BioWorld International Correspondent

LONDON - Celltech Group plc has secured the biggest deal ever by a European biotechnology company, agreeing to a co-development and marketing deal with Pharmacia Corp. worth up to US$280 million in up-front payments and milestones for the humanized antibody fragment CDP 870.

In addition, Celltech will receive a share of profits and royalties. CDP 870 is a tumor necrosis factor-alpha (TNF-alpha) inhibitor, currently under development in rheumatoid arthritis and Crohn's disease.

Pharmacia will make an up-front payment of $50 million. Celltech CFO Peter Allen told BioWorld International "the $230 million to come is mainly related to sales milestones, so we won't see much of that until after launch."

He added, "We think this is a very attractive financial package. The profit share is substantial, and it should enable us to get the product to market faster than if we went it alone, so we're very pleased with it."

Celltech has granted Pharmacia exclusive worldwide rights to CDP 870, and Celltech's other antibody-based anti-TNF-alpha compounds, in all indications. This includes CDP 571, or Humicade, which is in Phase II trials in rheumatoid arthritis. The UK company retains the rights to CDP 870 and CDP 571 in Crohn's disease and will fund development costs. CDP 571 has FDA fast-track status in Crohn's disease. In addition, Celltech has retained limited rights to co-promote CDP 870 in rheumatoid arthritis.

Apart from Crohn's disease, Pharmacia will manage future development and fund the majority of development costs for rheumatoid arthritis and all other indications.

CDP 870 is currently in a Phase IIb dose-ranging study in more than 200 patients with active rheumatoid arthritis. Results are expected by mid-2001, and will be used to select doses for evaluation in Phase III.

Celltech previously said it expected to start Phase III in the second half of 2001. Allen said it was now due to start sometime within the next year, and there is no information on how long the trial will take. As yet there are no plans to start clinical trials in other indications, although the partners said CDP 870 has potential in congestive heart failure.

Allen said Celltech, based in Slough, UK, has retained the rights in Crohn's disease because it is a "neat, self-contained market" that fits well with Celltech Medeva, the company's pharmaceutical sales and marketing arm. Celltech acquired the 550-strong sales and marketing team when it took over the vaccines group Medeva plc in January 2000.

In a separate deal, Celltech will acquire rights to co promote Pharmacia's arthritis treatment, Arthrotec, in the UK and France.

CDP 870 is a third-generation humanized antibody fragment that is pegylated to give a long half-life, and attractive dosing regimen. In the Phase II trial patients were dosed subcutaneously once a month. The product is manufactured with Celltech's proprietary bacterial fermentation technology. This is a much lower cost of manufacture than for Humicade, which makes it unlikely that Pharmacia will take CDP 571 forward in rheumatoid arthritis. The fast-track status of CDP571 in Crohn's disease means Celltech will continue development despite the higher cost of manufacture.