By Karen Pihl-Carey

In its third merger in less than a year, Celltech Group plc signed an agreement with Cistron Biotechnology Inc., purchasing the company for $18 million in stock.

Cistron, of Pine Brook, N.J., has been looking for a buyer since last year, announcing in late February a tentative deal with an undisclosed major biopharmaceutical company. That undisclosed company turned out to be Celltech, of Slough, UK. (See BioWorld Today, Feb. 24, 2000, p. 3.)

¿It¿s fundamentally the purchase of intellectual property,¿ said Celltech media spokesman Jon Coles. ¿Celltech is a world leader in antibody technology,¿ and Cistron holds patents in interleukin-1.

The $18 million purchase price includes $8.75 million for the intellectual property encompassing anti-interleukin 1-beta (IL-1b) antibodies as treatments for chronic inflammatory disorders and about $9.25 million for Cistron¿s cash reserves. The purchase will be made with about 850,000 Celltech American depository shares, with the price based on the five-day trailing average through Monday.

Cistron shareholders also will be entitled to receive up to $3.5 million in cash and $3.5 million in Celltech stock, if Aventis Pasteur, a subsidiary of Aventis SA, exercises the options previously granted by Cistron to acquire exclusive licenses to use the IL-1 technology in developing preventative and therapeutic vaccines. In July 1998, Cistron formed a $31 million collaboration with Pasteur Merieux Connaught, of Lyon, France, which is now called Aventis Pasteur. (See BioWorld Today, July 9, 1998, p. 2.)

Cistron has about $9.25 million in cash reserves as the result of a $21 million litigation settlement in 1996. Immunex Corp., of Seattle, settled on a suit in which Cistron alleged Immunex misappropriated the DNA sequence encoding IL-1b from Cistron. Under terms of the settlement, Immunex admitted no wrongdoing and assigned certain IL-1b patents to Cistron. (See BioWorld Today, Nov. 4, 1996, p. 1.)

The merger with Cistron is Celltech¿s third since June of last year.

It first merged with chiral chemistry company Chiroscience Group plc, of Cambridge, England. The merger gave Celltech a leading position in antibody engineering, a large genomics effort in identifying novel targets, and extensive medicinal chemistry. In November, the company merged with Medeva plc, of Speke, UK, in a $913 million stock deal. That merger gave Celltech an international pharmaceutical business with U.S. operations, enabling the company to retain an enhanced share of the value of certain products by marketing them itself. (See BioWorld Today, June 15, 1999, p. 1; and Nov. 12, 1999, p. 1.)

Celltech¿s stock (NYSE:CLL) closed Wednesday at $37.50, down 75 cents. Cistron¿s stock (OTC:CIST) closed at 71.87 cents, up 16.8 cents, or 31 percent.