Infectious complications in patients treated with immune checkpoint inhibitors

Cancer immunotherapy with immune checkpoint inhibitors and infections: A particular focus on mycobacterial infections

Cancer treatment is undergoing a major transformation with the advent of immunotherapy with immune checkpoint inhibitors. These drugs, which have a different mechanism of action from conventional cytotoxic chemotherapy, are transforming treatment paradigms for many patients suffering from advanced cancer. On the other hand, they are often complicated by specific adverse events, known as immune-related adverse events (irAEs). Infections occurring during immunotherapy with immune checkpoint inhibitors have recently received increasing attention and sometimes are seen as part of irAEs. Amongst these, mycobacterial infections have attracted particular attention. Recent reports have shown that infections occurring during immunotherapy can not only be caused by immunosuppression, but in addition new type of infections are observed that are not caused by immunosuppression. Specifically, tuberculosis (TB) has recently been shown to develop as a result of an imbalance in immunoregulation and an excessive immune response. This review highlights reports of infections during immunotherapy with immune checkpoint inhibitors, followed by a focus on the association with TB and nontuberculous mycobacteria. It concludes with a discussion of the possible mechanisms of pathogenesis and the implications for clinical practice.

Unintended Consequences: Risk of Opportunistic Infections Associated With Long-term Glucocorticoid Therapies in Adults

Glucocorticoids are widespread anti-inflammatory medications used in medical practice. The immunosuppressive effects of systemic glucocorticoids and increased susceptibility to infections are widely appreciated. However, the dose-dependent model frequently used may not accurately predict the risk of infection in all patients treated with long-term glucocorticoids. In this review, we examine the risks of opportunistic infections (OIs) in patients requiring glucocorticoid therapy by evaluating the influence of the glucocorticoid dose, duration, and potency, combined with biological and host clinical factors and concomitant immunosuppressive therapy. We propose strategies to prevent OIs, which involve screening, antimicrobial prophylaxis, and immunizations. While this review focuses on patients with autoimmune, inflammatory, or neoplastic diseases, the potential risks and preventative strategies are likely applicable to other populations. Clinicians should actively assess the benefit-harm ratios of systemic glucocorticoids and implement preventive efforts to decrease their associated infections complications.

Co-occurring infections in cancer patients treated with checkpoint inhibitors significantly increase the risk of immune related adverse events

Therapeutic antibodies designed to target immune checkpoint proteins such as PD-1, PD-L1, and CTLA-4 have been applied in the treatment of various tumor types, including small and non-small cell lung cancers, melanoma, renal cell carcinoma, and others. These treatments combat cancers by reactivating CD8 cytotoxic T-cells. Nevertheless, this unique targeted mode of action was found to be associated with a broader range of immune-related adverse events, irAEs, affecting multiple physiological systems. Depending on their severity, these irAEs often necessitate the suspension or discontinuation of treatment and, in rare instances, may lead to fatal consequences. In this study we investigated over eighty thousand adverse event reports of irAEs in patients treated with PD-1, PD-L1, and CTLA-4 inhibitors. FDA Adverse Event Reporting System MedWatch submissions were used as the data source. These therapeutics included pembrolizumab, nivolumab, cemiplimab, avelumab, durvalumab, atezolizumab, and ipilimumab. The data analysis of these reports revealed a statistically significant association of immune related adverse events, including serious and life-threatening events in patients who experienced infectious disease during treatment. Additionally, the association trend was preserved across all the three classes of checkpoint inhibitors and each of the seven individual therapeutic agent cohorts.

Infectious Complications in Patients With Non-small Cell Lung Cancer Treated With Immune Checkpoint Inhibitors

INTRODUCTION

Immune checkpoint inhibitors (ICI) are standard treatment for nonsmall cell lung cancer (NSCLC). However, the burden of infectious complications during ICI therapy is poorly described.

