Ipilimumab-induced colitis: experience from a tertiary referral center

Management of liver and gastrointestinal toxicity induced by immune checkpoint inhibitors: Position statement of the AEEH-AEG-SEPD-SEOM-GETECCU

The development of the immune checkpoint inhibitors (ICI) is one of the most remarkable achievements in cancer therapy in recent years. However, their exponential use has led to an increase in immune-related adverse events (irAEs). Gastrointestinal and liver events encompass hepatitis, colitis and upper digestive tract symptoms accounting for the most common irAEs, with incidence rates varying from 2% to 40%, the latter in patients undergoing combined ICIs therapy. Based on the current scientific evidence derived from both randomized clinical trials and real-world studies, this statement document provides recommendations on the diagnosis, treatment and prognosis of the gastrointestinal and hepatic ICI-induced adverse events.

Management of liver and gastrointestinal toxicity induced by immune checkpoint inhibitors: Position statement of the AEEH-AEG-SEPD-SEOM-GETECCU

The development of the immune checkpoint inhibitors (ICI) is one of the most remarkable achievements in cancer therapy in recent years. However, their exponential use has led to an increase in immune-related adverse events (irAEs). Gastrointestinal and liver events encompass hepatitis, colitis and upper digestive tract symptoms accounting for the most common irAEs, with incidence rates varying from 2 % to 40 %, the latter in patients undergoing combined ICIs therapy. Based on the current scientific evidence derived from both randomized clinical trials and real-world studies, this statement document provides recommendations on the diagnosis, treatment and prognosis of the gastrointestinal and hepatic ICI-induced adverse events.

Treatment and outcomes of immune checkpoint inhibitors-associated colitis/diarrhea: A systematic review and meta-analysis

BACKGROUND

Immune checkpoint inhibitors (ICIs) have improved the outcomes of cancer patients. However, ICIs often lead to colitis/diarrhea. This study aimed to assess the treatment of ICIs-associated colitis/diarrhea and outcomes.

METHODS

PubMed, EMBASE, and Cochrane Library databases were searched for eligible studies which investigated the treatment and outcomes of colitis/diarrhea developing in patients who received ICIs. The pooled incidences of any-grade colitis/diarrhea, low-grade colitis, high-grade colitis, low-grade diarrhea, and high-grade diarrhea as well as the pooled rates of response to treatment, mortality, and ICIs permanent discontinuation and restarts in patients with ICIs-associated colitis/diarrhea were estimated using a random-effects model.

RESULTS

Among the 11,492 papers initially identified, 27 studies were included. The pooled incidences of any-grade colitis/diarrhea, low-grade colitis, high-grade colitis, low-grade diarrhea, and high-grade diarrhea were 17%, 3%, 17%, 13%, and 15%, respectively. The pooled rates of overall response, response to corticosteroid therapy, and response to biological agents were 88%, 50%, and 96%, respectively. The pooled short-term mortality in patients with ICIs-associated colitis/diarrhea was 2%. The pooled incidences of ICIs permanent discontinuation and restarts were 43% and 33%, respectively.

CONCLUSION

ICIs-associated colitis/diarrhea is common, but rarely lethal. Half of them are responsive to corticosteroid therapy. There is a fairly high rate of response to biological agents in steroid-refractory colitis/diarrhea patients.

Severe and refractory gastrointestinal toxicity due to immune checkpoint inhibitors: clinical experience in a tertiary referral hospital

INTRODUCTION

immune checkpoint inhibitors (ICI) are increasingly used to treat several types of cancer. These drugs lead to a wide range of toxicities. Immune-related gastrointestinal adverse events are common and potentially severe. In this manuscript, we recount the real clinical experience in a tertiary center.

METHODS

a retrospective and observational study was conducted in adult patients under ICI treatment. Included patients had been referred to the Gastrointestinal Service of Hospital Universitario Vall d'Hebron for evaluation of severe toxicities, from January 2017 to January 2020, for whom the clinical, epidemiological and evolutive data were collected.

