Prima's Arthron signs deal with US based Xencor

Arthron, a subsidiary of Prima Biomed (ASX:PRR) has signed a license and option agreement with US biotechnology company Xencor to utilise Arthron's Fc receptor technology for enhancing the effect of anti-cancer antibodies.

Prima CEO Marcus Clark described the deal as "potentially significant", as it would provide an income stream outside the Melbourne-based company's core focus of autoimmune diseases such as rheumatoid arthritis.

Under the research program, Xencor will screen its library of engineered antibody fragments with Arthron's Fc gamma Rlla receptor, to ascertain which of the candidates had cell killing activity.

California-based Xencor has developed engineered Fc domains (one of two active regions of an antibody) which are designed to enhance the therapeutic properties of monoclonal antibodies. Xencor says its Fc domains can be inserted into antibody candidates against any target antigen and may improve one or more important effector functions, including enhanced antibody-mediated tumour cell killing, sustained half-life and increased structural stability.

Xencor is also collaborating with big pharmas and biotechs, including Genentech, Centocor, Hoffman-La Roche, and Chugai Pharmaceutical.

"We have negotiated terms of a commercial licence which is exercisable within two years which provides them the rights to develop and market products arising from their research program," Clark said.

Under the terms of the agreement, Arthron will receive an undisclosed upfront fee and a subsequent annual licence fee. In the event Xencor exercises the option, Arthron will receive an additional licence fee and is eligible to receive progress-dependent milestone payments and royalties on net sales of resulting products, as well as applicable sub-licensing fees.

Prima has retained the rights over recombinant protein product candidates and antibody-based inhibitors of the Fc receptor. "We still have the rights to develop antibodies with anti-inflammation activity and further licensing agreements are being pursued by our business development group," Clark said. "The company anticipates further development in the near future in this area."

This is the third deal for Prima, which has previously signed agreements with Zymogentics for anti-inflammatory therapeutics which remove the activation of Fc gamma RIIa, and AstraZeneca, which entered a research and option agreement for the development of small drug inhibitors of the receptors.