Faculty Bibliography

Blockade of the co-inhibitory receptor PD-1 has had unprecedented success in the treatment of metastatic melanoma, with response rates of approximately 40% in previously untreated patients. However, since the majority of patients fail to respond, a better understanding of the mechanisms of action involved in response/resistance and novel approaches to overcome resistance are needed. We evaluated T-cells present in peripheral blood samples of resected stage III/IV melanoma patients treated with adjuvant nivolumab. Data from intra-patient, paired pre-treatment/post-treatment samples showed a significant (p<0.05) increase in phosphorylated STAT3 (pSTAT3) in patients without relapse, but not in patients relapsing. Increases in regulatory T-cells (Tregs) (p<0.05) in relapsers, but not in non-relapsers, and OX40 expression on Tregs (p<0.05) in both relapsers and non-relapsers were also observed. Based on these data we evaluated the ability of PD-1 blocking antibodies to induce pSTAT3 signaling in vitro. Culturing with anti-PD-1 significantly increased levels of pSTAT3 in T-cells, including Tregs, both at the basal state (p<0.05) and post-CD3/CD28 activation (p<0.01). Additionally, culturing Tcells with PD-1 blocking antibodies increased the production of the STAT3 regulated cytokine IL-10 (p<0.05), the number of Tregs (p<0.01) and Treg expression of OX40 (p<0.05). Increases in all these markers/populations were abrogated with the addition of a STAT3 inhibitor (p<0.01). Similar increases in the number of Tregs and the expression of OX40 were also found when T-cells were treated in vitro with recombinant IL-10. Addition of IL-10 neutralizing antibodies ameliorated upregulation of Treg numbers and OX40 expression resulting from PD-1 blockade. Additionally, serum levels of IL-10 were found to be significantly elevated in non-relapsing patients relative to relapsers (p<0.05). RNA-seq analysis comparing Tregs from relapsers to non-relapsers further supported the observed increase in Tregs resulting from nivolumab treatment, with pathway analyses demonstrating significantly increased cell cycle, DNA replication, mitosis and other proliferation related pathways in Tregs from non-relapsed patients. Next we evaluated changes in the function of patient Tregs in an allogenic mixed lymphocyte suppression assay. Tregs from non-relapsers had a significant reduction in suppressive capacity post-nivolumab treatment in paired analyses (p<0.05), while Tregs from relapsers had no significant change. Post-treatment samples from relapses were also found to be significantly more suppressive (p<0.01) than those of non-relapsers. Additionally, decreased percentages of CCR4+CD45RA+ Tregs, previously described as having enhanced suppressive capacity, were found in non-relapsers post-treatment, but not in relapsers. A similar decrease in CCR4+CD45RA+ Tregs was achieved in vitro using OX40 agonist antibodies. Therefore, we propose that PD-1 blockade triggers STAT3 signaling, a hereunto unknown effect. These data support a model in which STAT3 induction by PD-1 blockade results in IL-10 production, which induces proliferation of Tregs with reduced suppressive capacity and triggers OX40 expression. Based on these results and previous findings of others demonstrating that ligation of OX40 expressed on Tregs hinders suppressive capacity, combining OX40 agonist antibodies may enhance the effectiveness of PD-1 blockade by reducing Treg suppression

