Syntarga Announces Patent Grant for SpaceLink Technology for Antibody-Drug Conjugation

July 16, 2009

Syntarga B.V. announces that as of today patents have been granted for its proprietary SpaceLink Technology in Europe (EP 1370298 B1), the United States (US 7,223,837), India, China, New Zealand and Australia. SpaceLink Technology comprises generally applicable releasable linkers to reversibly connect a drug to a targeting vehicle. The Company's internal SpaceLink R&D efforts concentrate on Antibody-Drug Conjugates (ADCs) that link Syntarga's extremely potent, proprietary duocarmycin toxins, a class of DNA minor groove binding agents, to tumor-specific antibodies.

The advantage of SpaceLink is that the linker can be applied in a modular fashion. This makes the technology highly flexible for toxin and linker-toxin optimization to yield premier ADC products. Syntarga has generated solid preclinical data for ADCs in which SpaceLink connects the antibody to the DNA alkylating unit or the DNA binding unit of the duocarmycin. Multiple ADCs based on different Linker-Drug combinations in which the linker is connected to distinct positions on the drug have yielded substantial anti-tumor efficacy with minimal or absent adverse effects. This underscores both the stability of the SpaceLink linker as well as efficient release of toxin in target cells. The data validate SpaceLink in the context of functional ADCs and emphasize SpaceLink's broad potential as a component of future ADC products.

The granted patents provide Syntarga with an important commercial/strategic advantage in the ADC space. "ADC therapeutics must meet a long list of criteria. The considerable flexibility provided by our SpaceLink Technology enables selection of the optimal linker- drug combination in order to maximally contribute to the many desirable properties of the Antibody-Drug Conjugate product" said Dr. Vincent de Groot, Chief Executive Officer of Syntarga.

Preclinical data for the Company's ADC technologies, including SpaceLink, will be presented during the "Antibody-Drug Conjugates" session of the "Next Wave of Antibody Therapeutics" track, which is part of the forthcoming IBC Drug Discovery & Development Week (August 3 - 5, 2009, Boston, USA).

About Potent Payload & SpaceLink Technologies

Syntarga Potent Payload Technology comprises extremely potent cell-killing agents that are coupled to suitable linker technologies for attachment to tumor-specific monoclonal antibodies. SpaceLink Technology is one of the linker technologies developed and employed by Syntarga. The targeting properties of monoclonal antibodies combined with Syntarga’s unique and fully synthetic Linker-Drug payload chemistries have yielded a variety of ADC products that have been validated in vivo and were shown to possess a large therapeutic window. The Company’s preclinical stage technologies are based on its duocarmycins, a class of DNA minor groove binding alkylating agents, which possess a range of unique characteristics making them highly suitable as ADC warheads.

About Syntarga BV
Syntarga is a private biopharmaceutical company engaged in the discovery and development of proprietary Antibody-Drug Conjugate technology for the treatment of cancer. The Company's cutting-edge chemistry capabilities and unique know-how have led to the creation of Potent Payload Technology, an antibody empowering technology to generate next generation antibody products for oncology. Syntarga is leveraging its proprietary technologies and expertise to assist established leaders in the antibody therapeutics space to generate and commercialize Antibody-Drug Conjugate product candidates based on their antibodies. For more information about Syntarga, visit its website at www.syntarga.com.