On December 5, the Center for Drug Evaluation (CDE) of China's National Administration for Drug Regulation's website announced that the clinical trial application of Pfizer's (PFE.US) new drug PF-07934040 had been accepted. According to public information, it is a KRAS pan-inhibitor under development by Pfizer, which is conducting a phase I clinical trial in the international community. This is the first time the product has applied for an IND in China, and the acceptance of PF-07934040's clinical application in China means that the product is expected to conduct clinical research in China soon.According to the information on Pfizer's website, PF-07934040 is a pan-KRAS "ON/OFF" inhibitor with activity against wild-type (wt) KRAS and major mutant subtypes, without activity against NRAS or HRAS. PF-07934040 shows binding to both the OFF (GDP-bound) and ON (GTP-loaded) states of KRAS wt, and the binding affinity to the mutants is very low, with a 5,000-fold selectivity for KRAS over HRAS/NRAS.Research has shown that PF-07934040 blocks the binding of RAF-RBD to GTP-loaded KRAS mutants, indicating that its mechanism of action may include binding to the ON state of KRAS and inhibiting the binding of RAF, regulating downstream signal transduction.According to ClinicalTrials.gov, Pfizer is conducting a phase I clinical study to evaluate the optimal dose, efficacy, and safety of PF-07934040 as a single agent or in combination with other targeted drugs in patients with KRAS gene mutations in advanced solid tumors. The study is planned to enroll 330 patients with non-small cell lung cancer, colorectal cancer, pancreatic ductal adenocarcinoma, etc. in the international community.