MATERIALS AND METHODS

We conducted a retrospective study of patients with NSCLC treated with ICIs between 2007 and 2020 at a tertiary academic center. The incidence, characteristics, and healthcare utilization outcomes of infections during ICI therapy and within 3 months of ICI discontinuation are presented using descriptive statistics. Cox proportional hazard models are used to examine infection-free survival by demographic and treatment factors. Associations between patient or treatment characteristics and hospitalization or ICU admission are analyzed by logistic regression, presented as odds ratios (OR).

RESULTS

Of 298 patients, infections occurred in 54.4% (n = 162). Of these patients, 59.3% (n = 96) required hospitalization and 15.4% (n = 25) required ICU admission. The most common infection was bacterial pneumonia. Fungal infections occurred in 12 patients (7.4%). Patients with chronic obstructive pulmonary disease (COPD) (OR 2.15, 95% CI, 1.01-4.58), corticosteroid treatment within 1 month prior to infection onset (OR 3.04, 95% CI, 1.47-6.30), and concomitant irAE and infection (OR 5.48, 95% CI, 2.15-14.00) had higher odds of hospitalization. Corticosteroid use was associated with higher odds of ICU admission (OR 3.09, 95% CI, 1.29-7.38).

CONCLUSION

In this large single-institution study we identify that more than half of patients with ICI-treated NSCLC develop infectious complications. We identify that patients with COPD, recent corticosteroid use, and concomitant irAE and infection have higher odds of hospitalization, and that unusual infections (eg, fungal) can occur. This highlights clinical awareness of infections as important complications during ICI therapy in patients with NSCLC.

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.

Navigating the challenges of invasive pulmonary aspergillosis in lung cancer treatment: a propensity score study

Background

Invasive pulmonary aspergillosis (IPA) can negatively impact cancer patients' survival. It remains uncertain whether IPA's impact on patient outcomes varies by treatment approach in advanced lung cancer.

Objectives

To explore the association between IPA and outcomes in patients with advanced lung cancer receiving different treatments.

Design

A retrospective cohort study.

Methods

We enrolled patients with advanced-stage lung cancer between 2013 and 2021 at a college hospital in Taiwan and used the 2021 European Organization for Research and Treatment of Cancer/Mycoses Study Group Education and Research Consortium consensus for IPA diagnosis. Multivariable logistic regression was used to identify the IPA risk factors. We compared overall survival (OS) and postgalactomannan (GM) test survival between the IPA and control groups using multivariable Cox proportional hazards regression and the Kaplan-Meier method with propensity score matching (PSM).

Results

Among 2543 patients with advanced-stage lung cancer, 290 underwent a GM test, of which 34 (11.7%) were diagnosed with IPA. Patients undergoing chemotherapy (HR = 4.02, p = 0.027) and immunotherapy [hazard ratio (HR) = 3.41, p = 0.076] tended to have IPA. Compared to the control group, the IPA group had shorter median OS (14.4 versus 9.9 months, p = 0.030) and post-GM test survival (4.5 versus 1.9 months, p = 0.003). IPA was associated with shorter OS (log-rank p = 0.014 and 0.018 before and after PSM, respectively) and shorter 1-year and 2-year survival post-GM test (HR = 1.65 and 1.66, respectively). Patients receiving chemotherapy or immunotherapy had a shorter post-GM test survival if they had IPA.

Conclusions

IPA tended to be diagnosed more frequently in patients receiving chemotherapy or immune checkpoint inhibitors. Patients diagnosed with IPA are associated with shorter survival. Larger cohort studies are needed to verify the observations.

