Thymic epithelial tumors (TETs) are one of the rarest adult malignancies. Among TETs, thymoma is the most predominant, characterized by a unique association with autoimmune diseases, followed by thymic carcinoma, which is less common but more clinically aggressive. Using multi-platform omics analyses on 117 TETs, we define four subtypes of these tumors defined by genomic hallmarks and an association with survival and World Health Organization histological subtype. We further demonstrate a marked prevalence of a thymoma-specific mutated oncogene, GTF2I, and explore its biological effects on multi-platform analysis. We further observe enrichment of mutations in HRAS, NRAS, and TP53. Last, we identify a molecular link between thymoma and the autoimmune disease myasthenia gravis, characterized by tumoral overexpression of muscle autoantigens, and increased aneuploidy.

National Cancer Institute and Merck KGaA.

Background Avelumab, a fully human IgG1 immune checkpoint inhibitor targeting programmed death ligand 1 (PD-L1), has shown antitumour activity and an acceptable safety profile in patients with advanced solid tumours. Here, we assessed avelumab treatment in patients with advanced, platinum-treated non-small cell lung cancer (NSCLC). Methods In this dose-expansion cohort of a multicentre, open-label, phase 1 study, patients with progressive or platinum-resistant metastatic or recurrent NSCLC were enrolled at 58 sites in the United States. Eligible patients had confirmed stage IIIB or IV NSCLC with squamous or nonsquamous histology, measurable disease by Response Evaluation Criteria In Solid Tumors version 1.1 (RECIST v1.1), tumour biopsy or archival sample for biomarker assessment, and Eastern Cooperative Oncology Group performance status 0 or 1, among other criteria. Patient selection was not based on PD-L1 expression or other biomarkers, including EGFR or KRAS mutation or ALK translocation status. Patients received avelumab monotherapy 10 mg/kg every 2 weeks until disease progression or toxicity. The primary endpoint was safety and tolerability. Secondary endpoints included best overall response, progression-free survival, overall survival, and clinical activity associated with PD-L1 expression. Responses were evaluated using RECIST v1.1, and analyses of antitumour activity and safety were performed in all patients who received at least one dose of avelumab. This trial is registered with ClinicalTrials.gov (NCT01772004); enrolment in this cohort is closed and the trial is ongoing. Findings Between 10 September 2013 and 24 June 2014, 184 patients were enrolled and initiated treatment with avelumab. Median follow-up duration was 8·8 months (interquartile range [first and third quartiles], 7·2–11·9 months). The most common treatment-related adverse events of any grade were fatigue (n=46; 25%), infusion-related reaction (n=38; 21%), and nausea (n=23; 13%). Grade ≥3 treatment-related adverse events occurred in 23 of 184 patients (13%); the most common were infusion-related reaction (n=4; 2%), elevated lipase (n=3; 2%), constipation (n=2; 1%), and dyspnoea (n=2; 1%). 16 of 184 patients (9%) had a serious adverse event related to treatment with avelumab, with infusion-related reaction (4 [2%]) and dyspnoea (2 [1%]) occurring in more than one patient. Immune-related treatment-related events occurred in 22 patients (12%). The confirmed objective response rate, regardless of PD-L1 status, was 12% (95% CI, 8–18), including one complete response and 21 partial responses. Seventy patients had stable disease, for an overall disease-control rate of 50%. Interpretation Avelumab showed an acceptable safety profile and antitumour activity in patients with progressive or resistant NSCLC, providing a rationale for additional studies of avelumab in this disease setting. Funding Merck KGaA, Darmstadt, Germany and Pfizer, Inc, New York, USA.