Rare side-effects of checkpoint inhibitors

Cardiac Immune-Related Adverse Events in Immune Checkpoint Inhibition Therapy

Immune checkpoint inhibitors present clinicians with both an exciting step forward in cancer treatment and the unknown possibilities of an unshackled immune system. The latter phenomena, known as immune-related adverse events (irAEs), are of particular interest because they may affect any organ system with autoimmune-like pathologies, such as hepatitis and colitis. Within the cardiovascular system, irAEs associated with immune checkpoint blockade exist as a broad clinical spectrum, with autoimmune myocarditis being the best-characterized entity at this time. In general, irAEs are often reversible with immunosuppression. However, irAEs that affect the cardiovascular system pose the possibility of a rapid and fatal clinical deterioration. The mortality attributed to immune checkpoint blockade-associated autoimmune myocarditis, as reported in the WHO database, exists from 36% to 67%, dependent on the therapeutic regimen. Yet, despite the potential severity such events pose, guidelines dictating the identification of immune checkpoint inhibition irAEs do not exist, providing a stark contrast with other anticancer medications with known cardiovascular effects. The lack of guidelines may be related to the perceived rarity of these events, yet a recent study of immune checkpoint inhibition-associated autoimmune myocarditis suggests that this clinical entity may be more prevalent than initially believed. Until more standardized information regarding these potentially serious events is available, the study of documented cases is instructive to improve identification of such phenomena, as well as the outcomes for patients who develop them.

Hematological Side Effects of Immune Checkpoint Inhibitors: The Example of Immune-Related Thrombocytopenia

Immune-related hematological adverse events are amongst the rare but potentially life-threatening complications of immune checkpoint inhibitors. The spectrum of these toxicities is broadening as the number of patients exposed to these agents is increasing. Yet, they are still relatively unknown to many clinicians, possibly due to a lack of specific diagnostic criteria, which poses a challenge for their recognition and proper reporting, and partly due to their low incidence, often too low to be noted in most clinical trial publications. Since early detection and prompt intervention are crucial to prevent fatal consequences, it is of outmost importance that medical staff and patients be aware of these potential toxicities and learn to recognize and treat them adequately. This publication outlines strategies and offers guidance on the detection, diagnosis, risk assessment, monitoring and management of immune-related thrombocytopenia, a relatively common example of immune-related hematological toxicity of immune checkpoint inhibitors.

[Toxicity of immune checkpoints inhibitors]

INTRODUCTION

Anti-tumoral immunotherapy is currently the basis of a profound modification of therapeutic concepts in oncology, in particular since the arrival of immune checkpoint inhibitors (ICI). In addition to their efficacy profile, these immune-targeted agents also generate adverse events. With the increasing use of ICI for a growing number of tumor types, awareness of immunotherapy-related adverse events is essential to ensure prompt diagnosis and effective management of these potentially serious adverse events.

BACKGROUND

Cytotoxic T-lymphocyte antigen 4 (CTLA4) and programmed cell death protein 1 (PD1) are two co-inhibitory receptors that are expressed on activated T cells against which therapeutic blocking antibodies have reached routine clinical use. Immune checkpoint blockade can induce inflammatory adverse effects, termed immune-related adverse events (irAEs), which resemble autoimmune disease. Though severe irAEs remain rare, they can be fatal if not diagnosed and treated in an appropriate manner.

OUTLOOK AND CONCLUSION

Additional studies are needed to better understand the clinical characteristics and chronology of these adverse effects and to clarify their pathophysiological mechanisms.

Diffuse edema suggestive of cytokine release syndrome in a metastatic lung carcinoma patient treated with pembrolizumab

Immune checkpoint inhibitors (ICIs) are actually being indicated more commonly in the management of chemoresistant cancer patients in view of their favorable toxicity profile in comparison to cytotoxic chemotherapy. In this paper, we report, to our knowledge, the first case suggestive of cytokine release syndrome secondary to pembrolizumab in a patient with metastatic lung squamous cell carcinoma. In view of the quick approvals of ICI and the absence of sufficient knowledge of the corresponding toxicity profile, the occurrence of any clinical or biological sign or symptom in patients receiving ICI requires further investigation.

The second wave of immune checkpoint inhibitor tsunami: advance, challenges and perspectives

After the first wave of the tsunami of immune checkpoint inhibitors, 2016 was marked by the second wave, revealed by numerous US FDA approvals, publications and abstracts in relation with these drugs in different cancers and settings. First, we reported all new indications of anti-CTLA4, anti-programmed cell death protein 1 and anti-PDL1 approved by the FDA, the positive clinical trials published and the abstracts reported at important scientific meetings during 2016. Then, we highlighted the updates on debatable issues related to checkpoint inhibitors, since the first wave published in a previous issue. We focused on the predictive biomarkers, combination therapies, tumor response patterns and efficacy in particular settings and the side effect management. Finally, the impact of checkpoint inhibitors development on the care management of cancer centers will be discussed.

Toxicity management of immunotherapy for patients with metastatic melanoma

Checkpoint inhibitors have revolutionized the treatment of patients with metastatic melanoma offering improved responses and significant survival benefit. These agents are now approved for the treatment of metastatic melanoma, squamous and non-squamous non-small cell lung cancer (NSCLC) and kidney cancer, while they are now being investigated in a range of other malignancies. In addition, another anti-PD-L1 monoclonal antibody (atezolizumab) was recently approved for urothelial cancer. Ipilimumab, an anti-cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) antibody and the anti-PD-1 agents nivolumab and pembrolizumab have followed large clinical development programs, therefore, information regarding their safety and toxicity profile is readily available. Unique toxicities have been observed, which stem from and relate to the immune activation by these agents and are thus termed as immune-related adverse events (irAEs). Clinicians and patients should be aware of this different toxicity profile, so as to promptly recognize, identify and manage symptoms related to irAEs. Indeed, clinical experience has shown that these immune events, when they are early recognized and timely managed, are mostly reversible otherwise they can evoke severe or even life-threatening situations. Several recommendations and guidelines have been developed for the management of irAEs and algorithms have been published based primarily on our knowledge from the ipilimumab trials.