Interferon-Gamma-Producing CD8+ Tissue Resident Memory T Cells Are a Targetable Hallmark of Immune Checkpoint Inhibitor-Colitis.

BACKGROUND & AIMS: The pathogenesis of immune checkpoint inhibitor (ICI)-colitis remains incompletely understood. We sought to identify key cellular drivers of ICI-colitis and their similarities to idiopathic ulcerative colitis, and to determine potential novel therapeutic targets. METHODS: We used a cross-sectional approach to study patients with ICI-colitis, those receiving ICI without the development of colitis, idiopathic ulcerative colitis, and healthy controls. A subset of patients with ICI-colitis were studied longitudinally. We applied a range of methods, including multiparameter and spectral flow cytometry, spectral immunofluorescence microscopy, targeted gene panels, and bulk and single-cell RNA sequencing. RESULTS: We demonstrate CD8+ tissue resident memory T (TRM) cells are the dominant activated T cell subset in ICI-colitis. The pattern of gastrointestinal immunopathology is distinct from ulcerative colitis at both the immune and epithelial-signaling levels. CD8+ TRM cell activation correlates with clinical and endoscopic ICI-colitis severity. Single-cell RNA sequencing analysis confirms activated CD8+ TRM cells express high levels of transcripts for checkpoint inhibitors and interferon-gamma in ICI-colitis. We demonstrate similar findings in both anti-CTLA-4/PD-1 combination therapy and in anti-PD-1 inhibitor-associated colitis. On the basis of our data, we successfully targeted this pathway in a patient with refractory ICI-colitis, using the JAK inhibitor tofacitinib. CONCLUSIONS: Interferon gamma-producing CD8+ TRM cells are a pathological hallmark of ICI-colitis and a novel target for therapy.

Immune checkpoint inhibitor-related colitis assessment and prognosis: can IBD scoring point the way?

BACKGROUND: Immune checkpoint inhibitors (ICI) improve survival but cause immune-related adverse events (irAE). We sought to determine if CTCAE classification, IBD biomarkers/endoscopic/histological scores correlate with irAE colitis outcomes. METHODS: A dual-centre retrospective study was performed on patients receiving ICI for melanoma, NSCLC or urothelial cancer from 2012 to 2018. Demographics, clinical data, endoscopies (reanalysed using Mayo/Ulcerative Colitis Endoscopic Index of Severity (UCEIS) scores), histology (scored with Nancy Index) and treatment outcomes were analysed. RESULTS: In all, 1074 patients were analysed. Twelve percent (134) developed irAE colitis. Median patient age was 66, 59% were male. CTCAE diarrhoea grade does not correlate with steroid/ infliximab use. G3/4 colitis patients are more likely to need infliximab (p < 0.0001) but colitis grade does not correlate with steroid duration. CRP, albumin and haemoglobin do not correlate with severity. The UCEIS (p = 0.008) and Mayo (p = 0.016) scores correlate with severity/infliximab requirement. Patients with higher Nancy indices (3/4) are more likely to require infliximab (p = 0.03). CONCLUSIONS: CTCAE assessment does not accurately reflect colitis severity and our data do not support its use in isolation, as this may negatively impact timely management. Our data support utilising endoscopic scoring for patients with >grade 1 CTCAE disease, and demonstrate the potential prognostic utility of objective histologic scoring.

Pegargiminase Plus First-Line Chemotherapy in Patients With Nonepithelioid Pleural Mesothelioma: The ATOMIC-Meso Randomized Clinical Trial.

