By Charles Craig

Xoma Corp. expanded to the U.K. its ongoing U.S. and Canadian Phase III trials of Neuprex for children with severe meningococcemia, a potentially deadly infection.

Clinical studies of Neuprex, which is on FDA-approved fast-track development, now will be evaluated in more than 100 children. The Berkeley, Calif.-based company also expects to conduct the placebo-controlled trials at sites in Europe.

Meningococcemia is a seasonal infection, striking during cold winter months in the Northern Hemisphere. Xoma officials said the U.K. is experiencing a "serious outbreak" of the disease.

Meningococcemia is a blood-borne bacterial infection caused by Neisseria meningitidis, the same bug that is responsible for meningitis. In the blood, the bacteria trigger a damaging inflammatory response that can kill a child in hours, Xoma officials said.

The inflammatory cascade is caused by an endotoxin contained in the bacteria's cell walls and released into the blood. Antibiotics are used to kill the bugs, but as they die they dump endotoxin into the bloodstream, causing a surge in levels of the poisonous substance.

Ellen Martin, Xoma spokeswoman, said Neuprex, which is a recombinant bactericidal and permeability increasing protein (BPI21), neutralizes the endotoxin. The drug is used in association with antibiotics to treat the infection.

In Phase I/II studies, 25 of 26 children with meningococcemia survived the disease following treatment with Neuprex, which also has antibiotic effects.

The Phase III trials, begun in October 1996, are expected to be complete in two years.

Xoma's stock (NASDAQ:XOMA) Tuesday closed at $5.437, down $0.125. *