New Drug for Brain Cancer Too Dangerous for Pediatric Patients

By Alan Mozes
HealthDay Reporter
Monday, March 10, 2008; 1:00 PM

Copyright © 2008 ScoutNews, LLC. All rights reserved.

MONDAY, March 10 (HealthDay News) -- A cutting-edge drug for brain cancers may place pediatric patients at risk for bone damage and stunted growth, an animal study suggests.

The new red flag concerns a signal transduction inhibitor (STI) medication known as "HhAntag", a drug developed to treat medulloblastoma brain tumors by short-circuiting tumor growth on the molecular level. The fear is that a therapy proven safe and highly successful among adults may pose a unique set of risks to young patients.

"Within just two days of treatment with HhAntag, we found a permanent shortening of bones and an alteration of joint structure among young mice," noted study co-author Tom Curran, deputy scientific director of the Stokes Research Institute at the Children's Hospital of Philadelphia.

"It's a little scary," he added. "Of course, the drug works well for about one-third of brain cancers. However, this is the first time it's really been tested in young animals. And the pathways that are targeted by this treatment are very active and important in developing children. So, we have a serious problem."

Curran and his team are publishing their findings in the March issue of Cancer Cell.

The authors noted that medulloblastoma is the most common pediatric central nervous system cancer. Although traditional non-STI treatments -- such as surgery, radiation and chemotherapy -- offer a five-year survival rate in almost four out of five children, such therapies often provoke severe side effects such as movement disorders and cognitive impairments. Those treatments are also far less effective among children under the age of 3 or among those whose disease has spread.

To date, HhAntag has achieved non-toxic results among adults -- targeting the so-called "hedgehog" pathway and shutting down a signaling mechanism critical to cancer cell proliferation. However, that same pathway regulates bone development.

Concerned that the drug might throw the baby out with the bathwater among younger patients, the researchers focused on mice between 10 and 14 days old, all genetically engineered to have cancer.