Malaria Protein Effectively Delivered Cancer Drugs to Resistant Tumors

Tumors utilize numerous mechanisms to become resistant to cancer treatments. Once this occurs, there are limited options going forward.

However, the authors of a new study published by European Urology found that a drug created from a malaria protein may be able to treat chemotherapy-resistant bladder cancer. This experimental method — combining the protein with a cancer drug – was observed to inhibit tumor growth, and may present a novel treatment option for patients who fail to respond to standard treatment.

"This is the first study where we put the concept of using malaria proteins for cancer therapy into a direct clinical context," said researcher Mads Daugaard, PhD. "There is a massive clinical need to find new treatments for bladder cancer and we saw an opportunity to target this disease with our new malaria drug."

Previously, the authors discovered that the VAR2CSA protein from the malaria parasite was able to target numerous cancers.

In the current study, the authors implanted very aggressive chemotherapy-resistant bladder cancer tumors into mice. Then, the authors assessed whether the protein could be harnessed as a drug delivery method.

The cancerous tumors were observed to positively respond to the malaria protein-cancer drug combination, according to the study. After 70 days, 80% of treated mice models were alive, compared with all other control animals that died of bladder cancer.

Bladder cancer is a common form of the disease and is very costly on a per patient basis. Currently, there is only 1 first-line chemotherapy that is used to treat patients with invasive bladder cancer. Despite high incidence of the cancer, there have been little advances in treatment over the past 2 decades.

"No second line treatment option is available," Dr Daugaard said. "We're very excited by these results because it shows that we are on our way to developing a completely new treatment option for lethal bladder cancer. It has the potential to have a tremendous impact on patient care."

The authors previously found that the protein showed promise as a drug delivery vehicle, as it could bring the drugs right to the tumor. It does so by binding to a sugar molecule only present in cancerous tumors and the placenta of pregnant animals, according to the study.

The new findings show that the sugar is present in bladder cancers, especially among patients previously administered the standard treatment, cisplatin.

These positive results could be used to present another treatment for patients with chemotherapy-resistant disease. Since initial studies showed that the protein may target numerous cancers, it may also be explored in further disease states.

The authors are in the process of developing a drug that could be manufactured on a large scale to be used in clinical trials, the study concluded.