By Debbie Strickland

Burroughs Wellcome's unsuccessful drug for non-Hodgkin's lymphoma and rheumatoid arthritis has found new life as a potential treatment for chronic lymphocytic leukemia (CLL).

ILEX Oncology Inc. and LeukoSite Inc., a privately held company based in Cambridge, Mass., have formed L&I Partners LP to develop Campath-1H, a monoclonal antibody LeukoSite licensed from London-based British Technology Group earlier this year. LeukoSite made the decision after reviewing clinical trial data on more than 500 patients, including published reports on 64 patients diagnosed with CLL and related prolymphocytic leukemia.

A 50-50 joint-venture limited partnership, L&I's long-term capitalization is "in the range of $10 million total," according to Gus Lawlor, LeukoSite's chief financial officer and vice president for corporate development. The partnership will draw on employees of both companies, and work will be done at both sites. The official company address is ILEX's headquarters in San Antonio.

For now, the new business' sole project is Campath. Next year, L&I plans to file applications with U.S. and European regulatory agencies to begin a multicenter pivotal Phase III clinical trial of the compound in 50 to 100 treated CLL patients. If approved, Campath would be used to treat symptomatic CLL patients who fail to respond to current standard treatments, or are too weak to handle the side effects.

"Unlike available treatments, Campath specifically targets and binds to the CD52 cell surface antigen, which is found exclusively on lymphocytes," said Christopher Mirabelli, LeukoSite's chairman and CEO. "This mechanism destroys malignant cells while sparing the blood-forming [hematopoietic] stem cells that are vitally important to a functioning immune system."

CLL, the most prevalent form of adult leukemia in Western countries, affects approximately 60,000 adults in the U.S. and a comparable number in Europe. A malignant disorder, the disease is characterized by accumulation of abnormal lymphocytes in the body. Over time, these cells spread, causing bone-marrow dysfunction and enlargement of the lymph node, liver and spleen.

A variety of therapies already are on the market: alkylating agents such as chlorambucil, sometimes in combination with steroids; purine analogues such as fludarabine; combinations of purine analogues and other therapies, such as alkylating agents; and bone-marrow transplants.

Younger patients often receive fludarabine; for those who fail to respond to that drug, there is no alternative available, according to ILEX and LeukoSite. Campath could fill that void.

In a Campath study involving 29 refractory or relapsing patients, one had complete remission and 11 had partial remissions, representing a total of 12 major responses. The study was published in the April issue of the Journal of Clinical Oncology. Other Campath leukemia studies have averaged a 66 percent major response rate.

Burroughs Wellcome originally tested the drug for rheumatoid arthritis, non-Hodgkin's lymphoma, and solid organ and bone marrow transplantations. But it proved an inadequate treatment for non-Hodgkin's lymphoma, while its degree of lymphocyte depletion was too high for a rheumatoid arthritis indication.

The partnering companies hope CLL is the just-right application to get the drug out of the labs and into the marketplace.

"We are enthusiastic," said Richard Love, president and CEO of ILEX, adding that other applications may be introduced.

ILEX's other partners range from Paris-based Sanofi SA to MGI Pharma Inc., of Minnetonka, Minn. With Sanofi, the company has filed a new drug application for mitoguazone dihydrochloride, or MGBG, a second-line treatment for patients with AIDS-related non-Hodgkin's lymphoma. ILEX has a total of nine cancer treatment compounds under development.

The company netted $29 million through an initial public offering in February. Its available cash tops $50 million, with a monthly burn rate of between $250,000 and $300,000. Its stock (NASDAQ:ILXO) closed unchanged Wednesday, at $12.375.

With about $12 million in cash, LeukoSite has six research and development programs under way and three drug candidates in development. The company also is collaborating with Warner-Lambert Co., of Morris Plains, N.J., and Roche Bioscience, of Palo Alto, Calif. *