Genentech Inc. has agreed to pay Seattle Genetics Inc a technology access fee of $1.6 million to designate additional antigen targets under the parties' existing antibody-drug conjugate (ADC) collaboration agreement. Under the terms of the agreement, Genentech has rights to use Seattle Genetics' ADC technology with antibodies against certain targets selected by Genentech, Seattle Genetics announced here.

"We are pleased by the continued progress of our ADC technology and the further expansion of our collaboration with Genentech," stated Clay B. Siegall, president and CEO of Seattle Genetics. "We believe our stable linker systems and synthetic drug payloads position our ADC technology at the forefront of the industry, enabling us and our partners to develop more potent antibody-based therapies," he added.

To date, Seattle Genetics has received approximately $20 million in upfront payments, research and material supply fees and equity investments from Genentech pursuant to the ADC collaboration, which was established in April 2002 and expanded in December 2003. Genentech has also agreed to make progress-dependent milestone payments and pay royalties on net sales of any resulting ADC products. Genentech is responsible for research, product development, manufacturing and commercialization of any products resulting from the collaboration.

Seattle Genetics' ADC technology utilizes the targeting ability of monoclonal antibodies to deliver potent, cell-killing payloads to specific cells. This ADC technology employs synthetic, highly potent drugs that can be attached to antibodies through proprietary linker systems. The linkers are designed to be stable in the bloodstream but to release the drug payload under specific conditions once inside target cells, thereby sparing non-target cells many of the toxic effects of traditional chemotherapy. By linking drug payloads to monoclonal antibodies, ADCs can increase the therapeutic potential of antibodies that have inherent cell targeting ability but lack sufficient cell-killing activity, the company release explained.