Cancer combination therapies by angiogenesis inhibitors; a comprehensive review

Abnormal vasculature is one of the most conspicuous traits of tumor tissue, largely contributing to tumor immune evasion. The deregulation mainly arises from the potentiated pro-angiogenic factors secretion and can also target immune cells' biological events, such as migration and activation. Owing to this fact, angiogenesis blockade therapy was established to fight cancer by eliminating the nutrient and oxygen supply to the malignant cells by impairing the vascular network. Given the dominant role of vascular-endothelium growth factor (VEGF) in the angiogenesis process, the well-known anti-angiogenic agents mainly depend on the targeting of its actions. However, cancer cells mainly show resistance to anti-angiogenic agents by several mechanisms, and also potentiated local invasiveness and also distant metastasis have been observed following their administration. Herein, we will focus on clinical developments of angiogenesis blockade therapy, more particular, in combination with other conventional treatments, such as immunotherapy, chemoradiotherapy, targeted therapy, and also cancer vaccines. Video abstract.

Combination therapy with immune checkpoint inhibitors (ICIs); a new frontier

Recently, immune checkpoint inhibitors (ICIs) therapy has become a promising therapeutic strategy with encouraging therapeutic outcomes due to their durable anti-tumor effects. Though, tumor inherent or acquired resistance to ICIs accompanied with treatment-related toxicities hamper their clinical utility. Overall, about 60-70% of patients (e.g., melanoma and lung cancer) who received ICIs show no objective response to intervention. The resistance to ICIs mainly caused by alterations in the tumor microenvironment (TME), which in turn, supports angiogenesis and also blocks immune cell antitumor activities, facilitating tumor cells' evasion from host immunosurveillance. Thereby, it has been supposed and also validated that combination therapy with ICIs and other therapeutic means, ranging from chemoradiotherapy to targeted therapies as well as cancer vaccines, can capably compromise tumor resistance to immune checkpoint blocked therapy. Herein, we have focused on the therapeutic benefits of ICIs as a groundbreaking approach in the context of tumor immunotherapy and also deliver an overview concerning the therapeutic influences of the addition of ICIs to other modalities to circumvent tumor resistance to ICIs.

Small Molecular Immune Modulators as Anticancer Agents

After decades of intense effort, immune checkpoint inhibitors have been conclusively demonstrated to be effective in cancer treatments and thus are revolutionizing the concepts in the treatment of cancers. Immuno-oncology has arrived and will play a key role in cancer treatment in the foreseeable future. However, efforts to find novel methods to improve the immune response to cancer have not ceased. Small-molecule approaches offer inherent advantages over biologic immunotherapies since they can cross cell membranes, penetrate into tumor tissue and tumor microenvironment more easily, and are amenable to be finely controlled than biological agents, which may help reduce immune-related adverse events seen with biologic therapies and provide more flexibility for the combination use with other therapies and superior clinical benefit. On the one hand, small-molecule therapies can modulate the immune response to cancer by restoring the antitumor immunity, promoting more effective cytotoxic lymphocyte responses, and regulating tumor microenvironment, either directly or epigenetically. On the other hand, the combination of different mechanisms of small molecules with antibodies and other biologics demonstrated admirable synergistic effect in clinical settings for cancer treatment and may expand antibodies' usefulness for broader clinical applications. This chapter provides an overview of small-molecule immunotherapeutic approaches either as monotherapy or in combination for the treatment of cancer.

Immunotherapy for glioma: Current management and future application

Gliomas are intrinsic brain tumors that originate from neuroglial progenitor cells. Conventional therapies, including surgery, chemotherapy, and radiotherapy, have achieved limited improvements in the prognosis of glioma patients. Immunotherapy, a revolution in cancer treatment, has become a promising strategy with the ability to penetrate the blood-brain barrier since the pioneering discovery of lymphatics in the central nervous system. Here we detail the current management of gliomas and previous studies assessing different immunotherapies in gliomas, despite the fact that the associated clinical trials have not been completed yet. Moreover, several drugs that have undergone clinical trials are listed as novel strategies for future application; however, these clinical trials have indicated limited efficacy in glioma. Therefore, additional studies are warranted to evaluate novel therapeutic approaches in glioma treatment.

