Promising cancer drug may endanger child's bones

WASHINGTON (Reuters) - A compound that looked promising for treating a brain tumor found mostly in children may damage growing bone -- possibly making it too dangerous to use in young patients, researchers reported on Monday.

The drug fully eradicated medulloblastoma tumors in mice in 2004. But further testing showed it caused permanent bone damage in immature mice, Tom Curran of The Children's Hospital of Philadelphia and colleagues found.

Writing in the journal Cancer Cell, they said the drug, known by its experimental name HhAntag, will need to be developed with caution.

And, they said, similar drugs will need careful testing.

HhAntag, made by California-based Genentech, affects a gene called Hedgehog, involved in both normal development and in cancer.

It is a so-called signal transduction inhibitor, designed to interrupt Hedgehog's cancer-causing effects.

Several such drugs are currently in pediatric clinical trials.

"While it is not clear that the bone defects we observed in mice would also occur in children, and while signal transduction inhibitors may still represent a highly promising approach to treating pediatric cancer, it may be important to perform preclinical testing in young animals before moving ahead to clinical trials," Curran said in a statement.

Medulloblastomas account for about one in five childhood brain tumors.