Synta Announces Results from Interim Analysis of the Randomized Phase 2b/3 GALAXY Trial Evaluating Ganetespib plus Docetaxel in Second-Line Non-Small Cell Lung Cancer

Synta Pharmaceuticals Corp.

today announced encouraging results from a planned interim analysis of the GALAXY trial, a randomized Phase 2b/3 study designed to evaluate the efficacy and safety of the Company's lead Hsp90 inhibitor, ganetespib, in combination with standard-of-care docetaxel vs. docetaxel alone as second-line treatment for advanced non-small cell lung cancer (NSCLC). The GALAXY trial is based on a two-stage, operationally adaptive design. The first-stage, randomized, open-label, 240-patient Phase 2b portion of the trial is designed to enroll Stage IIIB/IV NSCLC patients who have progressed following one prior line of therapy, with the goal of determining biomarkers predictive of ganetespib activity. Results will be used to guide choice of patient population for the Phase 3 stage of the trial. Patients in the GALAXY trial are randomized 1:1 to receive ganetespib plus docetaxel or docetaxel alone. Patients in both arms receive a standard regimen of docetaxel 75 mg/m2 on day 1 of a 21-day cycle; patients in the combination arm receive in addition ganetespib 150 mg/m2 on days 1 and 15. Treatment continues until disease progression per RECIST 1.1 criteria. The co-primary endpoints of GALAXY are PFS (progression-free survival) in patients with elevated baseline level of serum LDH (lactate dehydrogenase), and PFS in the mutant KRAS population. PFS and OS (overall survival) in all adenocarcinoma patients are key secondary endpoints. Serum LDH levels and tumor KRAS mutation status are assessed by independent central laboratories.