Thursday, February 17, 2011

Cancer drug could prevent blindness in premature babies

The cancer drug Avastin could help prevent blindness in premature babies born before their eyes developed completely, the same condition that affected singer Stevie Wonder, according to a U.S. study.
About 50,000 people worldwide are blind, including Wonder, because of this condition, known as "retinopathy of prematurity" (ROP) for its effects on the retina.


The study, reported in The New England Journal of Medicine, showed that a single injection of Avastin into the eyes of premature babies prevented blindness more effectively than laser surgery, the usual method used when there are signs of problems.

While more research is needed, the ease of the intervention and its light physical burden on frail babies are pluses, said Helen Mintz-Hittner of the University of Texas Health Science Center, who was lead author.

The injection "takes a few seconds," she told Reuters Health.
As opposed to this process, which involves in all numbing the baby's eyes and injecting the inexpensive drug, laser surgery takes special equipment and requires both sedation and a breathing tube.

"It's a major clinical setback for a baby whose tube may have just been removed," Mintz-Hittner said.
Roche's Avastin, known generically as bevacizumab, is approved by the U.S. FDA for several cancers, including colon cancer that has spread.

In the study, 150 premature infants were randomly assigned to have their eyes treated with injections or with lasers. All had advanced retina damage in the zones of the retina nearest to the optic nerve, which carries information from the eye to the brain.

Among the 75 infants who received Avastin and whose damage was in the zone of the retina closest to the optic nerve, 6 percent had a recurrence of ROP compared with 42 percent treated with laser surgery.
For babies like these, traditionally among the hardest cases to treat, this is "a true breakthrough," wrote James Reynolds of the University of Buffalo in New York, in an editorial published along with the article about the study.

Conventional laser therapy permanently destroys the blood vessels supporting peripheral vision, but the injections allow for continued blood vessel growth, the researchers said.

Though the safety of the injections could not be assessed because there were two few babies in the study, because so many adults with cancer have taken the drug, and the dose was very small, it "seems reasonable to assume" that the injections are safe and at least as safe as laser treatment, Reynolds said.
But he did emphasize the injections were not without some risk, adding that the timing was critical.

Mintz-Hittner said the findings will be especially important in nations where more premature babies are surviving but monitors are not available to prevent the newborns from being exposed to too much oxygen, which sets the stage for the disease.
"I think it's going to be embraced pretty quickly and widely accepted," she added.

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