Real-World Clinical and Economic Outcomes in Selected Immune-Related Adverse Events Among Patients with Cancer Receiving Immune Checkpoint Inhibitors

Outcomes of High-Grade Immune Checkpoint Inhibitor Hepatitis in Hospitalized and Nonhospitalized Patients

BACKGROUND & AIMS

Guidelines recommend hospitalization for severe immune checkpoint inhibitor (ICI) hepatitis. We compared patient outcomes in the inpatient versus outpatient settings.

METHODS

We conducted a multicenter, retrospective cohort study of 294 ICI-treated patients who developed grade 3-4 ICI hepatitis. The primary outcome was time to alanine aminotransferase (ALT) normalization (≤40); secondary outcomes included time to ALT ≤100 U/L and time to death. To account for confounding by indication, inverse probability of treatment weighting was applied to perform Cox regression. A sensitivity analysis was performed excluding patients with grade 4 hepatitis.

RESULTS

One hundred and sixty-six patients (56.5%) were hospitalized for a median of 6 (interquartile range, 3-11) days. On inverse probability of treatment weighting Cox regression, hospitalization was not associated with time to ALT normalization (hazard ratio [HR], 1.11; 95% confidence interval [CI], 0.86-1.43; P = .436) or time to ALT ≤100 U/L (HR, 1.11; 95% CI, 0.86-1.43; P = .420). In the sensitivity analysis limited to patients with grade 3 hepatitis, hospitalization was also not associated with time to ALT normalization (HR, 1.11; 95% CI, 0.83-1.50; P = .474) or time to ALT ≤100 U/L (HR, 1.19; 95% CI, 0.90-1.58; P = .225). In a subgroup analysis of 152 patients with melanoma, hospitalization was not associated with reduced risk of all-cause death (HR, 0.93; 95% CI, 0.53-1.64; P = .798). Notably, despite their Common Terminology Criteria for Adverse Events classification of high-grade hepatitis, 94% of patients had "mild" liver injury based on International Drug-Induced Liver Injury Criteria.

CONCLUSIONS

Hospitalization of patients with high-grade ICI hepatitis was not associated with faster hepatitis resolution and did not affect mortality. Routine hospitalization may not be necessary in all patients with high-grade ICI hepatitis and Common Terminology Criteria for Adverse Events criteria may overestimate severity of liver injury.

Immune checkpoint inhibitors and risk of immune-mediated adverse events: a cohort study comparing extended versus standard interval administration

The COVID-19 pandemic precipitated the implementation of extended interval immune checkpoint inhibitors (ICIs) in an effort to limit hospital visits, but few studies have examined their safety. This study aimed to compare in oncology outpatients, immune-mediated adverse events (IMAEs) in terms of total number, incidence, severity, and time to occurrence, based on exposure to standard or extended interval ICIs. A retrospective cohort study was conducted in patients who received at least one dose of an ICI between 2015 and 2021. Data were collected from patient records and pharmacy software. Adjusted logistic, Poisson, and Cox regression models were estimated. A total of 310 patients with a mean age of 67.1 years were included, 130 of whom had the extended interval. No statistically significant differences were observed between the groups. With the standard and extended intervals, the mean total number of IMAE per participant was 1.02 and 1.18, respectively; the incidence of an IMAE was 62% and 64%. Of the 147 IMAE episodes in the standard interval group, 14 (9.5%) were grade 3 or higher, while there were 15 (12.4%) among the 121 IMAE episodes in the extended interval group. Compared with standard interval, the use of extended interval did not increase the risk of having a first IMAE (adjusted hazard ratio 0.92 (95% CI 0.67-1.26)). This study suggests that the administration of an ICI according to extended interval is as safe as the administration according to standard interval in oncology outpatients.

Outcomes of weight-based vs. fixed dose of Pembrolizumab among patients with non-small cell lung cancer

OBJECTIVE

This study aims to assess outcomes among patients with non-small cell lung cancer (NSCLC) who received treatment with pembrolizumab on a weight-based dose (WBD) or fixed-dose (FD) regimen using a non-inferiority (NI) analysis.

MATERIAL AND METHODS

This retrospective cohort study included adult patients with NSCLC weighing under 100 kg who received pembrolizumab between 1 January 2015 and 31 December 2020. Patients were grouped into either WBD or FD cohort based on the initial pembrolizumab dose and dosing regimen. The primary effectiveness outcome was overall survival (OS), analyzed using NI analysis with a lower margin of 10% comparing WBD to FD. Safety outcomes were all-cause emergency room visits or hospitalizations and incidence of selected immune-related adverse events (irAEs) and analyzed using NI analysis with an upper margin of 10%. All patients were followed until the end of health plan membership, death, or 30 June 2022, whichever occurred first.

