Mersana Therapeutics, Inc. to Present Preclinical Data on XMT-1001 at American Association of Cancer Research Annual Meeting

Mersana Therapeutics, Inc. to Present Preclinical Data on XMT-1001 at American Association of Cancer Research Annual Meeting

April 16, 2007

    CAMBRIDGE, Mass., April 16 /Xinhua-PRNewswire/ --
Mersana, a cancer therapeutics company, announced today
that results of preclinical studies with its lead product
candidate, XMT-1001, will be presented in two posters at
the 2007 Annual Meeting of the American Association of
Cancer Research (AACR) taking place April 14-18th in Los
Angeles, CA.  Full text of the abstracts can be viewed
online at the AACR website at http://www.AACR.org .

    The presentation schedule is as follows:

    Abstract #781 "XMT-1001, a novel polymeric prodrug
of camptothecin, is a potent inhibitor of LS174 and A2780
human tumor xenografts in a mouse model" will be
presented in a poster session on Sunday, April 15th from
8:00 am - 12:00 pm.  Alex Yurkovetskiy and Russell C.
Petter are the presenting authors.

    Abstract #4723 "Pharmacokinetics of a novel
camptothecin conjugate (XMT-1001) in the rat and dog"
will be presented in a poster session on Tuesday, April
17th from 1:00 - 5:00 pm.  Ullrich Schwertschlag and Alex
Yurkovetskiy are the presenting authors.
 
    About XMT-1101

    XMT-1001 is Mersana's most advanced Fleximer(R)-based
product candidate.  It utilizes a novel, dual release
mechanism to liberate a camptothecin prodrug, which is then
converted within cells into camptothecin, a DNA
topoisomerase I inhibitor.  In preclinical studies,
XMT-1001 was better tolerated and more efficacious than
either camptothecin or irinotecan in models of human
cancer, showing extended plasma half-life and high
concentrations in tumor tissue.

    About Fleximer Technology

    Fleximer(R) technology improves the therapeutic index
of cytotoxic compounds useful as anti-cancer agents by
uniquely combining biodegradability with "biological
stealth" properties, making Fleximer(R) materials and
their conjugates long-circulating and non-immunotoxic. 
Fleximer(R) molecules are characterized by solubility in
water, stability in common manufacturing procedures and in
normal physiological conditions, and non-enzymatic
biodegradability upon uptake by cells.  

    About Mersana Therapeutics, Inc.

    Mersana, a privately held, venture-backed company, is
developing novel oncology agents based on clinically
validated drugs through the use of Fleximer(R), a
proprietary bio-degradable and bio-inert material that
enhances the pharmacokinetics, safety, and solubility of
drugs.  Mersana has an exclusive license from the
Massachusetts General Hospital for its core technologies. 
Mersana's pipeline includes compounds with activity against
multiple tumor types and human proof-of-concept that are
improved by its proprietary technologies.  Mersana's
investors include Fidelity Biosciences, ProQuest
Investments, Rho Ventures, Harris & Harris Group and
PureTech Ventures.


    For more information, please contact: 

     Pete Leone
     COO
     Mersana
     Tel: [phone]