Tyrosine kinase and immune checkpoints inhibitors in favorable risk metastatic renal cell carcinoma: Trick or treat?

Over the past decade, the management of metastatic renal cell carcinoma (RCC) has undergone rapid evolution, culminating in a significant improvement in prognosis with frontline immunotherapy. RCC is a highly immunogenic and pro-angiogenic cancer, and mounting evidence has established the immunosuppressive effects of pro-angiogenic factors on the host's immune system. Anti-angiogenic agents such as tyrosine kinase inhibitors (TKIs) and bevacizumab, which obstruct the vascular endothelial growth factor pathway, have demonstrated the potential to enhance antitumor activity and improve the efficacy of immune checkpoint inhibitors (ICIs). Consequently, various combinations of TKIs and ICIs have been assessed and are currently considered the preferred regimens for all metastatic RCC patients, regardless of their prognostic risk score. Nevertheless, some inquiries have arisen within the medical community, as metastatic RCC patients with favorable risk scores who received ICIs and TKIs in combination showed no statistically significant advantage in overall survival compared to those treated with sunitinib alone. Considering these concerns, this review aims to elucidate the rationale behind TKI and ICI combination therapies, provide a summary of current first-line metastatic RCC combinations approved for use, with a focus on favorable-risk patients, and outline present challenges and future perspectives in this context.

Evaluation of Fruquintinib in the Continuum of Care of Patients with Colorectal Cancer

The management of patients with metastatic colorectal cancer (mCRC) has the continuum of care as the treatment paradigm. To date, trifluridine/tipiracil, a biochemically modulated fluoropyrimidine, and regorafenib, a multi-kinase inhibitor, remain the main options for the majority of patients who progressed to standard doublet- or triplet-based chemotherapies, although a tailored approach could be indicated in certain circumstances. Being highly selective for vascular endothelial growth factor receptor (VEGFR)-1, -2 and -3, fruquintinib demonstrated a strong anti-tumor activity in preclinical models and received approval from China's National Medical Products Administration (NMPA) in 2018 for the treatment of patients with chemo-refractory mCRC. The approval was based on the results of the phase III FRESCO trial. Then, in order to overcome geographic differences in clinical practice, the FRESCO-2 trial was conducted in the US, Europe, Japan, and Australia. In a heavily pretreated patient population, the study met its primary endpoint, demonstrating an advantage of fruquintinib over a placebo in overall survival (OS). Here, we review the clinical development of fruquintinib and its perspectives in gastrointestinal cancers. Then, we discuss the introduction of fruquintinib in the continuum of care of CRC paying special attention to unmet needs, including the identification of cross-resistant and potentially susceptible populations, evaluation of radiological response, and identification of novel biomarkers of clinical benefit.

Perioperative Tailored Treatments for Gastric Cancer: Times Are Changing

Resectable gastric or gastroesophageal (G/GEJ) cancer is a heterogeneous disease with no defined molecularly based treatment strategy. Unfortunately, nearly half of patients experience disease recurrence despite standard treatments (neoadjuvant and/or adjuvant chemotherapy/chemoradiotherapy and surgery). In this review, we summarize the evidence of potential tailored approaches in perioperative treatment of G/GEJ cancer, with a special focus on patients with human epidermal growth factor receptor-2(HER2)-positive and microsatellite instability-high (MSI-H) tumors. In patients with resectable MSI-H G/GEJ adenocarcinoma, the ongoing INFINITY trial introduces the concept of non-operative management for patients with complete clinical-pathological-molecular response, and this could be a novel and potential practice changing strategy. Other pathways involving vascular endothelial growth factor receptor (VEGFR), fibroblast growth factor receptor (FGFR), claudin18 isoform 2 (CLDN18.2), and DNA damage repair proteins are also described, with limited evidence until now. Although tailored therapy appears to be a promising strategy for resectable G/GEJ cancer, there are several methodological issues to address: inadequate sample size for pivotal trials, underestimation of subgroup effects, and choice of primary endpoint (tumor-centered vs. patient-centered endpoints). A better optimization of G/GEJ cancer treatment allows maximizing patient outcomes. In the perioperative phase, although caution is mandatory, times are changing and tailored strategies could introduce new treatment concepts. Overall, MSI-H G/GEJ cancer patients possess the characteristics to be the subgroup that could receive the most benefit from a tailored approach.

