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Introduction : Treatment of extensive-stage SCLC is still a challenge but immunotherapy with checkpoint inhibitors is showing promising results. Nivolumab alone or in combination with ipilimumab has demonstrated a benefit in terms of response and survival in patients with pre-treated extensive-stage disease and has been approved as third-line therapy after failure of chemotherapy. However, data from two phase III trials with nivolumab are negative. In the first trial, nivolumab was administered as a single agent compared to second-line chemotherapy, while in the second it was given alone or in combination with ipilimumab as maintenance treatment after platinum-based chemotherapy. Areas covered : Our review focuses on the role of immunotherapy, and in particular nivolumab, in the treatment of SCLC, describing the results of the main trials and its future perspectives, with reference to clinical trials with other checkpoint inhibitors. Expert opinion : The future of nivolumab in the treatment of SCLC needs to be clarified with further clinical trials, in which improved patient selection and a more specific setting and/or timepoint of the disease may be identified.

The inhibitory immune checkpoint PD-L1/PD1 promotes the alternative splicing of the FKBP5 gene, resulting in increased expression of its variant 4 in the peripheral blood mononuclear cells of melanoma patients. The variant 4 transcript is translated into the truncated FKBP51s protein. Given the importance of co-inhibitory signalling in tumour immune escape, here we tested the potential for using FKBP51s expression to predict immunotherapy outcomes. To do this, we immunophenotyped PBMCs from 118 melanoma patients and 77 age- and sex-matched healthy controls. Blood samples were collected before patients underwent ipilimumab treatment. In 64 of the 118 patients, FKBP51s expression was also assessed in regulatory T cells (Tregs). We found that each PBMC subset analysed contained an FKBP51s pos fraction, and that this fraction was greater in the melanoma patients than healthy controls. In CD4 T lymphocytes, the FKBP51s neg fraction was significantly impaired. Tregs count was increased in melanoma patients, which is in line with previous studies. Also, by analyses of FKBP51s in Tregs, we identified a subgroup of ipilimumab nonresponder patients (p = 0.002). In conclusion, FKBP51s-based immunophenotyping of melanoma patients revealed several profiles related to a negative immune regulatory control and identified an unknown Treg subset. These findings are likely to be useful in the selection of the patients that are candidate for immunotherapy.

The anti-PD-1 agent, nivolumab, has been approved both as monotherapy and in combination with ipilimumab for the treatment of unresectable or metastatic melanoma in the USA and European Union. Here we present the case of a patient with treatment-naive, metastatic mucosal melanoma and baseline LDH approximately seven times the upper limit of normal. The patient was enrolled in a clinical trial (CheckMate 066) and achieved a partial response, followed by a durable complete response with nivolumab treatment. The patient's LDH levels were documented in each cycle and dropped markedly within 2 months, when partial response to treatment was already evident. LDH levels remained low for the rest of follow-up, consistent with the ongoing complete response to treatment. The patient experienced only mild immune-related adverse events (grade 1-2), which included vitiligo and rash. This exceptional response suggests that patients with high LDH levels at baseline should be considered for nivolumab treatment. LDH levels, however, should not serve as a predictive marker of response to nivolumab. Moreover, this case suggests the need to identify patients who will achieve the greatest benefit from nivolumab monotherapy.

Background: Identifying response markers is highly needed to guide the treatment strategy in patients with metastatic melanoma. Methods: A retrospective study was carried out in patients with unresectable/metastatic melanoma (stage IIIb–IV), treated with anti-PD-1 in the first line setting, to better explore the role and the timing of neutrophil/lymphocyte ratio (NLR) as potential biomarker of response. The relationship of NLR with inflammation-immune mediators and the underlying negative effect of raising NLR during immunotherapy, have been investigated with transcriptomic gene analysis. Results: The results confirmed previous findings that a high baseline NLR is associated with a poorer prognosis and with higher serum level of lactate dehydrogenase (LDH), regardless of the presence of brain metastases. The transcriptomic analysis showed that high baseline NLR is associated with a characteristic gene signature CCNA1, LDHA and IL18R1, which correlates with inflammation and tumorigenesis. Conversely, low baseline NLR is associated with the signature CD3, SH2D1A, ZAP70 and CD45RA, linked to the immune-activation. The genes positively associated with NLR (CD39 (ENTPD1), PTEN, MYD88, MMP9 and LDH) are involved in processes of immunosuppression, inflammation and tumor-promoting activity. Increased expression of CD39 correlated with TGFβ2, a marker of the N2 neutrophils with immunosuppressive activity. Conclusions: These results suggest that increasing NLR is associated with an increased neutrophil population, with polarization to the N2 phenotype, and this process may be the basis for the negatively prognostic role of NLR. [ABSTRACT FROM AUTHOR]

