145P Everolimus for the treatment of thymic epithelial tumors (TETs): A real-world experience

TETs are rare malignancies of the anterior mediastinum ranging from more indolent thymoma (T) to aggressive thymic carcinoma (TC). There is no standard treatment after platinum-based chemotherapy in refractory setting. A phase II trial reported clinical benefit for everolimus (EVE) 10mg (DCR 88%). EVE has immune modulatory activity, interest patients (pts) with auto-immune disorders (AIDs), detected up 30% pts. Few data exist real-world studies. We selected pts under as a front-line or beyond single cancer center. analyzed epidemiologic, and pathological characteristics Toxicity was evaluated according CTCAE v4, local evaluation efficacy. From July 2017 January 2022, 24 were included. Median (m) age at diagnosis 47,5 (35-74), 58,3% men, 9/24 (37,5%) showed AIDs. TC T B2 most frequent subtypes (n=8, 33,3% both. used ≥2 line 91% (n=22) pts, mainly starting 10 mg/daily. summarized table. 3/24 (12,5%) discontinued due intolerance. 5/24 (20,8%) required dose reduction. 1/7 (14,2%) achieved AID control EVE. DCR 62,5% (95%CI 43-81), 37.5% 75% (with 4 PR). The m follow-up 51 months (mo) 10, 65-91, 34); mTTF 3 mo (2,21-3,78 mo). mPFS (95% CI 2,42-5,57 mo) mOS 31 20,76-41,83). 8 vs 2 TC, respectively (p=0,08). 47 mo, 7 showing PR, SD PD (p<0,001). 9 underwent molecular analysis, reporting P53 mutation (mut) PTEN PI3K mut 1 respectively. these prolonged disease control, patient PR 18 (receiving front-line).Table 145PToxicityTreatment related AEsAll grades n (%)Grade 3-4 (%)Weight loss7 (29)2 (8)Asthenia6 (25)2 (8)Mucositis6 (25)1 (4)Diarrhea4 (16)1 (4)Pneumonitis2 (8)2 (8)Pancytopenia2 (8)Neutropenia1 (4)1 (4)Hand-foot syndrome1 (4)Others6 (25)0 (0) Open table new tab limited efficacy TC. Among 16 T, 25% had very long duration response. Further work identify predictors response needed improve patient’s selection.