Emerging Role of Immune Checkpoint Blockade in Pancreatic Cancer.

Immune checkpoint blockade (ICB) with programmed cell death protein-1(PD-1)/programmed death ligand -1(PD-L1) antibodies has revolutionized the management of several cancers, especially non-small cell lung cancer, melanoma, urothelial, and renal cancer. Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers associated with high morbidity and mortality. Based on available data, it's obvious that ICB has limited success in PDACs, which can be explained by the low immunogenicity and immunosuppressive tumor microenvironment of these tumors. In this review article, we focus on PD-L1 expression and microsatellite instability (MSI) in PDAC, and their roles as prognostic and predictive markers. We also discuss data supporting combination therapies to augment cancer immunity cycle. Combining anti-PD-1/PD-L1 agents with other modalities such as vaccines, chemotherapy, and radiation could potentially overcome resistance patterns and increase immune responsiveness in PDAC.

Increased interleukin-6/C-reactive protein levels are associated with the upregulation of the adenosine pathway and serve as potential markers of therapeutic resistance to immune checkpoint inhibitor-based therapies in non-small cell lung cancer.

BACKGROUND: Systemic immune activation, hallmarked by C-reactive protein (CRP) and interleukin-6 (IL-6), can modulate antitumor immune responses. In this study, we evaluated the role of IL-6 and CRP in the stratification of patients with non-small cell lung cancer (NSCLC) treated with immune checkpoint inhibitors (ICIs). We also interrogated the underlying immunosuppressive mechanisms driven by the IL-6/CRP axis. METHODS: In cohort A (n=308), we estimated the association of baseline CRP with objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) in patients with NSCLC treated with ICIs alone or with chemo-immunotherapy (Chemo-ICI). Baseline tumor bulk RNA sequencing (RNA-seq) of lung adenocarcinomas (LUADs) treated with pembrolizumab (cohort B, n=59) was used to evaluate differential expression of purine metabolism, as well as correlate IL-6 expression with PFS. CODEFACS approach was applied to deconvolve cohort B to characterize the tumor microenvironment by reconstructing the cell-type-specific transcriptome from bulk expression. Using the LUAD cohort from The Cancer Genome Atlas (TCGA) we explored the correlation between IL-6 expression and adenosine gene signatures. In a third cohort (cohort C, n=18), plasma concentrations of CRP, adenosine 2a receptor (A2aR), and IL-6 were measured using ELISA. RESULTS: In cohort A, 67.2% of patients had a baseline CRP≥10 mg/L (CRP-H). Patients with CRP-H achieved shorter OS (8.6 vs 14.8 months; p=0.006), shorter PFS (3.3 vs 6.6 months; p=0.013), and lower ORR (24.7% vs 46.3%; p=0.015). After adjusting for relevant clinical variables, CRP-H was confirmed as an independent predictor of increased risk of death (HR 1.51, 95% CI: 1.09 to 2.11) and lower probability of achieving disease response (OR 0.34, 95% CI: 0.13 to 0.89). In cohort B, RNA-seq analysis demonstrated higher IL-6 expression on tumor cells of non-responders, along with a shorter PFS (p<0.05) and enrichment of the purinergic pathway. Within the TCGA LUAD cohort, tumor IL-6 expression strongly correlated with the adenosine signature (R=0.65; p<2.2e-16). Plasma analysis in cohort C demonstrated that CRP-H patients had a greater median baseline level of A2aR (6.0 ng/mL vs 1.3 ng/mL; p=0.01). CONCLUSIONS: This study demonstrates CRP as a readily available blood-based prognostic biomarker in ICI-treated NSCLC. Additionally, we elucidate a potential link of the CRP/IL-6 axis with the immunosuppressive adenosine signature pathway that could drive inferior outcomes to ICIs in NSCLC and also offer novel therapeutic avenues.

A Case of Warm Autoimmune Hemolytic Anemia Secondary to Epstein-Barr Virus Infection.

Autoimmune hemolytic anemia (AIHA) is a rare disease characterized by autoantibodies directed at red blood cells. Patients typically present with anemia and are diagnosed by positive direct antiglobulin (DAT) test. AIHA is subclassified into warm or cold based on antibodies involved and depending on their optimal temperature in which they react with RBC antigens. Warm AIHA can be either primary (idiopathic) or secondary depending on etiology. Secondary causes are associated with malignancy, connective tissue and inflammatory diseases, infections (typically viral infections), or drugs (e.g., antibiotics, chemotherapeutic agents). Epstein-Barr virus (EBV) is a herpes virus that is commonly associated with cold AIHA, with only one reported case of EBV-induced warm AIHA. It has been postulated that antibodies against EBV cross-react with antigens expressed on RBC membranes and activate the complement cascade similarly. This case report describes a case of a 32-year-old male who presented with warm AIHA secondary to EBV reinfection.

