The Gray Sheet

THE NEWS THIS WEEK

Vol. 27, No. 44

October 29, 2001

BD Set To Begin OnVax Vaccine Delivery System Clinical Studies

BD Corp. will begin human trials within the next few weeks for its OnVax system, which could be used to deliver vaccines for smallpox and anthrax in response to a bioterrorist attack.

In animal studies completed by the company, the response of the OnVax has been three to 1,000 times better than traditional delivery methods, the firm told the House Medical Technology Caucus Nov. 15.

The microdelivery system focuses on the skin as a primary site for contact with the immune system. "Immune cells are right there under the skin," BD VP-Corporate Medical Affairs David Durack, MD explained. "When we''ve given vaccines in the past, we''ve often gone right by them with a big needle into muscle or subcutaneous tissue."

The OnVax technology is based on an array of very small vaccine-carrying silicon teeth. Applied directly to the skin''s surface, the delivery system feels like a rough patch of fine sandpaper. The "swipe and go" method of delivery reduces the vaccine dosage a patient requires, and can eliminate the need for booster doses, BD says. "This could help relieve the strain on the nation''s store of smallpox vaccine by helping to use it in a more efficient way," Durack attested.

The possibility of reducing the number of required doses could be even more important for a vaccine that may be given many times, such as the anthrax vaccine. "In the setting of an epidemic or a bioterrorist threat with very large numbers of people who need to be vaccinated...if we could reduce the amount of vaccine needed from six doses to three or two this would be a tremendous improvement," Durack said. BD also emphasized that the noninvasive, painless procedure enables a patient to self-administer a vaccine.

The firm is developing additional micro-technologies applicable to bioterrorism. "We have completed feasibility studies for micro-needles, tiny needles too small in some cases almost to see, certainly too small to be painful," Durack reported. "They deliver right at the very surface where the immune cells are waiting to receive the antigen or vaccine." Self-administered nasal delivery systems are also in the works.

Normally, the investigational delivery system would take three to five years to reach the market, according to Durack. Under the threat of bioterrorist attacks, "we don''t have three to five years," he said.