Adjuvant Therapy for Renal Cell Carcinoma: Hype or Hope?

Renal cell carcinoma (RCC) is the third most common genitourinary cancer accounting for approximately 180,000 deaths worldwide in 2020. Although over two-thirds of patients initially present localized disease, up to 50% of them may progress to metastatic disease. Adjuvant therapy aims to reduce the recurrence risk and improve outcomes in several types of cancers but is currently an unmet need in RCC. The results achieved with tyrosine kinase inhibitors in metastatic RCC led to the evaluation of these target therapies in an early setting with conflicting results for disease-free survival and no overall survival (OS) benefit. Likewise, the results of immune checkpoint inhibitors (ICIs) in an adjuvant setting are conflicting. Available data did not show an improvement in OS with ICIs in the early phase, although a positive trend for pembrolizumab has been recorded, receiving the Food and Drug Administration's approval in this setting. However, the disappointing results of several ICIs and the heterogeneous pattern of RCC warrant biomarker identification and subgroup analyses to evaluate which patients could benefit from adjuvant therapy. In this review, we will discuss the rationale for adjuvant treatment in RCC, summarizing the results of the most important adjuvant therapy trials and current applications, to outline possible future directions.

Therapeutic cancer vaccines: From biological mechanisms and engineering to ongoing clinical trials

Therapeutic vaccines are currently at the forefront of medical innovation. Various endeavors have been made to develop more consolidated approaches to producing nucleic acid-based vaccines, both DNA and mRNA vaccines. These innovations have continued to propel therapeutic platforms forward, especially for mRNA vaccines, after the successes that drove emergency FDA approval of two mRNA vaccines against SARS-CoV-2. These vaccines use modified mRNAs and lipid nanoparticles to improve stability, antigen translation, and delivery by evading innate immune activation. Simple alterations of mRNA structure- such as non-replicating, modified, or self-amplifying mRNAs- can provide flexibility for future vaccine development. For protein vaccines, the use of long synthetic peptides of tumor antigens instead of short peptides has further enhanced antigen delivery success and peptide stability. Efforts to identify and target neoantigens instead of antigens shared between tumor cells and normal cells have also improved protein-based vaccines. Other approaches use inactivated patient-derived tumor cells to elicit immune responses, or purified tumor antigens are given to patient-derived dendritic cells that are activated in vitro prior to reinjection. This review will discuss recent developments in therapeutic cancer vaccines such as, mode of action and engineering new types of anticancer vaccines, in order to summarize the latest preclinical and clinical data for further discussion of ongoing clinical endeavors in the field.

Liquid biopsy in colorectal cancer: No longer young, but not yet old

Colorectal cancer (CRC) is one of the most prevalent cancers and the second leading cause of cancer-related deaths worldwide. The treatment strategy employed in CRC patients is becoming highly dependent on molecular characteristics present at diagnosis and during treatment. Liquid biopsy is an emerging field in the management of this cancer, and its relevance as a potential diagnostic, prognostic, monitoring, and therapeutic tool makes it a viable strategy in the clinical management of CRC patients. Liquid biopsy also has certain limitations, but these limitations seem to be at the reach of near-future technological development. In this letter, we focus on the clinical perspectives of liquid biopsy in CRC with particular regard to the various biomarkers recently identified that have been shown to be potentially useful in multiple aspects of early stage or metastatic CRC.