RESULTS

a total of 18 patients were included. Fifty-five percent received anti-programmed cell death protein 1 (PD-1)/anti-programmed death-ligand 1 (anti PD-L1), 11 % received anti-cytotoxic T lymphocyte antigen 4 (CTLA-4) and 33 % received both treatments. The toxicities were manifested as enterocolitis, microscopic colitis and gastritis. Upper gastrointestinal endoscopy was performed in seven patients; all were proved to have histological changes on duodenum biopsies. Treatment was stopped in all patients and steroids were initiated. Sixty-six per cent achieved clinical remission with steroids. Five patients received anti-TNF treatment (infliximab). Only one of the five had responded. Two anti-TNF refractory patients received ustekinumab, with an appropriate clinical response. One patient received apheresis granulocyte as concomitant treatment. A patient with a steroid-dependent course started vedolizumab. Three patients had other immune-related adverse events.

CONCLUSION

gastrointestinal immune-related adverse events are acquiring a higher profile in daily practice and gastroenterologists play an even greater role in the management of these patients.

Pharmacological Treatments Available for Immune-Checkpoint-Inhibitor-Induced Colitis

Immune checkpoint inhibitor treatment has shown revolutionary therapeutic effects in various carcinomas. However, immune-related adverse events (irAE) following this treatment can sometimes lead to treatment discontinuation. One such frequently encountered adverse event is immune-related colitis (irAE colitis). Corticosteroids (CS) are the first-line treatment for irAE colitis, but we often encounter CS-refractory or -resistant cases. The application of multiple biologics has been proposed as a therapy to be administered after CS treatment; however, the efficacy and safety of biologics for patients with irAE colitis who do not respond to CS have not been established. This review summarizes the treatment regimens available for irAE colitis, focusing on the mechanism of action of corticosteroids, infliximab, vedolizumab, and other drugs.

Immune Checkpoint Inhibitor-associated Diarrhea and Colitis: A Systematic Review and Meta-analysis of Observational Studies

BACKGROUND

Immune checkpoint inhibitors (ICIs) have transformed the management of advanced malignancies but are associated with diarrhea and colitis. The objective of our systematic review and meta-analysis was to determine the incidence and outcomes of ICI-associated diarrhea and colitis. Bibliographic databases were searched through August 13, 2019, for observational studies of ICI therapy reporting the incidence and/or treatment of diarrhea or colitis. The primary outcome was ICI-associated diarrhea and colitis. Meta-analyses were performed with random-effects models. Twenty-five studies (N=12,661) were included. All studies had a high risk of bias in at least 1 domain. The overall incidence of diarrhea/colitis was 12.8% [95% confidence interval (CI), 8.8-18.2, I2=96.5]. The incidence was lower in patients treated with anti-programmed cell death 1/programmed death-ligand 1 (4.1%, 95% CI, 2.6-6.5) than in those treated with anti-cytotoxic T-cell lymphocyte-associated antigen 4 (20.1%, 95% CI, 15.9-25.1). The remission of diarrhea and/or colitis was higher in patients treated with corticosteroids plus biologics (88.4%, 95% CI, 79.4-93.8) than in those treated with corticosteroids alone (58.3%, 95% CI, 49.3-66.7, Q=18.7, P<0.001). ICI were permanently discontinued in 48.1% of patients (95% CI, 17.8-79.1). ICI were restarted after temporary interruption in 48.6% of patients (95% CI, 18.2-79.4) of whom 17.0% (95% CI, 6.4-30.0) experienced recurrence. Real-world incidence of ICI-associated diarrhea/colitis exceeds 10%. These events lead to permanent ICI discontinuation in just over 50% of patients, while <20% have recurrence of symptoms if ICI are resumed. Further studies are needed to identify patients who would benefit from early treatment with biologics as well as appropriate patients to resume ICI therapy.

Predicting and Preventing Immune Checkpoint Inhibitor Toxicity: Targeting Cytokines

Cancer immunotherapies can successfully activate immune responses towards certain tumors. However, this can also result in the development of treatment-induced immune-related adverse events (irAEs) in multiple tissues. Growing evidence suggests that cytokine production in response to these therapeutics potentiates the development of irAEs and may have predictive value as biomarkers for irAE occurrence. In addition, therapeutic agents that inhibit cytokine activity can limit the severity of irAEs, and their use is being tested in the clinical setting. This review provides an in-depth analysis of strategies to uncouple the cytokine response, that precipitates irAEs following cancer immunotherapies, from the benefit gained in promoting antitumor immunity.

