Abstract
INTRODUCTION: CPI has significant efficacy and toxicities. We describe our experience with CPI treated patients diagnosed with irAE encephalitis. METHODS: Patients treated with CPI during 2017–2018 were identified from institute’s EMR. Patients treated for irAE encephalitis were identified from the database of the Neuro-Oncology Unit of the Institute. Results: Eleven patients were diagnosed with irAE encephalitis out of 1500 treated with CPI at the Institute (0.73%). Four patients had NSCLC, 3 had melanoma, the one patient had each of SCLC, uterine carcinoma, RCC and breast cancer. Median age was 69 years (49–87). Four of 11 were treated with chemo-CPI, 3-with CPI combinations. Median onset of symptoms was at 19 days (5–180) following initial treatment. All events were high grade severity. Eight patients fully recovered after immunotherapy discontinuation and steroid treatment, of these, 2 melanoma patients underwent uncomplicated CPI re-challenge. Three patients, all non-melanoma, had severe neurological sequelae. Two of them were treated with steroids, PLEX and cyclophosphamide: one improved neurologically although died 6 months later from cancer. One patient was oncologically stable but died from neurological deterioration 7 months later. The additional patient was treated with steroids only because his advanced age and decease in hospice 2 months later. CONCLUSION: Encephalitis, as an irAE of CPI, seems to be more common and severe than previously thought, predominantly in non melanoma patients. Nevertheless, in the majority of cases it is reversible and in some melanoma patients immunotherapy re-challenge is safe. Future studies will have to define risk factors and severity prediction.