Evaluation of the pharmacokinetics and metabolism of pembrolizumab in the treatment of melanoma

Introduction: Advanced melanoma is a devastating disease that has propelled research in therapeutics beyond chemotherapy and radiotherapy. Being highly immunogenic, melanoma is a model tumor for immunotherapy and has highlighted the therapeutic potential of the immune checkpoint inhibitors.

Areas covered: This review discusses the pharmacologic properties, clinical efficacy, and safety profile of pembrolizumab, an IgG4-kappa humanized monoclonal antibody against the programmed cell death protein 1 (PD-1) receptor, for the treatment of unresectable or metastatic melanoma.

Expert opinion: Pembrolizumab was the first PD-1 inhibitor to be approved by the U.S. Food and Drug Administration (FDA). Remarkably, this accelerated approval for the treatment of advanced, heavily pretreated melanoma was based on response rates alone from a phase I trial. As anticipated, pembrolizumab confirmed a survival advantage in phase II and III trials and has led the way for the study of other drugs that share its mechanism of action. Defining disease and patient characteristics associated with a response remains amongst the most pressing priorities.     

The safety of nivolumab for the treatment of metastatic melanoma

Introduction: Nivolumab, a human IgG4 monoclonal antibody directed against PD-1, is a checkpoint inhibitor that is licenced in the treatment of metastatic melanoma either as a monotherapy or in combination with ipilimumab, a CTLA-4 inhibitor. The introduction of immune checkpoint inhibitors to the therapeutic landscape has dramatically altered outcomes in a proportion of patients with metastatic melanoma. Immune checkpoint inhibitors result in a toxicity profile that is distinct from that of chemotherapy or targeted therapy based on their immunomodulatory mechanism and similarly can result in patterns of response that are unique.

Areas covered: Herein we will profile nivolumab’s efficacy and safety both as a combination therapy and a monotherapy and discuss the results of relevant clinical trials in this respect.

Expert opinion: The future of immunotherapy in melanoma will evolve around the development of biomarkers, the refinement of criteria to define patterns of response and toxicity and the combination of current immunotherapies with existing and novel agents to maximise responses.     

Safety evaluation of pembrolizumab for treating recurrent head and neck squamous cell carcinoma

ABSTRACT

Introduction

Programmed death 1 (PD-1) blockade has changed the therapeutic landscape of recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) with convincing overall response rates and overall survival benefits when compared to chemotherapy alone. The toxicity profile of pembrolizumab appears to be similar to that of other PD-1 or PD-L1 inhibitors, with frequent diarrhea, hypothyroidism or cutaneous rash cases, and rare cases of grade 3 to 5 pneumonitis.     

Pembrolizumab for the treatment of melanoma

The immune system plays a vital role in regulating tumor growth, and the oncology community has witnessed an exciting resurgence in clinical research to develop effective immunotherapeutic strategies. The utility of these strategies in advanced melanoma has been at the forefront of these developments. In particular, blockade of programmed cell death protein 1 (PD-1) in advanced melanoma has proven to be a most promising new anticancer strategy. Pembrolizumab is a humanized IgG4 anti-PD-1 antibody that exerts its anti-tumor effect through blocking the interaction of the immune inhibitory molecule PD-1 with its ligands. Its effect has been most convincingly demonstrated in the setting of advanced melanoma, with growing evidence of clinical responses across a broad spectrum of other solid and hematological malignancies.     

Targeting the PD-1 pathway: a new hope for gastrointestinal cancers

Background: VEGF, HER2 and EGFR targeted agents are currently used in gastric, esophageal and colorectal cancers. However, treatment outcomes are still poor in most gastrointestinal (GI) cancers. Immune checkpoints are one of the most promising immunotherapy approaches. In this review article, we aim to discuss the efficacy and safety of anti-PD-1/PD-L1 therapies in GI cancers, including gastric, esophageal and colorectal cancer in published or reported recent studies.

Scope: A literature search was made from PubMed and ASCO Annual Meeting abstracts by using the following search keywords: “nivolumab”, “pembrolizumab”, “avelumab”, “GI cancers” “anti-PD1 therapy” and “anti-PD-L1 therapy”. The last search was on 2 November 2016. The most important limitation of our review is that most of the data on anti-PD-1/PD-L1 therapies in GI cancers relies on phase 1 and 2 trials.