Incidence and predictors of infections in patients with advanced non-small cell lung cancer treated with checkpoint inhibitor immunotherapies: A monocentric retrospective cohort study

Immune checkpoint inhibitors (ICIs) represent the cornerstone of the current treatment of non-small cell lung cancer (NSCLC). However, the occurrence of concomitant infections might hamper success. All consecutive patients with advanced NSCLC who started ICIs as a first- or second-line therapy from January 1, 2017 to June 30, 2020 were retrospectively evaluated. The occurrence of infectious events during ICIs was correlated with clinical characteristics, including previous Cytotoxic Chemotherapy (CC), occurrence of immune-related-adverse-events (irAEs). A total of 211 patients were included, 46 (22%) females, with a median (q1-q3) age of 69 (62-76) years. Overall, 85 patients (40%) received ICIs as a first treatment line and 126 (60%) as a second line; 40 patients (19%) had at least one infection during ICIs, and 17 (8%) more than one. Notably, autoimmune diseases (P < .005), neutropenia (P = .001) or infections during previous CC (P = .001), irAEs (P = .006), or steroid therapy for irAEs (P < .001) were associated with infection development. By multivariate Cox-regression, autoimmune diseases (aHR = 6.27; 95%CI = 2.38-16.48; P < .001) and steroid therapy for irAEs (aHR = 2.65; 95%CI = 1.27-5.52; P < .009) were associated with a higher risk of infection during ICIs. Interestingly, autoimmune diseases were confirmed as risk factors in patients treated with ICIs as a first line, while previous infections were the only independent predictor of infections in patients treated with ICIs as a second line. Patients with NSCLC treated with ICIs with concurrent autoimmune disease, receiving steroid therapy for management of irAEs, or having a history of previous infections during CC should be actively monitored for the risk of developing infectious complications.

Pyodermitis during Nivolumab Treatment for Non-Small Cell Lung Cancer: A Case Report and Review of the Literature

Immunotherapy in oncology is replacing traditional therapies due to it specific action and limited side effects. Despite the high efficacy of immunotherapy, side effects such as bacterial infection have been reported. Bacterial skin and soft tissue infections represent one of the most important differential diagnoses in patients presenting with reddened and swollen skin and soft tissue. Among these infections, cellulitis (phlegmon) and abscesses are the most frequent. In most cases, these infections occur locally with possible contiguous spread, or as a multifocal manifestation, especially in immunocompromised patients. Herein, we report a case of pyodermitis in an immunocompromised district in a patient treated with nivolumab for non-small cell lung cancer. A 64-year-old, smoker male patient showed cutaneous lesions at a different evolution level in the left arm, all in a tattooed area, with one phlegmon and two ulcerated lesions. Microbiological cultures and gram staining revealed an infection caused by a methicillin-susceptible but erythromycin-resistant (ER-R), clindamycin-resistant (CL-R), and gentamicin-resistant (GE-R) Staphylococcus aureus strain. Despite immunotherapy becoming a milestone in oncologic treatment, more than the spectrum of immune-mediated toxicities of these agents needs to be investigated. This report highlights the importance of considering lifestyle and cutaneous background before starting immunotherapy for cancer treatment, with an emphasis on pharmacogenomics and the possibility of modified skin microbiota predisposing to cutaneous infections in patients treated with PD-1 inhibitors.

The Spectrum of Infections in Patients with Lung Cancer

Although diagnostic and therapeutic advances in lung cancer (LC) have increased the survival of patients, infection and its complications are still among the most important causes of mortality. The disruption of tissue caused by tumor mass, management of cancer therapy and alteration in the humoral/cellular immune systems due to both cancer itself and therapy considerably increase susceptibility to infection in cancer patients. Particularly, opportunistic microorganisms should be considered, then applying rapid and sensitive diagnostic methods for them. Thus, cancer patients who are already exposed to difficult, long-term and expensive treatments can be prevented from dying from complications related to infections.