Importance: Arginine deprivation using ADI-PEG20 (pegargiminase) combined with chemotherapy is untested in a randomized study among patients with cancer. ATOMIC-Meso (ADI-PEG20 Targeting of Malignancies Induces Cytotoxicity-Mesothelioma) is a pivotal trial comparing standard first-line chemotherapy plus pegargiminase or placebo in patients with nonepithelioid pleural mesothelioma. Objective: To determine the effect of pegargiminase-based chemotherapy on survival in nonepithelioid pleural mesothelioma, an arginine-auxotrophic tumor. Design, Setting, and Participants: This was a phase 2-3, double-blind randomized clinical trial conducted at 43 centers in 5 countries that included patients with chemotherapy-naive nonepithelioid pleural mesothelioma from August 1, 2017, to August 15, 2021, with at least 12 months' follow-up. Final follow-up was on August 15, 2022. Data analysis was performed from March 2018 to June 2023. Intervention: Patients were randomly assigned (1:1) to receive weekly intramuscular pegargiminase (36.8 mg/m2) or placebo. All patients received intravenous pemetrexed (500 mg/m2) and platinum (75-mg/m2 cisplatin or carboplatin area under the curve 5) chemotherapy every 3 weeks up to 6 cycles. Pegargiminase or placebo was continued until progression, toxicity, or 24 months. Main Outcomes and Measures: The primary end point was overall survival, and secondary end points were progression-free survival and safety. Response rate by blinded independent central review was assessed in the phase 2 portion only. Results: Among 249 randomized patients (mean [SD] age, 69.5 [7.9] years; 43 female individuals [17.3%] and 206 male individuals [82.7%]), all were included in the analysis. The median overall survival was 9.3 months (95% CI, 7.9-11.8 months) with pegargiminase-chemotherapy as compared with 7.7 months (95% CI, 6.1-9.5 months) with placebo-chemotherapy (hazard ratio [HR] for death, 0.71; 95% CI, 0.55-0.93; P = .02). The median progression-free survival was 6.2 months (95% CI, 5.8-7.4 months) with pegargiminase-chemotherapy as compared with 5.6 months (95% CI, 4.1-5.9 months) with placebo-chemotherapy (HR, 0.65; 95% CI, 0.46-0.90; P = .02). Grade 3 to 4 adverse events with pegargiminase occurred in 36 patients (28.8%) and with placebo in 21 patients (16.9%); drug hypersensitivity and skin reactions occurred in the experimental arm in 3 patients (2.4%) and 2 patients (1.6%), respectively, and none in the placebo arm. Rates of poststudy treatments were comparable in both arms (57 patients [45.6%] with pegargiminase vs 58 patients [46.8%] with placebo). Conclusions and Relevance: In this randomized clinical trial of arginine depletion with pegargiminase plus chemotherapy, survival was extended beyond standard chemotherapy with a favorable safety profile in patients with nonepithelioid pleural mesothelioma. Pegargiminase-based chemotherapy as a novel antimetabolite strategy for mesothelioma validates wider clinical testing in oncology. Trial Registration: ClinicalTrials.gov Identifier: NCT02709512.

The type 1 insulin-like growth factor receptor pathway.

Research conducted over the past two decades has shown the importance of the type 1 insulin-like growth factor receptor (IGF1R) in tumorigenesis, metastasis, and resistance to existing forms of cancer therapy. The IGF1R itself has only recently been accepted as a credible treatment target, however, perhaps reflecting the potential problems for drug design posed by normal tissue IGF1R expression, and close homology with the insulin receptor. Currently approximately 12 anti-IGF1R therapeutics are undergoing clinical evaluation, including blocking antibodies and tyrosine kinase inhibitors. This review will summarize the principal signaling pathways activated by IGF1R and the preclinical data that validated this receptor as a treatment target. We will review clinical progress in the testing of IGF1R inhibitory drug candidates, the relative benefits and potential toxicities of coinhibition of the insulin receptor, and the rationale for combining IGF1R blockade with other cancer treatments. An understanding of IGF1R signaling is important because it will guide the incorporation of appropriate molecular markers into clinical trial design. This will be key to the identification of patients most likely to benefit, and so will influence the ability of IGF1R inhibition to make the transition from experimental intervention to clinical therapy.

Value of Supraregional Multidisciplinary Review for the Contemporary Management of Testicular Tumors.

PURPOSE: Testicular cancers are an uncommon and highly curable group of tumors that are typically managed by specialist multidisciplinary teams (MDTs). Although recent guidelines have emphasized the importance of tumor prognostic factors in predicting recurrence and personalizing therapy in early-stage disease, the role of central pathology review in determining these factors is unclear. PATIENTS AND METHODS: We compared the referral histopathology reports with those obtained after expert central review for all cases reviewed by the UK Thames Valley Cancer Network testicular tumor MDT from August 2004 to September 2012. For cases in which the findings differed, we recorded the effect of the alteration on the estimates of patient prognosis and predicted clinical management using international (European Society of Medical Oncology [ESMO]) and local guidelines. RESULTS: The histopathology reports were altered after central review in 129 of 465 cases (27.7%) referred to the testicular tumor MDT during the study period. These resulted in changes in the estimation of prognosis for 42 patients (9.0% total), with a predicted affect on management according to the ESMO guidelines in 30 cases (6.5%). These proportions were broadly similar for both seminoma and nonseminoma, although the reasons for the discrepancies differed between the 2 (principally errors in categorization of rete testis invasion in seminoma and of lymphovascular invasion in nonseminoma). Changes to the tumor type were uncommon (2 cases). CONCLUSION: Central MDT review results in frequent, clinically relevant alterations to testicular tumor histopathology reports for testicular tumors. The results of our study demonstrate the importance of specialist MDTs to inform patient-centered care and ensure best practice in the management of these uncommon cancers.

Leptomeningeal carcinomatosis in non-small-cell lung cancer: initial response to erlotinib followed by relapse despite continuing radiological resolution of disease.

A 60-year-old male was diagnosed with T3, N3, M1b epidermal growth factor receptor (EGFR) mutant lung adenocarcinoma. Five months later he developed significant headaches, weakness and numbness of the left leg, and unsteadiness of gait. Magnetic resonance imaging (MRI) brain demonstrated subtle gyral enhancement indicative of early leptomeningeal infiltration. He was commenced on second-line erlotinib which improved his lower limb symptoms. Three months later he developed increased urinary frequency and redeveloped leg symptoms. MRI brain showed improvement in the gyral enhancement. Four weeks later, the patient developed new onset confusion and decrease in mobility. Examination of the cerebrospinal fluid (CSF) demonstrated leptomeningeal carcinomatosis. This case demonstrates radiological and clinical response of leptomeningeal disease to erlotinib in EGFR mutant lung cancer with subsequent clinical relapse despite continued radiological resolution of leptomeningeal disease. This suggests that CSF examination should be considered when monitoring leptomeningeal disease response following treatment as the disease can be undetectable on repeat radiological imaging.

