XOMA Corp. said Thursday that it was discontinuing developmentof its CD5 Plus product, after assessing Phase III data that showedthe monoclonal antibody conjugate did not show statisticalsignificance in acute graft-vs.-host disease (GvHD).

The Berkeley, Calif., company earlier stopped development of thedrug in rheumatoid arthritis after a Phase II trial. Ortho Biotech Inc.,a Raritan, N.J., subsidiary of Johnson & Johnson, held worldwiderights (except parts of Asia) to CD5 Plus for GvHD.

The primary endpoint of the Phase III trial was complete remissionof GvHD in all organs at day 43. "We did not feel it showedsufficient activity to warrant continued development, or meet ourcriteria for commercial success," David Ringler, XOMA's director,corporate communications, told BioWorld.

"This product was an orphan's orphan," he said. "It would haveaddressed a very small worldwide market." Company officialsestimated the market at between 1,500 and 3,000 patients.

XOMA now primarily will concentrate on its recombinantbactericidal/permeability increasing (BPI) protein, Neuprex, which isbeing tested in a Phase I trial for severe Gram-negative sepsis andhemorrhagic shock trauma. Ringler said XOMA intends to announcein early 1995 that it will begin Phase II trials of Neuprex in multipleindications.

Separately, the company, with partner Pfizer Inc., is developing E5anti-endotoxin monoclonal antibody. That product is in a Phase IIItrial for Gram-negative sepsis. Pfizer, of New York, has filed aproduct license application in Japan for that product in thatindication.

The Phase III trial is the third undertaken for E5 in sepsis. Ringlersaid accrual of the 1,700 patients is expected to be completed in late1995 or early 1996.

XOMA's stock (NASDAQ:XOMA) closed at $2.63 a share, down13 cents. n

-- Jim Shrine

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