Immunomodulatory properties of anticancer monoclonal antibodies: is the 'magic bullet' still a reliable paradigm?

Efficacy and safety of first-line checkpoint inhibitors-based treatments for non-oncogene-addicted non-small-cell lung cancer: a systematic review and meta-analysis

Background

Frontline immune checkpoint inhibitors (ICI)-based regimens in non-oncogene-addicted non-small-cell lung cancer (NSCLC) have been deeply investigated. To rank the available therapeutic options, we carried out a systematic review and Bayesian meta-analysis.

Methods

A comprehensive search for randomized controlled trials (RCTs) of ICI regimens, and a pairwise and a network meta-analysis (NMA) with an all-comers and a stratified strategy were conducted. Endpoints were overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and treatment-related adverse events (TRAEs).

Results

Nineteen RCTs involving 17 treatment regimens were included. For the all-comers population, pembrolizumab/chemotherapy (CT) and cemiplimab were most likely the best treatments. For programmed death-ligand 1 (PD-L1) <1% nivolumab/ipilimumab with/without CT, for PD-L1 >1% and 1%-49% pembrolizumab/CT and for PD-L1 >50% cemiplimab ranked first for OS. In non-squamous (NSQ), pembrolizumab with/without CT ranked first for OS; cemiplimab ranked worse than the unselected population. In squamous (SQ), pooled hazard ratio (HR) showed a better chance in improving efficacy for combination strategy, while monotherapy did not, except for cemiplimab that ranked second. Atezolizumab/CT/bevacizumab ranked first in most subgroups for PFS. Direct comparison showed a non-statistically significant benefit of ICI regimens for the liver metastases cohort in OS, with a good ranking for pembrolizumab/CT and atezolizumab/bevacizumab/CT. Regarding brain metastases, all ICI regimens demonstrated an improvement in OS and PFS compared to CT. Nivolumab/ipilimumab/CT ranked better in this subset.

Conclusions

Our meta-analysis updated on the most recent findings demonstrates that different ICI treatments rank differently in specific NSCLC settings (histology, biomarker and clinical presentation) offering a novel challenging scenario for clinical decision making and research planning.

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Several frontline checkpoint inhibitors regimens for wild-type NSCLC are available.

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Efficacy and safety of these regimens were compared and ranked using a meta-analysis.

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Different ICI treatments rank differently in specific NSCLC cohorts of interest.

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Head-to-head RCTs are awaited to confirm this comprehensive and updated analysis.

Anti-cancer activity of dose-fractioned mPE +/- bevacizumab regimen is paralleled by immune-modulation in advanced squamous NSLC patients

Background

Results from the BEVA2007 trial, suggest that the metronomic chemotherapy regimen with dose-fractioned cisplatin and oral etoposide (mPE) +/- bevacizumab, a monoclonal antibody to the vascular endothelial growth factor (VEGF), shows anti-angiogenic and immunological effects and is a safe and active treatment for metastatic non-small cell lung cancer (mNSCLC) patients. We carried out a retrospective analysis aimed to evaluate the antitumor effects of this treatment in a subset of patients with squamous histology.

Methods

Retrospective analysis was carried out in a subset of 31 patients with squamous histology enrolled in the study between September 2007 and September 2015. All of the patients received chemotherapy with cisplatin (30 mg/sqm, days 1-3q21) and oral etoposide (50 mg, days 1-15q21) (mPE) and 14 of them also received bevacizumab 5 mg/kg on the day 3q21 (mPEBev regimen).

Results

This treatment showed a disease control rate of 71% with a mean progression free survival (PFS) and overall survival (OS) of 13.6 and 17 months respectively. After 4 treatment courses, 6 patients showing a remarkable tumor shrinkage, underwent to radical surgery, attaining a significant advantage in term of survival (P=0.048). Kaplan-Meier and log-rank test identified the longest survival in patients presenting low baseline levels in neutrophil-to-lymphocyte ratio (NLR) (P=0.05), interleukin (IL) 17A (P=0.036), regulatory-T-cells (T_regs) (P=0.020), and activated CD83+ dendritic cells (DCs) (P=0.03).

Conclusions

These results suggest that the mPE +/- bevacizumab regimen is feasible and should be tested in comparative trials in advanced squamous-NSCLC (sqNSCLC). Moreover, its immune-biological effects strongly suggest the investigation in sequential combinations with immune check-point inhibitors.

Immunotherapy of colorectal cancer: new perspectives after a long path

Although significant therapeutic improvement has been achieved in the last 10 years, the survival of metastatic colorectal cancer patients remains in a range of 28 to 30 months. Presently, systemic treatment includes combination chemotherapy with oxaliplatin and/or irinotecan together with a backbone of 5-fluorouracil/levofolinate, alone or in combination with monoclonal antibodies to VEGFA (bevacizumab) or EGF receptor (cetuximab and panitumumab). The recent rise of immune checkpoint inhibitors in the therapeutic scenario has renewed scientific interest in the investigation of immunotherapy in metastatic colorectal cancer patients. According to our experience and view, here, we review the immunological strategies investigated for the treatment of this disease, including the use of tumor target-specific cancer vaccines, chemo-immunotherapy and immune checkpoint inhibitors.

