PD-1+Tim-3- CD8+ T cells represent the largest subset of NY-ESO-1-specific CD8+ T cells in melanoma patients. These cells were partially dysfunctional, producing less IFN-γ than BTLA- T cells, but more IFN-γ, TNF and IL-2 than the highly dysfunctional subset expressing all three receptors. Unlike PD-1, BTLA expression by NY-ESO-1-specific CD8+ T cells does not increase with higher T cell dysfunction or upon cognate antigen stimulation, suggesting that BTLA upregulation occurs independently of functional exhaustion driven by high antigen load. Finally, BTLA blockade adds to PD-1 and Tim-3 blockades, enhancing NY-ESO-1-specific CD8+ T cell expansion, proliferation and cytokine production. Collectively, our findings support the targeting of BTLA, PD-1 and Tim-3 pathways to reverse tumor-induced T cell dysfunction in patients with advanced melanoma.

Abstract 5557: Mutation analysis of melanoma tumor samples from ECOG 2603 clinical trial

The BRAF kinase, a member of the MAP kinase pathway, has emerged as an attractive molecule to target in melanoma. In an initial attempt to target BRAF in melanoma, a randomized, phase III trial (ECOG 2603) of carboplatin, paclitaxel, and sorafenib versus carboplatin, paclitaxel, and placebo was performed. Patients enrolled on the trial had either unresectable, locally advanced Stage III or Stage IV melanoma. We analyzed patients’ tumor samples for 74 mutations in 13 genes using a custom iPlex (Sequenom). We have preliminarily analyzed 157 tumor samples from patients enrolled in this clinical trial. Analysis of the initial data set demonstrates that 62 samples (42%, 62/148, 95% CI 34%,50%) carried BRAF mutations - 60 samples with V600 and two samples having a BRAF V601 mutation. Thirty eight samples (26%, 38/148, 95% CI 19%,33%) were positive for NRAS mutations, with 33 with Q61, two G12 and three G13 mutations. With the exception of one tumor sample, the BRAF and NRAS mutations were negatively correlated with each other, consistent with prior observations. We also observed a number of rare mutations in our samples including one in AKT1, one in AKT3, four in CDK4, five in beta-catenin, two in GNAQ and three in KIT. The results of this study demonstrated no difference between the two treatment arms in OS and PFS and no association with treatment outcome and BRAF and NRAS mutations. Consequently, the treatment arms were collapsed, and we examined the relationship of BRAF and NRAS mutations with OS and PFS. Interestingly, our data demonstrated that the BRAF and NRAS mutations did not correlate with OS or PFS. This sample population is unique in that it provides a large data set of melanoma tumor samples, all of whom were entered on a clinical trial, unselected for pre-existing mutations. Using the Sequenom assay platform, we have identified a number of mutations in a subset of genes known to be involved in melanoma in patient tumor samples. In the future, these tumor samples will be informative as we continue to examine and identify additional genetic alterations in melanoma, providing information regarding the natural history and distribution of certain mutations. Future studies will use array comparative genomic hybridization to further investigate additional somatic mutations occurring in melanoma tumors and correlate these with clinical outcome, as well as provide insight into the pathogenesis of melanoma. These results may lead to further opportunities for clinical trials.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5557. doi:1538-7445.AM2012-5557

Abstract B144: Elesclomol, an inducer of oxidative stress, targets oxidative phosphorylation (oxphos) in melanoma cells

Mitochondria are important gatekeepers of cell survival in melanoma cells and their role as oxygen sensors, ATP producers, or inducers of reactive oxygen species are established. However, the role(s) of metabolic processes other than glycolysis are not well characterized in melanoma development and progression. Here we show that melanoma cells exhibit higher levels of oxidative phosphorylation (Oxphos) compared to human epidermal melanocytes. Furthermore, we present several independent lines of evidence (bioenergetics analysis using Seahorse XF24, stable isotope labeling of melanoma cells in culture, immunoblot analysis of isolated mitochondria, electron microscopy, and rho zero cells) that elesclomol, an inducer of oxidative stress, suppresses Oxphos in melanoma cells without a significant effect on glycolysis in vitro. Melanoma cells with intrinsically high levels of glycolysis are less sensitive to elesclomol. In addition, following chronic continuous drug exposure, resistant cells manifest a high glycolytic phenotype. Finally hypoxia inducible factor 1 alpha, a master metabolic switch of cell metabolism towards glycolysis, is upregulated following elesclomol treatment in a number of melanoma cell lines examined. Our results suggest that Oxphos is an important therapeutic target and that elesclomol specifically impinges on this process.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B144.

