Pegamotecan, a pegylated-camptothecin, is a topoisomerase-I inhibitor with a prolonged circulating half-life, tolerability, and passive tumor accumulation. Enzon Pharmaceutical used pegamotecan in trials for the treatment of cancer of the stomach, sarcoma, soft tissue, and gastroesophageal cancer. However, in 2005 Enzon Pharmaceuticals announced that it had discontinued further development of that drug. The Company's decision was based on an interim analysis of the data from a Phase 2b trial in patients with gastric or gastroesophageal cancers. Based on a strategic analysis of the potential investment return versus the required resource allocation and associated development risks, the Company decided not to pursue other potential indications for pegamotecan.