Findings: Currently, there are two anti-PD-1 (nivolumab and pembrolizumab) and one anti-PDL1 (atezolizumab) agents approved by FDA. After the treatment efficacy of immune checkpoint blockade was shown in melanoma, renal cell cancer and non-squamous lung cancer, trials which evaluate immune checkpoint blockade in GI cancers are ongoing. Early results of trials have been promising and encouraging for patients with advanced stage gastroesophageal cancer. According to early results of published trials, response to anti-PD1/PD-L1 agents appears to be associated with tumor PD-L1 levels. According to two recently published phase 2 trials, the clinical benefits of immune checkpoint blockade with both nivolumab and pembrolizumab were limited in patients with microsatellite instability (MSI) positive advanced colorectal cancer. However, several phase 2/3 trials are still ongoing.

Conclusion: Both pembrolizumab and nivolumab show promising efficacy with acceptable safety data in published trials in GI cancers, especially in refractory MSI positive metastatic colorectal cancer.     

Optimizing Patient Outcomes with PD-1/PD-L1 Immune Checkpoint Inhibitors for the First-Line Treatment of Advanced Non–Small Cell Lung Cancer

The rapidly expanding repertoire of immune checkpoint inhibitors (ICIs) now includes two agents, pembrolizumab and atezolizumab, approved for first-line treatment of advanced non–small cell lung cancer (aNSCLC) as monotherapy or as part of chemoimmunotherapy. This review summarizes the clinical evidence supporting these indications, with a focus on strategies to optimize patient outcomes. These strategies include patient and tumor factors, adverse-effect profiles, pharmacokinetic and pharmacodynamic drug interactions, and quality of life and cost-effectiveness considerations. We performed a systematic literature search of the PubMed, Scopus, and Google Scholar databases, as well as a search of the conference proceedings of the American Society of Clinical Oncology, European Society for Medical Oncology, and American Association for Cancer Research (through August 31, 2019). The addition of ICIs to conventional chemotherapy as first-line treatment against aNSCLC is now part of the standard of care options. However, even though ICIs may be cost-effective in patients with aNSCLC, high drug and other associated costs can still be a barrier to treatment for patients. Moreover, the adverse-effect profiles of ICIs differ significantly from conventional chemotherapy, and some immune-related adverse effects may have a lasting impact on quality of life. Therefore, in adhering to a patient-centered model of care, clinicians should be mindful of patient- and treatment-specific factors when considering therapeutic options for patients with aNSCLC. Although the role of the immune system in cancer progression and regression has not been fully elucidated, the full clinical potential of immunotherapeutics in the treatment of cancer likely remains to be unleashed.     

Novel immunotherapy in the treatment of advanced non-small cell lung cancer

Introduction: Lung cancers remain the principal cause of death cancer-related worldwide with a poor survival rate at five years from diagnosis. In patients with NSCLC harboring specific genetic alterations the anti EGFR TKIs and the ALK TKIs have improved the response rate and the quality of life compared to standard platinum-based chemotherapy. New approaches possibly applicable at the major of patients are needed.

Areas covered: The discovery that the immune system plays a fundamental role in the fight against cancer. The cancer cells use mechanisms able to avoid the immune control has led to the development of drugs able to overcome this escape route. The best known checkpoint pathways are the CTLA-4 and PD-1/PD-L1; they suppress T-cell activity in different ways: CTLA-4 regulates T-cell activity at an early stage whereas PD-1 regulates later effector T-cell activity within tissue and tumors. The best characterized checkpoint inhibitors in advanced NSCLC setting are ipilimumab and tremelimumab, (anti-CTLA-4 antibodies), nivolumab and pembrolizumab (anti-PD-1 antibodies), atezolizumab and durvalumab (anti-PD-L1 antibodies). Nivolumab and pembrolizumab have received the FDA and EMA approval for the treatment of NSCLC in second-line setting.

Expert commentary: The role played by tumor microenvironment may be the next area of research to overcome the resistance at the checkpoint inhibitors as well as the identification of biomarkers to better select patients. In addition checkpoint inhibitors are investigate in combination with other agent involved in immune control with promising results in solid tumors.     

Neurologic complications of immune checkpoint inhibitors

ABSTRACT

Introduction: Immune checkpoint inhibitors (ICI) are associated with a wide spectrum of neurologic immune-related adverse events (irAEs) including meningo-encephalitis, myasthenia gravis and various neuropathies. Although relatively rare, they often present significant diagnostic complexity and may be under-recognized. Permanent neurologic deficits and/or fatality have been described but improvement is noted in most cases with ICI discontinuation and immunosuppressive therapy.

Areas covered: This review highlights the most frequently reported ICI-associated neurologic toxicities with a particular focus on those that may be more severe and/or fatal. Data from case series and pharmacovigilance studies is leveraged to provide an overview of associated clinical features, expected outcomes and appropriate management. Various immunobiologic triggers have been proposed to explain why certain patients might develop neurologic irAEs and are also briefly discussed.

