Hemophilia Gene Therapy Results

Scientists reported yesterday encouraging but preliminary data from a widely watched human test of gene therapy that could treat or possibly cure one form of hemophilia.

If the approach works, it would be the first gene therapy success ever.

The approach, developed by a team at Children's Hospital of Philadelphia, aims to insert the gene for blood-clotting factor IX into the cells of people with hemophilia B.

An estimated 2,800 males in the United States suffer from that form of hemophilia, an inherited disorder that prevents the blood from clotting. Although it is carried by the mother, it occurs only in males.

Preliminary data from a nine-patient trial, presented at the American Society of Hematology meeting in New Orleans, shows that there is "a clear benefit" from the experimental therapy, said John Monahan, a biochemist at Avigen, an Alameda, Calif., firm that has licensed the approach from the hospital.

He reported that the first three people in the trial, who were given a low dose of the experimental gene-therapy drug, were now producing their own factor IX, allowing them to "significantly reduce" their reliance on weekly injections of artificial factor IX protein, which causes the blood to clot.

Many hemophilia B sufferers must inject themselves two or three times a week at a cost of about $100,000 a year.

The experimental gene therapy involves one-time multiple injections in the thigh, all done in a 15-minute session, Monahan said. The first patient to be injected has been producing factor IX for five months, he said.

The trial, which began in June, is designed to test the safety of the gene therapy at three different dosing levels--low, medium and high. Three patients will be enrolled in each group. The reported results are from the three patients in the low-dose group. Enrollment in the other groups is not yet complete.

Academy Rejects Oral Polio Vaccine

The American Academy of Pediatrics recommended that doctors abandon oral polio vaccines for routine childhood vaccinations and switch over to safer injections that contain no live polio virus.

The recommendation is a change from one the group issued a year ago when it suggested that injections be used for the first two vaccinations at 2 and 4 months, followed by shots or oral doses for the next treatments at 6 to 18 months and again at 4 to 6 years of age.

There has been a long-running controversy over the oral vaccine, which contains the live but weakened polio virus, because the live virus carries the possibility of causing the disease it is designed to prevent. The academy's new policy states that vaccine-caused cases of polio "cannot be totally eliminated until oral polio virus vaccine no longer is given."

The statement, published in the December issue of Pediatrics, the journal of the academy, said the all-injection schedule should be in place at the start of the new year.