Immunotherapy strategies for the treatment of melanoma have achieved impressive clinical outcomes over the past decade. Response rates to checkpoint blockade by PD-1 and CTLA-4 antibodies range from 15-40%, while in adoptive cell therapy using tumor infiltrating lymphocytes (TILs), anti-tumor response is observed in approximately 50%. However, the need to improve immunotherapies is evident as the majority of patients are unresponsive to treatment. Dysfunctional T-cells are thought to contribute to failed responses to checkpoint inhibition. As such we sought to investigate the ability of drugs targeting the epigenetic regulatory machinery as a means to alter T-cell function(s) and improve the anti-melanoma response. Here we demonstrate that the HDAC6 selective inhibitor ACY1215 disrupts mTORC signaling pathways in T-cells obtained from melanoma patients. Phosphorylation of mTOR, RAPTOR and the downstream molecules AKT, SGK1, PKCa and S6K were reduced on CD4 and CD8⁺ T-cells after ACY1215 in vitro treatment (p<0.05). The levels of the Th2 cytokines IL-4, IL-6, IL-10 generated by ACY1215-treated T-cells (p<0.05) were also decreased. Similar results were achieved with an SGK1 inhibitor, in agreement with published data demonstrating SGK1 as a regulator of Th2 polarization. Since the mTOR/RAPTOR complex is known to be involved in determining T regulatory (Treg) function, the effects of ACY1215 on Tregs were evaluated. Treatment in vitro with ACY1215 decreased phosphorylated mTOR and RAPTOR in Tregs, and reduced the levels of FOXP3. In a functional suppression assay, ACY1215-treated Tregs displayed a reduced ability to impair proliferation of effector T-cells (Teff) compared to control (DMSO: 10% vs ACY1215: 25% Teff proliferation, p<0.05). To explore whether HDAC inhibition during expansion of tumor infiltrating lymphocytes (TIL) for adoptive transfer would improve their quality and anti-tumor reactivity, TIL isolated from melanoma surgical biopsies were cultured in vitro with IL-2 and ACY1215. Treatment with ACY1215 led to an accumulation of central memory CD4 and CD8⁺ TILs (p<0.01 and p<0.05, respectively), which was maintained even after rapid expansion with anti-CD3 and anti-CD28 stimulation in vitro. Similarly, ACY1215 treatment of T-cells derived from peripheral blood of melanoma patients and healthy donors also displayed an increased central memory phenotype, characterized by expression of CD45RO, CD62L and CCR7 (p<0.05). Inhibition of AKT has been shown to increase T-cells with memory characteristics, and the use of an AKT inhibitor also resulted in accumulation of central memory T-cells. Confirming the observed phenotypic changes, microarray analysis of ACY1215-treated TILs revealed up-regulation of genes associated with a T-cell central memory and inflammatory response (e.g. SELL, LEF1, TNFRSF9) and downregulation of genes associated with Treg function (e.g. LGMN, CXCL8). Collectively these data suggest that reprogramming T-cells with epigenetic modulators may improve melanoma immunotherapy by reducing Treg suppression and production of immunosuppressive cytokines, while favoring generation of central memory T-cells

PURPOSE/OBJECTIVE:Retrospective analysis of irAEs in melanoma patients treated with nivolumab. EXPERIMENTAL DESIGN/METHODS:Data were pooled from 148 patients (33 resected, 115 unresectable) treated with nivolumab plus peptide vaccine or nivolumab alone every 2 weeks for 12 weeks. Patients with stable disease or regression received an additional 12-week cycle, then nivolumab alone every 12 weeks for up to 2 additional years. Frequency, grade, and characteristics of immune-related adverse events (irAE) were analyzed. A 12-week landmark survival analysis using a multivariate time-dependent Cox proportional hazard model assessed difference in overall survival (OS) in the presence or absence of irAEs. RESULTS:IrAEs of any grade were observed in 68.2% of patients (101 of 148). Grade III/IV irAEs were infrequent: 3 (2%) had grade III rash, 2 (1.35%) had asymptomatic grade III elevation in amylase/lipase, and 2 (1.35%) had grade III colitis. A statistically significant OS difference was noted among patients with any grade of irAE versus those without (P ≤ 0.001), and OS benefit was noted in patients who reported three or more irAE events (P ≤ 0.001). Subset analyses showed statistically significant OS differences with rash [P = 0.001; HR, 0.423; 95% confidence interval (CI), 0.243-0.735] and vitiligo (P = 0.012; HR, 0.184; 95% CI, 0.036-0.94). Rash and vitiligo also correlated with statistically significant OS differences in patients with metastatic disease (P = 0.004 and P = 0.028, respectively). No significant survival differences were seen with other irAEs (endocrinopathies, colitis, or pneumonitis). CONCLUSIONS:Cutaneous irAEs are associated with improved survival in melanoma patients treated with nivolumab, and clinical benefit should be validated in larger prospective analyses.

The prognosis of patients with gastrointestinal (GI) melanoma metastases is poor. Surgery renders select patients disease free and/or palliates symptoms. We reviewed our single-institution experience of resection with GI melanoma metastases. A retrospective review was performed on patients who underwent surgery for GI melanoma metastases from 2007 to 2013. Fifty-four patients were identified and separated based on completeness of resection into curative 13 (24%) and palliative 41 (75.9%) groups. Thiry-six (63.2%) were symptomatic preoperatively with bleeding and/or obstruction/pain with 91.7 per cent achieving objective symptom relief. Thirty-day operative mortality was 0 per cent. The most common complication was wound infection (n = 5); major complications like anastomotic leak (n = 1) were uncommon. With a median follow-up of 9.5 months (range 0.2-75.8), median overall survival was not reached (curative) versus 9.53 months (palliative group). Median recurrence-free and progression-free survival after resection were 18.89 and 1.97 months in the curative versus palliative groups, respectively. On multivariate analysis, resection to no clinical evidence of disease (P = 0.012) and presence of single metastases (P = 0.031) were associated with improved overall survival. Surgery for GI metastases from melanoma provides symptomatic relief without major morbidity. Fewer metastases and curative resection were associated with improved survival.

