ObjectiveTo define the characteristics and the outcome of myelitis associated with immune checkpoint inhibitors (ICIs).MethodsWe performed a retrospective research in the databases of the French Pharmacovigilance Agency and the OncoNeuroTox network for patients who developed myelitis following treatment with ICIs (2011–2020). A systematic review of the literature was performed to identify similar cases.ResultsWe identified 7 patients who developed myelitis after treatment with ICIs (anti-PD1 [n = 6], anti-PD1 + anti-CTLA4 [n = 1]). Neurologic symptoms included paraparesis (100%), sphincter dysfunction (86%), tactile/thermic sensory disturbances (71%), and proprioceptive ataxia (43%). At the peak of symptom severity, all patients were nonambulatory. MRI typically showed longitudinally extensive lesions, with patchy contrast enhancement. CSF invariably showed inflammatory findings. Five patients (71%) had clinical and/or paraclinical evidence of concomitant cerebral, meningeal, caudal roots, and/or peripheral nerve involvement. Despite the prompt discontinuation of ICIs and administration of high-dose glucocorticoids (n = 7), most patients needed second-line immune therapies (n = 5) because of poor recovery or early relapses. At last follow-up, only 3 patients had regained an ambulatory status (43%). Literature review identified 13 previously reported cases, showing similar clinical and paraclinical features. All patients discontinued ICIs and received high-dose glucocorticoids, with the addition of other immune therapies in 8. Clinical improvement was reported for 10 patients.ConclusionMyelitis is a rare but severe complication of ICIs that shows limited response to glucocorticoids. Considering the poor functional outcome associated with longitudinally extensive myelitis, strong and protracted immune therapy combinations are probably needed upfront to improve patient outcome and prevent early relapses.

Adult glioblastomas, IDH-wildtype represent a heterogeneous group of diseases. They are resistant to conventional treatment by concomitant radiochemotherapy and carry a dismal prognosis. The discovery of oncogenic gene fusions in these tumors has led to prospective targeted treatments, but identification of these rare alterations in practice is challenging. Here, we report a series of 30 adult diffuse gliomas with an in frame FGFR3-TACC3 oncogenic fusion (n = 27 WHO grade IV and n = 3 WHO grade II) as well as their histological and molecular features. We observed recurrent morphological features (monomorphous ovoid nuclei, nuclear palisading and thin parallel cytoplasmic processes, endocrinoid network of thin capillaries) associated with frequent microcalcifications and desmoplasia. We report a constant immunoreactivity for FGFR3, which is a valuable method for screening for the FGFR3-TACC3 fusion with 100% sensitivity and 92% specificity. We confirmed the associated molecular features (typical genetic alterations of glioblastoma, except the absence of EGFR amplification, and an increased frequency of CDK4 and MDM2 amplifications). FGFR3 immunopositivity is a valuable tool to identify gliomas that are likely to harbor the FGFR3-TACC3 fusion for inclusion in targeted therapeutic trials.

Abstract Background Actionable fibroblast growth factor receptor 3 (FGFR3)–transforming acidic coiled-coil protein 3 fusions (F3T3) are found in approximately 3% of gliomas, but their characteristics and prognostic significance are still poorly defined. Our goal was to characterize the clinical, radiological, and molecular profile of F3T3 positive diffuse gliomas. Methods We screened F3T3 fusion by real-time (RT)-PCR and FGFR3 immunohistochemistry in a large series of gliomas, characterized for main genetic alterations, histology, and clinical evolution. We performed a radiological and radiomic case control study, using an exploratory and a validation cohort. Results We screened 1162 diffuse gliomas (951 unselected cases and 211 preselected for FGFR3 protein immunopositivity), identifying 80 F3T3 positive gliomas. F3T3 was mutually exclusive with IDH mutation (P < 0.001) and EGFR amplification (P = 0.01), defining a distinct molecular cluster associated with CDK4 (P = 0.04) and MDM2 amplification (P = 0.03). F3T3 fusion was associated with longer survival for the whole series and for glioblastomas (median overall survival was 31.1 vs 19.9 mo, P = 0.02) and was an independent predictor of better outcome on multivariate analysis. F3T3 positive gliomas had specific MRI features, affecting preferentially insula and temporal lobe, and with poorly defined tumor margins. F3T3 fusion was correctly predicted by radiomics analysis on both the exploratory (area under the curve [AUC] = 0.87) and the validation MRI (AUC = 0.75) cohort. Using Cox proportional hazards models, radiomics predicted survival with a high C-index (0.75, SD 0.04), while the model combining clinical, genetic, and radiomic data showed the highest C-index (0.81, SD 0.04). Conclusion F3T3 positive gliomas have distinct molecular and radiological features, and better outcome.

Patients with adult MLG present with unique clinical and molecular characteristics, differing from their pediatric counterparts. The identification of potentially actionable mutations in a subset of adult MLG highlights the importance of comprehensive genomic analysis in this rare affection.