Association of immune-checkpoint inhibitors and the risk of immune-related colitis among elderly patients with advanced melanoma: real-world evidence from the SEER-Medicare database

Background:

The use of anti-cytotoxic T-lymphocyte antigen 4 (anti-CTLA4) therapy (ipilimumab) and anti-programmed cell-death 1 (anti-PD1) agents (nivolumab and pembrolizumab) in advanced melanoma have been associated with immune-related adverse events (irAEs) including colitis. We aimed to estimate the incidence and the risk of colitis in elderly patients with advanced melanoma treated with anti-CTLA4 and anti-PD1 in the real-world setting.

Methods:

Elderly patients (age ⩾ 65 years) diagnosed with advanced melanoma between 2011 and 2015 and treated with anti-CTLA4 or anti-PD1 agents were identified from the Surveillance, Epidemiology, and End Results (SEER)–Medicare data. We estimated the risk of colitis from start of treatment up to 90 days from the last dose of therapy. We used the log-rank test and logistic regression with adjustment for potential confounders using the inverse probability of treatment weighting method. We conducted several sensitivity analyses.

Results:

A total of 274 elderly patients with advanced melanoma were included in our cohort. The risk of colitis was similar between anti-PD1 users and anti-CTLA4 users based on log-rank test (p = 0.17) and logistic regression [odds ratio (OR) = 0.35, 95% confidence interval (95%CI) 0.04–2.79]. Sensitivity analyses for patients with all-stage melanoma showed a significantly lower risk of colitis in anti-PD1 compared with anti-CTLA4 treated patients based on log-rank test (p = 0.017) and logistic regression (OR = 0.21, 95%CI 0.09–0.53).

Conclusion:

Elderly with advanced melanoma treated with anti-CTLA4 or anti-PD1 had a similar risk of developing colitis. However, there was a statistically significant difference in the risk of colitis between anti-CTLA4 or anti-PD1 users among all-stage-melanoma patients.

Plain Language Summary

Risk of colitis (inflammation of the large intestine) in elderly patients with melanoma treated with immune-checkpoint inhibitors (a group of medications that uses the patient’s immune system to fight cancer)

While the anti-cancer agents known as immune-checkpoint inhibitors have had a great impact on the treatment of melanoma, they may also have side effects. This study estimated the risk of colitis, a chronic inflammation of the colon, in elderly patients with melanoma treated with anti-cytotoxic T-lymphocyte antigen 4 (anti-CTLA4) or anti-programmed cell-death 1 (anti-PD1) agents, using data from the Surveillance, Epidemiology, and End Results (SEER)–Medicare linked database. Overall, we found that the risk of colitis was not different between anti-PD1 users and anti-CTLA4 users with advanced-stage melanoma. However, after including patients across all stages of melanoma, we found a significantly lower risk of colitis with anti-PD1 compared with anti-CTLA4.

Gastrointestinal side effects of cancer treatments

Cancer survival rates have significantly improved over the last number of years due to advancements in cancer therapies. Unfortunately this has come at a cost. Therapeutic side effects are feared complications of therapy that may result in decreased quality of life and early cessation of the therapy, which can have knock-on effects on outcomes. This article outlines the main gastrointestinal side effects seen with radiation therapy, chemotherapy and immunotherapy, and discusses appropriate investigation and management.

Chronic diarrhoea in an oncology patient - Clinical assessment and decision making

Cancer survival is improving rapidly due to advances in treatments that will often involve radiotherapy, chemotherapy and novel biological agents in addition to surgery. This comes at the price of living with chronic symptoms, of which diarrhoea is particularly common. There is good evidence that for many patients these symptoms become part of everyday life, their "normality" is adjusted and symptoms are tolerated even when limiting activities severely. Clinicians often fail to appreciate the impact of these problems, as the focus of follow up tends to be on cancer recurrence. However, the rapid identification of patients in significant trouble can lead to earlier diagnosis of treatable pathologies and improvement of patients' symptoms. The aim of this review is to highlight the mechanisms which cause oncology patients to develop diarrhoea and highlight useful investigational and treatment strategies.

