Oncomab, Medarex to develop antibodies

Prima BioMed (ASX:PRR) subsidiary Oncomab has entered into a joint venture with US humanised antibody company Medarex to co-develop and commercialise fully human antibodies for the treatment of cancer.

The collaboration centres around a tumour-targeting monoclonal antibody developed by researchers at the Austin Research Institute (ARI), and picked up for investment by Prima in May last year.

The antibody is active against a specific protein preferentially expressed on a wide range of cancers including breast, colon and prostate cancer, causing inhibition of tumour cell survival and induction of apoptosis (cell death). In vitro and animal studies have demonstrated both prevention of tumour formation as well as killing of existing tumours.

But the rodent-derived monoclonal is not suitable for human therapeutic use, and Prima has been looking at potential partners to produce a fully humanised version.

"Securing a partner to humanise the antibody was a key part of our development program. This deal with Medarex is the result of six months of internal review of international companies with patented technology to generate human antibodies," Prima BioMed CEO Marcus Clark said. "We believe we have an exceptional target and it was therefore important to select the company that shares a sense of this position and provided the priority we were seeking."

The deal was foreshadowed earlier this year when Annarie Lyles, senior director of business development at Medarex, visited the ARI and Prima BioMed.

According to Prima's business development director Vanessa Waddell, the agreement calls for all costs in the development and commercialisation of the humanised antibody to be split by the two companies equally. Likewise any future revenues resulting from the development of antibody products will be shared equally between the two parties.

Initially, Medarex will undertake the generation of antibodies to the Oncomab target using their proprietary transgenic mouse platform with the resulting humanised antibodies to be tested by Oncomab researchers at the ARI and compared to the existing rodent-derived monoclonal in vitro and in animal models, said Waddell. The company hopes to complete this by the end of 2003.

Waddell said that several models for clinical development of the humanised antibodies were being discussed by the two companies, including the formation of a jointly owned company, or partnering with a larger pharmaceutical company after phase II or for marketing and distribution purposes.

Medarex currently has ten monoclonal antibody products in clinical development through a variety of collaborations and licensing agreements. The NASDAQ-listed company (NASDAQ:MEDX) has around $US350 million in cash.