By Randall Osborne

While competing parties await an appeals court's decision in a patent fight over their stem cell replenishment systems, one combatant — Nexell Therapeutics Inc. — has been asked by the FDA to provide more information related to the premarket approval application for its product.

William McIntosh, president and CEO of Nexell, said the FDA's questions are confidential but characterized them as "routine," adding they would probably be answered in four weeks.

"There are a number of questions that we've already responded to, and those in some ways didn't make sense to us," he said. "We can cut the data another way for the FDA, if that's what they want."

A meeting is scheduled with the agency next week.

"I would not expect we could clear the deck in a short meeting, but what we're hopeful of doing is getting some focus on what, if anything, is left," McIntosh told BioWorld Today.

Nexell is jointly owned by Irvine, Calif.-based Vimrx Pharmaceuticals Inc., and Baxter Healthcare Corp., the principal U.S. operating subsidiary of Deerfield, Ill.-based Baxter International Inc.

The patent battle pits CellPro Inc., of Bothell, Wash., against three entities: Baxter; Johns Hopkins University, in Baltimore (which developed the cell isolation technology with government funds); and Becton Dickinson Co., of Franklin Lakes, N.J., to which Johns Hopkins licensed the patents. Becton in turn licensed the technology for therapeutic uses to Baxter.

Nexell's products are the Isolex 300 and Isolex 300i Cell Selection Systems. CellPro's product is the Ceprate SC Stem Cell Concentration System. Both are used to select and purify cells from cancer patients to replenish their bone marrow, which is ravaged by chemotherapy and radiation.

Last month, CellPro reorganized, cutting its staff by 11 percent while awaiting word from the appeals court on the patent-infringement lawsuit, which has lasted six years. (See BioWorld Today, June 10, 1998, p. 1.)

Richard Murdock, president and CEO of CellPro, said the court decision is more important to the company than the FDA's letter to Nexell.

"It's hard to say whether it means a delay [for Nexell] or not," he said. "That depends a lot on what the questions are and what the answers are."

CellPro has been asked some "pretty detailed and extensive" questions by the FDA in the past, he added.

"At the end of the day, I'm always happy to have a competitor in the field," he said. "All we want is a fair fight."

McIntosh said he wants the same.

"[The court decision] is important, but our interest is in getting the PMA approved and getting the [product] out into the U.S. market," he said. CellPro would have to take its product off the market three months after the PMA's approval, he added.

"The litigation for them means life or death," McIntosh said. "They're not on very good ground, legally or, at this point, financially."

Vimrx's stock (NASDAQ:VMRX) closed Wednesday at $0.968, down $0.093. CellPro's shares (NASDAQ:CPRO) ended the day at $3.50, up $0.375. *