The difference between sunitinib and apatinib: comparison of efficacy, scope of application and side effects

Sunitinib and apatinib (Apatinib) are targeted anti-cancer drugs that mainly act on angiogenesis-related receptor tyrosine kinases (RTKs) to inhibit tumor angiogenesis, thereby preventing the growth of cancer cells. However, there are obvious differences in the indications, mechanism of action, side effects and efficacy of the two. In clinical application, the choice needs to be based on the patient's specific condition.

1. Differences in mechanism of action

Sunitinib is a multi-target tyrosine kinase inhibitor (TKI) that can inhibit multiple receptor tyrosine kinases, including vascular endothelial growth factor receptors (VEGFR1, VEGFR2, VEGFR3), platelet-derived growth factor receptors (PDGFR-α and PDGFR-β), stem cell factor receptor (c-KIT), etc. It not only inhibits tumor angiogenesis, but also directly inhibits the proliferation of certain tumor cells, making it applicable to a wider range of solid tumor types.

Apatinib is mainly a highly selectiveVEGFR-2 inhibitor, and its inhibitory effect on other targets is relatively weak. It reduces the angiogenesis of tumor tissue by inhibiting VEGFR-2, causing tumor cells to grow restricted due to lack of nutrient supply. Therefore, apatinib is mainly used against angiogenesis-related cancers, such as advanced gastric cancer.

2. Differences in indications

Sunitinib has a wide range of indications and is approved by FDA and EMA for the treatment of advanced renal cell carcinoma (RCC), gastrointestinal stromal tumor (GIST) , pancreatic neuroendocrine tumor (pNET), etc. Especially for patients with gastrointestinal stromal tumors who cannot receive imatinib treatment, sunitinib is considered a first-line alternative. In addition, some clinical trials are also exploring the potential efficacy of sunitinib in other solid tumors such as lung cancer and liver cancer.

Apatinib was initially approved by China's National Medical Products Administration (NMPA) for the treatment of advanced or metastatic gastric cancer in patients after failure of standard treatments. In recent years, some studies have also explored the efficacy of apatinib in tumors such as liver cancer, lung cancer, and breast cancer, but its scope of indications is still more limited than that of sunitinib.

3. Comparison of efficacy

Sunitinib has superior performance in the treatment of advanced renal cell carcinoma. Studies have shown that its progression-free survival (PFS) can reach about 11 months, which is significantly better than traditional interferon treatment. For patients with gastrointestinal stromal tumors (GIST), the PFS of sunitinib can reach 6-8 months, and it can still provide a good survival benefit after imatinib resistance. For patients with pancreatic neuroendocrine tumors, the median progression-free survival can be extended to 11.4 months after treatment with sunitinib.

The efficacy of apatinib in advanced gastric cancer has been confirmed by multiple studies. Phase III clinical trials have shown that compared with the placebo group, it can significantly extend PFS to 2.6 months and improve overall survival (OS) to 6.5 months. For patients with liver cancer, apatinib has also shown certain efficacy. Some studies have shown that its PFS can reach 4-5 months. However, due to the lack of research data, it has not yet been listed as a standard treatment option.

4. Comparison of side effects

Sunitinib has a wide range of side effects. Common adverse reactions include hypertension, fatigue, hand-foot syndrome, gastrointestinal reactions (such as diarrhea, nausea, decreased appetite), bone marrow suppression (anemia, leukopenia), abnormal liver function, etc. Long-term use may also lead to hypothyroidism, so regular monitoring of thyroid function is required. In addition, sunitinib may cause cardiotoxicity, such as decreased left ventricular ejection fraction (LVEF), so it needs to be used with caution in patients with cardiovascular disease.

The main side effects of apatinib focus on hypertension, proteinuria, bleeding risk and gastrointestinal discomfort. Because its main target is VEGFR-2, the incidence of hypertension is high, and some patients need to be managed with antihypertensive drugs. In addition, proteinuria is common, and long-term use may cause kidney function damage, so urine protein levels need to be measured regularly. Some patients may be at risk of gastrointestinal bleeding or perforation, especially those with a history of gastrointestinal ulcers or bleeding and should be used with caution.

5. How to choose suitable drugs?

1. Disease type and stage

If patients have advanced renal cell carcinoma, gastrointestinal stromal tumor, or pancreatic neuroendocrine tumor, sunitinib is the first choice treatment option. If the patient has advanced gastric cancer after failure of standard treatments, apatinib may be an option.

2. Individualized tolerance

If the patient has cardiovascular disease (such as heart failure, arrhythmia), sunitinib should be used with caution, and apatinib may be more suitable. If patients are at risk for gastrointestinal bleeding or have severe hypertension, they need to weigh the side effects of apatinib and take appropriate precautions.

3. Economic factors and accessibility

As an imported targeted drug, sunitinib is relatively expensive, but it is covered by medical insurance in many countries. Apatinib is a domestically produced targeted drug, which is relatively cheaper and easier to obtain in the Chinese market.

Reference materials:https://www.sutent.com/