By Randall Osborne

West Coast Editor

Less than three months after starting Phase III trials of LymphoCide (epratuzumab), its humanized antibody for non-Hodgkins lymphoma (NHL), Immunomedics Inc. has entered a licensing deal with Amgen Inc. that provides $18 million up front, with the potential for as much as $290 million more.

The high end is "realistic, or at least achievable," said Cynthia Sullivan, president and chief operating officer of Morris Plains, N.J.-based Immunomedics.

Under the terms of the agreement, Thousand Oaks, Calif.-based Amgen will shell out, in addition to the $18 million, as much as $65 million in milestone payments and royalties, and between $50 million and $225 million more if sales reach between $500 million and $1 billion.

"That's being projected for Rituxan [rituximab] now," Sullivan said.

Rituxan is the currently marketed antibody drug for NHL, developed by Idec Pharmaceuticals Corp., of San Diego, and South San Francisco-based Genentech Inc.

Amgen gets rights to develop and commercialize LymphoCide in the U.S. and Australia, and will take over manufacturing as well as sponsorship of investigational new drug applications.

Second-generation products developed by Amgen would yield even more for Immunomedics, which this fall began a pivotal Phase III study of LymphoCide in low-grade NHL patients who do not respond or respond poorly to Rituxan. (See BioWorld Today, Sept. 27, 2000.)

Rather than a competitor for Rituxan, LymphoCide "is going to be one more tool in the available therapies," Sullivan told BioWorld Today.

It also will be studied in pivotal trials involving NHL patients with the aggressive form of the disease who have received other therapy, and it's in a Phase I/II study with Rituxan in patients with both forms of the disease who have not been treated with an antibody-based product.

"We were very pleased with the initial response in the aggressive patients in Phase I/II," Sullivan said. "Thirty percent responded, and half of those were complete responses." Such patients are the ones in whom Rituxan most often fails to work, she added.

About 300,000 patients in the U.S. have NHL, and 50,000 more are diagnosed early year. Early clinical studies indicated LymphoCide, with its shorter infusion time, may be easier to administer than Rituxan. The latter binds to the CD20 cell surface protein, whereas LymphoCide binds to CD22. Immunomedics' deal with Amgen could also be expanded to include CD22 radiolabeled antibody products.

"We've moved this product into very capable hands, and now we can turn around and focus on other things in the pipeline," Sullivan said.

Next on the runway is CEA-Cide, a humanized antibody that targets carcinoembryonic antigen (CEA)-expressing tumors, such as colorectal, pancreatic, breast, lung and ovarian cancers.

In June, the company reported results from ongoing Phase II studies using the CEA-Cide antibody radiolabeled with iodine-131 for treatment of patients with metastatic colorectal cancer who failed or were intolerant to prior chemotherapy. Eight of nine patients, or 89 percent, who had liver metastases surgically removed and were at high risk for recurrence, remained disease-free for more than 15 months.

"We have one [CEA-Cide antibody] for liver cancer and one for multiple myeloma that we want to get into the clinic in 2001," Sullivan said.

Immunomedics' stock (NASDAQ:IMMU) closed Monday at $22.437, up $1.937. Amgen's shares (NASDAQ:AMGN) ended the day at $63.812, up $3.875. n