Gene therapy originally emerged with the tenet that replication be restricted. Over the past decade, though, some in academia and in biotech firms have broken away--allowing, even encouraging, viral replication to selectively infiltrate and destroy only cancerous cells while propagating the cure. Researchers want to exploit the relationships between these deadly human enemies, and when they can't, engineer new ones.
| ©2001Journal of Clinical Investigation |
 Electron micrograph (left) and enlarged section (right) of a squamous carcinoma cell from a patient injected with ONYX-015 |
Among the oncolytic candidates are unaltered viruses such as reovirus, Newcastle disease, and vesicular stomatitis, along with mutated versions of adenovirus, herpes simplex virus type 1 (HSV1), and vaccinia. Biotechnology companies are paying to begin human testing, and some have shown enough intriguing data for big pharmaceuticals to take notice. The biotechs involved give five- to 10-year estimates for Food and Drug Administration approval on many of these viral ...