RESULTS

A total of 1413 patients were evaluated. OS was observed in 36.6% of the FD group, and 37.7% in the WBD group (rate difference: 1%, 90% CI: -6%-8%, NI p-value < 0.01). NI was met in all three safety outcomes: proportion of all-cause emergency room visits (rate difference: 1.1%, NI p-value < 0.01); proportion of hospitalizations (rate difference: 2%, NI p-value < 0.01); and composite incidence of irAEs (rate difference: -2.2%, NI p-value = 0.03).

CONCLUSION

These findings suggest that WBD of pembrolizumab may be as appropriate as FD for the treatment of lung cancer.

Severe thyrotoxicosis induced by tislelizumab: a case report and literature review

Immune checkpoint inhibitors (ICIs) have made significant breakthroughs in the treatment of a variety of malignancies. As its use increases, the unique immune-mediated toxicity profile of ICls are becoming apparent. We report a case of immune-related endocrine adverse events (irAE) in a patient with hepatocellular carcinoma treated with anti-programmed cell death protein 1 (PD-1) (tislelizumab). Although many irAEs have been reported, few cases of severe thyrotoxicosis have been described after immunotherapy in the literature. We present the case of a 49-year-old male who experienced a Grade 3 tislelizumab-related adverse reaction according to Common Terminology Criteria for Adverse Events (CTCAE5.0) and received methylprednisolone, thiamazole, and levothyroxine sodium tablets. Early identification of irAEs, risk factors, regular monitoring, use of steroids and/or immunoglobulins, and adjuvant supportive care are critical to the clinical prognosis of patients. It should be underlined that the tumor benefits of ICI therapy outweigh the risks associated with ICI-induced endocrine disorders, and ICI treatment should not be stopped or delayed except in rare cases (adrenal crisis, severe thyrotoxicosis). The familiarity of healthcare professionals with irAEs of the thyroid when thyrotoxicosis occurs is important to facilitate an effective diagnosis and appropriate treatment of this increasingly common thyroid disorder.

Role-Specific Curricular Needs for Identification and Management of Immune-Related Adverse Events

Immune checkpoint inhibitors (ICIs) activate the immune system against cancer and have become standard of care for many cancers. With increased ICI use, their toxicities known as immune-related adverse events (irAEs) are becoming more common, but it is unclear how prepared relevant clinicians feel to diagnose and treat irAEs. The objective of this study was to assess irAE knowledge, confidence, and experience among generalists and oncology clinicians to guide future curricular interventions related to irAEs. A 25-item survey with questions assessing knowledge, experience level, confidence, and resource utilization regarding irAE diagnosis and management was sent to University of Chicago-affiliated (UChicago) internal medicine residents and hospitalists (inpatient irAE management) along with UChicago oncology fellows, attendings, nurse practitioners (NPs), and physician assistants (PAs) (inpatient and outpatient) as well as Chicago community oncologists (outpatient) in June 2022. Overall response rate was 37% (171/467). Knowledge scores averaged below 70% for all clinicians. "No idea" responses were most common with knowledge questions on steroid-sparing agent use and ICI use for patients with preexisting autoimmune disease. IrAE experience correlated with higher knowledge for oncology attendings (p = 0.015) and hematology/oncology NPs/PAs (p = 0.031). IrAE experience correlated with higher confidence for residents (p = 0.026), oncology fellows (p = 0.047), and hematology/oncology NPs/PAs (p = 0.042). Most commonly utilized resources were colleagues and UpToDate, and most clinicians were very likely to use online resources in the future. Knowledge and confidence gaps exist, and they were somewhat mitigated by experience. Future irAE curricula can fill these needs through online role-specific resources: irAE identification for generalists versus irAE identification and management for oncologists.

Identification and prediction of immune checkpoint inhibitors-related pneumonitis by machine learning

Background

Immune checkpoint inhibitor (ICI)-related pneumonitis (IRP) is a common and potentially fatal clinical adverse event. The identification and prediction of the risk of ICI-related IRP is a major clinical issue. The objective of this study was to apply a machine learning method to explore risk factors and establish a prediction model.

