OXiGENE ( OXGN) was soaring Tuesday morning after the company said a study of its antitumor compound yielded positive results when used on mice. The company said that OXi4503 "significantly" blocked the flow of blood to the core and periphery of solid tumors transplanted into mice. The results of the study were published in the journal Anticancer Research. The study showed that the compound had a "significant effect on tumor growth," according to OXiGENE. Additionally, OXiGENE said it was working with Cancer Research UK, a cancer research organization, on the final preclinical development of OXi4503. Cancer Research UK plans to complete preclinical studies on OXi4503, then move the compound into Phase I human clinical trials. OXiGENE's lead compound, Combretastatin A4 Prodrug, is being evaluated in three concurrent clinical trials, including a Phase II study in patients with advanced anaplastic carcinoma of the thyroid. OXiGENE, which develops vascular-targeting agents that attack existing blood vessels associated with cancerous tumors, saw its shares add $1.70, or 60%, to $4.50 in Instinet trading.