By Randall Osborne

To develop and commercialize its huC242-DM1 cancer drug, ImmunoGen Inc. signed a deal with SmithKline Beecham plc worth up to $45 million.

"We've been living, for the past four or five years, rather hand-to-mouth," said Mitchel Sayare, chairman and CEO of Norwood, Mass.-based ImmunoGen. "This is real money."

Under the terms of the deal, which the companies are expected to disclose today, London-based SmithKline will provide up-front cash and milestone payments totaling more than $40 million. SmithKline may also purchase up to $5 million of ImmunoGen's common stock during the next two years.

"The choice is ours," Sayare told BioWorld Today. "We'll do it, if the price is reasonable."

If development goes as planned, ImmunoGen will see a "significant portion of the money the first year" of the agreement, he added.

"That doesn't mean all or half," Sayare said. "It means we'd get a pretty good piece of it."

The drug - which has shown "amazing efficacy" in animals, Sayare said - is a humanized monoclonal antibody directed against markers that occur on the cell surfaces of colorectal cancer, non-small-cell lung cancer, and pancreatic cancer.

"We're taking all comers" in the Phase I trials, which are planned for the third quarter of this year, he said. Indications will be narrowed down in Phase II studies.

"Each is a serious disease, although clearly colorectal [cancer] has larger numbers than anything else," Sayare said.

ImmunoGen has taken aim at cancer before, with Oncolysin B, which combined a monoclonal antibody with a modified form of the plant toxin ricin to attack B-cell lymphomas and leukemias. In the spring of 1997, Oncolysin B failed in preliminary data from Phase III trials, and ImmunoGen dropped the drug. (See BioWorld Today, March 19, 1997, p. 1.)

The new drug, huC242-DM1, was developed simultaneously with Oncolysin B, but in a separate program that has been ongoing for about six years. HuC242-DM1 joins the tumor-targeting antibody huC242 with DM1, a chemotherapeutic agent in the maytansinoid family. The drug works by binding the huC242 antibody to an antigen called CanAg, expressed on the tumor - thus delivering the chemotherapy specifically to tumor cells, and leaving others unaffected.

"We have a similar product [to huC242-DM1] in a similar stage of clinical development in small-cell lung cancer," Sayare said. "We're just starting a safety test in primates."

Other Cancer Drugs In The Pipeline

That product, known as N901-DM1, is behind huC242-DM1 in preclinical development.

"We also have an antibody directed against prostate cancer," he said. "We have not yet done the studies in animals we've done on these other two products, but it holds promise. All of these [products] use the same platform: the notion of attaching an effector molecule to a humanized monoclonal antibody for repeated delivery to human cancer."

In another deal for anticancer drugs, ImmunoGen's 97-percent-owned subsidiary, Apoptosis Technology Inc., launched a collaboration in August 1997 with BioChem Pharma Inc., of Laval, Quebec, granting BioChem an exclusive, worldwide license to screens based on two families of proteins involved in apoptosis. The screens will be used in identifying leads for cancer drug development. The deal also covers identification of targets and development of new screens.

ImmunoGen's stock (NASDAQ:IMGN) closed Tuesday at $2.656, up $0.156.