TESARO Presents Initial Phase 1 Clinical Data for TSR-011 at ECC 2013

TESARO, Inc.

, an oncology-focused biopharmaceutical company, presented initial data from a Phase 1 trial of TSR-011 today at the European Cancer Congress in Amsterdam. TSR-011 is a potent inhibitor of both anaplastic lymphoma kinase (ALK) and tropomyosin-related kinases (TRK). Preliminary clinical activity has been observed in this study in one papillary thyroid carcinoma patient and one pancreatic cancer patient without ALK expression, and in three patients with ALK-positive non-small cell lung cancer (NCSLC) who progressed following prior treatment with crizotinib. Of the three ALK-positive NSCLC patients who progressed on prior crizotinib treatment, one achieved a RECIST partial response after four weeks of treatment with TSR-011; one, with disease not evaluable by RECIST criteria, achieved an investigator-assessed partial response; and one has stable disease. Each of these three patients remains on study today. In addition, one patient with papillary thyroid carcinoma and one patient with pancreatic