Background: Nivolumab is an anti-PD1 antibody that has dramatically improved metastatic melanoma patients' outcomes. Nevertheless, many patients are resistant to PD-1 inhibition, occasionally experiencing severe off-target immune toxicity. In addition, no robust and reproducible biomarkers have yet been validated to identify the correct selection of patients who will benefit from anti-PD-1 treatment avoiding unwanted side effects. However, the strength of CD26 expression on CD4+ T lymphocytes permits the characterization of three subtypes with variable degrees of responsiveness to tumors, suggesting that the presence of CD26-expressing T cells in patients might be a marker of responsiveness to PD-1-based therapies. Methods: The frequency distribution of peripheral blood CD26-expressing cells was investigated employing multi-parametric flow cytometry in 69 metastatic melanoma patients along with clinical characteristics and blood count parameters at baseline (W0) and compared to 20 age- and sex-matched healthy controls. Percentages of baseline CD4+CD26high T cells were correlated with the outcome after nivolumab treatment. In addition, the frequency of CD4+CD26high T cells at W0 was compared with those obtained after 12 weeks (W1) of therapy in a sub-cohort of 33 patients. Results: Circulating CD4+CD26high T cells were significantly reduced in melanoma patients compared to healthy subjects (p = 0.001). In addition, a significant association was observed between a low baseline percentage of CD4+CD26high T cells (< 7.3%) and clinical outcomes, measured as overall survival (p = 0.010) and progression-free survival (p = 0.014). Moreover, patients with clinical benefit from nivolumab therapy had significantly higher frequencies of circulating CD4+CD26high T cells than patients with non-clinical benefit (p = 0.004) at 12 months. Also, a higher pre-treatment proportion of circulating CD4+CD26high T cells was correlated with Disease Control Rate (p = 0.014) and best Overall Response Rate (p = 0.009) at 12 months. Interestingly, after 12 weeks (W1) of nivolumab treatment, percentages of CD4+CD26high T cells were significantly higher in comparison with the frequencies measured at W0 (p < 0.0001), aligning the cell counts with the ranges seen in the blood of healthy subjects. Conclusions: Our study firstly demonstrates that peripheral blood circulating CD4+CD26high T lymphocytes represent potential biomarkers whose perturbations are associated with reduced survival and worse clinical outcomes in melanoma patients. [ABSTRACT FROM AUTHOR]

Immunotherapy denotes an exemplar change in an oncological setting. Despite the effective application of these treatments across a broad range of tumors, only a minority of patients have beneficial effects. The efficacy of immunotherapy is affected by several factors, including human immunity, which is strongly correlated to genetic features, such as intra-tumor heterogeneity. Classic imaging assessment, based on computed tomography (CT) or magnetic resonance imaging (MRI), which is useful for conventional treatments, has a limited role in immunotherapy. The reason is due to different patterns of response and/or progression during this kind of treatment which differs from those seen during other treatments, such as the possibility to assess the wide spectrum of immunotherapy-correlated toxic effects (ir-AEs) as soon as possible. In addition, considering the unusual response patterns, the limits of conventional response criteria and the necessity of using related immune-response criteria are clear. Radiomics analysis is a recent field of great interest in a radiological setting and recently it has grown the idea that we could identify patients who will be fit for this treatment or who will develop ir-AEs. [ABSTRACT FROM AUTHOR]