Systematic review with meta-analysis: effectiveness of anti-inflammatory therapy in immune checkpoint inhibitor-induced enterocolitis

BACKGROUND

Immune checkpoint inhibitors have revolutionised cancer treatment, but at the cost of off-target immune-mediated organ damage. This includes checkpoint inhibitor-induced enterocolitis which frequently requires hospitalisation and may be life-threatening. Empiric treatment typically includes corticosteroids and infliximab, although no large-scale studies have confirmed their effectiveness.

AIM

To investigate the effectiveness of anti-inflammatory therapy in checkpoint inhibitor-induced enterocolitis METHODS: We performed a systematic review and meta-analysis of studies reporting clinical outcomes of checkpoint inhibitor-induced enterocolitis in adult cancer patients treated with anti-inflammatory agents. We searched Medline, EMBASE, and the Cochrane library through April and extracted the proportion of patients responding to anti-inflammatory therapy. Variation in effect size was studied using a random-effects meta-regression analysis, with checkpoint inhibitor agent and tumour type as the variables.

RESULTS

Data were pooled from 1210 treated patients across 39 studies. Corticosteroids were effective in 59% (95% CI 54- 65) of patients, with response significantly more favourable in patients treated with anti-PD-1/L1 monotherapy, compared with anti-CTLA-4 containing regimens (78%, 95% CI 69-85 vs 56 %, 95% CI 49-63, P = 0.003), and more favourable in lung cancer patients compared with melanoma patients (88%, 95% CI 62-97 vs 55%, 95% CI 47-63, P = 0.04). Infliximab was effective in 81% (95% CI 73-87) of patients, and vedolizumab in 85% (95% CI 60-96).

CONCLUSION

Corticosteroids, infliximab and vedolizumab, are effective in the treatment of checkpoint inhibitor-induced enterocolitis. Checkpoint inhibitor regimen and cancer type were significant moderators in response to corticosteroid therapy.

British Society of Gastroenterology endorsed guidance for the management of immune checkpoint inhibitor-induced enterocolitis

Immune checkpoint inhibitors are a novel class of cancer treatment that have improved outcomes for a subset of cancer patients. They work by antagonising inhibitory immune pathways, thereby augmenting immune-mediated antitumour responses. However, immune activation is not cancer-specific and often results in the activation of immune cells in non-cancer tissues, resulting in off-target immune-mediated injury and organ dysfunction. Diarrhoea and gastrointestinal tract inflammation are common and sometimes serious side-effects of this type of therapy. Prompt recognition of gastrointestinal toxicity and, in many cases, rapid institution of anti-inflammatory or biologic therapy (or both) is required to reverse these complications. Management of organ-specific complications benefits from multidisciplinary input, including engagement with gastroenterologists for optimal management of immune checkpoint inhibitor-induced enterocolitis. In this British Society of Gastroenterology endorsed guidance document, we have developed a consensus framework for the investigation and management of immune checkpoint inhibitor-induced enterocolitis.

Management of Patients With Immune Checkpoint Inhibitor-Induced Enterocolitis: A Systematic Review

Immune checkpoint inhibitors (ICIs) have improved the treatment of several cancers. These drugs increase T-cell activity and the antitumor immune response but also have immune-related adverse effects that can affect the gastrointestinal (GI) tract. These adverse effects have been observed in 7% to 30% of patients treated with ICIs. As the number of diseases treated with ICIs increases, gastroenterologists will see more patients with ICI-induced GI adverse events. We performed a systematic review of the incidence, risk factors, clinical manifestations, and management of the adverse effects of ICIs on the GI tract. Treatment with anti-cytotoxic T-lymphocyte-associated antigen-4 often causes severe enterocolitis, whereas treatment with inhibitors of programmed cell death 1 have less frequent and more diverse adverse effects. Management of patients with GI adverse effects of ICIs should involve first ruling out other disorders, followed by assessment of severity, treatment with corticosteroids, and rapid introduction of infliximab therapy for nonresponders.

Systematic review and case series: flexible sigmoidoscopy identifies most cases of checkpoint inhibitor-induced colitis

BACKGROUND

Immune checkpoint inhibitors are used in the treatment of multiple advanced stage cancers but can induce immune-mediated colitis necessitating treatment with immunosuppressive medications. Diagnostic colonoscopy is often performed but requires bowel preparation and may delay diagnosis and treatment. Sigmoidoscopy can be performed rapidly without oral bowel preparation or sedation.

