By Randall Osborne

Its drug delivery technology based on microscopic, DNA-encoded gold particles brought a deal worth $321 million to PowderJect Pharmaceuticals plc, which will provide Glaxo Wellcome plc with exclusive worldwide rights to a hepatitis B vaccine, along with options on 10 others using the PowderJect system.

"The partnership is very broad," said Paul Drayson, chairman and CEO of Oxford, U.K.-based PowderJect, which is testing the prophylactic hepatitis B vaccine in Phase I trials.

Under the terms of the deal, London-based Glaxo will take over the development of that vaccine, for which it will pay a license fee of $4 million. Glaxo also will make a $20 million investment in PowderJect, buying 4.9 million ordinary shares, which is 7.71 percent of its equity.

"There's another $297 million of milestones, research and license fee payments," Drayson said, and those will be made as Glaxo exercises options on the other DNA vaccines injected without needles.

Included in the options are therapeutic vaccines for hepatitis B and HIV; cancer vaccines using two undisclosed antigens; two therapeutic vaccines for undisclosed infectious diseases; and four more DNA vaccine products to be selected by Glaxo.

Schaefer Price, president of Madison, Wis.-based PowderJect Vaccines Inc., a wholly owned subsidiary of PowderJect, said the deal is a "research collaboration that spins off licenses."

The research agreement is for five years.

"Surviving beyond that will be the individual licenses for product development," Price said.

Glaxo will handle all preclinical and clinical development of the 11 vaccines, as well as regulatory procedures and marketing, with royalties paid to PowderJect, which will manufacture and supply its device

PowderJect's 25-employee vaccine division develops genetic and conventional vaccines. To administer a DNA vaccine, the company coats onto microscopic gold particles a DNA construct that encodes for the desired antigen.

"We tried a whole bunch of dense carrier particles," Price said, including tungsten and glass. "Gold had no toxicity and seemed to fit the bill."

Using PowderJect's pen-sized device, patients can administer drugs themselves, directly into targeted tissue layers, Drayson said.

"We make [the drug] as dry particles, and use a helium jet within this little device to accelerate the particles to high speed, about 1,400 mph," he said. "That gives them enough momentum to penetrate the skin. It's painless."

Inside the skin cells, the DNA separates from the gold particles and becomes transcriptionally active, resulting in a transient burst of gene expression for an immune response tailored to the encoded antigen.

In February, the FDA approved an investigational new drug application for PowderJect and Chiroscience Group plc, of Cambridge, U.K., to begin clinical evaluation of the local anesthetic lidocaine.

Last September, PowderJect signed a $15 million deal with Boehringer Mannheim GmbH, of Mannheim, Germany, to develop the system for delivery of a novel therapeutic protein. (See BioWorld International, Sept. 17, 1997, p. 2.)

PowderJect's shares (LSE:PJP) closed Tuesday at £4.185, up £1.04. Glaxo's stock (LSE:GLXO) ended the day at £16.49, up £0.01. *