Interferon (IFN) and PEG-IFN are the only drugs approved as adjuvant therapy in patients with melanoma at high-risk of recurrence after surgical resection. Several clinical trials of adjuvant IFN, using different doses and durations of therapy, have been conducted in these patients. Results generally suggest relapse-free survival and overall survival benefits; however, questions over the optimal dose and duration of treatment and concerns over toxicity have limited its use. IFN exerts its biological activity in melanoma via multiple mechanisms of action, most of which can be considered as indirect immunomodulatory effects. As such, IFN may also be of benefit in the neoadjuvant setting, where it may have a role in melanoma patients with locally advanced disease for whom immediate surgical excision is not possible. However, this has not been well studied. The use of IFN in patients with metastatic melanoma is controversial, with limited data and no convincing evidence of a survival benefit. However, IFN therapy combined with novel biological and immunotherapies offers the potential for a synergistic effect and improved clinical outcomes. Predictive and prognostic factors to better select melanoma patients for IFN treatment have been identified (e.g. disease stage, ulceration, various cytokines) and may also enhance its therapeutic efficacy, but their incorporation into the clinical decision-making process requires validation in prospective trials. In conclusion, the modest efficacy of IFN shown in clinical trials is largely a reflection of differences in response between patients. Despite advancements in the understanding of its biological mechanisms of action, the huge potential of IFN remains to be fully explored and utilized in patients with melanoma. [ABSTRACT FROM AUTHOR]

Introduction Immunotherapy with the anti-cytotoxic T-lymphocyte antigen-4 monoclonal antibody ipilimumab has been shown to improve overall survival in previously treated and treatmentnaïve patients with unresectable stage III or IV melanoma. Consistent with its proposed immunomodulating mechanism of action, the most common toxicities associated with ipilimumab therapy are immune-related in nature and include those related to the skin and gastrointestinal tract, with endocrine and hepatic events also frequent. Other rare adverse events, including haematological aberrations, may also occur and can have serious consequences if unrecognised. Here we describe three patients who developed serious haematological adverse events during or after treatment with ipilimumab. Case presentation Three Caucasian patients (two women aged 68 and 49 years and one man aged 70 years) with metastatic melanoma experienced anaemia and/or leukopenia (neutropenia) with toxicity of various grades during or after treatment with ipilimumab, without significant changes to other haematological values. Two of the patients stopped treatment after the third ipilimumab dose, one because of severe anaemia that required blood transfusion and the other due to febrile neutropenia that was treated with antibiotics and granulocyte-macrophage colony-stimulating factor stimulation. The third patient developed anaemia and leukopenia after treatment during the follow-up period. The results of autoimmunity tests performed were positive and corticosteroids were used to treat these events as per side-effects treatment algorithms specifically developed for the management of immune-related adverse events associated with ipilimumab, an approach that was safe and effective. Conclusions Haematological toxicity is a rare but potentially serious immune-related side effect of ipilimumab therapy. However, if promptly recognised and treated, haematological toxicity is manageable and can be reversed with standard corticosteroid treatment as recommended for other ipilimumab immune-related side effects. [ABSTRACT FROM AUTHOR]

Background: In cancer immunotherapy, dendritic cells (DCs) play a fundamental role in the dialog between innate and adaptive immune response, but several immunosuppressive mechanisms remain to be overcome. For example, a high number of CD4+CD25++Foxp3+ regulatory T-cells (Foxp3+Tregs) have been observed in the peripheral blood and tumor microenvironment of cancer patients. On the basis of this, we conducted a study on DC-based vaccination in advanced melanoma, adding low-dose temozolomide to obtain lymphodepletion. Methods: Twenty-one patients were entered onto our vaccination protocol using autologous DCs pulsed with autologous tumor lysate and keyhole limpet hemocyanin. Patients received low-dose temozolomide before vaccination and 5 days of low-dose interleukin-2 (IL-2) after vaccination. Circulating Foxp3+Tregs were evaluated before and after temozolomide, and after IL-2. Results: Among the 17 evaluable patients we observed 1 partial response (PR), 6 stable disease (SD) and 10 progressive disease (PD). The disease control rate (PR+SD = DCR) was 41% and median overall survival was 10 months. Temozolomide reduced circulating Foxp3+Treg cells in all patients. A statistically significant reduction of 60% was observed in Foxp3+Tregs after the first cycle, whereas the absolute lymphocyte count decreased by only 14%. Conversely, IL-2 increased Foxp3+Treg cell count by 75.4%. Of note the effect of this cytokine, albeit not statistically significant, on the DCR subgroup led to a further 33.8% reduction in Foxp3+Treg cells. Conclusions: Our results suggest that the combined immunological therapy, at least as far as the DCR subgroup is concerned, effectively reduced the number of Foxp3+Treg cells, which exerted a blunting effect on the growthstimulating effect of IL-2. However, this regimen, with its current modality, would not seem to be capable of improving clinical outcome. [ABSTRACT FROM AUTHOR]

