Mersana Reports Preliminary Phase 1 Results of XMT-1001 in Patients with Advanced So...( - Results Presented at American Socie...)

- Results Presented at American Society of Clinical Oncology (ASCO) Meeting Show Fleximer(R) Conjugated Drug Is Well Tolerated with Favorable Pharmacokinetics and Prolonged Stable Disease in Refractory Tumors -

CAMBRIDGE, Mass., June 1 /PRNewswire/ -- Mersana Therapeutics presented preliminary results of a Phase 1 clinical trial for its lead development candidate, XMT-1001, in a poster session at the 2009 Annual Meeting of the American Society of Clinical Oncology (ASCO) in Orlando. XMT-1001 is a broad-spectrum cytotoxic, based on camptothecin (CPT), conjugated to Mersana's biodegradable polymer platform, Fleximer(R).

Ten of 37 evaluable patients dosed to date demonstrated evidence of stable disease and seven patients had prolonged stable disease for at least 12 weeks. The study has also demonstrated that XMT-1001 can be safely given to patients. Toxicities such as hemorrhagic cystitis and serious diarrhea were not observed in this preliminary assessment. In addition, a favorable pharmacokinetic profile was observed. Full text of the abstract can be viewed online at the ASCO website at www.abstract.asco.org.

"We are encouraged by the favorable safety and pharmacokinetic profile demonstrated by XMT-1001 thus far," said Julie Olson, Chief Executive Officer of Mersana. "These preliminary results build on our preclinical studies, which showed that XMT-1001 has greater efficacy in human tumor xenograft models than comparable doses of irinotecan, an agent with a similar mechanism of action as camptothecin and that is approved to treat patients with colon cancer. We look forward to advancing XMT-1001 into a Phase 2 trial in a solid tumor indication."

About the XMT-1001 Preliminary Study

The Phase 1 trial is an open label, dose escalation study of XMT-1001 administered as an IV infusion once every three weeks in pat
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