Association of Pulmonary Sepsis and Immune Checkpoint Inhibitors: A Pharmacovigilance Study

Background: Although some sepsis cases were reported with immune checkpoint inhibitors (ICIs) in clinical trials, the link between pulmonary sepsis and ICIs remains mostly unknown. We aim to investigate the association between pulmonary sepsis and ICIs, and to describe the clinical features. Methods: A disproportionality analysis was performed using FAERS data and compared rates of pulmonary sepsis in cancer patients receiving ICIs vs. other drug regimens (such as chemotherapy and targeted therapy). Associations between ICIs and sepsis were assessed using reporting odds ratios (ROR) and information component (IC). We also detected drug interaction signals based on the Ω shrinkage measure. Age and gender distribution were compared between pulmonary sepsis and all adverse events associated with ICIs. Results: We identified 120 reports of pulmonary sepsis associated with ICIs between Q1, 2011 to Q3, 2021. A total of 82 of 120 (68.3%) patients on ICIs suffered from pulmonary sepsis and progressed to death. In addition, there is no significant difference in age and gender in the occurrence of pulmonary sepsis in cancer patients on ICIs. Overall ICIs, nivolumab, and atezolizumab still have a significant signal of pulmonary sepsis (ROR025 > 1, IC025 > 0, p < 0.001) compared with targeted therapy (such as tyrosine kinase inhibitors) or chemotherapy. Co-administration of ICIs and glucocorticoids or proton pump inhibitors synergistically increased the risk of pulmonary sepsis (Ω025 > 0). Conclusions: Our study suggested ICIs, especially nivolumab and atezolizumab, tended to increase the risk of pulmonary sepsis more than other anticancer regimens. Clinicians should be vigilant in the prevention and management of pulmonary sepsis during ICIs therapy.

Impact of Infections in Patients Receiving Pembrolizumab-Based Therapies for Non-Small Cell Lung Cancer

Background: Immune checkpoint inhibitor (ICI) therapy has significantly improved outcomes across a range of malignancies. While infections are a well-known contributor to morbidity and mortality amongst patients receiving systemic chemotherapy regimens, little is known about the impact of infections on patients receiving ICI therapy. This study aims to assess incidence, risk factors, and outcomes in patients who develop infections while on pembrolizumab-based therapies for non-small cell lung cancer (NSCLC). Methods: Patients receiving pembrolizumab for stage III/IV NSCLC from 1/1/2017-8/1/2021 across seven hospitals were identified. Incidence and type of infection were characterized. Covariates including baseline demographics, treatment information, treatment toxicities, and immunosuppressive use were collected and compared between infected and non-infected patients. Outcomes included the rate of infections, all-cause hospital admissions, median number of treatment cycles, overall survival (OS), and progression free survival (PFS). Univariable and multivariable analysis with reported odds ratio (OR) and 95% confidence intervals (CI) were utilized to evaluate infection risks. OS and PFS were analyzed by Kaplan−Meier analysis and tested by log-rank test. p-value < 0.05 was considered statistically significant. Results: There were 243 NSCLC patients that met the inclusion criteria. Of these, 111 (45.7%) had one documented infection, and 36 (14.8%) had two or more. Compared to non-infected patients, infected patients had significantly more all-cause Emergency Department (ED) [37 (33.3%) vs. 26 (19.7%), p = 0.016], hospital [87 (78.4%) vs. 53 (40.1%), p < 0.001], and ICU visits [26 (23.4%) vs. 5 (3.8%), p < 0.001], and had poorer median OS (11.53 [95% CI 6.4−16.7] vs. 21.03 [95% CI: 14.7−24.2] months, p = 0.033). On multivariable analysis, anti-infective therapy (OR 3.32, [95% CI: 1.26−8.76], p = 0.015) and ECOG of >1 (OR 5.79, [95% CI 1.72−19.47], p = 0.005) at ICI initiation conferred an increased risk for infections. At last evaluation, 74 (66.7%) infected and 70 (53.0%) non-infected patients died (p = 0.041). Conclusion: Infections occurred in nearly half of patients receiving pembrolizumab-based therapies for NSCLC. Infected patients had frequent hospitalizations, treatment delays, and poorer survival. ECOG status and anti-infective use at ICI initiation conferred a higher infection risk. Infection prevention and control strategies are needed to ameliorate the risk for infections in patients receiving ICIs.

