BeiGene and SpringWorks Announce Presentation of Preclinical Data Combining RAF Dimer Inhibitor Lifirafenib with MEK Inhibitor Mirdametinib and Provide Update on Ongoing Phase 1b/2 Clinical Trial

Preclinical data presented at the American Association for Cancer Research 2020 Virtual Annual Meeting II

Ongoing Phase 1b/2 clinical trial on track to commence dose expansion cohorts in KRAS mutant solid tumors by the end of 2020

CAMBRIDGE, Mass. and BEIJING and STAMFORD, Conn., June 22, 2020 (GLOBE NEWSWIRE) -- BeiGene, Ltd. (NASDAQ: BGNE; HKEX: 06160), a commercial-stage biotechnology company focused on developing and commercializing innovative molecularly-targeted and immuno-oncology drugs for the treatment of cancer, and SpringWorks Therapeutics, Inc. (NASDAQ: SWTX), a clinical-stage biopharmaceutical company focused on developing life-changing medicines for patients with severe rare diseases and cancer, today announced the presentation of preclinical data and provided a program update on their ongoing Phase 1b/2 study evaluating the combination of BeiGene’s investigational RAF dimer inhibitor, lifirafenib, with SpringWorks’ investigational MEK inhibitor, mirdametinib, in patients with advanced or refractory solid tumors harboring mutations in the MAPK pathway, including those with RAS mutations.

The preclinical data were presented today in a poster at the American Association for Cancer Research (AACR) 2020 Virtual Annual Meeting II by researchers from BeiGene, SpringWorks, and Memorial Sloan Kettering Cancer Center. Among the findings presented, lifirafenib and mirdametinib demonstrated potent and synergistic activity in vitro and in vivo across a panel of RAS-mutated cancer models harboring a variety of mutations using clinically relevant concentrations of the compounds. Furthermore, in KRAS Q61K and KRAS G12C xenograft models, the combination demonstrated synergy as validated by pharmacodynamic pathway inhibition and tumor regressions. These preclinical findings provided further support for the ongoing Phase 1b/2 combination study of lifirafenib and mirdametinib, which is evaluating this “vertical inhibition” strategy for treating patients whose cancers harbor RAS mutations and other MAPK pathway aberrations.

Based on the progress of the program and the clinical data observed to date, the companies reiterated their previous guidance to complete the dose escalation portion of the trial by the end of 2020 and to commence dose expansion cohorts in tumor types of interest thereafter, including KRAS-mutated non-small cell lung cancer and KRAS-mutated endometrial cancer. Initial clinical data from the trial is expected to be presented at a medical conference in 2021.