Expert opinion: All providers who care for patients with cancer should be made aware of common neurologic irAEs and able to recognize when prompt evaluation and consultation with appropriate specialists are indicated. Symptoms suggestive of encephalitis, myasthenia-gravis or an acute polyradiculopathy such as Guillain-Barre Syndrome (GBS) in patients exposed to these agents warrant immediate attention with a low threshold for hospitalization to expedite work-up and monitor for severe and/or life-threatening manifestations.     

The safety of anti PD-1 therapeutics for the treatment of melanoma

Introduction: The introduction of immunotherapies into clinical practice has substantially improved the prognosis of metastatic melanoma patients as well as patients suffering from other cancers. The two FDA-approved checkpoint inhibitors against PD-1 (nivolumab and pembrolizumab) have been shown to significantly improve patient survival while being less toxic than previous treatment options.

Areas covered: The current scientific literature on safety and adverse events (AEs) related to anti-PD-1 therapies has been investigated with special attention to case reports and to the latest results announced at the major clinical cancer and melanoma meetings, including ASCO (American Society of Clinical Oncology), ESMO (European Society of medical Oncology) and EADO (European Association of Dermato-Oncology) annual meetings.

Expert opinion: Even though anti-PD-1 therapies are better tolerated than conventional chemo- or other immune-therapies, they still induce a plethora of AEs. Given the mechanism of action, it is supposed that most if not all of them are immune related. Fortunately, the majority are mild and manageable. However, due to the increase in patients’ life expectancy, there is a substantial need to understand and prevent severe cutaneous, pulmonary, neurological and other AEs which have major impact on the quality of life. The safety profile after long term use of these medications is still unclear. In addition, non-steroid based immune interventions to control autoimmunity are still to be developed.     

Optimal drugs for second-line treatment of patients with small-cell lung cancer

Introduction: Despite the high response rate to chemotherapy, there have been few advances in the treatment of small-cell lung cancer (SCLC) in the last decades. The state-of-the-art second-line therapy and future research developments in relapsed SCLC are reviewed.

Areas covered: There are no optimal drugs for second-line treatment of recurrent SCLC but only agents registered for this use. Topotecan remains the standard-of-care for the treatment of second-line platinum-sensitive SCLC patients worldwide, while amrubicin is another option, but registered only in Japan. To date, no targeted agents reporting interesting results in second-line SCLC treatment are available. The next-generation DNA sequencing should discover somatic gene alterations and their roles in SCLC to help in selecting patients who could benefit from a targeted agent. Two immunotherapeutics, ipilimumab and nivolumab, have shown promising preliminary results and are being investigated in ongoing trials.

Expert opinion: Second-line treatment is not an option for most SCLC patients. Given the evidence up to now, the potentials for immuno-oncology in SCLC are high. The hope is that these expectations are met, and that all drugs being developed will offer new and improved treatment options for SCLC patients.     

Nivolumab for the treatment of cancer

Introduction: One mechanism by which tumor cells are thought to evade the host’s immune system is by inducing negative signals that cause T-cell suppression. An important interaction that results in this phenomenon is the one between programmed death-1 (PD-1) on the T cell and its ligand PD ligand-1 (PD-L1) on the tumor cell. PD-1 pathway blocking agents, such as nivolumab, are therefore capable of reversing T-cell suppression and ultimately induce antitumor responses.

Areas covered: In this review, the authors summarize investigations related to the safety and efficacy of nivolumab in a variety of malignancies thus far, including advanced melanoma, renal cell carcinoma (RCC) and NSCLC.

Expert opinion: The results have been promising with a large number of objective responses and favorable safety profiles inspiring several Phase III trials in these settings. More recent studies are exploring the role of this drug in the treatment of various other cancers. Combination therapies involving nivolumab are also being studied and are yielding interesting results. Finally, the role of tumor PD-L1 expression as a predictive biomarker remains to be ascertained. Thus, with rational refinement through biomarker and combination clinical trials, nivolumab and other PD-1 blocking agents will likely lead to significant improvements in cancer therapeutics.     

Selecting immuno-oncology–based drug combinations – what should we be considering?

ABSTRACT

Introduction: Checkpoint inhibitor immunotherapy has revolutionized the treatment of many advanced stage cancers. Preexisting immunity is necessary for a response to these agents, which are most effective in inflamed tumors since they principally act by reinforcing preexisting antitumor T-cell responses. An important goal of therapy is to convert the tumor environment from non-inflamed to inflamed in order to facilitate subsequent response to checkpoint inhibitors. Clinical trials are underway to identify checkpoint inhibitor-based combination approaches, which may help to achieve this goal.