Treatment of rheumatic adverse events of cancer immunotherapy

Immune checkpoint inhibitors (ICIs), used to treat many advanced cancers, activate the immune system to elicit an antitumor response. ICIs can also cause immune-related adverse events (irAEs) when nontumor tissues are affected by excess inflammation and autoimmunity. Rheumatic irAEs include inflammatory arthritis, myositis, sicca syndrome, polymyalgia rheumatica, and several other rare phenotypes. Treating rheumatic irAEs requires balancing the desire to decrease off-target inflammation while not negatively impacting the antitumor immune response. In this review, treatment recommendations for rheumatic irAEs have been discussed. Pathogenesis of rheumatic irAEs has been briefly reviewed. Knowledge about the effects of corticosteroids and steroid-sparing agents on tumor responses has been detailed to give context for treatment decisions. Recommendations ultimately depend not only on the clinical presentation and severity of the irAE but also on the goals of cancer treatment. Finally, how to safely use ICI therapy in patients with preexisting autoimmune diseases is considered.

Serial interferon-gamma release assay in lung cancer patients receiving immune checkpoint inhibitors: a prospective cohort study

Recent advancements in cancer immunotherapy using immune checkpoint inhibitors (ICIs) have received considerable attention. Although advantageous, ICI therapies cause unique immune-related adverse events (irAEs) in some patients. Moreover, infectious diseases, such as tuberculosis, have been recognized as emerging concerns during immunotherapy. We aimed to evaluate the interferon-gamma release assay (IGRA) conversion rate and active tuberculosis incidence during immunotherapy to elucidate the incidence of tuberculosis reactivation after ICI therapy induction.We prospectively assessed IGRA results in lung cancer patients who received ICI monotherapy before ICI treatment and at 6 and 12 months after ICI treatment. We also assessed computed tomography findings to determine the presence of active tuberculosis when positive IGRA results were obtained. The ICIs used were nivolumab, pembrolizumab, atezolizumab, and durvalumab.In all, 178 patients were prospectively recruited between March 2017 and March 2020. Of these, 123 completed serial IGRAs, of whom 18, 101, and 4, respectively, had positive, negative, and indeterminate IGRAs at baseline. Three and four patients, respectively, showed IGRA reversion and conversion during immunotherapy. One patient with a sustained, stable positive IGRA and one with IGRA conversion developed active pulmonary tuberculosis during immunotherapy.We found that 3.3% and 1.6% of the patients developed IGRA conversion and active tuberculosis, respectively. Of the four patients who developed IGRA conversion, one developed active pulmonary tuberculosis during immunotherapy. Another patient with sustained, stable positive IGRA developed active tuberculosis. Physicians should be alert to tuberculosis development during ICI therapy, and IGRA testing is a useful tool to assess the risk of developing active tuberculosis.

Severe infections in recipients of cancer immunotherapy: what intensivists need to know

PURPOSE OF REVIEW

Given the increased number of cancer patients admitted in the ICU and the growing importance of immunotherapy in their therapeutic arsenal, intensivists will be increasingly confronted to patients treated with immunotherapies who will present with complications, infectious and immunologic.

RECENT FINDINGS

Apart from their specific immunologic toxicities, cancer immunotherapy recipients also have specific immune dysfunction and face increased infectious risks that may lead to intensive care unit admission.

SUMMARY

Chimeric antigen receptor T-cell therapy is associated with profound immunosuppression and the risks of bacterial, fungal and viral infections vary according to the time since infusion.Immune checkpoint blockers are associated with an overall favorable safety profile but associations of checkpoint blockers and corticosteroids and immunosuppressive drugs prescribed to treat immune-related adverse events are associated with increased risks of bacterial and fungal infections.The T-cell engaging bispecific therapy blinatumomab causes profound B-cell aplasia, hypogammaglobulinemia and neutropenia, but seems to be associated with fewer infectious adverse events compared with standard intensive chemotherapy.Lastly, intravesical administration of Bacillus Calmette-Guérin (BCG) can lead to disseminated BCGitis and severe sepsis requiring a specific antibiotherapy, often associated with corticosteroid treatment.

