已經有越來越多的資料支持使用血管靶向藥物（vascular targeting agents, VTAs），這種藥物被設計用來尋找并通過阻斷腫瘤血供來摧毀癌組織內的血管生成。

血管靶向藥物的作用機制不同于廣為人知的血管生成抑制劑（angiogenesis inhibitors），血管生成抑制劑通過切斷新血管的形成來減緩腫瘤生長。美國德克薩斯州西南醫療中心（Dallas，TX，USA）的Jin He博士最近在他的研究中報道說：放射治療能夠顯著增加一種被命名為3G4的Tarvacin等價物的抗腫瘤活性。Tarvacin是由Peregrine制藥公司（Peregrine Pharmaceuticals，Tustin，CA，USA）研制成功的血管靶向藥物。使用3G4聯合外源性輻射治療實驗動物，結果腫瘤生長速度下降了98％，而單獨使用放射治療或者3G4治療分別是85％和67％。

2004年11月在美國劍橋（Cambridge，MA，USA）舉行的血管靶向藥物會議的展示會上，Peregrine制藥公司的Philip Thorpe博士評論說：“血管靶向藥物正從臨床前研究階段進展到了臨床試驗階段。這次會議很特別，因為會議聚集了各領域的專家。這樣我們可以親自討論研究項目、互相學習、產生新的理念、并將這些新理念融會貫通，然后帶回實驗室，并最終進入臨床應用。”

Peregrine制藥公司致力于研究癌癥治療與診斷藥物，包括血管靶向藥物、抗血管生成藥物、促進血管滲透性藥物（vasopermeation enhancement agents, VEAs）。該公司與美國食品藥品管理局（FDA）緊密合作，開展了首次Tarvacin臨床試驗。Tarvacin是一種抗體，結合于磷脂酰絲氨酸磷脂，直接結合于腫瘤血管從而抑制腫瘤的生長形成。

Vascular Targeting Reduces Tumor Growth by 98%
 
A growing body of practical data supports the use of vascular targeting agents (VTAs), which are designed to seek and destroy preexisting blood vessels within cancerous tumors by blocking off the tumor’s blood supply.

VTAs represent a therapeutic approach that is different from the more widely known angiogenesis inhibitors, which slow tumor growth by cutting off new blood vessel formation. Dr. Jin He, from the University of Texas Southwestern Medical Center (Dallas, TX, USA) has recently reported in his studies that radiation therapy had significantly increased the antitumor activity of a Tarvacin equivalent named 3G4. Tarvacin is a VTA developed by Peregrine Pharmaceuticals (Tustin, CA, USA;). In lab animals treated with 3G4 plus external beam radiation, tumor growth was reduced by 98% as compared with 85% for radiation therapy alone or 67% with 3G4 alone.

At a presentation at the Vascular Targeting Agents conference in Cambridge (MA, USA) in November 2004, Philip Thorpe, Ph.D., a member of Peregrine Pharmaceuticals remarked, “VTAs are progressing through preclinical development and into clinical trials. This conference is unique in that it brings together experts in all of the various approaches--we can discuss the research in person, learn from each other and take new ideas coming out of that mix back to the lab, and ultimately, to the clinic.”

Peregrine Pharmaceuticals develops cancer therapeutics and diagnostics including VTAs, and anti-angiogenesis and vasopermeation enhancement agents (VEAs). The company is working closely with the U.S. Food and Drug Administration (FDA) to start its first clinical trial using Tarvacin. Tarvacin is an antibody that binds to the phospholipid phosphatidylserine, which binds directly to tumor blood vessels to inhibit tumor growth and development.