By Debbie Strickland

Staff Writer

Eleven years after its founding, Protein Design Labs Inc. has achieved a string of firsts: Its first corporate collaboration, begun eight years ago, has paid off with the company's first product to be submitted for marketing clearance from the FDA.

"Zenapax is the first product created by the company that has been the subject of a filing, and that's always a momentous event," said Fred Kurland, vice president and chief financial officer.

Company officials said Zenapax (dacliximab) is also the first humanized monoclonal antibody and the first antibody to the interleukin-2 receptor to be submitted for FDA approval.

Zenapax's monoclonal antibody prevents transplant recipients' immune systems from attacking donor organs by binding to the interleukin-2 receptor on T cells to inhibit their proliferation.

Collaborative partner Hoffmann-La Roche Inc., of Basel, Switzerland, holds an exclusive worldwide license to the drug. Roche submitted the biologics license application to the FDA for prevention of rejection episodes in kidney transplantation.

The filing triggered a milestone payment--in an undisclosed amount -- from Roche to Protein Design.

Wall Street reaction to the news, announced last week, was muted. The company's stock (NASDAQ:PDLI) closed Monday at $32, up $0.063 from Friday's close and just 0.375 from its close June 10, the day before the announcement of the FDA filing.

There is plenty of room for share price growth, according to analysts Sharon Seiler and Matthew Geller, of Oppenheimer & Co. Inc., in New York. Their one-year price target is $60 per share.

They wrote Monday, "The probability that the [FDA] panel will recommend approval of Zenapax is close to 100 percent, based on the drug's strong efficacy in two Phase III studies and the pristine, no meaningful side-effects safety profile."

"It's an incredibly clean application," said Seiler.

The analysts expect late-1997 approval for the kidney transplant indication. The worldwide market for the drug for the prevention of organ transplant rejection is potentially $500 million.

Zenapax Tested In Other Indications

Zenapax also is undergoing clinical trials as a combination therapy with CellCept, a drug marketed by Roche, to potentially eliminate cyclosporine, which is a standard treatment in preventing transplant rejections. In addition, Zenapax is being evaluated as a therapy for two autoimmune disorders, uveitis and tropical spastic paraparesis (a model for multiple sclerosis).

Approval for autoimmune diseases could open up multibillion-dollar markets, according to the analysts.

Seiler likened Zenapax to the anti-clotting drug ReoPro, originally approved for the "niche indication" of patients at high risk of post-angioplasty blood clots but now viewed as a potential treatment for a host of cardiovascular indications; and to the antiviral drug 3TC, approved for HIV but now in advanced clinical trials for hepatitis B.

"Zenapax is going to be approved for one indication, with a sizable market on its own," she said, "but it has potential for even larger markets."

Protein Design has three other products at various stages of clinical development -- a humanized monoclonal antibody treatment for acute myeloid leukemia, and human monoclonal antibody drugs for hepatitis B and cytomegalovirus.

At the end of the first quarter, the company had $163.9 million in cash, boosted by a public offering earlier this year that raised $73 million. (See BioWorld Today, March 20, 1997, p. 1.) Protein Design's quarterly burn rate was $4.1 million. *