The Risk of Opportunistic Infections and the Role of Antibiotic Prophylaxis in Patients on Checkpoint Inhibitors Requiring Steroids

BACKGROUND

Immune-related adverse events (irAEs) often require treatment with high-dose systemic steroids (SS) and other immunosuppressive agents (ISAs). NCCN Guidelines recommend prophylactic antibiotics for Pneumocystis jirovecii pneumonia (PJP) for patients receiving prolonged SS/ISAs. However, there is a paucity of evidence regarding the incidence of opportunistic infections (OIs) and non-OIs and the role of prophylactic antibiotics in patients on SS/ISAs for irAEs.

METHODS

A retrospective analysis was conducted of patients treated using immune checkpoint inhibitor (ICI) therapy at 5 MedStar Health hospitals from January 2011 to April 2018. OIs were defined per the Infectious Diseases Society of America guidelines for the prevention and treatment of OIs in patients with HIV. The study cohort included patients who received ≥20 mg daily of a prednisone equivalent for ≥4 weeks to manage irAEs.

RESULTS

The study cohort identified 112 (15%) of 758 total patients treated using ICIs. Baseline characteristics included the following: median age was 64 years, 74% (n=82) of patients were White, 89% (n=100) had an ECOG performance status ≤1, 61% (n=68) had melanoma, 19% (n=21) had non-small cell lung cancer, 45% (n=50) were treated using an anti-PD-(L)1 ICI, and 33% (n=37) were treated using an anti-PD-1/anti-CTLA-4 combination. The median starting SS dose was 100 mg of a prednisone equivalent, and 25% of patients required additional ISAs, with infliximab (n=15) and mycophenolate mofetil (n=9) being the most common. We found that 20% (n=22) of patients developed any infection, including 7% (n=8) with OIs (oral candidiasis [n=4], nondisseminated varicella zoster infection [n=2], PJP [n=1], and Listeria monocytogenes endophthalmitis [n=1]) and 13% (n=14) with non-OIs (most common: Clostridium difficile and pneumonia [n=5 each]). PJP prophylaxis with sulfamethoxazole/trimethoprim was given to 13% (n=14) patients, of whom 43% (n=6) developed OIs/non-OIs.

CONCLUSIONS

Our study highlights the fundamental issues for patients on ICI therapy who require SS/ISAs for irAEs: the degree of immunosuppression and the relative risk of OI. We noted a low incidence of OIs overall and breakthrough infections despite PJP prophylaxis. We question whether PJP prophylaxis is efficacious or necessary. Prospective trials are required to answer these questions.

Analysis of interactions of immune checkpoint inhibitors with antibiotics in cancer therapy

The discovery of immune checkpoint inhibitors, such as PD-1/PD-L1 and CTLA-4, has played an important role in the development of cancer immunotherapy. However, immune-related adverse events often occur because of the enhanced immune response enabled by these agents. Antibiotics are widely applied in clinical treatment, and they are inevitably used in combination with immune checkpoint inhibitors. Clinical practice has revealed that antibiotics can weaken the therapeutic response to immune checkpoint inhibitors. Studies have shown that the gut microbiota is essential for the interaction between immune checkpoint inhibitors and antibiotics, although the exact mechanisms remain unclear. This review focuses on the interactions between immune checkpoint inhibitors and antibiotics, with an in-depth discussion about the mechanisms and therapeutic potential of modulating gut microbiota, as well as other new combination strategies.

