Spread of Peritoneal Mesothelioma Slows with Apatinib

An investigational drug called apatinib may help stop the growth and spread of peritoneal mesothelioma. Chinese researchers recently tested the VEGF inhibitor on mice infected with human mesothelioma. 

They found that the spread of peritoneal mesothelioma slowed way down in the presence of apatinib. The drug worked in the lab and in live mice with few serious side effects. If larger experiments confirm apatinib’s effectiveness, the next step could be trials in human mesothelioma patients. 

Apatinib Blocks Blood Vessel Formation

Apatinib is also known as Rivoceranib. It keeps cancer cells from using the protein VEGF. VEGF (vascular endothelial growth factor) allows tumors to spawn new blood vessels. A rich supply of fresh blood fuels the growth and spread of peritoneal mesothelioma. 

Apatinib is still experimental. A Chinese company is developing it for use against gastric cancers, metastatic breast cancer, and liver cancer. 

But some mesothelioma patients may also benefit. Peritoneal mesothelioma starts on the membrane that surrounds the abdominal organs. It accounts for about one in five cases of mesothelioma and is highly resistant to standard cancer treatments.

The liver and spleen are prime areas for the spread of peritoneal mesothelioma. If apatinib can prevent the spread of peritoneal mesothelioma to these and other critical organs, it could save lives. 

Blocking the Spread of Peritoneal Mesothelioma

The new tests on apatinib took place at Beijing Shijitan Hospital. Researchers tested the drug on mesothelioma cells in the lab. They also created a mouse model of mesothelioma using human cells. This allowed them to test apatinib’s impact on the spread of peritoneal mesothelioma. 

Researchers delivered apatinib directly into the stomachs of the sick mice using a technique called gastric gavage. Afterward, they measured how far the cancer spread in the abdomen. The amount of spread is the peritoneal cancer index (PCI). The lower the PCI, the better. 

“Our results showed that apatinib significantly inhibited the proliferation and migration of malignant peritoneal mesothelioma cells in vitro [in the lab] and induced cell cycle arrest,” writes study author Zhi-Ran Yang. 

Even more exciting was the fact that apatinib blocked the spread of peritoneal mesothelioma into the livers and spleens of mice. 

Tests of the treated mice showed that the drug also stimulated the immune system. It brought cancer-killing white blood cells to the area around the tumor. 

“We successfully established MPM PDX models and primary cell lines, and confirmed that apatinib effectively inhibited proliferation and metastasis of MPM in vitro and in vivo study,” writes Dr. Yang. 

The researchers say that apatinib “did not affect the function of important organs” or the body mass of the treated mice. 

Drug May Help with Pleural Disease, Too

In addition to slowing the spread of peritoneal mesothelioma, previous experiments suggest that apatinib may also help people with pleural mesothelioma. Pleural mesothelioma is more common than peritoneal mesothelioma. These tumors start on the membrane around the lungs. 

In 2018, apatinib kept a Chinese patient’s mesothelioma from growing for five months after two kinds of chemotherapy failed to stop it. Researchers suggested that apatinib could be an effective third-line treatment against chemo-resistant pleural mesothelioma. 

Sources:

Yang, ZR, et al, “Apatinib Mesylate Inhibits the Proliferation and Metastasis of Epithelioid Malignant Peritoneal Mesothelioma In Vitro and In Vivo”, December 7, 2020, Frontiers in Oncology, eCollection, https://www.frontiersin.org/articles/10.3389/fonc.2020.585079/full

Du, S, et al, “Apatinib for salvage treatment of advanced malignant pleural mesothelioma: A case report”, November 2018, Medicine (Baltimore), https://journals.lww.com/md-journal/Fulltext/2018/11090/Apatinib_for_salvage_treatment_of_advanced.46.aspx