Use of complementary therapies by patients with IBD may indicate psychosocial distress.

BACKGROUND: Complementary and alternative medicine (CAM) is used increasingly by patients with chronic diseases. We have assessed the use of CAM in general medicine and gastrointestinal outpatients focusing particularly on factors predisposing to its use in patients with inflammatory bowel disease (IBD). METHODS: 239 consecutive patients attending gastrointestinal and general medical outpatient clinics answered a questionnaire about their use of CAM: patients with IBD also completed a validated disease-specific quality of life (QOL) inflammatory bowel disease questionnaire (IBDQ). RESULTS: 26% of all patients used CAM, most commonly herbal remedies (43%). CAM was used significantly more by younger than older patients and by single than married or widowed ones. There were no differences by gender or ethnicity. More patients with irritable bowel syndrome used CAM than those with other diagnoses. In IBD patients, CAM users had significantly poorer QOL scores for emotional and social factors than nonusers. 53% of users stated that CAM alleviated their symptoms. CONCLUSIONS: Use of CAM is common in gastroenterological outpatients, particularly if they are young, single, or have irritable bowel syndrome (IBS). Most patients deem it helpful. In IBD, poor QOL predisposes to use of CAM. Conversely, use of CAM may serve as a marker of emotional or social unease in these patients. Physicians need to be aware of widespread usage of CAM by their patients.

Depletion of the type 1 IGF receptor delays repair of radiation-induced DNA double strand breaks.

BACKGROUND AND PURPOSE: IGF-1R depletion sensitizes prostate cancer cells to ionizing radiation and DNA-damaging cytotoxic drugs. This study investigated the hypothesis that IGF-1R regulates DNA double strand break (DSB) repair. METHODS: We tested effects of IGF-1R siRNA transfection on the repair of radiation-induced DSBs by immunoblotting and immunofluorescence for γH2AX, and pulsed-field gel electrophoresis. Homologous recombination (HR) was quantified by reporter assays, and cell cycle distribution by flow cytometry. RESULTS: We confirmed that IGF-1R depletion sensitized DU145 and PC3 prostate cancer cells to ionizing radiation. DU145 control transfectants resolved radiation-induced DSBs within 24 h, while IGF-1R depleted cells contained 30-40% unrepaired breaks at 24 h. IGF-1R depletion induced significant reduction in DSB repair by HR, although the magnitude of the repair defect suggests additional contributory factors. Radiation-induced G2-M arrest was attenuated by IGF-1R depletion, potentially suppressing cell cycle-dependent processes required for HR. In contrast, IGF-1R depletion induced only minor radiosensitization in LNCaP cells, and did not influence repair. Cell cycle profiles were similar to DU145, so were unlikely to account for differences in repair responses. CONCLUSIONS: These data indicate a role for IGF-1R in DSB repair, at least in part via HR, and support use of IGF-1R inhibitors with DNA damaging cancer treatments.

Type 1 insulin-like growth factor receptor translocates to the nucleus of human tumor cells.

The type 1 insulin-like growth factor receptor (IGF-1R) is a transmembrane glycoprotein composed of two extracellular alpha subunits and two beta subunits with tyrosine kinase activity. The IGF-1R is frequently upregulated in cancers and signals from the cell surface to promote proliferation and cell survival. Recent attention has focused on the IGF-1R as a target for cancer treatment. Here, we report that the nuclei of human tumor cells contain IGF-1R, detectable using multiple antibodies to alpha- and beta-subunit domains. Cell-surface IGF-1R translocates to the nucleus following clathrin-mediated endocytosis, regulated by IGF levels. The IGF-1R is unusual among transmembrane receptors that undergo nuclear import, in that both alpha and beta subunits traffic to the nucleus. Nuclear IGF-1R is phosphorylated in response to ligand and undergoes IGF-induced interaction with chromatin, suggesting direct engagement in transcriptional regulation. The IGF dependence of these phenomena indicates a requirement for the receptor kinase, and indeed, IGF-1R nuclear import and chromatin binding can be blocked by a novel IGF-1R kinase inhibitor. Nuclear IGF-1R is detectable in primary renal cancer cells, formalin-fixed tumors, preinvasive lesions in the breast, and nonmalignant tissues characterized by a high proliferation rate. In clear cell renal cancer, nuclear IGF-1R is associated with adverse prognosis. Our findings suggest that IGF-1R nuclear import has biological significance, may contribute directly to IGF-1R function, and may influence the efficacy of IGF-1R inhibitory drugs.