Combined PD-1 and CTLA-4-targeted immunotherapy with nivolumab and ipilimumab is effective against melanoma, renal cell carcinoma and non-small-cell lung cancer^1,2,3. However, this comes at the cost of frequent, serious immune-related adverse events, necessitating a reduction in the recommended dose of ipilimumab that is given to patients⁴. In mice, co-treatment with surrogate anti-PD-1 and anti-CTLA-4 monoclonal antibodies is effective in transplantable cancer models, but also exacerbates autoimmune colitis. Here we show that treating mice with clinically available TNF inhibitors concomitantly with combined CTLA-4 and PD-1 immunotherapy ameliorates colitis and, in addition, improves anti-tumour efficacy. Notably, TNF is upregulated in the intestine of patients suffering from colitis after dual ipilimumab and nivolumab treatment. We created a model in which Rag2^−/−Il2rg^−/− mice were adoptively transferred with human peripheral blood mononuclear cells, causing graft-versus-host disease that was further exacerbated by ipilimumab and nivolumab treatment. When human colon cancer cells were xenografted into these mice, prophylactic blockade of human TNF improved colitis and hepatitis in xenografted mice, and moreover, immunotherapeutic control of xenografted tumours was retained. Our results provide clinically feasible strategies to dissociate efficacy and toxicity in the use of combined immune checkpoint blockade for cancer immunotherapy.

Background: Programmed death-ligand 1 (PD-L1) may be induced by oncogenic signals or can be upregulated via interferon gamma (IFN-γ). We have explored whether the expression of IFNG, the gene encoding IFN-γ, is associated with clinical response to the immune checkpoint blockade in non-small cell lung cancer (NSCLC) and melanoma patients. The role of inflammation-associated transcription factors STAT3, IKBKE, STAT1 and other associated genes has also been examined. Methods: Total RNA from 17 NSCLC and 21 melanoma patients was analyzed by quantitative reverse transcription PCR. STAT3 and Rantes, YAP1 and CXCL5, DNMT1, RIG1 and TET1, EOMES, IFNG, PD-L1 and CTLA4, IKBKE and NFATC1 mRNA were examined. PD-L1 protein expression in tumor and immune cells and stromal infiltration of CD8⁺ T-cells were also evaluated. Progression-free survival and overall survival were estimated. Results: A total of 17 NSCLC patients received nivolumab and 21 melanoma patients received pembrolizumab. Progression-free survival with nivolumab was significantly longer in NSCLC patients with high versus low IFNG expression (5.1 months versus 2 months, p = 0.0124). Progression-free survival with pembrolizumab was significantly longer in melanoma patients with high versus low IFNG expression (5.0 months versus 1.9 months, p = 0.0099). Significantly longer overall survival was observed for melanoma patients with high versus low IFNG expression (not reached versus 10.2 months p = 0.0183). There was a trend for longer overall survival for NSCLC patients with high versus low IFNG expression. Conclusions: IFN-γ is an important marker for prediction of response to immune checkpoint blockade. Further research is warranted in order to validate whether IFNG is more accurate than PD-L1.

Cancer is one of the main public health problems in the world. Systemic therapies such as chemotherapy and more recently target therapies as well as immunotherapy have improved the prognosis of this large group of complex malignant diseases. However, the frequent emergence of multidrug resistance (MDR) mechanisms is one of the major impediments towards curative treatment of cancer. While several mechanisms of drug chemoresistance are well defined, resistance to immunotherapy is still insufficiently unclear due to the complexity of the immune response and its dependence on the host. Expression and regulation of immune checkpoint molecules (such as PD-1, CD279; PD-L1, CD274; and CTLA-4, CD152) play a key role in the response to immunotherapy. In this regard, immunotherapy based on immune checkpoints inhibitors (ICIs) is a common clinical approach for treatment of patients with poor prognosis when other first-line therapies have failed. Unfortunately, about 70 % of patients are classified as non-responders, or they progress after initial response to these ICIs. Multiple factors can be related to immunotherapy resistance: characteristics of the tumor microenvironment (TME); presence of tumor infiltrating lymphocytes (TILs), such as CD8 + T cells associated with treatment-response; presence of tumor associated macrophages (TAMs); activation of certain regulators (like PIK3γ or PAX4) found present in non-responders; a low percentage of PD-L1 expressing cells; tumor mutational burden (TMB); gain or loss of antigen-presenting molecules; genetic and epigenetic alterations correlated with resistance. This review provides an update on the current state of immunotherapy resistance presenting targets, biomarkers and remedies to overcome such resistance.

A bstract: According to the World Health Organization (WHO), cancer is a leading cause of death worldwide. The identification of novel targets for cancer treatment is an area of intense work that has led Bcl-2 over-expression to be proposed as one of the hallmarks of cancer and Bcl-2 inhibition as a promising strategy for cancer treatment. In this review, we describe the different pathways related to programmed cell death, the role of Bcl-2 family members in apoptosis resistance to anti-cancer treatments, and the potential utility of Bcl-2 inhibitors to overcome resistance to chemo- and immunotherapy.

We hypothesized that the abundance of PD1 mRNA in tumor samples might explain the differences in overall response rates (ORR) observed following anti-PD1 monotherapy across cancer-types. RNASeqv2 data from 10,078 tumor samples representing 34 different cancer-types was analyzed from TCGA. Eighteen immune-related gene signatures and 547 immune-related genes, including PD1, were explored. Correlations between each gene/signature and ORRs reported in the literature following anti-PD1 monotherapy were calculated. To translate the in-silico findings to the clinical setting, we analyzed the expression of PD1 mRNA using the nCounter platform in 773 formalin-fixed paraffin embedded (FFPE) tumor samples across 17 cancer-types. To test the direct relationship between PD1 mRNA, PDL1 immunohistochemistry (IHC), stromal tumor-infiltrating lymphocytes (sTILs) and ORR, we evaluated an independent FFPE-based dataset of 117 patients with advanced disease treated with anti-PD1 monotherapy. In pan-cancer TCGA, PD1 mRNA expression was found strongly correlated (r > 0.80) with CD8 T-cell genes and signatures and the proportion of PD1 mRNA-high tumors (80^th percentile) within a given cancer-type was variable (0-84%). Strikingly, the PD1-high proportions across cancer-types were found strongly correlated (r = 0.91) with the ORR following anti-PD1 monotherapy reported in the literature. Lower correlations were found with other immune-related genes/signatures, including PDL1. Using the same population-based cutoff (80^th percentile), similar proportions of PD1-high disease in a given cancer-type were identified in our in-house 773-tumor dataset as compared to TCGA. Finally, the pre-established PD1 mRNA FFPE-based cutoff was found significantly associated with anti-PD1 response in 117 patients with advanced disease (PD1-high 51.5%, PD1-intermediate 26.6% and PD1-low 15.0%; odds ratio between PD1-high and PD1-intermediate/low=8.31; P < 0.001). In this same dataset, PDL1 tumor expression by IHC or percentage of sTILs were not found associated with response. Our study provides a clinically applicable assay that links PD1 mRNA abundance, activated CD8 T-cells and anti-PD1 efficacy.