How does Selumetinib/Coseyou exert its efficacy?

Selumetinib (Selumetinib) is a targeted therapy drug that mainly works by inhibiting the MEK (MAPK/ERK kinase) signaling pathway. MEK is a key enzyme that plays a vital role in the regulation of cell proliferation, differentiation and survival. In patients with neurofibromatosis type 1 (NF1), the MEK signaling pathway is often abnormally activated due to NF1 gene mutations, leading to the occurrence and growth of plexiform neurofibromas (PN). Selumetinib inhibits the activity of MEK enzyme and prevents the activation of the downstream ERK pathway, thereby effectively slowing down the proliferation of tumor cells and inducing apoptosis.

ForNF1 patients, plexiform neurofibromas are a common and troublesome disease manifestation, and these tumors are often unresectable by surgery, which has a significant impact on patients' quality of life. Traditional treatments such as radiation therapy and surgical resection are not suitable for all patients, so medical treatment becomes an important option. By targeting the MEK pathway, selumetinib can effectively reduce tumor volume and improve patients' clinical symptoms, such as pain, skin deformities and dysfunction caused by tumors.

In addition to its inhibitory effect on tumor growth, selumetinib also has a certain safety profile and is generally tolerated by patients. However, patients still need to be treated under the guidance of a doctor when using this drug, because long-term use may cause certain side effects. Common side effects include rash, diarrhea, abnormal liver function, etc., so regular blood tests and monitoring of liver and kidney function are required.

In clinical trials, the efficacy of selumetinib has been verified. Studies have shown that for patients with plexiform neurofibromas that cannot be removed by surgery, selumetinib can significantly shrink the tumors and improve the patients' quality of life. In addition, the drug has also been shown to have good results in the treatment of children 1 year old and above.

References：https://www.ema.europa.eu/en/medicines/human/EPAR/koselugo