Targeting PD-1 and Tim-3 pathways to reverse tumor antigen-specific CD4+ T cell dysfunction in patients with advanced melanoma (66.1)

The coexistence of spontaneous tumor antigen-specific immune T cell responses with progressive disease in cancer patients furthers the need to dissect the molecular pathways involved in tumor-induced T cell dysfunction and exhaustion. We have previously observed in patients with advanced melanoma that NY-ESO-1-specific CD8+ T cells upregulate PD-1 and a fraction of PD-1+ NY-ESO-1-specific CD8+ T cells upregulates Tim-3. We have found that Tim-3+PD-1+ NY-ESO-1-specific CD8+ T cells represent highly dysfunctional T cells. Importantly, Tim-3 and PD-1 pathway blockades synergized to enhance immune functions of NY-ESO-1-specific CD8+ T cells upon prolonged antigen stimulation. Whether the upregulation of PD-1 and Tim-3 is associated with tumor antigen-specific CD4+ T cell dysfunction remains unknown. Here, our findings in advanced melanoma patients show that in contrast to virus-specific and total CD4+ T cells, PD-1 and Tim-3 expression is upregulated by NY-ESO-1-specific CD4+ T cells. Interestingly, PD-1 and Tim-3 pathway blockades synergized to restore the numbers of cytokine-producing and proliferating NY-ESO-1-specific CD4+ T cells. Collectively, our findings support the use of Tim-3 and PD-1 pathway blockades to reverse tumor-induced CD8+ and CD4+ T cell exhaustion in patients with advanced melanoma. Our findings have significant implication in terms of novel immunotherapeutic strategies aiming at promoting T cell-mediated tumor regression in patients with advanced cancers.

Charge interaction between particle-laden fluid interfaces

Experiments are described where two oil/water interfaces laden with charged particles move at close proximity relative to one another. The particles on one of the interfaces were observed to be attracted toward the point of closest approach, forming a denser particle monolayer, while the particles on the opposite interface were repelled away from this point, forming a particle depletion zone. Such particle attraction/repulsion was observed even if one of the interfaces was free of particles. This phenomenon can be explained by the electrostatic interaction between the two interfaces, which causes surface charges (charged particles and ions) to redistribute in order to satisfy surface electric equipotential at each interface. In a forced particle oscillation experiment, we demonstrated the control of charged particle positions on the interface by manipulating charge interaction between interfaces.

A multi-center phase II evaluation of the small molecule survivin suppressor YM155 in patients with unresectable stage III or IV melanoma

Melanoma continues to be a major health problem with no effective therapy. Melanocytes, both benign and malignant, express many anti-apoptotic factors. Survivin is a member of the family of inhibitors of apoptosis proteins (IAP) and is preferentially expressed in tumor cells, including melanoma. YM155 is a small molecule suppressant of survivin that has been shown in preclinical cell lines, xenograft models and phase I studies to have anti-tumor activity.

METHODS

This was an open-label, multi-center, study of YM155 monotherapy in subjects with unresectable stage III or IV melanoma. Thirty-four chemotherapy naïve subjects were treated with YM155 at a dose of 4.8 mg/m(2)/day administered by continuous infusion for 168-hours (7 days) followed by a 14-day rest period, for up to 6 cycles or until disease progression.

RESULTS

One subject had a partial response to treatment seen at cycle two and lasting through cycle eight. Median progression-free survival was 1.3 months (95% CI; 1.3-2.7). Median overall survival was 9.9 months (95% CI; 7.0-14.5). Overall, YM155 was well tolerated with the most common (>20%) adverse events reported as fatigue, nausea, pyrexia, headache, arthralgia and back pain. Only four subjects required dose reductions.

