Mesothelioma Drug Delivery System May Impact Effectiveness

Egyptian and Japanese researchers indicate that they have found a way to deliver the cancer drug Alimta, so that it is a more effective in the treatment for mesothelioma, a rare and deadly form of cancer linked to asbestos exposure. 

In a study published in the March issue of the Biological and Pharmaceutical Bulletin, researchers from the University of Tokushima in Japan and Zagazig University in Egypt indicate that Alimta could be a more effective mesothelioma treatment if it is delivered in artificially created bubbles, known as liposomes.

Alimta (pemetrexed; or PMX) is a new multi-targeted anti-folate used to treat solid tumors. The drug does not, however, usually perform well against malignant pleural mesothelioma (MPM) tumors when introduced by standard means.

Researchers looked at what would happen if Alimta was encapsulated in liposomes, which are small, fluid-filled bubbles of cholesterol or other lipids. They tested various forms of Alimta-bearing liposomes against human mesothelioma cell lines and found that it showed a much better in vitro cytotoxic effect against mesothelioma tumor cells.

“In consideration of such promising results, liposomal PMX surely holds great promise in conquering aggressive MPM, in vivo, by potentiating the efficacy of the entrapped PMX at the target organ/tissue while minimizing its adverse side effects,” the researchers determined. “Further studies are currently being conducted in our laboratory to emphasize the in vivo potential of our liposomal PMX formulation against MPM.”

Mesothelioma is only known to be caused by exposure to asbestos and breathing asbestos fibers. It is an especially lethal form of cancer, which is often at a very advanced stage when a diagnosis is made, resulting in a very short life-expectancy.

The disease is often the subject of asbestos lawsuits among individuals diagnosed with mesothelioma, involving allegations that manufacturers of various asbestos-containing products failed to take adequate safety measures or warn about the risk of cancer long after exposure to the substance. More than 600,000 people throughout the United States having filed a cases against more than 6,000 defendants after being diagnosed with mesothelioma or other related injuries that were allegedly caused by inhaling asbestos fibers.

In addition to claims for workers exposed to asbestos in the course of her employment, in recent years there have been a growing number of secondary exposure mesothelioma cases have been brought on behalf of spouses, children and other family members alleging they developed the disease after breathing asbestos fibers brought home in the hair or on the clothing of individuals who worked directly with the material.