AIMS

Characterize the colonic distribution of immune-mediated colitis to determine the most efficient endoscopic approach.

METHODS

A systematic review of checkpoint inhibitor-induced colitis case reports and series was conducted in both PubMed and Embase through 3 January 2017. A single centre retrospective chart review of patients who underwent endoscopic evaluation for diarrhoea after treatment with a checkpoint inhibitor (ipilimumab, nivolumab or pembrolizumab) between 1 January 2011 and 3 January 2017 was performed. Clinical, endoscopic and histologic data were collected.

RESULTS

A detailed systematic review resulted in 61 studies, in which 226 cases of colitis were diagnosed by lower endoscopy (125 colonoscopy, 101 sigmoidoscopy). Only four patients had isolated findings proximal to the left colon. In our centre, 31 patients had histologic features of checkpoint inhibitor-induced colitis, for which 29 patients had complete data. The left colon was involved in all cases. Sigmoidoscopy would be sufficient to diagnose >98% of reported cases of checkpoint inhibitor-mediated colitis diagnosed by lower endoscopy.

CONCLUSIONS

Moderate to severe checkpoint inhibitor-induced colitis involves the left colon in the majority of cases (>98%). Sigmoidoscopy should be the initial endoscopic procedure in the evaluation of this condition.

Enterocolitis due to immune checkpoint inhibitors: a systematic review

Immune checkpoint inhibitors targeting cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) and programmed death-1 (PD-1)/ligand are increasingly used to treat several types of cancer. These drugs enhance antitumour T-cell activity and therefore induce immune-related adverse effects (irAE), of which gastrointestinal (GI) irAE are among the most frequent and severe. This systematic literature review summarises the clinical manifestations, management and pathophysiology of GI irAE due to immune checkpoint inhibitors. GI irAE induced by anti-CTLA-4 are frequent, potentially severe and resemble IBD, whereas those induced by PD-1 blockade seem to be less frequent and clinically more diverse. Baseline symbiotic gut microbiota is associated with an enhanced antitumour response to immune checkpoint inhibitors and an increased susceptibility to developing enterocolitis, in patients treated with anti-CTLA-4. These findings open new perspectives for possible manipulation of the gut microbiota in order to better identify responders to immune checkpoint inhibitors and to increase their efficacy and safety.

Severe Gastritis after Administration of Nivolumab and Ipilimumab

Immune checkpoint inhibitors such as ipilimumab, a cytotoxic T-lymphocyte-associated antigen-4 inhibitor, have been widely used for advanced malignancies. As these inhibitors improve antitumor immunity via T-cell modulation, immune-mediated adverse events associated with T-cell activation, such as colitis, might occur. Herein, we describe a 75-year-old Japanese woman with metastatic malignant melanoma who developed hemorrhagic gastritis after ipilimumab treatment. There was no macroscopic or clinical improvement of gastritis after proton pump inhibitor treatment. However, her condition improved after approximately 3 weeks of corticosteroid therapy and Helicobacter pylori eradication. This case suggests a potential association between severe gastritis and immune checkpoint inhibitor treatment. Although several reports have mentioned ipilimumab-associated colitis, gastritis is considered to be rare. In the present case, H. pylori-associated gastritis might have been exacerbated by the T-cell modulation effect of ipilimumab. To date, no report has clarified the mechanism by which ipilimumab modifies H. pylori infection. The present treatment course provides a helpful perspective for similar cases.

Pharmacologic Modulation of Human Immunity in the Era of Immuno-oncology: Something Old, Something New

The concept of exploiting the immune system to treat cancer forms the basis of immuno-oncology. Since its birth in the late 1800s, immuno-oncology, or cancer immunotherapy, has come a long way. With better understanding of the complex relationship between tumor and the immune system, we have been able to explore and develop various modalities of anticancer therapies. In this review, we summarize the main strategies of immunotherapy that are available today: monoclonal antibodies, anticancer vaccines, cytokines, and adoptive T-cell therapy. We also highlight the unique set of adverse effects associated with modern immunotherapy and propose nonsteroidal immunomodulators and anticytokine antibodies as treatment options for toxicities. The future of immuno-oncology is discussed, including combination therapy, drug-antibody conjugates, epigenetic drugs, using nanoparticles for drug delivery, new antigen discovery, and developing biomarkers to assess treatment responses. A data search was conducted using PubMed and included studies published through November 1, 2017. Search terms used include cancer immunotherapy, pembrolizumab, ipilimumab, nivolumab, PD-1 inhibitors, PD-L1 inhibitors, checkpoint inhibitors, anticancer vaccines, TVEC, and adoptive cell therapy.

