It was almost a year ago that Immunomedics Inc. began two pivotal Phase III studies of epratuzumab to treat systemic lupus erythematosus. It said Wednesday it had licensed exclusive worldwide rights to develop, market and sell the product for all autoimmune disease indications to UCB SA.
In return, Morris Plains, N.J.-based Immunomedics will receive an up-front cash payment of $38 million, and will be entitled to milestone payments of up to $145 million in cash and $20 million in equity investments. The milestones are based on approvals in different geographic areas, as well as approvals for different indications. If sales reach a certain pre-specified level, Immunomedics also would receive a $135 million bonus, on top of royalties.
In total, the deal is worth up to $203 million for Immunomedics, not including the bonus.
The company's stock (NASDAQ:IMMU) climbed 40 cents Wednesday, or 14 percent, to close at $3.26.
Immunomedics' business model calls for the company to advance on its own antibody products through early clinical development, said Chau Cheng, the company's associate director of investor relations and business analysis. "Those that meet the criteria in terms of safety and efficacy, we will license them out for further development," he said, adding that epratuzumab was the perfect candidate to move forward.
UCB's rights are for only autoimmune disease indications on a worldwide basis. "We retain the rights to develop it for all oncology indications," Cheng told BioWorld Today.
Epratuzumab has demonstrated good safety, tolerability and clinical activity in more than 340 patients with non-Hodgkin's lymphoma. Immunomedics could move into Phase III trials with the drug for that indication, but the program has been put on hold since last year so the company could use its resources to advance epratuzumab in lupus.
Now, with Brussels, Belgium-based UCB assuming all clinical development and commercialization costs for the lupus program, Immunomedics will evaluate the next steps for epratuzumab in non-Hodgkin's lymphoma and its other pipeline products.
"We have not decided what is the best way to spend the $38 million" in initial funding, Cheng said.
The company has two other products in clinical trials: hCD20 (IMMU-106) in a Phase I/II study for non-Hodgkin's lymphoma; and yttrium-labeled PAM4 in Phase I/II for pancreatic cancer. Updated results of the hCD20 trial will be presented at the American Society of Clinical Oncology meeting in June.
Data from the Phase III studies of epratuzumab in lupus should be available by the second half of 2007, Cheng said. UCB has said it plans to expedite the ongoing pivotal trials. The companies have not disclosed the number of patients that are being enrolled at various sites in the U.S., Europe, South America and Canada, or when the filing of a new drug application might occur. The Phase III program began last June. (See BioWorld Today, June 3, 2005.)
Epratuzumab has fast-track designation in the U.S. for lupus. In terms of sales potential, the product is estimated to be "in the high hundreds-of-millions or billion-dollar range," Cheng said, adding that there has not been a new drug on the market for lupus patients in about 40 years.
"It's a wide-open market," he said. "There's a severe unmet medical need."
Lupus affects an estimated 3 million to 5 million people worldwide - about 1.5 million in the U.S. It results in chronic inflammation and pain primarily in women - they make up 90 percent of all patients with the disease. Current treatments include painkillers, anti-inflammatory drugs and steroids, but the disease often occurs during the child-bearing years and issues of toxicity are a major concern.
Epratuzumab is a humanized monoclonal antibody against the CD22 marker expressed on activated B cells.
"So far we have not seen any immunogenic reaction against [the drug] either in cancer patients or in patients with autoimmune diseases," Cheng said. Epratuzumab can be infused in less than an hour, and it "does not deplete 100 percent of B cells, it only depletes about 50 percent to 60 percent of B cells," he added. "We believe it modulates B-cell function. That is kind of a unique property."
UCB and Immunomedics have not disclosed what other autoimmune indications might be pursued under their agreement, but epratuzumab has been evaluated in a Phase I/II trial in Sjogren's syndrome, a disorder in which the immune system attacks the salivary glands. The data have shown that patients have retained clinical benefits six months after being treated with epratuzumab.
"What is going to happen is there will be an autoimmune guidance committee set up with equal representation from Immunomedics and UCB, with UCB having the deciding vote," Cheng said, "to monitor the Phase III [program] and to recommend the best alternative indications to go after."