CONCLUSIONS

YM155 was well tolerated in subjects with advanced melanoma; however, the pre-specified primary end-point for efficacy which required two responders in 29 evaluable subjects was not achieved.

Effect of TKI258 on plasma biomarkers and pharmcokinetics in patients with advanced melanoma

9020

Background: TKI258 (dovitinib lactate), is a multi-tyrosine kinase inhibitor of VEGF receptors-1,2,3, FGF receptors-1, 2, 3, PDGFR-β, and c-KIT. A phase I study was conducted to determine the maximum tolerated dose (MTD), the biological activity and the preliminary efficacy of TKI258 in patients with advanced melanoma. A panel of plasma biomarkers of angiogenesis and soluble receptors were evaluated to determine the pharmacodynamic effect of TKI258. Methods: Patients were treated orally with 200, 300, 400 or 500 mg/day on a once daily continuous dose schedule. The MTD was defined at 400 mg/day. Plasma samples from 43 patients were collected. Plasma concentration of TKI258 was measured by LC/MS/MS. Plasma VEGF, placental growth factor (PLGF), basic FGF (bFGF), and soluble VEGFR1 and VEGFR2 (sVEGFR1 and 2), and c-Kit were measured by multiplex assays using the Meso-Scale Discovery platform. Plasma FGF23 was evaluated by ELISA as a pharmcodynamic marker of FGFR1 inhibition. Results: Following 400 mg or 500 mg continuous daily dosing, the mean plasma exposure (AUC24hr) was approximately 3000 ng/mL*h and 4100 ng/mL*h, respectively. No accumulation in TKI258 plasma exposure was observed at doses of 400mg or below, while accumulation up to 2.5-fold was observed on day 15 following the 500 mg daily dose. At the end of the first treatment cycle, mean plasma VEGF, PLGF and FGF23 levels increased over baseline by 100%, 198% and 68%, respectively, while mean plasma sVEGFR2 levels decreased by 15% in patients treated with 400 and 500 mg/day TKI258. Further analysis of correlations with pharmacokinetic and clinical parameters is ongoing. Conclusions: TKI258 therapy is associated with increases of plasma VEGF and PLGF as well as decreases of sVEGFR2 suggesting VEGFR inhibition. Induction of plasma FGF23 suggest that FGFR may be inhibited at doses of 400 mg/day and above. This panel of circulating proteins may have utility as pharmacodynamic biomarkers of TKI258 activity in patients with advanced melanoma.

[Table: see text]

Continuous Intra-Lymphatic Dendritic Cell Infusion in Patients with Advanced Melanoma (41.51)

Continuous intralymphatic delivery of dendritic cells (DCs), using implantable lymphatic cannulas, allows to efficiently deliver "non-exhausted" DCs to draining lymph nodes without the disruption of nodal structures, and to recreate the physiologic kinetics of DC accumulation observed during physiologic immune responses.

We have completed initial feasibility and safety evaluation of semi-continuous intralymphatic infusions of antigen-loaded DCs (a total of 300,000 DCs over 4 days) in six patients with stage IIIb-IV melanoma in clinical trial UPCI 03-118. Four of the initial six patients received two four-day-long courses of the intralymphatic DC infusions, completing the protocol. Two patients did not complete the treatment for reasons unrelated to the protocol.

Already at this ultra-low dose of DCs, we have observed evidence of clinical efficacy of DC infusions in 3 of 4 patients with stage IV melanoma who completed both courses of treatment. We observed one near-complete response (currently &gt;20 months), and two disease stabilizations (10 months; and &gt; 7 months), with only one patient progressing. We have recently initiated the evaluation of "high-dose" intralymphatic infusions (total of 3 million DCs over 4 days).

Our data demonstrate the feasibility of prolonged intralymphatic delivery of biotherapeutic agents and provide preliminary indication that DCs can be clinically effective in patients with advanced cancer at the doses 100-fold lower than previously considered to be necessary.