Guru Seth Klarman (Trades, Portfolio), founder and president of Boston-based hedge fund Baupost Group, just added Atara Biotherapeutics Inc (ATRA) to his portfolio in the fourth quarter of last year, but he seems to be happy enough with it to want a second helping. He nearly doubled his stake in the first quarter of this year, apparently on the basis of Atara’s latest 13G filing with the Securities and Exchange Commission (SEC), making it the 19th-largest stake in his portfolio.
Last month, Atara Biotherapeutics obtained a breakthrough therapy designation for its work on an innovative treatment for a disease associated with Epstein-Barr virus, one of eight viruses in the herpes family and one of the most common viruses in humans. Epstein-Barr is probably best known as the cause of infectious mononucleosis (informally known as the “kissing disease”), but it is also linked to specific forms of cancer, such as Hodgkin's lymphoma, Burkitt's lymphoma, nasopharyngeal carcinoma and conditions associated with human immunodeficiency virus (HIV). Continue Reading »