Methods

We retrospectively analyzed 48 patients with IRP (IRP group) and 142 patients without IRP (control group) who were treated with ICIs. An Elastic Net model was constructed using a repeated k-fold cross-validation framework (repeat = 10; k = 3). The prediction models were validated internally and the final prediction model was built on the entire training set using hyperparameters with the best interval validation performance. The generalizability of the final prediction model was assessed by applying it to an independent test set. The overall performance, discrimination, and calibration of the prediction model were evaluated.

Results

Eleven predictors were included in the final predictive model: sindillizumab, number of ≥2 underlying diseases, history of lung diseases, tirelizumab, non-small cell lung cancer (NSCLC), percentage of CD4⁺ lymphocytes, body temperature, KPS score ≤70, hemoglobin, cancer stage IV, and history of antitumor therapy. The external validation of the risk prediction model on an independent test set of 37 patients and showed good discrimination and acceptable calibration ability: with AUC of 0.81 (95% CI 0.58-0.90), AP of 0.76, scaled Brier score of 0.31, and Spiegelhalter-z of -0.29 (P-value:0.77). We also designed an online IRP risk calculator for use in clinical practice.

Conclusion

The prediction model of ICI-related IRP provides a tool for accurately predicting the occurrence of IRP in patients with cancer who received ICIs.

Uncovering the Burden of Immune-Related Adverse Events in Immunotherapy: Insights from a Nationally Representative Sample

BACKGROUND

Immune checkpoint inhibitors have shown promising efficacy in multiple malignancies and, therefore, have been increasingly used over the past decade. Clinical data have suggested anti-cancer efficacy associated with immune-related adverse events that could have added healthcare resource utilization and costs.

OBJECTIVE

We used a nationwide dataset to investigate the association between immune-related adverse events and healthcare resource utilization, charges, and mortality among patients receiving various immune checkpoint inhibitors for indicated cancers.

METHODS

We performed a retrospective analysis of the National Inpatient Sample to identify patients hospitalized in the USA for immunotherapy between October 2015 and 2018. Data between patients who developed immune-related adverse events were compared to those who did not. Baseline characteristics, inpatient complications, and associated charges were collected and analyzed between these two groups.

RESULTS

Patients who developed immune-related adverse events in the hospital had high incidences of acute kidney injury, non-septic shock, and pneumonia, and managing these complications significantly contributed to higher healthcare resource utilization. The average charge of admission was highest in patients who developed an infusion reaction, followed by colitis, and adrenal insufficiency. In terms of cancer type, renal cell carcinoma had the highest charges, followed by Merkel cell carcinoma.

CONCLUSIONS

Immune checkpoint inhibitor-based regimens have shifted the treatment landscape among multiple malignancies and their use continues to expand. However, a significant proportion of patients still develop severe adverse effects leading to increased healthcare costs and impacting patients' quality of life. Closer attention should be given to recognizing and managing immune-related adverse events according to guidelines across healthcare facilities and clinical practice settings.

Health Care Utilization and Costs in Systemic Therapies for Metastatic Melanoma from 2016 to 2020

BACKGROUND

Widespread implementation of immune checkpoint inhibitors (ICI) and targeted therapies for metastatic melanoma has led to a decline in melanoma-related mortality but increased healthcare costs. We aimed to determine how healthcare utilization varied by systemic, non-adjuvant melanoma treatment from 2016 to 2020.

PATIENTS AND METHODS

Adults with presumed stage IV metastatic melanoma receiving systemic therapy from 2016 to 2020 were identified in Optum, a nationwide commercial claims database. Treatment groups were nivolumab, pembrolizumab, ipilimumab+nivolumab (combination-ICI), or BRAF+MEK inhibitor (BRAFi+MEKi) therapy. Outcomes included hospitalizations, days hospitalized, emergency room (ER) visits, outpatient visits, and healthcare costs per patient per month (pppm). Multivariable regression models were used to analyze whether cost and utilization outcomes varied by treatment group, with nivolumab as reference.

RESULTS

Among 2018 adult patients with metastatic melanoma identified, mean (SD) age was 67 (15) years. From 2016 to 2020, nivolumab surpassed pembrolizumab as the most prescribed systemic melanoma therapy while combination-ICI and BRAFi+MEKi therapies remained stable. Relative to nivolumab, all other therapies were associated with increased total healthcare costs (combination-ICI: β = $47 600 pppm, 95%CI $42 200-$53 100; BRAFi+MEKi: β = $3810, 95%CI $365-$7260; pembrolizumab: β = $6450, 95%CI $4420-$8480). Combination-ICI and BRAFi+MEKi therapies were associated with more inpatient hospital days.