Clinical activity of anti-CTLA-4 (cytotoxic T-lymphocyte antigen-4) monoclonal antibodies (mAb) has changed the approaches for the treatment of cancer in terms of patterns of response, duration of response, and adverse event profiles. In fact, antibodies that block the interaction of CTLA-4 with its ligands B7.1 and B7.2 can enhance immune responses, including anti-tumor immunity. Two recent studies using ipilimumab (an anti-CTLA-4 mAb) demonstrated improvements in overall survival in the treatment of advanced melanoma. These studies utilized two different schedules of treatment in different patient categories (first and second line of treatment). However, the results were quite similar despite the different dosage used and the combination with dacarbazine in the first line treatment. Ongoing clinical studies will establish the efficacy of ipilimumab as monotherapy or in combination with other drugs for the treatment of metastatic melanoma and a variety of other cancers. Other antibodies, such as CD137 agonists and PD-1 antagonists, are currently in various stages of pre-clinical and clinical development. Agonist antibodies directed against CD137 (4-1BB) on the surface of antigen-primed T-lymphocytes increase tumor immunity that is curative against some transplantable murine tumors. Programmed death-1 (PD1) is a surface molecule delivering inhibitory signals important to maintain T-cell functional silence against their cognate antigens. Interference with PD1 or its ligand PD-L1 (B7-H1) increases anti-tumor immunity. As a result, human mAbs anti-PD1 and anti-PD-L1 are under clinical development. This paper reviews recent studies in the treatment of advanced melanoma with these types of monoclonal antibodies. Ipilimumab can be considered a cornerstone of a new era in melanoma treatment. However, the aim is to optimize the therapy with anti-CTLA-4 antibodies to define the best schedule for next combination regimens (other immunomodulatory antibodies, BRAF/MEK inhibitors, vaccines, etc.) that represent the natural evolution of future melanoma therapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Immune checkpoint inhibitors have improved the prognosis for patients with advanced melanoma. Despite the recent success of immunotherapy, many patients still do not benefit from these treatments, and their real-life application may yield different outcomes compared to the advantage presented in clinical trials. There is therefore a need to select patients who can really benefit from these treatments. We have focused our study on a real-life retrospective analysis of metastatic melanoma patients treated with immunotherapy at a single institution—the Istituto Nazionale Tumori IRCCS Fondazione "G. Pascale" of Napoli, Italy. With the help of AI and machine learning we validated an algorithm based on clinical variables of patients—namely, the Clinical Categorization Algorithm (CLICAL)—that defines five predictable cohorts of benefit to immunotherapy with 95% accuracy. It can be a useful tool for the stratification of metastatic melanoma patients who may or may not improve from immunotherapy treatment. The real-life application of immune checkpoint inhibitors (ICIs) may yield different outcomes compared to the benefit presented in clinical trials. For this reason, there is a need to define the group of patients that may benefit from treatment. We retrospectively investigated 578 metastatic melanoma patients treated with ICIs at the Istituto Nazionale Tumori IRCCS Fondazione "G. Pascale" of Napoli, Italy (INT-NA). To compare patients' clinical variables (i.e., age, lactate dehydrogenase (LDH), neutrophil–lymphocyte ratio (NLR), eosinophil, BRAF status, previous treatment) and their predictive and prognostic power in a comprehensive, non-hierarchical manner, a clinical categorization algorithm (CLICAL) was defined and validated by the application of a machine learning algorithm—survival random forest (SRF-CLICAL). The comprehensive analysis of the clinical parameters by log risk-based algorithms resulted in predictive signatures that could identify groups of patients with great benefit or not, regardless of the ICI received. From a real-life retrospective analysis of metastatic melanoma patients, we generated and validated an algorithm based on machine learning that could assist with the clinical decision of whether or not to apply ICI therapy by defining five signatures of predictability with 95% accuracy. [ABSTRACT FROM AUTHOR]

