Biopharmaceutical company EntreMed ( ENMD) said its new blood cancer treatment has shown positive preclinical results. The treatment, a derivative of thalidomide, showed sustained tumor regression in multiple myeloma, a blood cancer that causes bone loss. The company said the treatment also showed less toxicity and greater anti-tumor activity than thaliodomide, now commonly used in experimental multiple myeloma treatment. The company previously licensed its thaliodomide treatment to Celgene Corporation and sold its future royalties for $24.3 million to Royalty-Pharma. The thaliodomide derivatives were excluded from that agreement. Shares of ENMD closed at $7.49 Friday on the Nasdaq.