Effects of B-Cell Lymphoma on the Immune System and Immune Recovery after Treatment: The Paradigm of Targeted Therapy

B-cell lymphoma and lymphoproliferative diseases represent a heterogeneous and complex group of neoplasms that are accompanied by a broad range of immune regulatory disorder phenotypes. Clinical features of autoimmunity, hyperinflammation, immunodeficiency and infection can variously dominate, depending on the immune pathway most involved. Immunological imbalance can play a role in lymphomagenesis, also supporting the progression of the disease, while on the other hand, lymphoma acts on the immune system to weaken immunosurveillance and facilitate immunoevasion. Therefore, the modulation of immunity can have a profound effect on disease progression or resolution, which makes the immune system a critical target for new therapies. In the current therapeutic scenario enriched by chemo-free regimens, it is important to establish the effect of various drugs on the disease, as well as on the restoration of immune functions. In fact, treatment of B-cell lymphoma with passive immunotherapy that targets tumor cells or targets the tumor microenvironment, together with adoptive immunotherapy, is becoming more frequent. The aim of this review is to report relevant data on the evolution of the immune system during and after treatment with targeted therapy of B-cell lymphomas.

Retrospective analysis of clinical trial safety data for pembrolizumab reveals the effect of co-occurring infections on immune-related adverse events

Biologics targeting PD-1, PD-L1, and CTLA-4 immune checkpoint proteins have been used in a variety of tumor types including small and non-small cell lung cancers, melanoma, and renal cell carcinoma. Their anti-tumor activity is achieved through amplifying components of the patient’s own immune system to target immune response evading cancer cells. However, this unique mechanism of action causes a range of immune related adverse events, irAEs, that affect multiple physiological systems in the body. These irAEs, depending on severity, often cause suspension or discontinuation of therapy and, in rare cases, may lead to fatal outcomes. In this study we focused on pembrolizumab, a PD-1 inhibitor currently approved for multiple types of cancer. We analyzed over ten thousand adverse event reports from Keynote clinical trials of pembrolizumab for various cancer indications with or without co-occurring infections, and observed a statistically significant 80% increase in the risk of developing an irAE in subjects with infections.

Infectious complications of immune checkpoint inhibitors in solid organ malignancies

Background

Immune checkpoint inhibitors (ICIs) are targeted cancer therapies regarded to have less toxicity than chemotherapy. Immune‐related adverse events (irAEs) of ICIs are well described in the literature but limited data exist on their infectious complications. The objective is to describe the spectrum and risk factors for developing serious infections in patients receiving ICIs.

Methods

Retrospective review of patients with melanoma, renal cell carcinoma, or nonsmall‐cell lung cancer on nivolumab, pembrolizumab, and/or ipilimumab from January 1, 2017 to November 30, 2017. Exclusion: receipt of less than two ICI doses or history of other malignancy. Characteristics: age, sex, prior chemotherapy, steroid use, and temozolomide or infliximab use. Data identified from microbiology, radiography, serology, or physician note documentation. Serious infection is defined as infections requiring hospitalization and/or IV antibiotics from initiation of ICI until the end of the study period.

Results

One hundred and eleven pts received ICIs. Suspected or confirmed bacterial infections occurred in 24% (27/111) with 8% (9/111) confirmed bacterial cultures. The overall serious infection rate was 14% (16/111) with 25% (4/16) confirmed bacterial cultures. Suspected or confirmed infection sites: genitourinary 20% (22/111), pneumonia 5% (7/111), skin/soft tissue 7% (8/111). Noninfectious pneumonitis (NIP) occurred in 5% (5/111). No association regarding the risk of infection between the type of malignancy and ICI used. Steroid use was the only risk factor significantly associated with serious infection: 12/16 (75%) on steroids versus 27/95 (28.4%) without steroid use (p = 0.0003).

Conclusion

The rate of serious infection with ICI was higher in our study compared with previous reports of pts treated with melanoma. Infectious complications are encountered with ICIs and correlate with steroid use.

