By Mary Welch

In a deal that could be worth more than $100 million, AltaRex Corp. granted Purdue Pharma LP an option to an exclusive worldwide license to develop and commercialize its two lead antibody drugs, OvaRex MAb and BrevaRex MAb.

Norwalk, Conn.-based Purdue also will buy $3.4 million of common stock in AltaRex, which disclosed its plan for a Canadian public offering last month. (See BioWorld Today, April 28, 1999, p. 1.)

The 180-day license option allows Purdue additional time to ¿exercise due diligence¿ with regard to the two products, said Edward Fitzgerald, AltaRex¿s senior vice president and chief financial officer. ¿However, we would not have made this announcement if the two companies did not have full expectation that it would occur, and the project [will] move forward.¿

Regarding the success of the financing, Fitzgerald said he was pleased but not surprised. ¿When we went visiting people about the offering, we found the response was really tremendous. So, we¿re very, very pleased but not totally surprised.¿

If exercised, Purdue will fund research and development over the next three years, as well as pay milestones. AltaRex, headquartered in Edmonton, Alberta, with executive offices in Waltham, Mass., will receive future royalty payments based on product sales.

Both OvaRex MAb and BrevaRex MAb are based on AltaRex¿s Anti-idiotype Induction Therapy (AIT), an antibody-based immunotherapeutic approach that the company believes enhances the body¿s immune system to produce its own antitumor response. AIT products are developed to target specific antigens associated with various cancers.

OvaRex is a novel modified monoclonal antibody-based immunotherapeutic associated with the ovarian cancer antigen CA125. Currently under way is a North American Phase IIb trial, with 221 of the required 280 patients enrolled so far. Enrollment should be finished by the third quarter of this year. A second U.S. Phase IIb trial may become a pivotal trial. Six out of the planned 102 patients have been enrolled.

Also, two open-label Phase II trials for late-stage ovarian cancer have started enrolling patients.

AltaRex plans to file a biologics license application for OvaRex in 2001.

BrevaRex, a cancer therapeutic, is currently in Phase I trials for people showing elevated MUC1 levels. AltaRex plans initially to focus on multiple myeloma, a rarely curable hematological malignancy related to leukemia and lymphoma.

¿For the time being, we will focus our efforts on developing these two lead products with Purdue,¿ said Fitzgerald. ¿But we have several other antibodies in preclinical development, and we will be looking for opportunities to develop them as well.¿

AltaRex¿s stock (TSE:AXO) closed Thursday at C$0.82 (US$0.563), up C$0.27. n