Purpose: Unleashing the immune system by PD-1 and/or CTLA-4 blockade can cause severe immune-related toxicity necessitating immunosuppressive treatment. Whether immunosuppression for toxicity impacts survival is largely unknown. Experimental Design: Using data from the prospective nationwide Dutch Melanoma Treatment Registry (DMTR), we analyzed the association between severe toxicity and overall survival (OS) in 1,250 patients with advanced melanoma who were treated with immune checkpoint inhibitors (ICI) in first line between 2012 and 2017. Furthermore, we analyzed whether toxicity management affected survival in these patients. Results: A total of 1,250 patients were included, of whom 589 received anti-PD1 monotherapy, 576 ipilimumab, and 85 combination therapy. A total of 312 patients (25%) developed severe (grade ≥3) toxicity. Patients experiencing severe ICI toxicity had a significantly prolonged survival with a median OS of 23 months compared with 15 months for patients without severe toxicity [hazard ratio (HRadj) = 0.77; 95% confidence interval (CI), 0.63–0.93]. Among patients experiencing severe toxicity, survival was significantly decreased in patients who received anti-TNF ± steroids for steroid-refractory toxicity compared with patients who were managed with steroids only (HRadj = 1.61; 95% CI, 1.03–2.51), with a median OS of 17 and 27 months, respectively. Conclusions: Patients experiencing severe ICI toxicity have a prolonged OS. However, this survival advantage is abrogated when anti-TNF is administered for steroid-refractory toxicity. Further prospective studies are needed to assess the effect of different immunosuppressive regimens on checkpoint inhibitor efficacy. See related commentary by Weber and Postow, p. 2085

PURPOSE: Retrospective studies suggest that immunosuppressive treatment of immune-related adverse events (irAEs) impairs survival in patients with melanoma who received immune checkpoint inhibitors. Here, we study this association across tumor types using data from six international phase II/III registrational trials. METHODS: A post hoc analysis was performed on individual patient data from the anti–programmed cell death-1 (anti–PD-1) + anti–cytotoxic T lymphocyte–associated protein-4 (anti–CTLA-4) treatment arms of six clinical trials (CheckMate-067, -142, -214, -648, -743, and -9LA). Among patients who received systemic immunosuppression for treatment-related adverse events (trAEs), associations of peak and cumulative corticosteroid dose, and use of second-line immunosuppression with overall survival (OS) and progression-free survival (PFS) were assessed using multilevel Cox regression with adjustment for age and sex. RESULTS: Of the 1,959 patients who received anti–PD-1 + anti–CTLA-4 therapy, 834 patients who were treated with immunosuppression for trAEs were included. Eight hundred and thirty-two patients (100%) received corticosteroids and 81 patients (10%) received second-line immunosuppressants. High corticosteroid peak dose was associated with worse PFS: adjusted hazard ratio (HR _adj ), 1.15 (95% CI, 1.02 to 1.29) for 1 versus 0.5 mg/kg prednisolone and HR _adj , 1.43 (95% CI, 1.05 to 1.96) for 2 versus 0.5 mg/kg. Similar effects were observed for OS: HR _adj , 1.21 (95% CI, 1.06 to 1.39) and HR _adj , 1.66 (95% CI, 1.17 to 2.37) for 1 and 2 versus 0.5 mg/kg, respectively. Cumulative corticosteroid dose was not associated with survival. HR _adj of use of second-line immunosuppression was 1.23 (95% CI, 0.90 to 1.68) for PFS and 1.25 (95% CI, 0.88 to 1.77) for OS. CONCLUSION: Higher corticosteroid peak dose for trAEs is associated with worse survival across tumor types, while cumulative dose is not. Too few patients received second-line immunosuppressants to confirm or reject an association with survival. These data argue for a reconsideration of irAE management approaches, starting with lower corticosteroid dose whenever feasible.

Immune checkpoint inhibitors (ICIs) have changed perspectives for patients with cancer, but come with severe immune-related adverse events (irAEs). To prevent fatality or chronicity, these irAEs are often promptly treated with high-dose immunosuppressants. Until recently, evidence on the effects of irAE management on ICI efficacy has been sparse. As a result, algorithms for irAE management are mostly expert-opinion based and barely consider possible detrimental effects of immunosuppressants on ICI efficacy. However, recent growing evidence suggests that vigorous immunosuppressive management of irAEs comes with unfavourable effects on ICI efficacy and survival. With expansion of the indications of ICIs, evidence-based treatment of irAEs without hampering tumour control becomes more and more important. In this review, we discuss novel evidence from pre-clinical and clinical studies on the effects of different irAE management regimens including corticosteroids, TNF inhibition and tocilizumab on cancer control and survival. We provide recommendations for pre-clinical research, cohort studies and clinical trials that can help clinicians in tailored irAE management, minimising patients’ burden while maintaining ICI efficacy.

