Mesothelioma is a rare cancer with a poor life expectancy. People diagnosed with pleural mesothelioma usually live for four to 18 months after diagnosis. The poor survival is a result of the aggressive nature of the cancer and that it is usually diagnosed at a late stage when it is less treatable. Once mesothelioma progresses, some patients might not be able to receive surgery along with chemotherapy and radiation, which is currently the most effective treatment available for mesothelioma. Other treatments are available including immunotherapy, but a definitive treatment that greatly improves or cures mesothelioma is still not available so new treatments need to be studied to find the best available treatment combination for the disease.
Chemotherapy is not very effective for mesothelioma. It can add some survival benefits and improve quality of life, but it cannot greatly extend the lives of patients or cure them. When combined with other treatments, chemotherapy can be a useful tool for mesothelioma. If researchers find other drugs that can be combined with chemotherapy to make it more effective, more patients could live longer and have a better quality of life.
Researchers are looking at a protein they believe could make chemotherapy more effective on mesothelioma. A California based company is performing a phase 3 clinical trial, which is showing that mesothelioma cells are more susceptible to chemotherapy drugs when given the protein pegargiminase. It blocks arginine, which is essential for cell survival and is especially important for the survival of cancer cells. Researchers are trying to find out if they can create stress, altered gene expression, and cell death in mesothelioma cells without hurting healthy cells. The company has stated that it has found good reasons to combine pegargiminase with other treatments to find the perfect treatment regimen for patients.
The phase 3 trial is being conducted at Barts Cancer Institute in London. The trial is randomized and double blind and involves pegargiminase, known as ADI-PEG 20, combined with pemetrexed and cisplatin. There were 125 patients in the study that had non-epithelioid mesothelioma. The conditional power for overall survival was 80 percent. The median overall survival increased from 7.66 months to 9.3 months, an increase of 21.4 percent. Patients who were in the treatment group had less serious side effects and adverse events compared with patients receiving the placebo.
