Mesothelioma patients unlikely to benefit from thalidomide
Thalidomide, a once-notorious drug being investigated to treat cancer, shows no promise for patients with mesothelioma, according to the results of a joint study by Dutch and Australian researchers.
The lead researcher, Paul Baas from the Netherlands Cancer Institute, told a gathering of cancer experts in Perth, Australia, today that a year-long clinical trial found that thalidomide does not slow the progression of malignant pleural mesothelioma, a rare but deadly cancer of the lining of the lung. The study also concluded that thalidomide does not improve survival rates in patients.
Once prescribed for morning sickness, thalidomide was blamed for at least 10,000 cases of severe birth defects in the 1950s and ‘60s. In 1994, Harvard researchers discovered that the drug inhibits the growth of new blood vessels, a process known as angiogenesis, which plays a critical role in the growth and spread of cancer cells.
Subsequent research determined that thalidomide slows the growth of myeloma cells and prevents them from attaching to bone marrow cells. In 2006, the U.S. Food and Drug Administration approved thalidomide for the treatment of newly diagnosed multiple myeloma in combination with dexamethasone, a corticosteroid. The FDA has also approved thalidomide to treat skin lesions caused by leprosy.
The joint study in mesothelioma patients tested the theory that adding an anti-vascular agent like thalidomide to the standard chemotherapy regimen would slow or halt tumor growth. The researchers gave 207 patients who had received the pemtrexed-cisplatin combination a 200/mg dose of thalidomide daily. The patients were monitored for a year, using CAT scans and physical exams.
The researchers concluded that while thalidomide was only mildly toxic, “there was no evidence of benefit in terms of slowing progression of the disease, nor in improving survival,” Baas said.
Malignant pleural mesothelioma is caused by asbestos exposure. An extremely aggressive cancer that is difficult to diagnose and treat, the disease kills 2,500-3,000 Americans each year. More than 20 million people, a majority of them men, are at risk of developing mesothelioma, which can take decades to develop after asbestos exposure. Mortality rates are expected to increase in the U.S. and most industrialized countries until about 2020.
Because surgery, chemotherapy and radiation have only modestly improved patient outcomes, researchers have been experimenting with new drugs and techniques, such as gene therapy to replace malignant cells, immunotherapies that trigger cancer-fighting responses in the body and the use of nanoparticles to deliver chemotherapies directly to tumors.