Areas covered: Anti-PD-1 agents are being assessed in combination with different treatments (e.g. TLR9 agonists, oncolytic peptides, oncolytic vaccines, LAG-3, HDAC inhibitors, GITR, recombinant human interleukin-2) with promising results. PD-1 agents are also being assessed in combination with other locoregional or systemic treatment modalities, including ECT, radiotherapy, chemotherapy, and targeted therapy, with promising results being achieved.

Expert commentary: Emerging approaches based on combinations with anti-PD-1 agents seem to offer increased efficacy compared to anti-PD-1 monotherapy. Such combinations also appear to be well tolerated, with safety profiles often comparable to those seen with anti-PD-1 monotherapy. These combination approaches are likely to become an increasing focus of research. There is also the potential for triplet anti-PD-1 combinations.     

Novel agents in development for the treatment of melanoma

In 2005, melanoma is estimated to affect 55,000 Americans. Of these, 7700 are estimated to die from the disease. Immunological approaches have yielded the only newly FDA-approved agents for melanoma in 30 years, which includes high-dose bolus IL-2, based on durable responses in some patients with metastatic melanoma. A survival advantage was shown in two of three randomised clinical trials with high-dose IFN-α_2b in the high-risk adjuvant setting. However, both agents are associated with high cost and toxicity rates. A number of novel therapeutic agents are undergoing active clinical investigation. The more promising of these will be discussed in this review, including bcl-2 antisense therapy, v-raf murine sarcoma viral oncogene homologue B1 inhibition, heat-shock proteins, anti-α_vβ₃ integrin monoclonal antibody, thalidomide and newer immunomodulatory drugs, and anti-cytotoxic T lymphocyte-associated protein-4 monoclonal antibody.     

The safety of second-line treatment options for non-small cell lung cancer

Introduction: Non-small-cell lung cancer (NSCLC) patients after first-line therapy ultimately suffer progression. At this time, many patients still have a good performance status and can be considered for further active treatment. Two chemotherapeutic agents, docetaxel and pemetrexed (only in non-squamous histology), and the biological drug anti-epidermal growth factor receptor (EGFR) erlotinib, were approved for clinical use in the second-line treatment of NSCLC patients. In the last few years further new second-line therapies have become available in the clinical practice.

Areas covered: This review will discuss the adverse events of the pivotal trials ledding to the approval of second-line therapies for the treatment of not oncogene-addicted NSCLC patients.

Expert opinion: In recent years, new second-line options for NSCLC are: the anti-EGFR, afatinib (only in squamous NSCLC); the anti-angiogenics, nintedanib (only in lung adenocarcinoma) and ramucirumab, in combination with docetaxel; the immunotherapeutics, nivolumab, pembrolizumab, and atezolizumab. In the second-line approach, the main endpoint of treatment should always be survival, but with great respect for symptoms palliation and preserving patients’ quality of life. Therefore, differing toxicity profiles of the available therapeutic options are often a deciding factor in second-line setting for NSCLC.     

Pharmacokinetics,pharmacodynamics and clinical efficacy of nivolumab in the treatment of metastatic renal cell carcinoma

Introduction: Nivolumab is a recombinant, humanized monoclonal antibody that binds PD-1. The binding of PD-1 with PD-L1, expressed on antigen-presenting cells and tumor cells, suppresses the ability of T-lymphocytes to recognize and destroy tumor cells. Nivolumab reverts this inhibitory signal and has led to a significant prolongation of overall survival in patients with metastatic renal cell carcinoma (RCC).

Areas covered: The rationale for immunotherapy in metastatic RCC, key immune checkpoint pathways, nivolumab pharmacodynamics, results from the main clinical trials, and predictors of response are discussed.

Expert opinion: Nivolumab demonstrated a statistically significant advantage over everolimus in overall survival in metastatic RCC patients after first-line antiangiogenic therapy. Nevertheless, a number of issues remain to be resolved regarding the use of this drug in RCC. It is now imperative to identify which patients can benefit most from immunotherapy and studies are ongoing to define its role in other settings and/or in combinations with antiCTLA4 or antiangiogenic drugs.     

An update on the safety of nivolumab for the treatment of advanced melanoma

ABSTRACT

Introduction: Due to its unique mechanism of action as an immune checkpoint inhibitor, nivolumab has high antitumor activity, but at the same time this mechanism is responsible for immune-related adverse events that may limit patients’ safety and therapy continuation.