Immune-modulating effects of bevacizumab in metastatic non-small-cell lung cancer patients

The mPEBev is an anticancer regimen which combines a chemotherapy doublet, based on cisplatin and oral etoposide (mPE), with bevacizumab (mPEBev), a mAb targeting the vasculo-endothelial growth factor (VEGF). In previous studies, this regimen showed powerful anti-angiogenetic effects and significant antitumor activity in metastatic non-small-cell lung cancer (mNSCLC) patients. We also recorded the best benefit in patients exhibiting low-systemic inflammatory profile at baseline. On these bases, we hypothesized that mPEBev antitumor activity could be partially related to bevacizumab-associated immunological effects. For this reason, we performed an immunological monitoring in 59 out of 120 stage IIIb-IV NSCLC patients enrolled in the BEVA2007 phase II trial, who received fractioned cisplatin (30 mg/sqm days 1-3q21) and oral etoposide (50 mg, days 1-15q21) (mPE doublet) ±bevacizumab. In this group of patients, 12 received the mPE doublet alone and 47 the doublet in combination with bevacizumab (5 mg/kg on the day 3q21; mPEBev regimen). Blood cell counts, serum analysis, multiplex cytokine assay and immunocytofluorimetric analysis, performed on baseline and post-treatment on blood samples from these patients, revealed that bevacizumab addition to the doublet decreased levels of pro-angiogenic (VEGF, Angiostatin-1 and Follistatin) and inflammatory cytokines (interferon (IFN)γ, IL4 and IL17), improved in vivo and in vitro cytotoxic T-lymphocytes (CTL) response and promoted dendritic cell activation. These results suggest that the mPEBev regimen improve the micro-environmental conditions for an efficient antigen-specific CTL response, making it a feasible candidate regimen to be assessed in combination with immune-checkpoint inhibitors in NSCLC patients.

A systematic review and meta-analysis of randomized trials on the role of targeted therapy in the management of advanced gastric cancer: Evidence does not translate?

It is still uncertain if targeted therapy-based regimens in advanced gastric cancer actually produce survival benefit. To shed light on this important question, we performed a systematic review and meta-analyses on each relevant targeted-pathway. By searching literature databases and proceedings of major cancer meetings in the time-frame 2005-2014, 22 randomized clinical trials exploring targeted therapy for a total of 7022 advanced gastric cancer patients were selected and included in the final analysis. Benefit was demonstrated for antiangiogenic agents in terms of overall survival (HR 0.759; 95%CI 0.655-0.880; p < 0.001). Conversely no benefit was found for EGFR pathway (HR 1.077; 95%CI 0.847-1.370; p = 0.543). Meta-analysis of HER-2 pathway confirmed improvement in terms of survival outcome, already known for this class of drugs (HR 0.823; 95%CI 0.722-0.939; p = 0.004). Pooled analysis demonstrated a significant survival benefit (OS: HR 0.823; PFS: HR 0.762) with acceptable tolerability profile for targeted-based therapies as compared to conventional treatments. This finding conflicts with the outcome of most individual studies, probably due to poor trial design or patients selection. In conclusion, our findings demonstrate a significant survival benefit for targeted therapy in its whole, which can be ascribed to anti-angiogenic and anti-HER2 agents.

Management of disease-modifying treatments in neurological autoimmune diseases of the central nervous system

The therapeutic armamentarium for autoimmune diseases of the central nervous system, specifically multiple sclerosis and neuromyelitis optica, is steadily increasing, with a large spectrum of immunomodulatory and immunosuppressive agents targeting different mechanisms of the immune system. However, increasingly efficacious treatment options also entail higher potential for severe adverse drug reactions. Especially in cases failing first-line treatment, thorough evaluation of the risk-benefit profile of treatment alternatives is necessary. This argues for the need of algorithms to identify patients more likely to benefit from a specific treatment. Moreover, paradigms to stratify the risk for severe adverse drug reactions need to be established. In addition to clinical/paraclinical measures, biomarkers may aid in individualized risk-benefit assessment. A recent example is the routine testing for anti-John Cunningham virus antibodies in natalizumab-treated multiple sclerosis patients to assess the risk for the development of progressive multi-focal leucoencephalopathy. Refined algorithms for individualized risk assessment may also facilitate early initiation of induction treatment schemes in patient groups with high disease activity rather than classical escalation concepts. In this review, we will discuss approaches for individiualized risk-benefit assessment both for newly introduced agents as well as medications with established side-effect profiles. In addition to clinical parameters, we will also focus on biomarkers that may assist in patient selection.

