BackgroundHigh C reactive protein (CRP) levels have been reported to be associated with a poor clinical outcome in a number of malignancies and with programmed cell death protein 1 immune checkpoint blockade in patients with advanced cancer. Little is known about the direct effects of CRP on adaptive immunity in cancer. Therefore, we investigated how CRP impacted the function of T cells and dendritic cells (DCs) from patients with melanoma.MethodsThe effects of CRP on proliferation, function, gene expression and phenotype of patient T cells and DCs, and expansion of MART-1 antigen-specific T cells were analyzed by multicolor flow cytometry and RNA-seq. Additionally, serum CRP levels at baseline from patients with metastatic melanoma treated on the Checkmate-064 clinical trial were assessed by a Luminex assay.ResultsIn vitro, CRP inhibited proliferation, activation-associated phenotypes and the effector function of activated CD4+ and CD8+ T cells from patients with melanoma. CRP-treated T cells expressed high levels of interleukin-1β, which is known to enhance CRP production from the liver. CRP also suppressed formation of the immune synapse and inhibited early events in T-cell receptor engagement. In addition, CRP downregulated the expression of costimulatory molecules on mature DCs and suppressed expansion of MART-1-specific CD8+ T cells in a dose-dependent manner by impacting on both T cells and antigen-presenting cells. High-serum CRP levels at baseline were significantly associated with a shorter survival in both nivolumab-treated and ipilimumab-treated patients.ConclusionsThese findings suggest that high levels of CRP induce an immunosuppressivemilieuin melanoma and support the blockade of CRP as a therapeutic strategy to enhance immune checkpoint therapies in cancer.Trial registration numberNCT01783938andNCT02983006.

The recent demonstration of the antitumor efficacy of checkpoint protein inhibition has resulted in the approval of blocking antibodies against the programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway in multiple different histologic findings. Therapeutic successes with PD-1/PD-L1 antibodies in melanoma and lung cancer have been followed by approvals in bladder, renal, and head and neck cancers and Hodgkin lymphoma, with others undoubtedly to come. However, PD-1 is only one of many checkpoints and agonistic regulatory molecules expressed on T cells by which maintenance of the balance between costimulatory and coinhibitory signaling pathways is perturbed in cancer. The manipulation of many of these molecules in cancer patients might be associated with clinical benefit. The majority of the T-cell cosignaling receptors belong to either the immunoglobulin superfamily or the tumor necrosis factor receptor superfamily. A total of 29 immunoglobulin superfamily and 26 tumor necrosis factor receptor superfamily cosignaling receptors have been identified that are expressed on T cells, providing fertile ground for development of inhibitory or agonistic antibodies and small molecules as cancer therapeutics. In the current work, we focus on some of the most promising new checkpoints and agonistic or cosignaling molecules that are in early clinical development as single agents or in combinations with PD-1/PD-L1, cytotoxic T-lymphocyte-associated protein 4 blockade, or chemotherapy with an emphasis on those that have reached the clinic and on important targets that are in late preclinical development.

The power of proteomics allows unparalleled opportunity to query the molecular mechanisms of a malignant cell and the tumor microenvironment in patients with ovarian cancer and other solid tumors. This information has given us insight into the perturbations of signaling pathways within tumor cells and has aided the discovery of new drug targets for the tumor and possible prognostic indicators of outcome and disease response to therapy. Proteomics analysis of serum and ascites has also given us sources with which to discover possible early markers for the presence of new disease and for the progression of established cancer throughout the course of treatment. Unfortunately, this wealth of information has yielded little to date in changing the clinical care of these patients from a diagnostic, prognostic, or treatment perspective. The rational examination and translation of proteomics data in the context of past clinical trials and the design of future clinical trials must occur before we can march forward into the future of personalized medicine.

9547 Background: Immune checkpoint blockade is standard therapy for advanced melanoma (MEL), yet not all patients (pts) benefit. Panobinostat (PAN), a pan inhibitor of class I, II, and IV histone deacetylases (HDAC) is immunomodulatory, decreases tumor associated inhibitory cytokines and inhibition of effector T-cells. This dose finding study aimed to determine the safety and efficacy of escalating doses of PAN combined with ipilimumab (IPI) in advanced MEL. Methods: Eligible pts with unresectable stage 3/4 MEL, up to 3 prior lines of therapy, and adequate laboratory values were treated with oral PAN 5mg thrice weekly (TIW) plus IPI at 3mg/kg IV every 3 weeks X 4 doses, followed by maintenance PAN until progression or intolerance. Using a modified Ji design, PAN dose escalation by 5mg was planned in 3-12 pt cohorts up to a maximum dose of 20mg TIW, without intra-pt dose escalation. Dose limiting toxicity (DLT) was assessed up to day 84 from start of therapy. Results: Seventeen pts (M/F: 13/4), median age 66 yrs (48, 80) were treated with a median of 4 cycles of IPI (1,4). Of 6 pts treated at PAN 5mg TIW, there was one DLT (G3 hydronephrosis). Eleven pts received PAN 10mg TIW; of 9 evaluable for DLT, there were 3 DLTs (G3 rash, G3 diarrhea, G4 thrombocytopenia) preventing further dose escalation. Other G3 toxicities included anemia, hypophysitis, diarrhea, fatigue (all n = 2); rash, colitis, nausea, dehydration, dizziness, hypotension, ↑ lipase, ↓ sodium, & ↑ glucose (all n = 1). Three pts had previous anti-PD1 therapy. The response rate was 12% (2 PRs) with 35% stable disease. One pt remains on PAN > 24m since start of therapy. Median progression free- and overall survival was 2.23m (95% CI,1.57, 5.8) and 20.97m (95% CI, 8.97, NR) respectively. Biomarker analysis from peripheral blood and limited tumor biopsies pre-and on treatment examining immunoregulatory markers, including EOMES promoter acetylation in T-cells from PAN are ongoing. Conclusions: At tolerated doses, PAN does not appear to increase response to standard IPI in advanced MEL. Biomarker analyses will inform if immunomodulation by PAM improves efficacy of IPI. Combinations with selective HDAC inhibitors may be more appropriate for future study. Supported by grant P50 CA168536, Moffitt Skin Cancer SPORE. Clinical trial information: NCT02032810.

Pancreatic neuroendocrine tumors (panNETs) are a type of neuroendocrine tumor with 5-year overall survival rates of approximately 50% when metastasis is present at diagnosis. Tumor grade, as defined by Ki-67 proliferation index, influences overall survival, with low-grade tumors portending a better outcome than intermediate- and high-grade tumors. This case report follows the clinical course and management of a patient with an insulin-secreting metastatic panNET who died 10 years after diagnosis after a treatment course with regional therapy and multiple forms of cytotoxic and molecularly targeted agents. This report presents the various treatment options available for patients with insulin-secreting metastatic panNETs.