Immune Checkpoint Inhibitors: Toward New Paradigms in Renal Cell Carcinoma

Immune modulatory treatment regimens, led by immune checkpoint inhibitors, have transformed the treatment of clear-cell renal cell carcinoma. First-in-class, the PD-1 inhibitor nivolumab improved overall survival in advanced renal cell carcinoma following prior anti-angiogenic therapy, an important shift in the management of clear-cell renal cell carcinoma. Further improvements of long-term outcomes will be driven by combinations in the first-line setting, including PD-1/PD-L1 associated with antiangiogenic therapies, or PD1/PD-L1 inhibitors with other immune checkpoint inhibitors such as anti-CTLA-4, anti-LAG-3 or TIM-3 targeted therapies. The first two randomized Phase 3 trials assessing these combinations have now challenged sunitinib in first-line setting. First, the CheckMate 214 trial demonstrated an objective response rate and overall survival benefit for the combination of nivolumab plus ipilimumab in the intermediate- and poor-risk patients. Second, the IMMotion 151 study demonstrated a progression-free survival benefit for the atezolizumab plus bevacizumab combination by investigator assessment. Further Phase 3 trials are awaited with tyrosine kinase and immune checkpoint inhibitor combinations. Clinical trials of immune checkpoint inhibitors are also actively investigated in the localized adjuvant or neoadjuvant setting. Nevertheless, the search for biomarkers along with new clinical trial designs will be crucial to better select the patients that may derive the greatest benefit from these advances. The continuing improvement of antitumor immunity comprehension and the emergence of new immune modulatory treatments will deeply change the management of renal cell carcinoma for the years to come.

Safety and efficacy of nivolumab in combination with sunitinib or pazopanib in advanced or metastatic renal cell carcinoma: the CheckMate 016 study

BACKGROUND

Combination treatment with immune checkpoint inhibitors and antiangiogenic drugs has shown encouraging preliminary antitumor activity across various tumor types including advanced or metastatic renal cell carcinoma (aRCC). The open-label, parallel-cohort, dose-escalation, phase I CheckMate 016 study evaluated the efficacy and safety of nivolumab in combination with antiangiogenic tyrosine kinase inhibitors or ipilimumab. Long-term outcomes from this study for the combination of nivolumab plus sunitinib or pazopanib in aRCC are presented.

METHODS

Patients with aRCC received nivolumab plus either sunitinib (50 mg/day, 4 weeks on/2 weeks off; N + S) or pazopanib (800 mg/day; N + P) until progression/unacceptable toxicity. The nivolumab starting dose was 2 mg/kg every 3 weeks, with planned escalation to 5 mg/kg every 3 weeks. Primary endpoints were safety and tolerability; antitumor activity was a secondary endpoint.

RESULTS

Arm N + S enrolled 33 patients, 19 of whom were treatment-naïve; this arm advanced to the expansion phase. Median follow-up was 50.0 months. Patients experienced high frequencies of adverse events (AEs) including treatment-related AEs (100%), grade 3/4 treatment-related AEs (82%), and treatment-related AEs leading to discontinuation (39%). Investigator-assessed objective response rate (ORR) was 55% (18/33) and median progression-free survival (PFS) was 12.7 months. Median overall survival (OS) was not reached. Arm N + P enrolled 20 patients, all had ≥1 prior systemic therapy; this arm was closed due to dose-limiting toxicities and did not proceed to expansion. Median follow-up was 27.1 months. Patients treated with N + P experienced high frequencies of AEs including treatment-related AEs (100%), grade 3/4 treatment-related AEs (70%), and treatment-related AEs leading to discontinuation (25%). Investigator-assessed ORR was 45% (9/20) and median PFS was 7.2 months. Median OS was 27.9 months.

CONCLUSIONS

The addition of standard doses of sunitinib or pazopanib to nivolumab resulted in a high incidence of high-grade toxicities limiting future development of either combination regimen. While there was no adverse impact on response and the OS outcome was notable, the findings suggest that the success of combination regimens based on immune checkpoint inhibitors and antiangiogenic drugs may be dependent on careful selection of the antiangiogenic component and dose.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT01472081 . Registered 16 November 2011.

