Syntarga Demonstrates In Vivo Proof of Concept for its Antibody-Drug Conjugate Technology

January 08, 2009

Syntarga B.V. announced today that it has demonstrated strong and broad In Vivo Proof of Concept for Antibody-Drug Conjugates (ADCs) incorporating the Company's payload technology. The proprietary platform combines extremely potent duocarmycins, a class of DNA minor groove binding agents, with linker chemistries that are stable in the circulation and release the cell- killing agent upon internalization by target-expressing cells.

Systemic administration of different ADCs in human tumor xenograft models with established tumors, led to strong antitumor efficacy at doses well below the MTD, ranging from substantial tumor growth inhibition to 100% complete and durable regressions, with varying study parameters such as dose (including single-digit mg/kg), dosing route and dosing schedule (including single-dose). Adverse effects were minimal as indicated by absent or minimal body weight changes in ADC treated groups compared to naked antibody treated groups. For several linker-duocarmycin chemistries a significant therapeutic window was demonstrated.

The results indicate the technology's broad applicability against multiple antigen targets and against a range of cancer indications, including solid tumors. Syntarga has established itself as a company with ADC technology and technological know-how as to the structural requirements for a drug-linker to generate successful ADCs.

Syntarga evaluates its payload chemistries through collaborations with contract research organizations (CROs) and major biopharmaceutical companies. A compilation of in vivo data will be presented at the forthcoming Protein Engineering Summit (April 6 - 10, 2009, Boston, USA) and at the American Association for Cancer Research Annual Meeting (April 18 - 22, 2009, Denver, USA).

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 applies its technologies and expertise to generate and commercialize Antibody-Drug Conjugate product candidates based on antibodies of its biopharmaceutical partner companies. For more information about Syntarga, visit its website at www.syntarga.com.