Hyperthermic Intraperitoneal Chemotherapy in the Management of Gastric Cancer: A Narrative Review

Gastric cancer (GC) patients with peritoneal metastasis tend to achieve poor clinical outcomes. Until recently, the treatment options were limited mainly to either palliative chemotherapy or radiation therapy in exceptional cases. Currently, these patients benefit from multimodal treatment, such as cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Despite good overall results, this treatment modality is still widely debated. The following study is designed to assess the papers about the possible application and utility of HIPEC in GC. A search in the PubMed, Web of Science, and Scopus databases was performed to assess the papers devoted to the role of HIPEC in GC treatment; a literature search was performed until March 21st; and, finally, 50 studies with a total number of 3946 patients were analyzed. According to the most recent data, it seems to be reasonable to limit the duration of HIPEC to the shortest effective time. Moreover, the drugs used in HIPEC need to have equal concentrations and the same solvent. Perioperative chemotherapy needs to be reported in detail and, furthermore, the term “morbidity” should be defined more clearly by the authors.

p53 Antibodies as a Diagnostic Marker for Cancer: A Meta-Analysis

Importance: The protein p53 is an unequivocal tumor suppressor that is altered in half of all cancers. The immune system produces systemic p53 autoantibodies (p53 Abs) in many cancer patients. Objective: This systemic review and meta-analysis focuses on the prognostic value of p53 Abs expressed in the serum of patients with solid tumors. Data Sources: All the clinical investigations were searched on PubMed from the first study dated 1993 until May 2021 (date of submission of the manuscript). Study Selection: Studies were included that met the following criteria: (1) participants with cancer; (2) outcome results expressed in relation to the presence of a p53 antibody; (3) a primary outcome (disease-free survival, overall survival or progression-free survival) expressed as hazard ratio (HR). The following exclusion criteria were used: (1) insufficient data available to evaluate outcomes; (2) animal studies; (3) studies with less than 10 participants. As a result, 12 studies were included in the analysis. Data Extraction and Synthesis: PRISMA guidelines were used for abstracting and assessing data quality and validity by three independent observers. The summary estimates were generated using a fixed-effect model (Mantel-Haenszel method) or a random-effect model (DerSimonian-Laird method), depending on the absence or presence of heterogeneity (I²). Main Outcome(s) and Measure(s): The primary study outcome was to determine the prognostic value of p53 Abs from a large population of patients with solid tumors, as determined before data collection. Results: In total, 12 clinical studies involving 2094 patients were included in the meta-analysis, and it was determined that p53 Abs expression in the serum significantly correlated with poorer survival outcomes of cancer patients (95% CI 1.48 [1.24, 1.77]; p < 0.00001). Conclusions and Relevance: This is the first meta-analysis proving the diagnostic utility of p53-Abs for cancer patients in predicting poorer outcomes. The serum-p53 value (s-p53-value) may be useful for future theranostics.

Gut Microbiome Modulation and Faecal Microbiota Transplantation Following Allogenic Hematopoietic Stem Cell Transplantation

Nowadays, allogenic hematopoietic stem cell transplantation (allo-HSCT) is a curative therapy that is mainly recommended for hematologic malignancies. However, complications (such as graft-versus-host disease, mucositis, disease relapse, and infections) associated with the HSCT procedure contribute to the development of gut microbiota imbalance, gut-barrier disruption, and increased intestinal permeability. In the present narrative review, the crosstalk between gut microbiota products and intestinal homeostasis is discussed. Notably, gut-microbiota-related aspects have an impact on patients' clinical outcomes and overall survival. In accordance with the most recent published data, gut microbiota is crucial for the treatment effectiveness of many diseases, not only gastrointestinal cancers but also hematologic malignancies. Therefore, it is necessary to indicate a therapeutic method allowing to modulate gut microbiota in HSCT recipients. Currently, fecal microbiota transplantation (FMT) is the most innovative method used to alter/restore gut microbiota composition, as well as modulate its activity. Despite the fact that some previous data have shown promising results, the knowledge regarding FMT in HSCT is still strongly limited, except for the treatment of Clostridium difficile infection. Additionally, administration of prebiotics, probiotics, synbiotics, and postbiotics can also modify gut microbiota; however, this strategy should be considered carefully due to the high risk of fungemia/septicemia (especially in case of fungal probiotics).