Multiple studies have suggested that gut microbiome may influence immune checkpoint inhibitor (ICI) efficacy, but its association with immune-related adverse events (irAEs) is less well studied. In this prospective cohort study, we assessed whether gut microbiome composition at start, or changes during ICI, are associated with severe irAEs. Stool samples of cancer patients treated with anti-PD-1 ± anti-CTLA-4 were analyzed using 16S rRNA gene sequencing and metagenomic shotgun sequencing. Differences in alpha and beta diversity between patients with and without severe irAE were assessed, as well as differential relative abundance (RA) of taxa, MetaCyc pathways, and seven prespecified literature-based bacterial groups including pathobionts and Ruminococcaceae. We analyzed 497 samples of 195 patients before and soon after starting ICI, at severe irAE onset and after starting immunosuppression. Mean RA of the pathobionts group was significantly higher in patients who developed a severe irAE (8.2 %) compared to those who did not (4.8 %; odds ratio 1.40; 95 %CI 1.07-1.87) at baseline, and also early during ICI treatment and at severe irAE onset. A significantly stronger decrease in RA of Ruminococcaceae after starting ICI was observed in patients who developed a severe irAE compared to those who did not. RAs of Ruminococcaceae, the genus Ruminococcus, and the species R. bromii and R. callidus were significantly lower at severe irAE onset compared to other time points. Gut microbiome dysbiosis signaled by higher RA of pathobionts and decrease in RA of Ruminococcaceae may predispose to severe irAEs.

Immune checkpoint inhibitors (ICI) have revolutionized the treatment landscape of advanced malignancies, but come with a diverse spectrum of immune-related adverse events (irAEs). Mechanistic studies can aid the transition from expert-opinion to evidence-based irAE treatment strategies. We aimed to longitudinally characterize peripheral blood T and B cell dynamics in ICI-treated patients by multicolor flow cytometry and serum multiplex immunoassay at baseline, ± 3 weeks and ± 6 weeks or upon clinically relevant irAEs. We analyzed samples from 44 ICI-treated patients (24 anti-PD-1 monotherapy, 20 combined anti-PD-1/anti-CTLA-4; cICI), of whom 21 developed irAEs, and 10 healthy donors. IrAEs after cICI were characterized by significantly enhanced proliferation of Th1-associated, mainly (CD4⁺) CD27⁻ effector memory T cells, as well as Th17-associated immune responses and germinal center activation (reflected by CXCL13 and IL-21 increases). We observed no changes in CD21^lo, memory, class-switched or newly activated B cell subsets. Particularly double-positive PD-1⁺LAG-3⁺ CD8⁺ T cells showed enhanced cytotoxic capacity in patients with irAEs after cICI. Within anti-PD-1 monotherapy, irAEs were associated with modestly enhanced Th1-associated responses reflected by increased serum CXCL9 and CXCL10. In conclusion, ICI-induced toxicity is dominated by enhanced Th1-associated responses, but in cICI we also found evidence for Th17-associated responses and germinal center activation. Together, our data add to the growing body of evidence that irAEs may be driven by newly activated CD4⁺ helper T cells, specifically after cICI. This study also supports tailored irAE treatment, based on ICI regimen, and to deploy specific strategies such as Th17 inhibition especially in cICI-associated irAEs. Graphical

Background: Although animal experiments suggest beneficial effects of physical activity (PA) on antitumor immunity, little is known about the effects of PA on immune checkpoint inhibitor (ICI) toxicity and effectiveness in humans. We assessed the association of PA with immune-related adverse events (irAE) and survival in patients undergoing ICI. Methods: Patients receiving ICI who completed the Dutch short questionnaire to assess health enhancing physical activity (SQUASH) questionnaire at the start of treatment as part of the prospective UNICIT study in an academic hospital were included. PA was quantified by calculating total metabolic equivalent task hours per week (total PA) and hours per week of moderate- to vigorous-intensity PA during sport and leisure time (MVPA-SL). Associations of PA with severe irAE occurrence within 1 year and overall survival (OS) were evaluated using logistic regression and Cox proportional hazard regression, respectively, with adjustment for probable confounders. Results: In total, 251 patients were included, with a median follow-up of 20 months. Moderate and high levels of total PA were associated with lower odds of severe irAE occurrence compared to low levels of total PA (adjusted OR: 0.34 [95% CI = 0.12 to 0.90] and 0.19 [95% CI = 0.05 to 0.55], respectively). Moderate and high levels of total PA were also associated with prolonged survival (adjusted HR: 0.58 [95% CI = 0.32 to 1.04] and 0.48 [95% CI = 0.27 to 0.89], respectively). Similar associations were observed in patients who performed more MVPA-SL. Conclusions: Higher physical activity levels at the start of ICI treatment are associated with lower risk of severe irAEs and probably prolonged survival. Randomized controlled trials are needed to investigate whether patients indeed benefit from increasing PA levels after diagnosis.