As widely acknowledged, 40–50% of all melanoma patients harbour an activating BRAF mutation (mostly BRAF V600E). The identification of the RAS–RAF–MEK–ERK (MAP kinase) signalling pathway and its targeting has represented a valuable milestone for the advanced and, more recently, for the completely resected stage III and IV melanoma therapy management. However, despite progress in BRAF-mutant melanoma treatment, the two different approaches approved so far for metastatic disease, immunotherapy and BRAF+MEK inhibitors, allow a 5-year survival of no more than 60%, and most patients relapse during treatment due to acquired mechanisms of resistance. Deep insight into BRAF gene biology is fundamental to describe the acquired resistance mechanisms (primary and secondary) and to understand the molecular pathways that are now being investigated in preclinical and clinical studies with the aim of improving outcomes in BRAF-mutant patients. [ABSTRACT FROM AUTHOR]

Background: Tumor microenvironment may have a key role in providing immunological markers that can help predict clinical response to treatment with checkpoint inhibitors. We investigated whether the baseline expression of PD-L1 in advanced melanoma patients treated with ipilimumab may correlate with clinical outcome. Methods: PD-L1 expression was assessed in 114 patients with advanced melanoma treated with ipilimumab and, in a cohort of 77 patients, a comprehensive assessment using multispectral imaging to assess the presence and distribution of CD3+, CD8+, CD163+, FOXP3+ and PD-L1+ cells inside and at periphery of the tumor was performed. Results: PD-L1 status alone was not a predictive biomarker for response or survival. There was an association between clinical benefit from ipilimumab therapy with the coexistence of low densities of CD8+ and high densities of CD163+ PD-L1+ cells at the periphery of the tumor. Conclusions: To explain the association of this peculiar microenvironment with clinical benefit from ipilimumab, we proposed a model where baseline CD8 cells levels are low due to inhibitory effect of Tregs and to pro-tumor activity of TAM M2 (CD163+ PD-L1+ cells). Ipilimumab treatment causes a decrease of Treg cells, mediated by ADCC from macrophages, with a concomitant change in TAM polarization that switches from M2 to M1 with a subsequent attraction of CD8 cells and the increase of antitumor response. [ABSTRACT FROM AUTHOR]

Checkpoint inhibitors have improved survival for patients with melanoma, non-small-cell lung cancer (NSCLC), bladder, head and neck and other cancers. Antibodies against PD-L1, including atezolizumab, avelumab and durvalumab, are also being developed and have been approved for various cancers. Compared with anti-CTLA-4 drugs, studies with anti-PD-1/PD-L1 agents have suggested higher response rates and improved survival. Targeting PD-L1 rather than PD-1 may also theoretically offer further benefit, with the potential for improved efficacy and reduced toxicity, although this has not been clearly shown by clinical experience to date. Anti-PD-L1 agents have shown good efficacy and manageable toxicity in several tumor types. [ABSTRACT FROM PUBLISHER]

The optimal sequencing of targeted treatment and immunotherapy in the treatment of advanced melanoma is a key question and prospective studies to address this are ongoing. Previous observations suggest that treating first with targeted therapy may select for more aggressive disease, meaning that patients may not gain full benefit from subsequent immunotherapy. In a single-center retrospective analysis, we investigated whether response to pembrolizumab was affected by previous BRAF inhibitor therapy. A total of 42 patients with metastatic cutaneous or mucosal melanoma who had received previous treatment with ipilimumab were treated with pembrolizumab as part of the Italian expanded access program. Sixteen of these patients had BRAF-mutated melanoma and had also been previously treated with a BRAF inhibitor (vemurafenib or dabrafenib), while 26 had BRAF wild-type melanoma (no previous BRAF inhibitor). Patients with BRAF-mutant melanoma who were previously treated with BRAF inhibitors had a significantly lower median progression-free survival (3 [2.3–3.7] versus not reached [2–8+] mo;p= 0.001) and disease control rate (18.6% versus 65.4%; p = 0.005) than patients with BRAF wild-type, while there was also a trend toward a lower response rate (assessed using immune-related response criteria) although this was not significantly different between groups (12.5% versus 36.4%; p = 0.16). These data are consistent with previous reports that BRAF inhibitor therapy may affect subsequent response to immunotherapy. [ABSTRACT FROM AUTHOR]