By Mary Welch

Tanox Inc. raised a total of $23.7 million in two private placements to fund development of its pipeline.

KBC Securities NV, of Brussels, Belgium, was the exclusive placement agent in Europe for the European offering. The second placement was done by the company, with the shares being bought by investors in Taiwan.

¿It was as much as we wanted to raise and both placements were about equal in size,¿ said John Blickenstaff, Tanox¿s vice president of administration. ¿The money will go toward our pipeline products, both in preclinical and clinical development.¿

Established in 1986, Houston-based Tanox recently started a Phase I/II trial in severe peanut allergy with Hu-901, an anti-immunoglobulin E (IgE) monoclonal antibody.

Still in the development phase is an in-licensed antibody that targets CD4, the cellular receptor for HIV. Tanox Pharma B.V., Tanox¿s subsidiary in Amsterdam, the Netherlands, is developing a monoclonal antibody that inhibits the CD40 pathway, which may have use in the treatment of several autoimmune diseases. This antagonist anti-CD40 antibody has shown beneficial activity in a primate model for multiple sclerosis. It is in a Phase I trial for Crohn¿s disease.

Tanox also is evaluating Hu-901 for the treatment of IgE-mediated allergic diseases. That program is separate from the clinical focus of rhuMab-E25 anti-IgE ¿ known as E25 ¿ which is being jointly developed with Genentech Inc., of South San Francisco, and Novartis Pharma AG, of Basel, Switzerland.

That clinical collaboration came about after a long-running patent dispute between Tanox and Genentech. Tanox sued Genentech in late 1989, charging a breach of a 1989 agreement between the two. A month later, Genentech filed a lawsuit claiming Tanox infringed upon its patent covering chimeric immunoglobulin compositions. (See BioWorld Today, Jan. 24, 1994, p. 1.)

After three years of battling in court, the companies agreed to pool resources since both had anti-IgE antibodies in Phase II trials ¿ Tanox for allergic reaction to mountain cedar pollen and asthma, Genentech for allergic rhinitis and asthma. As part of the settlement, the companies agreed to evaluate all the compounds following Phase II trials and jointly select the best one to bring into Phase III. Genentech¿s anti-IgE antibody, E25, was selected. (See BioWorld Today, July 10, 1996, p. 1.)

A pivotal Phase II trial of E25 for allergic rhinitis was completed in early 1998, and the results of a Phase III trial in birch seasonal allergic rhinitis were announced in the second quarter of 1999. The Phase III trials for asthma are expected to wind up in the next few months. Marketing applications are expected to follow shortly.

¿Genentech and Novartis are handling the trials, the filings and all information about it,¿ Blickenstaff said.

Anti-IgE antibodies are used to remove from the bloodstream IgE and IgE-producing B cells responsible for triggering allergic reactions cause by numerous antigens. The chimeric antibodies are derived from mice and genetically engineered with human proteins.

The company changed its name from Tanox Biosystems Inc. last year.