Introduction: Mutations in the genes isocitrate dehydrogenase (IDH) 1 and 2 have been reported in a limited number of tumors. In gliomas, IDH mutations are primarily detected in WHO grade II-III tumors and represent a major biomarker with diagnostic, prognostic, and predictive implications. The recent development of IDH inhibitors and vaccines suggests that the IDH mutation is also an appealing target for therapy. Areas covered: This review focuses on the role of IDH mutations in diffuse gliomas. Besides discussing their role in gliomagenesis, we will emphasize the role of IDH mutations in clinical practice as a diagnostic, prognostic and predictive biomarker, and as a potential therapeutic target. Noninvasive detection of the IDH mutation by means of liquid biopsy and MR spectroscopy will also be discussed. Expert commentary: While IDH mutation is a consolidated diagnostic and prognostic biomarker in clinical practice, its role in oncogenesis is far from being elucidated, and there are several pending issues. The routine use of noninvasive techniques for detection and monitoring of the IDH status remains challenging. Although the IDH mutation is a very early alteration in gliomagenesis, it may then be omitted during tumor progression. This observation has important implications when designing targeted clinical trials. KEYWORDS IDH1and IDH2 mutations; gliomagenesis; grade II and III gliomas; biomarkers; target therapy 65 mutations, common in acute myeloid leukemia [11], have not been reported in gliomas [12]. Mutations arising in IDH1 G97 [13,14], IDH1 R100 [14-16] (the homologous of IDH2 R140), IDH1 R109 [17], and IDH1 R314 [18] have been anecdotally reported in gliomas. 70 IDH1 and IDH2 are enzymes that physiologically convert isocitrate to α-ketoglutarate (α-KG). These two enzymes have similar function but different cell compartmentalization: IDH1 is located in the cytosol, while IDH2 in mitochondria. Mutations in either IDH1 or IDH2 result in a neomorphic enzy-75 matic activity, causing the stereospecific conversion of α-KG

The 2016 WHO classification of Tumors of the Central Nervous System brought major conceptual and practical changes in the classification of diffuse gliomas, by combining molecular features and histology into ‘integrated’ diagnoses. In diffuse gliomas, molecular profiling has thus become essential for nosological purposes, as well as to plan adequate treatment strategies and identify patients susceptible of target therapy. WHO grade II (low grade) and grade III (anaplastic) diffuse gliomas form a heterogeneous group of neoplasms, also known as ‘lower-grade gliomas’, characterized by a wide range of malignant potential. Molecular profile accounts for this biological diversity, and provides an accurate prognostic stratification of tumors in this group. Treatment strategies in lower-grade gliomas are ultimately based on molecular profile and WHO grade, as well as on patient characteristics such as age and Karnofsky performance status. The purpose of this review is to summarize recent advances in the classification of grade II and III gliomas, synthesize current treatment schemes according to molecular profile and describe ongoing research and future perspectives for the use of target therapies.

Background and ObjectivesTo describe the marked clinical and biological responses of a targeted treatment with anti–interleukin-6 (IL-6)–receptor antibody and Janus kinase (JAK) inhibitors in a patient with a severe, corticoresistant CNS toxicity of immune-checkpoint inhibitor (ICI) therapy.MethodsA 58-year-old man was admitted for subacute paraparesis, urinary retention, and ascending paresthesia. He was under treatment with ipilimumab and nivolumab for metastatic melanoma. Spine MRI disclosed multiple T2-hyperintense, contrast-enhancing longitudinally extensive lesions. A diagnosis of ICI-related acute transverse myelitis was made.ResultsICIs were immediately discontinued, and the patient received high-dose glucocorticoids plus 1 session of plasma exchange, but he did not improve. Based on the marked elevation of CSF IL-6 (505 pg/mL), a second-line targeted therapy with anti-IL-6-receptor tocilizumab (8 mg/kg/mo for 3 infusions) plus JAK inhibitor ruxolitinib (50 mg/d) was administered. Patient neurologic status started to improve shortly after, with corresponding radiologic resolution. At 9 months, the patient was able to walk independently, presenting only slight residual disability while remaining in oncologic partial response.DiscussionOur case suggests that some patients with severe, corticoresistant CNS immune-related toxicities of ICIs may benefit from cytokine blockade. Cytokine measurement in serum and CSF might help in selecting patients for personalized treatment strategies.

Background Neurological immune-related adverse events (nirAEs) are rare toxicities of immune-checkpoint inhibitors (ICI). With the increase of ICI oncological indications, their incidence is growing. Their recognition and management remain nevertheless challenging. Methods A national, web-based database was built to collect cases of neurological symptoms in patients receiving ICI and not attributable to other causes after an adequate workup. ResultsWe identified 27 patients who developed nirAEs (20 males, median age 69 years). Patients received anti-PD1/PDL1 (78%), anti-CTLA4 (4%), or both (19%). Most common cancers were melanoma (30%) and non-small cell lung cancer (26%). Peripheral nervous system was mostly affected (78%). Median time to onset was 43.5 days and was shorter for peripheral versus central nervous system toxicities (36 versus 144.5 days, p = 0.045). Common manifestations were myositis (33%), inflammatory polyradiculoneuropathies (33%), and myasthenia gravis (19%), alone or in combination, but the spectrum of diagnoses was broad. Most patients received first-line glucocorticoids (85%) or IVIg (15%). Seven patients (26%) needed second-line treatments. At last follow-up, four (15%) patients were deceased (encephalitis, 1; myositis/myasthenia with concomitant myocarditis, 2; acute polyradiculoneuropathy, 1), while seven (26%) had a complete remission, eight (30%) partial improvement, and six (22%) stable/progressing symptoms. ICI treatment was discontinued in most patients (78%). Conclusions Neurological irAEs are rare but potentially fatal. They primarily affect neuromuscular structures but encompass a broad range of presentations. A prompt recognition is mandatory to timely withheld immunotherapy and administrate glucocorticoids. In corticoresistant or severely affected patients, second-line treatments with IVIg or plasmapheresis may result in additional benefit.