Novel Immunohistochemistry Assay Distinguishes Non-Small Cell Lung Cancer (NSCLC) Subtypes

XMT-1536 Phase 1 Dose Escalation Ongoing With Data Reporting in the First Half of 2019

CAMBRIDGE, Mass., Sept. 25, 2018 (GLOBE NEWSWIRE) -- Mersana Therapeutics, Inc. (NASDAQ:MRSN), a clinical-stage biopharmaceutical company focused on discovering and developing a pipeline of antibody drug conjugates (ADCs) based on its Dolaflexin^® and other proprietary platforms, today announced preclinical data involving the company’s clinical candidate, XMT-1536, a NaPi2b-targeting ADC. The poster was presented as part of the International Association for the Study of Lung Cancer 19^thWorld Conference on Lung Cancer (IASLC WCLC 2018), being held September 23-26, 2018 in Toronto, Canada.

Details of the presentation are as follows:

Title: MERS67 is a Novel anti-NaPi2b Antibody and Demonstrates Differential Expression Patterns in Lung Cancer Histologic Subtypes
Poster Session: P2.09 Pathology, Poster 24
Date/Time: Tuesday, September 25, 2018, 9:45a.m. – 6:00 p.m. ET
Presenter: Rebecca Mosher, M.D., Executive Director, Translational Medicine, Mersana Therapeutics

“We continue to be gratified with the progress this program has made, and the data indicate how best to use immunohistochemistry as a means to characterize tumors and identify patients,” said Rebecca Mosher, M.D., Executive Director, Translational Medicine, Mersana Therapeutics. “These preliminary data are encouraging and support further investigation of this proprietary ADC compound and our belief that XMT-1536 can potentially expand the treatment benefits we can bring to patients with lung cancer."

Mersana’s poster presentation at IALSC WCLC 2018 evaluated the proprietary immunohistochemistry reagent (MERS67) for its ability to quantify NaPi2b expression in lung adenocarcinoma (ACA) versus lung squamous cell carcinoma (SqCC). Within a tumor tissue microarray, 99 individual cases were evaluable. By morphologic classification 63 cases were SqCC and 23 cases were ACA. Using a cut point of H=50, there was a statistically significant difference in the number of NaPi2b positive ACA cases (19/23) vs SqCC (3/63). Among 43 cases where p40 and TTF-1 were evaluable and were in agreement with morphologic diagnosis, 7/7 cases of ACA were positive for NaPi2b, while 0/36 SqCC were positive. This study was done in collaboration with the Hirsch Biomarker Laboratory, University of Colorado.

About Mersana Therapeutics

Mersana Therapeutics is a clinical-stage biopharmaceutical company using its differentiated and proprietary ADC platforms to develop highly targeted drugs with increased tolerability and expanded opportunities to deliver meaningful clinical benefit to patients.  Mersana’s product candidate XMT-1522 is in Phase 1 clinical trials in patients with advanced tumors expressing HER2, including breast cancer, non-small-cell-lung-cancer (NSCLC) and gastric cancer patients. The Company’s second product candidate, XMT-1536, is in Phase 1 clinical trials in patients with tumors expressing NaPi2b, including ovarian cancer, NSCLC and other cancers. In addition, multiple partners are using Mersana’s platform to advance their ADC pipelines.

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Source: Mersana Therapeutics, Inc.