Washington Editor

The word gridlock might be used at some point to describe the relationship between Repligen Corp. and Bristol-Myers Squibb Co. concerning development of CTLA4, a T-cell regulatory protein.

That's because a U.S. District Court ruled in favor of BMS in a complaint filed by Repligen and the University of Michigan related to the inventorship of CTLA4 patents, while around the same time, the U.S. patent office issued Repligen a patent covering methods of treating certain diseases with CTLA4-Ig, currently being studied by BMS. CTLA4-Ig is the soluble form of CTLA4, which is believed to have immunosuppressive activity.

Repligen's stock (NASDAQ:RGEN) dropped $1.60 Wednesday, or 19.4 percent, to close at $6.66.

Clearly impacted more than BMS, Repligen's trouble comes from the decision handed down by the U.S. District Court for the Eastern District of Michigan. Repligen and the University of Michigan had filed a complaint against BMS seeking "a correction of inventorship." The plaintiffs believe Craig Thompson, a scientist from the University of Michigan, made inventive contributions as part of a collaboration with BMS scientists, and therefore is a rightful inventor on CTLA4-Ig patents issued to BMS.

The court didn't quite see it that way, ruling that there was insufficient evidence to prove that claim.

The patents cover compositions and uses of CTLA4-Ig, which were derived from the earliest discoveries of its activities on cells, and therefore usefulness, Walter Herlihy, Repligen's president and CEO, told BioWorld Today.

Given that the ruling was issued just this week, Herlihy said the company hasn't decided its next step.

"We are still discussing it internally, what the strategy is going to be in terms of appeal," Herlihy said. "Our belief is no different than it was when we started this several years ago. Our belief still is that Craig Thompson is the rightful co-inventor, but there are issues of law that we need to consider. We'll file a notice of appeal or not in the next couple of weeks."

As for New York-based BMS, "We're pleased the court has reaffirmed that the company holds the sole ownership rights to several patents covering the soluble forms of CTLA4 and related methods of use," said Brian Henry, spokesman for BMS.

Repligen's CTLA4-Ig program includes an autoimmune thrombocytopenic purpura compound already studied in Phase I/II trials.

However, as pointed out by Herlihy, the law allows clinical research on such patented programs but prohibits commercialization without permission from the owner.

"If we are not able to reverse the court's decision, then we would be infringing on BMS's patents at launch, just as they would be infringing if they tried to launch a product off our issued patents," Herlihy said.

Specifically, Herlihy is speaking of Repligen's patent issued this week covering the use of CTLA4-Ig as a method of treating rheumatoid arthritis, multiple sclerosis, systemic lupus erythematosus and scleroderma and for the use of CTLA4-Ig in combination with other immunosuppressants. Repligen owns exclusive rights to the 17-year patent through a license agreement with the University of Michigan and through a cooperative research and development agreement with the U.S. Navy.

BMS is studying a form of CTLA4-Ig in Phase III trials for treatment of rheumatoid arthritis.

"BMS won't comment on future strategies as far as developing the product except for saying that we are in Phase III development of CTLA4-Ig for RA and we continue to move forward with the program, and similarly, we have [an earlier stage] development program in multiple sclerosis," Henry said. "But we will continue to work to bring this medicine to people who can benefit from it."