BACKGROUND: Manipulation of immune checkpoints such as CTLA4 or PD-1 with targeted antibodies has recently emerged as an effective anticancer strategy in multiple malignancies. Sarcomas are a heterogeneous group of diseases in need of more effective treatments. Different subtypes of soft tissue and bone sarcomas have been shown to express PD-1 ligand. METHODS: We retrospectively analyzed a cohort of patients (pts) with relapsed metastatic/unresectable sarcomas, who were treated with nivolumab provided under a patient assistance program from the manufacturer. Pts underwent CT or PET/CT imaging at baseline and after at least four doses of nivolumab; RECIST 1.1 criteria were used for response assessment. RESULTS: Twenty-eight pts with soft tissue (STS, N = 24) or bone sarcoma (N = 4), received IV nivolumab 3 mg/kg every 2 weeks from July 2015. Median age was 57 (24-78), male:female ratio was 14:14; the median number of nivolumab cycles was eight. Eighteen pts concomitantly received pazopanib at 400-800 mg daily. The most common side effect was grade 1-2 LFT elevations; grade 3-4 toxicity occurred in five patients (colitis, LFT elevations, pneumonitis). Twenty-four pts received at least four cycles. We observed three partial responses: one dedifferentiated chondrosarcoma, one epithelioid sarcoma and one maxillary osteosarcoma (last two patients on pazopanib); nine patients had stable disease including three leiomyosarcomas; 12 patients had progression of disease including 4 leiomyosarcoma. Clinical benefit (response + stability) was observed in 50% of the evaluable patients. CONCLUSIONS: These data provide a rationale for further exploring the efficacy of nivolumab and other checkpoint inhibitors in soft tissue and bone sarcoma.

BACKGROUND: Ipilimumab and peginterferon alfa-2b are established systemic treatment options for melanoma that have distinct mechanisms of action. Given the need for improved therapies for advanced melanoma, we conducted an open-label, single institution, phase Ib study to assess the safety and tolerability of using these two agents in combination. METHODS: Study treatment consisted of ipilimumab given every 3 weeks, for a total of four infusions, concurrent with peginterferon alfa-2b administered subcutaneous weekly for a total of 12 weeks. This was followed by maintenance therapy with peginterferon alfa-2b administered subcutaneously weekly for up to 144 additional weeks. The study was designed as a two-stage dose escalation scheme with continuous dose-limiting toxicity monitoring during the induction phase. RESULTS: Thirty one patients received at least 1 dose of study treatment and 30 were assessable for efficacy endpoints. We found that ipilimumab at 3 mg/kg dosing with peginterfeon alfa-2b at 2 mug/kg/week was the maximum tolerated dose of this combination. The incidence of grade 3 drug-related adverse events (AEs) was 45.2%. There were no grade 4/5 AEs. The overall response rate was 40% by immune-related response criteria. Median progression-free survival was 5.9 months. The median overall survival was not reached with at a median follow-up of 35.8 months. CONCLUSIONS: We report that the combination of ipilimumab at 3 mg/kg dosing combined with peginterfeon alfa-2b at 2 mug/kg/week demonstrated an acceptable toxicity profile and a promising efficacy signal. Further study of this combination is warranted. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01496807, Registered December 19th, 2011.

The European Society for Medical Oncology (ESMO) and the American Society of Clinical Oncology (ASCO) are publishing a new edition of the ESMO/ASCO Global Curriculum (GC) thanks to contribution of 64 ESMO-appointed and 32 ASCO-appointed authors. First published in 2004 and updated in 2010, the GC edition 2016 answers to the need for updated recommendations for the training of physicians in medical oncology by defining the standard to be fulfilled to qualify as medical oncologists. At times of internationalisation of healthcare and increased mobility of patients and physicians, the GC aims to provide state-of-the-art cancer care to all patients wherever they live. Recent progress in the field of cancer research has indeed resulted in diagnostic and therapeutic innovations such as targeted therapies as a standard therapeutic approach or personalised cancer medicine apart from the revival of immunotherapy, requiring specialised training for medical oncology trainees. Thus, several new chapters on technical contents such as molecular pathology, translational research or molecular imaging and on conceptual attitudes towards human principles like genetic counselling or survivorship have been integrated in the GC. The GC edition 2016 consists of 12 sections with 17 subsections, 44 chapters and 35 subchapters, respectively. Besides renewal in its contents, the GC underwent a principal formal change taking into consideration modern didactic principles. It is presented in a template-based format that subcategorises the detailed outcome requirements into learning objectives, awareness, knowledge and skills. Consecutive steps will be those of harmonising and implementing teaching and assessment strategies.