Infections due to dysregulated immunity: an emerging complication of cancer immunotherapy

Immune checkpoint inhibitors (ICIs) have revolutionised cancer treatment. However, immune-related adverse events (irAEs) are a common side effect which can mimic infection. Additionally, treatment of irAEs with corticosteroids and other immunosuppressant agents can lead to opportunistic infection, which we have classed as immunotherapy infections due to immunosuppression. However, emerging reports demonstrate that some infections can be precipitated by ICIs in the absence of immunosuppressive treatment, in contrast to the majority of reported cases. These infections are characterised by a dysregulated inflammatory immune response, and so we propose they are described as immunotherapy infections due to dysregulated immunity. This review summarises the rapidly emerging evidence of these phenomena and proposes a new framework for considering infection in the context of cancer immunotherapy.

High-dose corticosteroid use and risk of hospitalization for infection in patients treated with immune checkpoint inhibitors--A nationwide register-based cohort study

High‐dose corticosteroids have been associated with increased risk of serious infection in patients with metastatic melanoma treated with immune checkpoint inhibitors targeting cytotoxic T‐lymphocyte antigen 4. This potential association needs to be examined further among patients with other cancer types and for other immune checkpoint inhibitors. We examined whether receipt of high‐dose corticosteroids was associated with increased rates of hospitalization for infection among 981 Danish renal, urothelial, and lung cancer patients followed from first administration of programmed death receptor 1 (PD‐1)/programmed death ligand 1 (PD‐L1) immune checkpoint inhibitors. Our cohort analysis was based on the information from national medical registries. During follow‐up, 522 patients (53.2%) initiated treatment with high‐dose corticosteroids and 317 patients (32.3%) experienced at least one hospitalization for infection. In analyses adjusted for age, sex, and previous use of chemotherapy/targeted therapy, initiation of high‐dose systemic corticosteroids was associated with increased rate of hospitalization for infections (hazard ratio (HR) = 2.96, 95% confidence interval (CI) = 2.41–3.65) even in patients not receiving any chemotherapy/targeted therapy (HR = 3.66, 95% CI = 2.25–5.96). Our findings showed that high‐dose corticosteroid initiation is associated with hospitalization for infection in patients treated with PD‐1/PD‐L1 immune checkpoint inhibitors. Clinicians and patients should be aware of this risk of infection when initiating treatment with high‐dose corticosteroids.

Risk of infection associated with targeted therapies for solid organ and hematological malignancies

Higher risks of infection are associated with some targeted drugs used to treat solid organ and hematological malignancies, and an individual patient’s risk of infection is strongly influenced by underlying diseases and concomitant or prior treatments. This review focuses on risk levels and specific suggestions for management, analyzing groups of agents associated with a significant effect on the risk of infection. Due to limited clinical experience and ongoing advances in these therapies, recommendations may be revised in the near future. Bruton tyrosine kinase (BTK) inhibitors are associated with a higher rate of infections, including invasive fungal infection, especially in the first months of treatment and in patients with advanced, pretreated disease. Phosphatidylinositol 3-kinase (PI3K) inhibitors are associated with an increased risk of Pneumocystis pneumonia and cytomegalovirus (CMV) reactivation. Venetoclax is associated with cytopenias, respiratory infections, and fever and neutropenia. Janus kinase (JAK) inhibitors may predispose patients to opportunistic and fungal infections; need for prophylaxis should be assessed on an individual basis. Mammalian target of rapamycin (mTOR) inhibitors have been linked to a higher risk of general and opportunistic infections. Breakpoint cluster region-Abelson (BCR-ABL) inhibitors are associated with neutropenia, especially over the first months of treatment. Anti-CD20 agents may cause defects in the adaptative immune response, hypogammaglobulinemia, neutropenia, and hepatitis B reactivation. Alemtuzumab is associated with profound and long-lasting immunosuppression; screening is recommended for latent infections and prevention strategies against CMV, herpesvirus, and Pneumocystis infections. Checkpoint inhibitors (CIs) may cause immune-related adverse events for which prolonged treatment with corticosteroids is needed: prophylaxis against Pneumocystis is recommended.