Mersana Therapeutics Presents Positive Preclinical Data on Next-Generation Antibody-Drug Conjugate Technology at AACR 2013

Mersana Therapeutics, Inc., a biopharmaceutical company developing its Fleximer® antibody-drug conjugate (ADC) platform and pipeline of small molecule Fleximer conjugates, announced today that new data related to its conjugation technology used to create next-generation ADCs is being presented in a poster session at the 2013 Annual Meeting of the American Association for Cancer Research (AACR). AACR is being held April 6-10, 2013 in Washington, D.C. The preclinical data being presented confirms that Mersana’s technology generates cysteine-conjugated ADCs that are stable, highly active and selective in Her-2 expressing tumor models.

In the poster, Mersana details that its technology, which has previously been applied to create lysine-based ADCs, can also be expanded to create cysteine-based ADCs. The data show that conjugation of Mersana’s Fleximer polymer via cysteines in the antibody hinge region overcomes the destabilization of the antibody which has been reported with conventional, direct drug-cysteine linked ADCs. The stabilization with the Fleximer conjugation approach enhances the advantages of Mersana’s polymer approach to ADCs, which include significantly higher capacity for drug payload, superior payload flexibility and improved physicochemical properties. In this research, the benefits were shown in Her-2 expressing cell lines and preclinical models.

"Mersana has previously demonstrated that our Fleximer-based ADCs that utilize lysine modification are highly efficacious," said Timothy B. Lowinger, Chief Scientific Officer of Mersana. "These data demonstrate that the scope of our conjugation technology can also be expanded to create novel, highly stable cysteine-based ADCs that are highly active, selective and well-tolerated in preclinical tumor models."

"Research into how we can expand our technology is part of our commitment to creating truly next-generation ADCs that have the potential to address limitations of other technologies," said Nicholas Bacopoulos, Ph.D., President and Chief Executive Officer of Mersana. "These types of technological advancements will be utilized as we build our proprietary pipeline of ADC candidates and forge collaborations."