Paraneoplastic and Other Autoimmune Encephalitides: Antineuronal Antibodies, T Lymphocytes, and Questions of Pathogenesis

Autoimmune and paraneoplastic encephalitides represent an increasingly recognized cause of devastating human illness as well as an emerging area of neurological injury associated with immune checkpoint inhibitors. Two groups of antibodies have been detected in affected patients. Antibodies in the first group are directed against neuronal cell surface membrane proteins and are exemplified by antibodies directed against the N-methyl-D-aspartate receptor (anti-NMDAR), found in patients with autoimmune encephalitis, and antibodies directed against the leucine-rich glioma-inactivated 1 protein (anti-LGI1), associated with faciobrachial dystonic seizures and limbic encephalitis. Antibodies in this group produce non-lethal neuronal dysfunction, and their associated conditions often respond to treatment. Antibodies in the second group, as exemplified by anti-Yo antibody, found in patients with rapidly progressive cerebellar syndrome, and anti-Hu antibody, associated with encephalomyelitis, react with intracellular neuronal antigens. These antibodies are characteristically found in patients with underlying malignancy, and neurological impairment is the result of neuronal death. Within the last few years, major advances have been made in understanding the pathogenesis of neurological disorders associated with antibodies against neuronal cell surface antigens. In contrast, the events that lead to neuronal death in conditions associated with antibodies directed against intracellular antigens, such as anti-Yo and anti-Hu, remain poorly understood, and the respective roles of antibodies and T lymphocytes in causing neuronal injury have not been defined in an animal model. In this review, we discuss current knowledge of these two groups of antibodies in terms of their discovery, how they arise, the interaction of both types of antibodies with their molecular targets, and the attempts that have been made to reproduce human neuronal injury in tissue culture models and experimental animals. We then discuss the emerging area of autoimmune neuronal injury associated with immune checkpoint inhibitors and the implications of current research for the treatment of affected patients.

Gastroenteropancreatic Neuroendocrine Neoplasms (GEP NENs) : The Role of Checkpoint Inhibitors

Background: The treatment options for GEP-NENs includes various drugs and is based on grading, morphology and location of the primary Objective: The aim of our work is to investigate the clinical impact of new immune checkpoint inhibitors in order to define a new possible strategy of use within GEP-NENs. Method: A scientific literature search from 2015 to January 2020 was performed by using PubMed and Embase: reviews and prospective or retrospective studies with a minimum of twenty patients were selected; conference proceedings were included Results: several studies have been conducted to assess the role of immune checkpoint inhibitors in NENs, but nowadays the current knowledge in this field is mainly based on a phase I-II studies. Immunotherapy showed limited antitumor activity, but higher response rate was reported in poor-differentiated neuroendocrine tumors. No specific biomarkers were identified for patient selection and response assessment Conclusion: Immunotherapy appears as a powerful possibility to help our patients, but nowadays we see many gaps in this field. We must balance therapeutic possibility offered by precision oncology with the understanding the limitations of application of testing and treatment in clinical practice. Future efforts should focus on research of the best patients to candidate for immunotherapy in term of disease characteristics and previous treatments, and how to select them with accurate biomarkers.

Immune-related adverse events caused by combined immune checkpoint inhibitor therapy with nivolumab and ipilimumab for lung cancer

It has been less than a decade since immune checkpoint inhibitors became the mainstay of lung cancer treatment, and 2020 saw the advent of the era of complex immune checkpoint inhibitors. Although clinical trials have shown that the therapeutic effects of complex immune checkpoint inhibitors are favorable, they are associated with an increase in adverse events. The use of combined immune checkpoint inhibitors in clinical practice has progressed slowly, and the frequency and types of adverse events they cause remain unclear. Here we report the adverse events of six patients with lung cancer treated with regimens containing nivolumab and ipilimumab in 2021. Four of the six patients had grade 3 or higher adverse events, including one patient with lung injury and one patient with skin injury, both of whom died. The timing and nature of the adverse events were difficult to predict.

Dosimetric Risk Factors for Acute Radiation Pneumonitis in Patients With Prior Receipt of Immune Checkpoint Inhibitors

PurposeDosimetric parameters (e.g., mean lung dose (MLD), V20, and V5) can predict radiation pneumonitis (RP). Constraints thereof were formulated before the era of combined immune checkpoint inhibitors (ICIs) and radiotherapy, which could amplify the RP risk. Dosimetric predictors of acute RP (aRP) in the context of ICIs are urgently needed because no data exist thus far.Methods and MaterialsAll included patients underwent thoracic intensity-modulated radiotherapy, previously received ICIs, and followed-up at least once. Logistic regression models examined predictors of aRP (including a priori evaluation of MLD, V20, and V5), and their discriminative capacity was assessed by receiver operating characteristic analysis.ResultsMedian follow-up of the 40 patients was 5.3 months. Cancers were lung (80%) or esophageal (20%). ICIs were PD-1 (85%) or PD-L1 (15%) inhibitors (median 4 cycles). Patients underwent definitive (n=19), consolidative (n=14), or palliative (n=7) radiotherapy; the median equivalent dose in 2 Gy fractions (EQD2) was 60 Gy (IQR, 51.8-64 Gy). Grades 1-5 aRP occurred in 25%, 17.5%, 15%, 2.5%, and 5%, respectively. The only variables associated with any-grade aRP were V20 (p=0.014) and MLD (p=0.026), and only V20 with grade ≥2 aRP (p=0.035). Neither the number of prior ICI cycles nor the delivery of concurrent systemic therapy significantly associated with aRP risk. Graphs were constructed showing the incrementally increasing risk of aRP based on V20 and MLD (continuous variables).ConclusionsThis is the first study illustrating that V20 and MLD may impact aRP in the setting of prior ICIs. However, these data should not be extrapolated to patients without pre-radiotherapy receipt of prior ICIs, or to evaluate the risk of chronic pulmonary effects. If these results are validated by larger studies with more homogeneous populations, the commonly accepted V20/MLD dose constraints could require revision if utilized in the setting of ICIs.

Safety and Efficacy of Transarterial Chemoembolization Combined With Immune Checkpoint Inhibitors and Tyrosine Kinase Inhibitors for Hepatocellular Carcinoma

PurposeTo explore the safety and efficacy of transarterial chemoembolization (TACE) in combination with immune checkpoint inhibitors (ICIs) and tyrosine kinase inhibitors (TKIs) for the treatment of unresectable hepatocellular carcinoma (uHCC).Materials and MethodsFrom August 2019 to July 2020, patients who received TACE combined with ICIs and TKIs were retrospectively analyzed. Treatment-related adverse events (AEs) were recorded. The Kaplan–Meier method was used to estimate time to progression (TTP) and progression-free survival (PFS).ResultsIn total, 31 patients with uHCC were included. Eleven patients were classified as BCLC-C. Nineteen patients had multiple lesions, and the cumulative targeted lesions were 69 mm (range, 21-170 mm) according to mRECIST. Twenty-nine (93%) patients experienced at least one AE during the treatment. Four (12.9%) patients developed AEs of higher grade (grade≥3). The objective response rate (ORR) and disease control rate (DCR) were 64.5% and 77.4%, respectively. The median time to response was 7 weeks (range, 4-30 w), and the duration of response was 17.5 weeks (range, 2-46 w). From the first ICIs, TTP and PFS were 6.5 months (95% CI, 3.5-11) and 8.5 months (95% CI, 3.5-NE), respectively.ConclusionsTACE combined with ICIs and TKIs shows an acceptable safety profile and considerable efficacy in patients with HCC.