A Genetic Polymorphism in CTLA-4 Is Associated with Overall Survival in Sunitinib-Treated Patients with Clear Cell Metastatic Renal Cell Carcinoma

Purpose: The survival of patients with clear cell metastatic renal cell carcinoma (cc-mRCC) has improved substantially since the introduction of tyrosine kinase inhibitors (TKI). With the fact that TKIs interact with immune responses, we investigated whether polymorphisms of genes involved in immune checkpoints are related to the clinical outcome of cc-mRCC patients treated with sunitinib as first TKI.Experimental Design: Twenty-seven single-nucleotide polymorphisms (SNP) in CD274 (PD-L1), PDCD1 (PD-1), and CTLA-4 were tested for a possible association with progression-free survival (PFS) and overall survival (OS) in a discovery cohort of 550 sunitinib-treated cc-mRCC patients. SNPs with a significant association (P < 0.05) were tested in an independent validation cohort of 138 sunitinib-treated cc-mRCC patients. Finally, data of the discovery and validation cohort were pooled for meta-analysis.Results:CTLA-4 rs231775 and CD274 rs7866740 showed significant associations with OS in the discovery cohort after correction for age, gender, and Heng prognostic risk group [HR, 0.84; 95% confidence interval (CI), 0.72-0.98; P = 0.028, and HR, 0.73; 95% CI, 0.54-0.99; P = 0.047, respectively]. In the validation cohort, the associations of both SNPs with OS did not meet the significance threshold of P < 0.05. After meta-analysis, CTLA-4 rs231775 showed a significant association with OS (HR, 0.83; 95% CI, 0.72-0.95; P = 0.008). Patients with the GG genotype had longer OS (35.1 months) compared with patients with an AG (30.3 months) or AA genotype (24.3 months). No significant associations with PFS were found.Conclusions: The G-allele of rs231775 in the CTLA-4 gene is associated with an improved OS in sunitinib-treated cc-mRCC patients and could potentially be used as a prognostic biomarker. Clin Cancer Res; 24(10); 2350-6. ©2018 AACR.

New treatment options for metastatic renal cell carcinoma

During the last decade, the treatment of advanced or metastatic renal cell carcinoma (RCC) was revolutionised with the advent of antiangiogenic drugs and tyrosine-kinase inhibitors. Several agents targeting the vascular endothelial growth factor (VEGF) pathway (sunitinib, bevacizumab, pazopanib, axitinib) or the mammalian target of rapamycin pathway (temsirolimus, everolimus) were since then progressively approved for first-line or later-line use in the treatment of patients with advanced RCC and became the new standard of care. As a result, the survival of patients with advanced RCC has significantly improved from a median overall survival of approximately 12 months in the cytokines era to more than 26 months with first-line VEGF inhibitors. During the two last years, the treatment of advanced RCC has witnessed a second revolution with the advent of immune checkpoint inhibitors, especially agents targeting the programmed cell death-1 receptor, as well as with the advent of new generation tyrosine-kinase receptor inhibitors. This article will review the new therapeutic options available for the treatment of advanced RCC, as well as the future potential molecular targets that are currently being investigated.

Blocking the PD-1/PD-L1 pathway in glioma: a potential new treatment strategy

Gliomas are the most common type of primary brain tumor in adults. High-grade neoplasms are associated with poor prognoses, whereas low-grade neoplasms are associated with 5-year overall survival rates of approximately 85%. Despite considerable progress in treatment modalities, the outcomes remain dismal. As is the case with many other tumors, gliomas express or secrete several immunosuppressive molecules that regulate immune cell function. Programmed death-ligand 1 (PD-L1) is a coinhibitory ligand that is predominantly expressed by tumor cells. The binding of PD-L1 to its receptor PD-1 has been demonstrated to induce an immune escape mechanism and to play a critical role in tumor initiation and development. Encouraging results following the blockade of the PD-1/PD-L1 pathway have validated PD-L1 or PD-1 as a target for cancer immunotherapy. Studies have reported that the PD-1/PD-L1 pathway plays a key role in glioma progression and in the efficacy of immunotherapies. Thus, progress in research into PD-L1 will enable us to develop a more effective and individualized immunotherapeutic strategy for gliomas. In this paper, we review PD-L1 expression, PD-L1-mediated immunosuppressive mechanisms, and the clinical applications of PD-1/PD-L1 inhibitors in gliomas. Potential treatment strategies and the challenges that may occur during the clinical development of these agents for gliomas are also reviewed.

Response to anti-PD1 therapy with nivolumab in metastatic sarcomas

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.

