By Debbie Strickland

Staff Writer

A contractor's mishandling of clinical supplies of the monoclonal antibody drug HNK20 has delayed by at least a year OraVax Inc.'s plan to conduct Phase III pivotal trials for the prevention of respiratory syncytial virus (RSV) in infants.

"The problem that occurred was a [good manufacturing practices] violation by a contractor," Lance Gordon, president and CEO, told BioWorld Today. "It was unique to this particular batch; it's not related to the way any future batches will be made."

The batch in question was made two years ago by IDEC Pharmaceuticals Corp., of San Diego, during a manufacturing run that produced multi-trial quantities of the drug. Gordon noted the batch "passed all of its tests" for potency and sterility.

OraVax declined either to name the contractor that mishandled the drug or provide details as to what happened. Gordon said the company has acquired its own manufacturing facility and eliminated the step in which the product was mishandled.

To compensate for the clinical setback, OraVax will devote personnel to meeting the FDA's manufacturing facility requirements, a task typically done after Phase III success.

"What we've done is to take a block of work that would have been done after the Phase III and moved it before the Phase III," said Gordon. "The ultimate time to registration . . . wouldn't be substantially changed."

The Phase IIItrial, now rescheduled for the winter of 1998-99, is a 500- to 600- patient multinational study in North America and Europe. The trial had been slated to begin Dec. 1.

HNK20 earlier this year suffered a Phase III failure in children, triggering a plunge in the price of OraVax's shares. HNK20's target has since been refined. In Southern Hemisphere trials conducted this year, the drug produced a 50 percent reduction of pneumonia and a 42 percent reduction in hospitalizations.

"We think there is very good evidence for activity and clinical benefit," said Gordon. "The full execution of the program is something we remain committed to doing, together with additional corporate partners."

A prepared statement suggested corporate partnering may be essential to further development.

"The manufacture of the additional supply of the product necessary for the trial and the conduct of the trial will require additional funding and the company is continuing negotiations with potential corporate partners for such funding," it said.

The company's position hasn't shifted, said Gordon. "We had always planned to do development with corporate partners," he said. Negotiations are currently under way, and thus far have not been affected by the trial postponement.

"[HNK20] is one of five programs in the company," added Gordon. "I don't at this time anticipate any material changes because of the setback in the program.

"Our lead program has always been Helicobacter pylori," he said. The company is developing an oral vaccine against the ulcer-causing bacteria with Pasteur Merieux Serums & Vaccins SA, of Lyons, France. That product is currently in Phase II trials.

OraVax also last month obtained U.S. marketing rights to London-based Medeva plc's live-attenuated yellow fever vaccine. OraVax will conduct clinical trials for FDA approval of the vaccine and will assist in regulatory approvals in markets outside the U.S.

As of Sept. 30, the company had $9.6 million in cash and investments, following a net loss of $7.4 million for the first nine months of the year.

OraVax's shares (NASDAQ:ORVX) closed Thursday at $3.125, down $0.25. *