The gut microbiome and efficacy of cancer immunotherapy

Cancer treatment has been deeply changed by immunotherapy, achieving unprecedented improvement in overall and progression-free survival in several advanced and metastatic cancers. Currently, immune checkpoint inhibitor (ICI) antibodies against cytotoxic T-lymphocyte antigen (CTLA-4) and programmed death/ligand 1 (PD-1/PD-L1) are being tested and approved for different tumors, ranging from melanoma to lung carcinoma. However, only a subgroup of patients can reach treatment benefits and long-term responses, and reliable biomarkers that can accurately predict clinical responses to immunotherapy are still unidentified. In the last decade, accumulating evidence seems to suggest the gut microbiota as one of the modulators that can alter the efficacy and toxicity of immunotherapy drugs (as well as chemotherapeutics), mainly acting through the local and systemic immune system. Herein, we reviewed the highly dynamic and complex microbiome-immune system interface, its bidirectional relationship with cancer immunotherapies, and explored the future possibilities and risks in manipulating the gut microbiome.

Aflibercept Plus FOLFIRI as Second-Line Treatment for Metastatic Colorectal Cancer: A Single-Institution Real-Life Experience

Simple Summary

The continuum of care for mCRC might include anti-angiogenic drug as anti-VEGF/VEGFR moAb and recombinant proteins in combination with fluoropyrimidine-based regimens in first- and second-line treatment, and multikinase inhibitors in refractory patients. The addition of aflibercept to FOLFIRI has been demonstrated to improve survival in patients with metastatic colorectal cancer (mCRC) who progressed after receiving a standard oxaliplatin-based regimen. In this retrospective, single-institution, observational study we collected clinical data from mCRC patients who received aflibercept in combination with FOLFIRI in routine clinical practice to describe feasibility and efficacy of this regimen in a real-world population. Aflibercept-FOLFIRI is a feasible second-line treatment for mCRC in a real-life setting, and PFS in first-line therapy >12 months resulted as the only predictive marker of better survival.

Abstract

The addition of aflibercept to FOLFIRI has been demonstrated to improve survival in patients with metastatic colorectal cancer (mCRC) who progressed after receiving a standard oxaliplatin-based regimen. In this retrospective, single-institution, observational study we collected clinical data from mCRC patients who received aflibercept in combination with FOLFIRI in routine clinical practice from October 2012 to March 2021 to describe feasibility and efficacy of this regimen in a real-world population. Forty-nine patients receiving aflibercept-FOLFIRI as second-line treatment were identified, 40.8% of whom were aged over 65 years. The majority of patients had multi-organ metastases (73.5%), and had previously received bevacizumab in combination with chemotherapy (CT) as first-line treatment (79.6%). Median overall survival (OS) and progression-free survival (PFS) were 13 and 6 months, respectively; overall response rate (ORR) and disease control rate (DCR) were 12.3% and 49.1%, respectively. Several factors were associated with survival in univariate analysis, including PFS in first-line therapy, number of metastatic sites, bone metastases and others. However, in multivariate analysis, only PFS in first-line CT over 12 months was significantly associated with better OS (HR 0.32; 95% CI 0.13–0.79; p = 0.01). Hypertension was the most commonly reported grade (G) 3–4 adverse event (AE), affecting 18.4% of the overall population. Thromboembolic events were observed in 16.3% of patients, hemorrhagic events in 10.2%, and proteinuria in 8.2%. Neutropenia was the most frequently observed hematological G3–4 AE with an incidence of 10.2%. Aflibercept-FOLFIRI has been confirmed as a feasible second-line treatment for mCRC in a re-al-life setting, and PFS in first-line therapy >12 months resulted as the only predictive marker of better survival.

Gut Microbiota Modulation in the Context of Immune-Related Aspects of Lactobacillus spp. and Bifidobacterium spp. in Gastrointestinal Cancers

Accumulating evidence has revealed the critical roles of commensal microbes in cancer progression and recently several investigators have evaluated the therapeutic effectiveness of targeting the microbiota. This gut microbiota-related approach is especially attractive in the treatment of gastrointestinal cancers. Probiotics supplementation is a microbiota-targeted strategy that appears to improve treatment efficacy; Lactobacillus spp. and Bifidobacterium spp. are among the most commonly used probiotic agents. These bacteria seem to exert immunomodulatory effects, impacting on the immune system both locally and systemically. The gut microbiota are able to affect the efficiency of immunotherapy, mainly acting as inhibitors at immune checkpoints. The effects of immunotherapy may be modulated using traditional probiotic strains and/or next generation probiotics, such as Akkermansia municiphila. It is possible that probiotics might enhance the efficiency of immunotherapy based on PD-1/PD-L1 and CTLA-4 but more data are needed to confirm this speculation. Indeed, although there is experimental evidence for the efficacy of several strains, the health-promoting effects of numerous probiotics have not been demonstrated in human patients and furthermore the potential risks of these products, particularly in oncologic patients, are rarely mentioned.

