Shares of biotech firm Mirati Therapeutics (MRTX) are spiking higher on Monday after large-cap peer Amgen (AMGN) announced the first clinical results from a Phase 1 study evaluating investigational AMG 510, the first KRASG12C inhibitor to reach the clinical stage. In the trial, there were no dose-limiting toxicities at tested dose levels. AMG 510 showed anti-tumor activity when administered as a monotherapy in patients with locally-advanced or metastatic KRASG12C mutant solid tumors, Amgen said in a statement. MIRATI’S CANDIDATE: Mirati Therapeutics is developing a KRAS G12C Inhibitor like Amgen’s AMG 510. According to the company, MRTX849 has demonstrated broad-spectrum antitumor activity across a panel of KRAS G12C-positive patient- and cell-derived in vivo tumor models, including complete tumor regression in a subset of these models. MRTX849 is now in the clinic and has the potential to provide a long-awaited targeted therapy option for patients exhibiting a KRAS driver mutation, Mirati said on its website. PRICE ACTION: Shares of Mirati Therapeutics are up 31% to $88.39 in afternoon trading, while Amgen is up almost 5% to $174.41.