Two Cases of Sinusitis Induced by Immune Checkpoint Inhibition

We report the acute onset of aseptic sinusitis in 2 patients receiving the immune checkpoint inhibitors, ipilimumab and nivolumab, for treatment of metastatic melanoma. Ipilimumab, a monoclonal antibody targeting cytotoxic T-lymphocyte antigen-4, and nivolumab, targeting programmed cell death-1, have been associated with numerous immune-related adverse events. To the authors' knowledge, this is the first report of aseptic sinusitis as a consequence of immune checkpoint inhibition therapy.

Gastrointestinal toxicity of immune checkpoint inhibitors: from mechanisms to management

Immune checkpoint inhibitor therapies are a novel group of monoclonal antibodies with proven effectiveness in a wide range of malignancies, including melanoma, renal cell carcinoma, non-small-cell lung cancer, urothelial carcinoma and Hodgkin lymphoma. Their use in a range of other indications, such as gastrointestinal and head and neck cancer, is currently under investigation. The number of agents included in this drug group is increasing, as is their use. Although they have the potential to improve the treatment of advanced malignancies, they are also associated with a substantial risk of immune-related adverse events. The incidence of gastrointestinal toxicity associated with their use is second only in frequency to dermatological toxicity. Thus, gastroenterologists can expect to be increasingly frequently consulted by oncologists as part of a multidisciplinary approach to managing toxicity. Here, we describe this novel group of agents and their mechanisms of action. We review the manifestations of gastrointestinal toxicity associated with their use so that it can be recognized early and diagnosed accurately. We also discuss the proposed mechanisms underlying this toxicity and describe an algorithmic and, wherever possible, evidence-based approach to its management.

Immune Checkpoint Inhibitor-Induced Colitis: Diagnosis and Management

Immune checkpoint inhibitors are monoclonal antibodies indicated for an increasing number of malignant diseases. These agents can cause specific side effects, which need to be anticipated while clear patterns of management need to be established. Immune checkpoint inhibitor-mediated gastrointestinal side effects, including diarrhea and colitis, occur in up to 30% of patients. Severe colitis can lead to severe dehydration or intestinal perforation. Endoscopic lesions and histopathological features of immune checkpoint inhibitor-induced colitis are similar to an inflammatory bowel disease (IBD) flare. Patients with immune checkpoint inhibitor-induced diarrhea and colitis are treated with corticosteroids. Infliximab can be used in cases of corticosteroid failure. Rectosigmoïdoscopy or colonoscopy should be performed when severe immune checkpoint inhibitor-induced colitis is suspected, but endoscopic investigations should not delay treatment. Specific patient education as well as co-operation between oncologists and gastroenterologists is essential.

Application of the FDA Biosimilar Extrapolation Framework to Make Off-Label Determinations

BACKGROUND

The FDA's extrapolation framework allows for a biosimilar to obtain licensure for indications that were not explicitly studied in the context of a clinical trial by extending conclusions from studies in 1 population to make inferences in other populations. Within routine clinical care, drugs and biologics are routinely used for medically accepted off-label indications. The appropriateness of these products for off-label indications are typically curated by compendia and guidelines, which have established processes and criteria for reviewing and evaluating the evidence to make such determinations. The evidence paradigm for biosimilars is different from originator biologics and is one of comparability to a reference product, not to reestablish clinical benefit. Thus, this paradigm shift can be applied to the exercise of making off-label determinations for biosimilars, and the FDA's framework of extrapolation can be used by clinicians and coverage policy decision makers to determine appropriate off-label indications for biosimilars.

OBJECTIVE

To highlight how the FDA's biosimilar extrapolation framework can be used to make off-label policy decisions, using to 2 approved biosimilars for filgrastim and infliximab as case studies.