Association of Extended Dosing Intervals or Delays in Pembrolizumab-based Regimens With Survival Outcomes in Advanced Non-small-cell Lung Cancer.

BACKGROUND: Besides modeling/simulation-based analysis, no post-approval studies have evaluated the optimal administration frequency of pembrolizumab in non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: We performed a multicenter retrospective cohort study to evaluate the association between survival outcomes and treatment extensions/delays of pembrolizumab-based regimens in patients with advanced NSCLC. Those who had received at least 4 cycles in routine practice were divided into 2 groups: nonstandard (Non-Std, ≥ 2 cycles at intervals > 3 weeks + 3 days) and standard (Std, all cycles every 3 weeks or 1 cycle > 3 weeks + 3 days). RESULTS: Among 150 patients, 92 (61%) were eligible for the study (Non-Std, 27; Std, 65). The reasons for patients with extensions/delays in the Non-Std group included: immune-related adverse events (irAEs) (33%), non-irAE-related medical issues (26%), and patient-physician preference (41%). The Non-Std group was more likely to have a higher programmed death-ligand 1 tumor proportion score, a higher number of treatment cycles, and pembrolizumab monotherapy. Univariate and 6-month landmark analyses showed longer median overall survival and progression-free survival in the Non-Std group compared with the Std group. After multivariable adjustment for confounding factors, there was no significant difference in overall survival (hazard ratio, 1.2; 95% confidence interval, 0.3-4.8; P = .824) or progression-free survival (hazard ratio, 2.6; 95% confidence interval, 0.7-9.6; P = .157) between the 2 groups. CONCLUSION: Our study shows that a significant proportion of patients with advanced NSCLC receive pembrolizumab-based regimens with extended intervals or delays in routine clinical practice and with similar outcomes to those receiving treatment at label-specified 3-week intervals. Given the durability of benefit seen and the potential for cost reduction and decreased infusion frequency in these patients, this requires validation in prospective trials.

Clinical Outcomes and Toxic Effects of Single-Agent Immune Checkpoint Inhibitors Among Patients Aged 80 Years or Older With Cancer: A Multicenter International Cohort Study.

IMPORTANCE: Geriatric (aged ≥80 years) patients are historically underrepresented in cancer clinical trials. Little is known about the efficacy of immune checkpoint inhibitors (ICIs) in geriatric patients. These agents are associated with immune-related adverse events (irAEs), which may be particularly associated with morbidity in this population. OBJECTIVE: To provide insight into the clinical outcomes and safety of ICIs among geriatric patients (aged ≥80 years) with cancer. DESIGN, SETTING, AND PARTICIPANTS: A Multicenter, international retrospective study of 928 geriatric patients with different tumors treated with single-agent ICIs between 2010 to 2019 from 18 academic centers in the US and Europe. Analyses were conducted from January 2021 to April 2021. MAIN OUTCOMES AND MEASURES: Clinical outcomes and irAE patterns in geriatric patients treated with single-agent ICIs. RESULTS: Median (range) age of the 928 patients at ICI initiation was 83.0 (75.8-97.0) years. Most patients (806 [86.9%]) were treated with anti-programmed cell death 1 therapy. Among the full cohort, the 3 most common tumors were non-small cell lung cancer (NSCLC, 345 [37.2%]), melanoma (329 [35.5%]), and genitourinary (GU) tumors (153 [16.5%]). Objective response rates for patients with NSCLC, melanoma, and GU tumors were 32.2%, 39.3%, and 26.2%, respectively. Median PFS and OS, respectively, were 6.7 and 10.9 months (NSCLC), 11.1 and 30.0 months (melanoma), and 6.0 and 15.0 months (GU). Within histologically specific subgroups (NSCLC, melanoma, and GU), clinical outcomes were similar across age subgroups (aged <85 vs ≥85 years). Among all 928 patients, 383 (41.3%) experienced ≥1 irAE(s), including 113 (12.2%) that were reported to be grade (G) 3 to 4 based on Common Terminology Criteria for Adverse Events (version 5.0). The median time to irAE onset was 9.8 weeks; 219 (57%) occurred within the first 3 months after ICI initiation. Discontinuation of treatment with ICIs owing to irAEs occurred in 137 (16.1%) patients. There was no significant difference in the rate of irAEs among patients aged younger than 85, 85 to 89, and 90 years or older. Despite the similar rate of G3 or higher irAEs, ICIs were discontinued due to irAEs more than twice as often among patients aged 90 years or older compared with patients younger than 90 years (30.9% vs 15.1%, P = .008). CONCLUSIONS AND RELEVANCE: The findings of this international cohort study suggest that treatment with ICIs may be effective and generally well tolerated among older patients with cancer, though ICI discontinuation owing to irAEs was more frequent with increasing age.

