What is Surufatinib used for?

Surufatinib, also known under the trade names Sulanda and Fruquintinib, is a multi-targeted kinase inhibitor developed by Hutchison China MediTech Limited (Hutchmed). As an orally administered drug, Surufatinib primarily targets vascular endothelial growth factor receptor (VEGFR) subtypes 1, 2, and 3; fibroblast growth factor receptor (FGFR) 1; and colony-stimulating factor 1 receptor (CSF-1R). This makes it particularly effective in interrupting pathways crucial for tumor angiogenesis, immune evasion, and tumor cell proliferation. The drug has shown promise in the treatment of neuroendocrine tumors (NETs) as well as other solid tumors. Clinical trials have demonstrated considerable efficacy and tolerability, leading to its approval in China for the treatment of advanced NETs.

Surufatinib Mechanism of Action

Surufatinib works by inhibiting multiple receptor tyrosine kinases (RTKs) that are involved in tumor growth and angiogenesis. The primary targets of Surufatinib are VEGFR 1, 2, and 3. These receptors play a pivotal role in the formation of new blood vessels (angiogenesis), which tumors need to grow and metastasize. By blocking these receptors, Surufatinib effectively cuts off the blood supply to the tumor, starving it of the nutrients and oxygen it needs to grow. Additionally, Surufatinib targets FGFR1, which is involved in a variety of processes including cell growth, differentiation, and wound healing. FGFR1 inhibition can further disrupt the pathways that contribute to tumor growth. Lastly, Surufatinib inhibits CSF-1R, which is involved in the regulation of macrophages. Tumor-associated macrophages often promote tumor growth and metastasis; thus, inhibiting CSF-1R can modulate the immune microenvironment in a way that is less supportive of tumor growth.

How to Use Surufatinib

Surufatinib is administered orally, usually in the form of capsules. The typical dosage is 300 mg taken once daily. It is essential to swallow the capsules whole with water and not to crush or chew them. The drug can be taken with or without food, but it is advisable to follow a consistent schedule regarding meals to maintain stable drug levels in the body.

The onset of action for Surufatinib can vary depending on individual patient factors and the type of tumor being treated. However, clinical trials have shown that patients often begin to see significant anti-tumor activity within the first few weeks of treatment. Regular monitoring through imaging and laboratory tests is essential to evaluate the drug's efficacy and adjust the treatment plan as needed.

What is Surufatinib Side Effects

Like all medications, Surufatinib comes with a potential for side effects. The most common adverse effects observed in clinical trials include hypertension, proteinuria (excess protein in the urine), and hand-foot syndrome (a skin reaction typically involving redness, swelling, and pain on the palms of the hands and soles of the feet). Gastrointestinal issues such as diarrhea, nausea, and vomiting are also frequently reported. Fatigue and decreased appetite are other commonly observed side effects.

Serious side effects, though less common, can include severe hypertension, gastrointestinal perforation, and hepatotoxicity (liver damage). Patients are advised to undergo regular monitoring of blood pressure, liver function, and renal function to detect and manage any potential complications early.

Contraindications for the use of Surufatinib include a history of severe cardiovascular diseases, uncontrolled hypertension, and significant bleeding disorders. Patients who are pregnant or breastfeeding should not use this medication due to potential risks to the fetus or infant.

What Other Drugs Will Affect Surufatinib

Drug interactions are an important consideration when prescribing Surufatinib. Co-administration with strong CYP3A4 inhibitors, such as ketoconazole or itraconazole, can increase the plasma concentration of Surufatinib, potentially leading to enhanced side effects. Conversely, strong CYP3A4 inducers like rifampin or phenytoin can decrease Surufatinib's plasma concentration, reducing its efficacy.

Additionally, caution should be taken when using Surufatinib alongside other medications that have a known risk of prolonging the QT interval, a measure of delayed heart repolarization that can lead to serious heart arrhythmias. Drugs like amiodarone or certain antipsychotics fall into this category.

Patients should always inform their healthcare provider about all medications, supplements, and herbal products they are currently taking to manage any potential interactions effectively. This includes over-the-counter drugs and dietary supplements that might seem harmless but could have significant implications when combined with Surufatinib.

In conclusion, Surufatinib represents a promising advancement in the treatment of neuroendocrine tumors and other solid tumors through its multi-targeted approach to inhibiting key pathways essential for tumor growth and survival. With its oral administration and manageable side effect profile, it offers a convenient and effective option for patients. However, careful monitoring and consideration of potential drug interactions are essential to optimize its use and ensure patient safety.