You might call biotech Valentis (VLTS) a late bloomer. On Dec. 29, it traded at 2.49 but by Feb. 25 had jumped to 5.72. What happened? George Soros, through his Perseus-Soros BioPharmaceutical Fund, bought more shares in a private deal, upping his stake to 20%. Valentis' lead product, Deltavasc, is a novel angiogenesis -- that is, it's designed to grow new blood vessels in patients suffering from arterial disease. Dennis Purcell, managing director at Perseus-Soros Fund, says Soros wants to help biotechs with good products complete their clinical trials. Initial results from Valentis' Phase 2 trials, which test for safety, look promising...according to Gene G. Marcial...