Areas covered: Long-term safety of nivolumab including 5-year follow-up, safety of nivolumab treatment after ipilimumab therapy, safety of nivolumab in challenging subgroups (elderly, patients with brain metastases, patients with autoimmune disorders), safety of nivolumab in with rare melanoma subtypes (including mucosal melanoma), as well as specificity of AEs reported for nivolumab treatment in melanoma patients in comparison to other cancer types and other immunotherapy molecules, and impact of AEs on response rates and PFS on nivolumab treatment are discussed.

Expert opinion: Search for biomarkers that would help us to identify patient populations that may suffer from severe nivolumab toxicity could help in selecting patients that should not be treated with this type of therapy. Novel combinations and immunotherapy drugs including use of NKTR-214 (IL-2 pathway), lymphocyte-activation gene 3 (LAG-3), local injections of talimogene laherparepvec (T-VEC), or systemic use of T-cell receptors agonists such as OX40, CD137, ICOS-1, could provide regimens with limited toxicity and higher activity.     

The safety and efficacy of pembrolizumab for the treatment of non-small cell lung cancer

ABSTRACT

Introduction: Lung cancer is the leading cancer-related cause of death worldwide. The introduction of immune checkpoint inhibitors (ICIs) for the treatment of lung cancer has significantly improved the outcome of these patients. Pembrolizumab, a monoclonal IgG4-kappa antibody against programmed-death-1 (PD-1) protein, nowadays represents a standard of care for NSCLC patients. Although it has a favorable toxicity profile, some immune-related adverse events (irAEs) can be life-threatening, therefore its knowledge may help to optimize the care of these patients.

Areas covered: The authors review data regarding the efficacy and safety of pembrolizumab from the most relevant clinical trials as well as toxicities reported in the clinical use. Special considerations of use in special populations will be noted. Finally, its toxicity profile will be compared with other ICIs used in NSCLC.

Expert opinion: In the scenario of NSCLC, pembrolizumab shows a favorable safety profile with less than 10% serious immune-related adverse events (irAEs) when used in monotherapy and without adding relevant extra-toxicity to chemotherapy when used in combination. Monotherapy with pembrolizumab is associated with better health-related quality of life than chemotherapy. Early recognition and appropriate treatment of irAEs is of prime importance as most are reversible if correctly managed. Rechallenge with pembrolizumab is frequently feasible.     

Kinase inhibitors and immune check-point blockade for the treatment of metastatic melanoma and advanced cancer: synergistic or antagonistic?

In recent years, therapeutic approaches for many tumors have broadened or even shifted entirely from cytotoxic chemotherapy to specific targeting of dysregulated proteins (predominately kinases), and more recently, harnessing of the anti-tumor immune response. The most prominent example of this shift is the management of metastatic melanoma, where BRAF and MEK inhibition and CLTA-4 blockade have established an entirely new standard of care in the last 3 years. Targeted kinase inhibition and immune checkpoint blockade have different strengths and weaknesses. Kinase inhibitors generally have rapid and impressive response rates but modest progression-free survival while immunotherapy can achieve durable tumor control, but is often associated with lower response rates and slower time to clinical benefit. These approaches would seem to be complementary however the results of early combination studies suggest that caution is advised when combining targeted kinase inhibition with immunotherapy. In this context, rigorous biomarker driven clinical trials are needed to further elucidate mechanisms of both benefit and toxicity. Depending on disease specific biology, it seems likely that both combination and sequential approaches of kinase inhibitors with immunotherapy will be required in order to harness the full potential of these approaches.     

Emerging monoclonal antibodies for the treatment of renal cell carcinoma (RCC)

Introduction: Advanced renal cell carcinoma (RCC) was considered refractory to most cancer therapies until the 1980s, after which immune modulating agents and targeted agents were developed. Recently the rapid development of therapeutic monoclonal antibodies targeting immune checkpoint pathways has provided significant clinical benefit in patients with many distinct cancer types. Nivolumab, an anti-PD1 monoclonal antibody showed improvement in response rate and overall survival in patients with previously treated RCC and received US FDA approval in late 2015. Current efforts with anti-PD1-based therapy include combinations with ipilimumab and with VEGF pathway blockers in the hopes on building on the activity of single agent therapy.

Areas covered: We describe our current understanding of tumor immunology including the basis of the tumor-specific immune response and the adaptive mechanisms used by the tumor for immune escape. We describe the mechanisms of action as well as the therapeutic application of the antibodies, ipilimumab, nivolumab and atezolizumab in patients with RCC. We identify key areas of active research in biomarker development and combination therapies.

Expert opinion: Clinical trials and the field of RCC therapeutics are expected to move in the direction of combination therapies using immune checkpoint inhibitors, extending overall survival as a benchmark for new drug approvals, and biomarker validation for improved selection of patients for specific therapies.