Systemic inflammatory status at baseline predicts bevacizumab benefit in advanced non-small cell lung cancer patients

Bevacizumab is a humanized anti-VEGF monoclonal antibody able to produce clinical benefit in advanced non-squamous non-small-cell lung cancer (NSCLC) patients when combined to chemotherapy. At present, while there is a rising attention to bevacizumab-related adverse events and costs, no clinical or biological markers have been identified and validated for baseline patient selection. Preclinical findings suggest an important role for myeloid-derived inflammatory cells, such as neutrophils and monocytes, in the development of VEGF-independent angiogenesis. We conducted a retrospective analysis to investigate the role of peripheral blood cells count and of an inflammatory index, the neutrophil-to-lymphocyte ratio (NLR), as predictors of clinical outcome in NSCLC patients treated with bevacizumab plus chemotherapy. One hundred and twelve NSCLC patients treated with chemotherapy ± bevacizumab were retrospectively evaluated for the predictive value of clinical or laboratory parameters correlated with inflammatory status. Univariate analysis revealed that a high number of circulating neutrophils and monocytes as well as a high NLR were associated with shorter progression-free survival (PFS) and overall survival (OS) in bevacizumab-treated patients only. We have thus developed a model based on the absence or the presence of at least one of the above-mentioned inflammatory parameters. We found that the absence of all variables strongly correlated with longer PFS and OS (9.0 vs. 7.0 mo, HR: 0.39, p = 0.002; and 20.0 vs. 12.0 mo, HR: 0.29, p < 0.001 respectively) only in NSCLC patients treated with bevacizumab plus chemotherapy. Our results suggest that a baseline systemic inflammatory status is marker of resistance to bevacizumab treatment in NSCLC patients.

Immunological off-target effects of standard treatments in gastrointestinal cancers

The effects on immune cells and the inflammatory microenvironment of commonly applied cancer treatments (chemotherapeutic or biologic agents, interventional radiologic procedures) have become better appreciated. Likewise, the contribution of the immune system toward the effectiveness of these treatments is clearer. The relevance of immune evasion by developing tumors is endorsed by its inclusion as one of the (updated) hallmarks of cancer. A greater understanding of this dimension can potentially lead to novel applications of existing standard of care therapies, in addition to potentiating their effect. This review summarizes the immune aspects of currently employed therapies-cytotoxic chemotherapeutics, biologic agents and interventional radiologic procedures-in solid tumor malignancies with a particular focus on those agents used in gastrointestinal cancers.

Cetuximab ± chemotherapy enhances dendritic cell-mediated phagocytosis of colon cancer cells and ignites a highly efficient colon cancer antigen-specific cytotoxic T-cell response in vitro

Cetuximab is a human/mouse chimeric IgG1 monoclonal antibody (mAb) to epidermal growth factor receptor, approved for colorectal carcinoma treatment in combination with chemotherapy. The immune-mediated effects elicited by its human fraction of crystallization moiety might critically contribute to the overall anti-tumor effectiveness of the antibody. We therefore investigated cetuximab ability to promote colon cancer cell opsonization and phagocytosis by human dendritic cells (DCs) that are subsequently engaged in antigen-cross presentation to cytotoxic T-lymphocyte (CTL) precursors. Human colon cancer cell lines were evaluated for susceptibility to DC-mediated phagocytosis before and after treatment with chemotherapy ± cetuximab in vitro. Human DCs loaded with control or drug-treated cetuximab-coated colon cancer cells were used to in vitro generate cytotoxic T cell clones from peripheral blood mononuclear cells of human leucocyte antigen-A(*)02.01(+) donors. T-cell cultures were characterized for immune-phenotype and tumor-antigen specific CTL activity. The results confirmed that treatment of tumor cells with irinotecan + L-folinate + 5-flurouracil (ILF) or with gemcitabine + ILF increased tumor antigen expression. Moreover, malignant cells exposed to chemotherapy and cetuximab were highly susceptible to phagocytosis by human DCs and were able to promote their activation. The consequent DC-mediated cross-priming of antigens derived from mAb-covered/drug-treated cancer cells elicited a robust CTL anti-tumor response. On the basis of our data, we suggest a possible involvement of CTL-dependent immunity in cetuximab anti-cancer effects.

Is immunotherapy re-entering the kidney cancer arena from the back door? Considerations from the Phase I/II study of siltuximab

Evaluation of: Rossi JF, Negrier S, James ND et al.: A Phase I/II study of siltuximab (CNTO 328), an anti-interleukin-6 monoclonal antibody, in metastatic renal cell cancer. Br. J. Cancer 103, 1154-1162 (2010). For years, immunotherapy was the mainstay of treatment for advanced kidney cancer. The recent development of molecularly targeted agents, and of antiangiogenic agents in particular, has completely changed this scenario, leaving immunotherapy with a minor role in treatment, if any. Recent insights in the mechanisms of resistance to these drugs suggest that the immune system could play a relevant role. In particular, IL-6 appears to cooperate with other growth factors in the recruitment of bone marrow-derived immune cells, ultimately leading to resistance to antiangiogenic agents. Furthermore, it is now clear that monoclonal antibodies actively interact with the immune system and show significant immune-modulating effects per se. Further translation research on this issue is much needed.