** Clarity Pharmaceuticals CU6.AX rises 1.4% to A$3.315; set for third straight session of gains
** Stock has gained 13.5% since Wednesday after Jefferies upgraded to "buy" from "hold"
** Brokerage said Phase 2 trial data shows clinical-stage radiopharmaceutical's 64Cu-Sartate in patients with neuroendocrine tumours identified more lesions than competition
** YTD, CU6 down 20.5%
(Reporting by Shruti Agarwal in Bengaluru)
((Shruti.Agarwal@thomsonreuters.com))