CONCLUSIONS

Amid the evolving landscape of systemic therapy for advanced melanoma, nivolumab monotherapy emerged as the most used and least costly systemic treatment from 2016 to 2020. Its sharp increase in use in 2018 and lower costs relative to pembrolizumab may in part be due to earlier adoption of less frequent dosing intervals.

Hospitalized cancer patients with comorbidities and low lymphocyte counts had poor clinical outcomes to immune checkpoint inhibitors

Background

Immune checkpoint inhibitor (ICI) therapy has improved survivals with a favorable toxicity profile in a variety of cancer patients. We hypothesized that hospitalized cancer patients who have acute or chronic comorbidities may have suppressed immune systems and poor clinical outcomes to ICIs. The objective of this study was to explore clinical outcomes and predictive factors of hospitalized cancer patients who received ICI therapy at an NCI-designated Comprehensive Cancer Center.

Methods

A retrospective review of electronic medical records was conducted for adult cancer patients who received an FDA-approved ICI during admission from 08/2016 to 01/2022. For each patient we extracted demographics, cancer histology, comorbidities, reasons for hospitalization, ICI administered, time from treatment to discharge, time from treatment to progression or death, and complete blood counts. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method and compared using the log-rank test. The 95% confidence interval for survival was calculated using the exact binomial distribution. Statistical significance was defined as 2-sided p<0.05.

Results

Of 37 patients identified, 2 were excluded due to lack of complete blood counts on admission. Average hospital stay was 24.2 (95% CI 16.5, 31.9) days. Ten (27.0%) patients died during the same hospitalization as treatment. Of those who followed up, 22 (59.5%) died within 90 days of inpatient therapy. The median PFS was 0.86 (95% CI 0.43, 1.74) months and median OS was 1.55 (95% CI 0.76, 3.72) months. Patients with ≥3 comorbidities had poorer PFS (2.4 vs. 0.4 months; p=0.0029) and OS (5.5 vs. 0.6 months; p=0.0006). Pre-treatment absolute lymphocyte counts (ALC) <600 cells/µL were associated with poor PFS (0.33 vs. 1.35 months; p=0.0053) and poor OS (0.33 vs. 2.34 months; p=0.0236). Pre-treatment derived neutrophil to lymphocyte ratio (dNLR) <4 was associated with good median PFS (1.6 vs. 0.4 months; p=0.0157) and OS (2.8 vs. 0.9 months; p=0.0375).

Conclusions

Administration of ICI therapy was associated with poor clinical outcomes and high rates of both inpatient mortality and 90-day mortality after inpatient ICI therapy. The presence of ≥3 comorbidities, ALC <600/μL, or dNLR >4 in hospitalized patients was associated with poor survival outcomes.

The role of immune checkpoint inhibitors in clinical practice: an analysis of the treatment patterns, survival and toxicity rates by sex

PURPOSE

Our aim is to describe the role of immune checkpoint inhibitors (ICI) in clinical practice by providing the patient and tumor characteristics as well as survival and toxicity rates by sex.

METHODS

We used electronic health records to identify patients treated at the Cancer Center of the University Hospital Bern, Switzerland between January 1, 2017 and June 16, 2021.

RESULTS

We identified 5109 patients, 689 of whom (13.5%) received at least one dose of ICI. The fraction of patients who were prescribed ICI increased from 8.6% in 2017 to 22.9% in 2021. ICI represented 13.2% of the anticancer treatments in 2017 and increased to 28.2% in 2021. The majority of patients were male (68.7%), who were older than the female patients (median age 67 vs. 61 years). Over time, adjuvant and first line treatments increased for both sexes. Lung cancer and melanoma were the most common cancer types in males and females. The incidence of irAEs was higher among females (38.4% vs. 28.1%) and lead more often to treatment discontination in females than in males (21.1% vs. 16.8%). Independent of sex, the occurrence of irAEs was associated with greater median overall survival (OS, not reached vs. 1.1 years). Female patients had a longer median OS than males (1.9 vs. 1.5 years).

CONCLUSIONS

ICI play an increasingly important role in oncology. irAEs are more frequent in female patients and are associated with a longer OS. More research is needed to understand the association between patient sex and toxicity and survival.