Association Between Immune-Related Adverse Events and Clinical Outcomes to Programmed Cell Death Protein 1/Programmed Death-Ligand 1 Blockade in SCLC.

INTRODUCTION: The development of immune-related adverse events (irAEs) has been associated with improved efficacy of immune checkpoint inhibitors in patients with urothelial cancer, melanoma, and NSCLC. Whether this association exists in patients with SCLC is currently unknown. METHODS: We conducted a multicenter retrospective study to evaluate the relationship between irAEs and immunotherapy efficacy in SCLC. To account for the lead-time bias resulting from the time-dependent nature of irAEs, the development of irAEs was considered as a time-varying covariate in univariate and multivariate Cox proportional hazard models. RESULTS: Of the 183 patients treated with immunotherapy, 73 (39.9%) experienced at least one irAE. A total of 42 patients (22.9%) had grade 1 to 2 irAEs, whereas 31 patients (16.9%) had grade 3 to 4 irAEs. The median time of onset to the first irAE was 24 days (interquartile range: 14-55). The baseline clinicopathologic features were well-balanced between patients with and without irAEs. At a median follow-up of 24 months (95% confidence interval [CI]: 17.0-31.6), the median progression-free survival was significantly longer in the irAE group than the non-irAE group (3.8 versus 1.3 mo, p < 0.0001). The median overall survival was also significantly longer among patients with irAEs than patients without irAEs (13.8 versus 2.9 mo, p < 0.0001). When analyzed as a time-varying covariate, the development of irAEs was associated with a significant improvement in progression-free survival (hazard ratio: 0.44 [95% CI: 0.29-0.66], p < 0.001) and overall survival (hazard ratio: 0.47 [95% CI: 0.32-0.71], p < 0.001) in multivariate models. CONCLUSIONS: The development of irAEs is associated with improved clinical outcomes for immunotherapy in patients with advanced SCLC.

Isolated neutropenia as a rare but serious adverse event secondary to immune checkpoint inhibition.

BACKGROUND: Compared to conventional chemotherapy, Immune checkpoint inhibitors (ICI) are known to have a distinct toxicity profile commonly identified as immune-related adverse events (irAEs). These irAEs that are believed to be related to immune dysregulations triggered by ICI can be serious and lead to treatment interruptions and in severe cases, precipitate permanent discontinuation. Isolated neutropenia secondary to ICI has been rarely documented in the literature and needs further description. We report a case of pembrolizumab related severe isolated neutropenia in a patient with metastatic non-small cell lung cancer. We were also able to obtain serial blood and plasma-based biomarkers for this patient during treatment and during neutropenia to understand trends that may correlate with the irAE. In addition we summarize important findings from other studies reporting on ICI related neutropenia. CASE PRESENTATION: A 74 years old Caucasian male treated with single-agent pembrolizumab for metastatic non-small cell lung cancer presented with fevers, chills, and an isolated neutrophil count (ANC) of 0 2 weeks after the fourth dose. In addition to antibiotics, due to the strong suspicion of this neutropenia being immune-mediated, he was started on 1 mg/kg of steroids and also received filgrastim to accelerate neutrophil recovery. Serial trends in C-reactive protein and certain other inflammatory cytokines demonstrated a corresponding rise at the time of neutropenia. Post recovery, his pembrolizumab was kept on hold. Eight weeks later he had a second episode of neutropenia which was again managed similar to the first episode. Despite permanent discontinuation of ICI after the first neutropenia, his disease showed an ongoing complete metabolic response on imaging. Our literature review reveals that hematological toxicities constitute < 1% irAEs with isolated neutropenia roughly accounting for one-fourth of the hematological irAEs. Based on the handful of ICI related neutropenia cases reported to date, we identified nivolumab to be the most common offender. The median number of ICI cycles administered before presenting with neutropenia was three, and the median time to recovery was approximately two weeks. All of these neutropenic episodes were ≥ grade 3 and led to permanent ICI discontinuation. Using immunosuppressive therapies in conjunction with granulocyte-colony stimulating factor was the most common strategy described to have favorable results. CONCLUSION: Neutropenia as an isolated irAE secondary to ICI is rare but represents a severe toxicity that needs early recognition and can often result in treatment discontinuations. Careful monitoring of these patients with the prompt initiation of immunosuppressive and supportive measures to promote rapid recovery as well as prevent and treat infectious complications should be part of the management algorithms. Serial monitoring of blood and plasma-based biomarkers from more extensive studies may help in identifying patients at risk for irAEs and thus guide patient selection for ICI.