METHODS

This study describes the FDA extrapolation framework for evaluating whether there are any differences in the mechanism of action, pharmacokinetics/biosdistribution, immunogenicity, and toxicity between on-label and off-label indications. Two case studies are presented that evaluate the biosimilars filgrastim-sndz and infliximab-dyyb for the offlabel indications of treating symptomatic anemia in patients with myelodysplastic syndromes and immune-mediated colitis, respectively. The analytical, nonclinical, and clinical pharmacology, along with clinical studies demonstrating that filgrastim-sndz and infliximab-dyyb are biosimilar to their respective reference products, are reviewed and discussed in context with the extrapolation framework to ascertain whether use of the biosimilar within the off-label indications is scientifically justified.

RESULTS

The mechanism of action of filgrastim and infliximab between their FDA-approved and off-label indications are the same. In addition, there is a high degree of similarity with the analytical and nonclinical characteristics of filgrastim-sndz and infliximab-dyyb and their respective reference products. There is no expectation of differences in safety and immunogenicity across the patient populations. Thus, some decision makers may determine that filgrastim-sndz and infliximab-dyyb be used for the off-label indications of treating symptomatic anemia in patients with myelodysplasia and immune-mediated colitis, respectively.

CONCLUSIONS

In some cases, the use of biosimilars for off-label indications can be scientifically justified. Since coverage policy decisions are intimately tied to compendia and guideline listings, it is incumbent upon these groups to conduct formal assessments of biosimilar off-label indications using the FDA extrapolation framework.

DISCLOSURES

No outside funding supported this study. Li discloses that he has received honoraria and/or paid travel expenses as an advisory board and speaker's bureau participant for Pfizer; for speaking on behalf of Mylan and Apobiologix; and for participating on advisory boards for Eli Lilly and Mylan. Lobaina has nothing to disclose. Li was responsible for study design and manuscript revision. Li took the lead in data collection and interpretation and manuscript preparation, along with Lobaina.

Coinhibitory Receptor Expression and Immune Checkpoint Blockade: Maintaining a Balance in CD8+ T Cell Responses to Chronic Viral Infections and Cancer

In cancer and chronic viral infections, T cells are exposed to persistent antigen stimulation. This results in expression of multiple inhibitory receptors also called “immune checkpoints” by T cells. Although these inhibitory receptors under normal conditions maintain self-tolerance and prevent immunopathology, their sustained expression deteriorates T cell function: a phenomenon called exhaustion. Recent advances in cancer immunotherapy involve blockade of cytotoxic T lymphocyte antigen-4 and programmed cell death 1 in order to reverse T cell exhaustion and reinvigorate immunity, which has translated to dramatic clinical remission in many cases of metastatic melanoma and lung cancer. With the paucity of therapeutic vaccines against chronic infections such as HIV, HPV, hepatitis B, and hepatitis C, such adjunct checkpoint blockade strategies are required including the blockade of other inhibitory receptors such as T cell immunoreceptor with immunoglobulin (Ig) and immunoreceptor tyrosine-based inhibitory motif domains, T cell Ig and mucin-domain containing-3, lymphocyte activation gene 3, and V-domain Ig-containing suppressor of T cell activation. The nature of different chronic viral infections and cancers is likely to influence the level, composition, and pattern of inhibitory receptors expressed by responding T cells. This will have implications for checkpoint antibody blockade strategies employed for treating tumors and chronic viral infections. Here, we review recent advances that provide a clearer insight into the role of coinhibitory receptor expression in T cell exhaustion and reveal novel antibody-blockade therapeutic targets for chronic viral infections and cancer. Understanding the mechanism of T cell exhaustion in response to chronic virus infections and cancer as well as the nature of restored T cell responses will contribute to further improvement of immune checkpoint blockade strategies.

Pathogenesis, clinical manifestations and management of immune checkpoint inhibitors toxicity

Immune checkpoint inhibitors have emerged as an effective treatment for several tumor types and their use in clinical practice is expected to further increase in the immediate future. Although these agents are well tolerated, they are associated with a peculiar spectrum of toxicity, which is immune mediated and may potentially affect every organ. However, immune-related adverse events are mostly reversible if promptly diagnosed and adequately treated. Therefore, it is crucial that medical oncologists know how to diagnose and treat immune-related adverse events. This review focuses on the pathogenesis, clinical manifestations and management of immune-related toxicity of anti-CTLA-4 and anti-PD-1 antibodies.