Monitoring Endocrine Complications of Immunotherapy: A Screening Tool

Introduction The advent of immunotherapy has revolutionized cancer therapy in recent years. Immunotherapy using monoclonal antibodies against checkpoint molecules, including programmed death (PD)-1, PD ligand (PD-L)1, and cytotoxic T-lymphocyte antigen 4 (CTLA)-4, has become a cornerstone in cancer therapy. However, due to the physiologic role of checkpoint molecules in preventing autoimmunity, immune-related adverse events (irAEs) have emerged as frequent complications. As the use of immunotherapy increases, a better understanding of irAEs and screening tools for timely diagnosis and management are needed. Materials and methods We surveyed oncology providers at our institution with 10 questions assessing their knowledge, and comfort levels in diagnosing and managing endocrine irAEs. We created an endocrine clinic referral order specifically for oncology-related endocrinopathies and created a screening tool for diagnosing these endocrinopathies. We met with our oncology providers in three different hour-long sessions. A post-intervention survey was sent out six months after our initial meeting to assess changes in the participants' knowledge and comfort levels. We also reviewed the electronic medical records system for the number of new referrals to endocrinology clinic. Results A total of 27 (N) participants responded to the initial survey and 14 (n) responded to the subsequent survey six months later. Based on the initial survey, only a minority (26%) of respondents were comfortable diagnosing and managing (15%) immunotherapy-related adrenal dysfunction whereas more respondents were comfortable diagnosing (55%) and managing (56%) thyroid dysfunction. The majority (67%) of the respondents knew which immunotherapies commonly are implicated in hypophysitis but only 42% of them were aware of the next steps of its management. We noted a significant increase in self-reported comfort levels in diagnosing (p < 0.05) and managing (p < 0.05) adrenal disorders post-intervention. There was also a trend of improvement in participants' comfort levels regarding diagnosing and managing thyroid dysfunction, management of hypophysitis, and immunotherapies implicated in thyroid dysfunction but the changes did not reach statistical significance. There was no significant change in their knowledge regarding immunotherapies implicated in hypophysitis and natural history of thyroid dysfunction in this setting. In the six months following our intervention, 30% (n=21) of the patients referred to the endocrine clinic were for immune-related endocrinopathies compared to 19% (n=7) of patients over a similar duration before the intervention. Data on the time between referral and endocrinology appointment was available for 16 out of the 21 patients and the mean (±SD) time to endocrine clinic appointment was 2.66 (±1.95) weeks. Nine (43%) of the 21 referred patients were seen in endocrinology clinic within two weeks. Conclusions Although immune-related endocrinopathies are rarely fatal, they have a significant impact on patients' quality of life. Endocrinopathies are typically manageable with prompt recognition and treatment. But the subtle and non-specific manifestations make the diagnostic process a challenge. Standardized and practical screening tools can help in diagnosing these adverse events promptly, seeking specialized care if needed and may also aid in reducing healthcare-related costs.

Association of Rare Immune-Related Adverse Events to Survival in Advanced Cancer Patients Treated with Immune Checkpoint Inhibitors: A Real-World Single-Center Cohort Study

Immune checkpoint inhibitors (ICIs) are associated with immune-related (ir) adverse events (AEs) resembling autoimmune diseases. In this retrospective cohort study of patients (pts) treated with ICIs at Oulu University Hospital from 2014-2020, we analysed the spectrum of severe irAEs and their prognostic nature, focusing on rare irAEs. Pts (n = 173) with lung cancer (n = 76, 43.9%), melanoma (n = 56, 32.4%), renal and bladder cancers (n = 34, 19.7%), head and neck cancers (n = 4, 2.3%), SCC (n = 2, 1.2%), and CRC (n = 1, 0.6%) receiving single anti-PD-(L)1 (n = 160) or combination (ICI-ICI n = 9, ICI-chemotherapy n = 4) therapy were included. The survival analysis focused on single anti-PD-(L)1-treated patients with melanoma, lung cancer, and renal and bladder cancers (n = 142). Grade ≥ 3 irAEs of multiple aetiology occurred in 29 patients treated with single-PD-L1 therapy (20.4%), which was associated with improved progression-free survival (PFS) (HR 0.50, CI 0.31-0.78) but not overall survival (OS) (HR 0.88, CI 0.52-1.50). Rare grade ≥ 3 events occurred in 10 (7.0%) pts with no association with PFS (HR 0.90, CI 0.42-1.94). Hence, the presence of rare grade ≥ 3 irAEs was associated with a tendency for inferior OS (HR 1.44, CI 0.66-3.11). Pts with rare grade ≥ 3 irAEs had inferior OS, possibly reflecting the delay in diagnostic workflow and the treatment of irAEs. One explanation for the high incidence of irAEs could be the Finnish population-based genetic variation affecting the immune system.