TAPPAS phase III trial shows ApoStream effective in capturing tumour cells in angiosarcoma.- Precision for Medicine.

Precision for Medicine and TRACON Pharmaceuticals announced the publication of biomarker results from the TAPPAS phase III clinical trial that utilized ApoCell's proprietary circulating tumor cell (CTC) enrichment system, ApoStream. The study, titled Detection of Endoglin-Expressing CTCs in Patients Enrolled in an Adaptive Enrichment Phase III Trial of TRC105 and Pazopanib Versus Pazopanib Alone in Patients with Advanced Angiosarcoma (TAPPAS), is the first of its kind to show the detection and capture of CTCs from angiosarcoma cancer patients. Forty blood samples (25 at C1D1, 15 at C3D1) from 28 patients were analyzed. Paired pre- and post-treatment samples were available for 13 patients. Endoglin+ CTCs were detected in 100% of samples (median = 1.5/mL; range 0.13 - 1,172/ml). Endoglin+ CTCs decreased between C1D1 and C3D1 in 13 patients with paired samples treated with TRC105/P or single agent P (C1D1 mean = 184.3/ml; median = 1.5/ml; range 0.13 - 1172/ml); C3D1 mean = 6.39/ml; median = 0.88/ml; range 0.44 - 26/ml). Diff-Kwik staining confirmed the enriched CTCs had atypical morphology containing hemosiderin deposits and large irregularly shaped nuclei in all cases. In conclusion, ApoStream technology isolated endoglin+ CTCs from the whole blood of AS patients. The ApoStream technology is currently being used to evaluate the pharmacodynamic effects of TRC105 on CTCs in the TAPPAS trial. Interim study results were presented at the Connective Tissue Oncology Society (CTOS) annual meeting.

See: "Detection of endoglin-expressing CTCs in patients enrolled in an adaptive enrichment phase 3 trial of TRC105 and pazopanib versus pazopanib alone in patients with advanced angiosarcoma (TAPPAS)." Vinod Ravi et al. Journal of Clinical Oncology 36, no. 15_suppl - published online before print DOI: 10.1200/JCO.2018.36.15_suppl.e23570