Maintenance in gastric cancer: New life for an old issue?

The interest in maintenance therapy for patients with advanced cancers has been rapidly growing. Maintenance therapy is a useful strategy that may strengthen results of induction therapy thus extending survival and preserving the quality of life (QoL) with less toxicity. Maintenance also represents a suitable setting to investigate novel agents. The value of maintenance therapy after first-line chemotherapy has been well established in several solid tumours, such as colorectal, lung, breast, and ovarian cancer in which it is largely adopted. To date, there is no established role for maintenance therapy following first-line chemotherapy for advanced gastric cancer (GC). This review summarizes the current knowledge regarding maintenance strategies in advanced GC exploring cytotoxic agents, biologic agents and immunotherapy. We also critically review new issues to optimize randomized clinical trials for maintenance therapies and suggest clinical consideration to guide a personalized approach in daily clinical practice for this setting.

Focus on Biochemical and Clinical Predictors of Response to Immune Checkpoint Inhibitors in Metastatic Urothelial Carcinoma: Where Do We Stand?

Urothelial bladder cancer is one of the most lethal cancers worldwide with barely 5% five-year survival in patients with metastatic disease. Intravesical immunotherapy with Bacillus Calmette-Guérin and platinum-based chemotherapy are currently the standard of care for non-muscle invasive and advanced or metastatic urothelial cancer (mUC), respectively. Recently, a subset of patients with locally advanced or mUC has shown to be responsive to immune checkpoint inhibitors (ICIs), e.g., the anti-cytotoxic T-lymphocyte-associated protein 4 and programmed cell death -1/programmed death-ligand1 (PD-1/PD-L1) antibodies. Due to the relevant clinical benefit of immunotherapy for mUC, in 2016, the United States Food and Drug Administration (FDA) approved five immunotherapeutic agents as second-line or first-line treatments for patients with advanced bladder cancer who did not profit from or were ineligible for standard therapy. In this review, we discuss the role of immunotherapy in bladder cancer and recent clinical applications of PD-1/PD-L1 blockade in mUC. Furthermore, we evaluate a variable response rate to ICIs treatment and outline potential biomarkers predictive of immunotherapy response.

Immune Checkpoint Inhibitors in Pre-Treated Gastric Cancer Patients: Results from a Literature-Based Meta-Analysis

Immunotherapy has recently changed the treatment of several cancers. We performed a literature-based meta-analysis of randomised controlled trials to assess the efficacy of the novel immune checkpoint inhibitors (ICIs) in metastatic gastric cancer. The main outcome was overall survival. Based on age (cut-off agreed at 65 years), tumour location (gastric vs. gastro-oesophageal junction), programmed death-ligand 1 (PD-L1) status, sex and Eastern Cooperative Oncology Group (ECOG) status (1 vs. 0), we scheduled a subgroup analysis for the overall survival. Three studies were included in the analysis for a total of 1456 cases (811 cases were in the experimental group and 645 cases in the control group). The pooled analysis showed improved overall survival in the experimental arm in the absence of statistical significance (hazard ratio (HR) = 0.87, 95% CI: 0.64-1.18; p = 0.37). The subgroup of patients with PD-L1-positive tumours (HR = 0.82 vs. 1.04) and gastro-oesophageal junction cancer (HR = 0.82 vs. 1.04) showed a statistically significant advantage of overall survival. This study supports the efficacy of immune checkpoint inhibitors in the subgroup of patients with metastatic gastric cancer with PD-L1-positive and gastro-oesophageal junction tumour location. Future studies are needed with the aim of identifying reliable predictive biomarkers of ICI efficacy.