NeoRx and Immunomedics duel over monoclonal patent claims

Federal judge denies motion to dismiss lawsuit

A patent infringement lawsuit between monoclonal antibody competitorsNeoRx and Immunomedics has moved one step closer to trial. A federaljudge presiding over the case cleared up pretrial maneuveringthis month by ruling on a number of motions submitted by the twosides.

Both Immunomedics and NeoRx were claiming victory as a resultof the rulings handed down April 1 by Judge H. Lee Sarokin inU.S. District Court in New Jersey. NeoRx of Seattle filed thelawsuit in 1991, charging Immunomedics of Morris Plains, NJ, withbreach of contract and patent infringement of NeoRx patents onradionuclide labeling technologies (SCAN 9/11/91).

NeoRx charges that several Immunomedics imaging products infringeon a patent it holds for direct labeling of antibodies with technetiumand rhenium isotopes. Those products encompass several of Immunomedics'technetium-99m agents, including the firm's ImmuRAID-CEA colorectalimaging agent.

NeoRx wants to permanently bar Immunomedics from U.S. salesand manufacturing of the allegedly infringing products, some ofwhich are making their way toward market in the U.S. and Europe.Immunomedics filed a product license application with the Foodand Drug Administration for ImmuRAID-CEA for colorectal cancerin April 1991. The product is also under review by the Committeefor Proprietary Medicinal Products in Europe. ImmuRAID-CEA forlung cancer is in phase three trials, while a breast cancer productis in phase one and phase two trials in the U.S.

The two sides had exchanged motions on various issues in thecase, on which Sarokin ruled this month. Immunomedics tried tohave the lawsuit dismissed under a federal statute that grantsan exemption from patent law to products that have not yet beenapproved by the FDA. The law was originally written to shieldgeneric drug makers from litigation while they developed genericversions of products under patent protection.

Sarokin ruled that Immunomedics' product development activitiesin the U.S. are covered by the exemption. He did not grant thecompany's motion to have the lawsuit dismissed due to two issuesrelating to its foreign product development activities, however.

Immunomedics shipped products to foreign regulatory agenciesand one of the company's German investigators had not submittedthe appropriate paperwork to the FDA before working with ImmuRAID-CEA.Those activities were not related to acquiring U.S. regulatoryapproval for the company's products, and Sarokin ruled that atrial could proceed on those issues.

In a victory for Immunomedics, however, Sarokin denied NeoRx'smotion for declaratory judgment in the case based on the allegationthat Immunomedics is infringing on the NeoRx patent or will beinfringing when ImmuRAID-CEA is granted FDA approval. Sarokinalso rejected a NeoRx claim that Immunomedics submitted falsedata to the FDA.

The case is now cleared to go to trial on the issue of patentinfringement relating to Immunomedics' European activities. Adate for the trial has not been set, but a NeoRx spokespersonsaid the company expects the case to go to trial this year.

In other NeoRx news, the firm's marketing partner, BoehringerIngelheim, filed a product license application (PLA) and an establishmentlicense application (ELA) last month with the FDA for the leadNeoRx agent, OncoTrac, designed for imaging small-cell lung cancer.BI has worldwide manufacturing and marketing rights outside NorthAmerica, while NeoRx retained marketing rights to the productin the U.S. (SCAN 6/3/92). OncoTrac is a technetium-based agentbut does not use the direct-labeling technology involved in thedispute between Immunomedics and NeoRx.

Boehringer Ingelheim must submit an ELA for OncoTrac to showthe FDA that its version of the product, manufactured by its Dr.Karl Thomae GmbH subsidiary, is comparable to that used in OncoTrac'sclinical trials. That version was manufactured by NeoRx's previousmanufacturing contractor, Invitron of St. Louis. NeoRx switchedto Boehringer Ingelheim after Invitron was bought by Centocorin 1990.