New advances in genitourinary cancer: evidence gathered in 2014

This review provides updated information published in 2014 regarding advances and major achievements in genitourinary cancer. Sections include the best in prostate cancer, renal cancer, bladder cancer, and germ cell tumors. In the field of prostate cancer, data related to treatment approach of hormone-sensitive disease, castrate-resistant prostate cancer, mechanisms of resistance, new drugs, and molecular research are presented. In relation to renal cancer, relevant aspects in the treatment of advanced renal cell carcinoma, immunotherapy, and molecular research, including angiogenesis and von Hippel-Lindau gene, molecular biology of non-clear cell histologies, and epigenetics of clear renal cell cancer are described. New strategies in the management of muscle-invasive localized bladder cancer and metastatic disease are reported as well as salient findings of biomolecular research in urothelial cancer. Some approaches intended to improve outcomes in poor prognosis patients with metastatic germ cell cancer are also reported. Results of clinical trials in these areas are discussed.

Checkpoint inhibitors in bladder and renal cancers: results and perspectives

The field of immunotherapy in urinary malignancy is expanding in several directions and checkpoint inhibitors are leading the way. The aim of this report is to highlight the efficacy and safety profile of the two classes of molecules, anti-cytotoxic T-lymphocyte antigen-4 and anti-programmed death receptor-1/programmed death ligand type 1, that are under investigation and represent potential candidates to be used in the near future for the management of bladder and renal cell cancer. The preliminary results as well as the future perspectives of this novel immunotherapy are analyzed. Novel immune checkpoint targets are reviewed as well.

Clinical impact of checkpoint inhibitors as novel cancer therapies

Immune responses are tightly regulated via signaling through numerous co-stimulatory and co-inhibitory molecules. Exploitation of these immune checkpoint pathways is one of the mechanisms by which tumors evade and/or escape the immune system. A growing understanding of the biology of immune checkpoints and tumor immunology has led to the development of monoclonal antibodies designed to target co-stimulatory and co-inhibitory molecules in order to re-engage the immune system and restore antitumor immune responses. Anti-cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) antibodies were among the first to be tested in the clinic, and ipilimumab was the first immune checkpoint inhibitor approved for an anticancer indication. Agents targeting the programmed death 1 (PD-1) pathway, either PD-1 or one of its ligands, programmed death ligand 1, are in active clinical development for numerous cancers, including advanced melanoma and lung cancer. Understanding the different mechanisms of action, safety profiles, and response patterns associated with inhibition of the CTLA-4 and PD-1 pathways may improve patient management as these therapies are moved in to the clinical practice setting and may also provide a rationale for combination therapy with different inhibitors. Additional immune checkpoint molecules with therapeutic potential, including lymphocyte activation gene-3 and glucocorticoid-induced tumor necrosis factor receptor-related gene, also have inhibitors in early stages of clinical development. Clinical responses and safety data reported to date on immune checkpoint inhibitors suggest these agents may have the potential to markedly improve outcomes for patients with cancer.

Current status and future directions of the immune checkpoint inhibitors ipilimumab, pembrolizumab, and nivolumab in oncology

OBJECTIVE

To provide the clinician with an update and the current status and future direction of approved immune checkpoint inhibitors (ICIs) in oncology.

DATA SOURCES

A PubMed search from January 1, 1966 to March 13, 2015 was performed using the key terms ipilimumab, pembrolizumab, lambrolizumab, nivolumab, immune checkpoint inhibitor, MDX-010, MDX-101, BMS-734016, MK-3475, SCH 900475, MDX-1106, BMS-936558, ONO-4538, CTLA-4, PD-1, or PD-L1 and cancer, oncology, or neoplasm. Additional references were identified from the investigators(') personal files, recent oncology meetings, review articles, clinical guidelines, and package inserts.

STUDY SELECTION AND DATA EXTRACTION

All English-language clinical trials assessing the safety and efficacy of ipilimumab, nivolumab, and pembrolizumab in cancer were considered. The PubMed search resulted in 215 trials; 33 met inclusion criteria. A further 28 trials were identified from the above sources; 61 trials from 2005 to 2015 were included. We consolidated and clarified treatment recommendations for the management of immune-related adverse events (irAEs), assessed response criteria, and calculated the clinical utility of leading tumor profiling options.

DATA SYNTHESIS

Ipilimumab and nivolumab, but not pembrolizumab, have an overall survival (OS) advantage over chemotherapy first line in unresectable/metastatic melanoma. Nivolumab has an OS advantage versus chemotherapy in second-line squamous non-small-cell lung cancer. Data in other settings are promising. Nivolumab and pembrolizumab are better tolerated than ipilimumab. Further validation of response criteria is needed. Tumor profiling to predict clinical benefit is premature but promising.

CONCLUSIONS

The treatment landscape in oncology is quickly evolving with the advent of ICIs.