Clinical-stage biopharmaceutical company Mersana Therapeutics, Inc. has reportedly presented interim efficiency and safety data from its current Phase 1 dose-escalation study evaluating its first-in-class ADC candidate XMT-1536 aimed at NaPi2b, in patients suffering from non-small cell lung (NSCLC) adenocarcinoma, ovarian cancer, and other tumor types. As per trusted sources, the data will be exhibited in a poster session and poster discussion at the 2019 American Society of Clinical Oncology Annual Meeting.

Among the 37 registered patients the tumor types observed include 22 ovarian, primary peritoneal or fallopian tube cancer, eight endometrial, two papillary renal, four NSCLC and one salivary duct cancer. Patients received heavy pre-treatment through a median of 4 prior lines of treatment (range 1-13) for the entire group of patients and a median of 5 lines of pre-treatment for ovarian cancer patients (range 1-11), cited sources close to the development. 

According to sources familiar with the interim results, the most common TRAEs were Grade 1-2 nausea, headache, fatigue and the most frequent Grade-3 TRAE was transient AST elevation. Among patients with tumor types chosen for the strategic expansion phase, specifically NSCLC adenocarcinoma and platinum-resistant ovarian cancer, treated with ≥20 mg/m² (N=18), 17% showed partial responses and 44% attained stable disease demonstrating a disease control rate of 11/18 (61%), with the treatment period lasting for more than 16 weeks in 9 patients.

Mersana Therapeutics continues to assess patients in the dose escalation period of the clinical trial within the 36 mg/m² once-every-four-week dose level. On completing the 36 mg/m² evaluation, the dose that the company expects to go with for the study’s dose expansion phase will be either the 30 mg/m² dose or the 36 mg/m² every four weeks dose levels. Moreover, the company is also planning on dosing patients during the dose expansion phase within the third quarter of 2019, reported sources.

Source Credit
http://ir.mersana.com/news-releases/news-release-details/mersana-presents-interim-phase-1-data-xmt-1536-2019-american