Response to anti-PD1 therapy with nivolumab in metastatic sarcomas.

BACKGROUND: Manipulation of immune checkpoints such as CTLA4 or PD-1 with targeted antibodies has recently emerged as an effective anticancer strategy in multiple malignancies. Sarcomas are a heterogeneous group of diseases in need of more effective treatments. Different subtypes of soft tissue and bone sarcomas have been shown to express PD-1 ligand. METHODS: We retrospectively analyzed a cohort of patients (pts) with relapsed metastatic/unresectable sarcomas, who were treated with nivolumab provided under a patient assistance program from the manufacturer. Pts underwent CT or PET/CT imaging at baseline and after at least four doses of nivolumab; RECIST 1.1 criteria were used for response assessment. RESULTS: Twenty-eight pts with soft tissue (STS, N = 24) or bone sarcoma (N = 4), received IV nivolumab 3 mg/kg every 2 weeks from July 2015. Median age was 57 (24-78), male:female ratio was 14:14; the median number of nivolumab cycles was eight. Eighteen pts concomitantly received pazopanib at 400-800 mg daily. The most common side effect was grade 1-2 LFT elevations; grade 3-4 toxicity occurred in five patients (colitis, LFT elevations, pneumonitis). Twenty-four pts received at least four cycles. We observed three partial responses: one dedifferentiated chondrosarcoma, one epithelioid sarcoma and one maxillary osteosarcoma (last two patients on pazopanib); nine patients had stable disease including three leiomyosarcomas; 12 patients had progression of disease including 4 leiomyosarcoma. Clinical benefit (response + stability) was observed in 50% of the evaluable patients. CONCLUSIONS: These data provide a rationale for further exploring the efficacy of nivolumab and other checkpoint inhibitors in soft tissue and bone sarcoma.

Chromogenic in situ hybridization accurately identifies EGFR amplification in small cell glioblastoma multiforme, a common subtype of primary GBM.

Primary glioblastoma multiforme (GBM) commonly overexpresses the epidermal growth factor receptor (EGFR) gene and its ligand-independent mutant, EGFRvIII. Amplification of the EGFR gene has been implicated in the pathogenesis of primary GBM, in particular the small cell phenotype, and this finding may contribute to its aggressive clinical behavior. Anti-EGFR clinical trials for GBM are being conducted, and it would be useful to identify a rapid technique to determine whether EGFR expression and the small cell phenotype are associated with a response to therapy. In the present study we examined 56 cases of GBM using chromogenic in situ hybridization (CISH). CISH analysis and morphology identified 22 small cell (SCGBM) and 22 non-small cell glioblastoma (NSCGBM), and 12 cases of a mixed phenotype. Fourteen cases of SCGBM (14/22) showed EGFR amplification, while only 5 NSCGBM (5/22) cases showed amplification. We have therefore used CISH as an efficient, economic and reliable means for routinely assessing EGFR amplification in GBM, including the small cell variant.