In 2011, the FDA approved the use of Xalkori (which goes by the generic name of crizotinib) to treat people suffering from late-stage, non-small cell lung cancers. Xalkori is a treatment option if these people also have the gene known as the abnormal anaplastic lymphoma kinase (ALK) gene. Those with the ALK gene are most receptive to treatment with Xalkori (and incidentally, least responsive to traditional treatments). Now, researchers are working to determine whether the ALK gene is also present in some patients with pleural mesothelioma. If so, Xalkori could be the new drug of choice for these patients.
What is Pleural Mesothelioma?
Mesothelioma is a long name for a form of cancer that is caused by exposure to asbestos. Mesothelioma affects the membranes (mesothelial cells) surrounding the internal organs. The most common form of this rare, and so far incurable, cancer is pleural mesothelioma. Pleural mesothelioma affects the membranes around the lungs, and accounts for about 75% of asbestos-related cancers.
Cause and Symptoms of Pleural Mesothelioma
The disease is caused by repeated on-the-job exposure to asbestos fibers in the air. The asbestos is inhaled and the fibers lodge in the pleural membrane (the membrane surrounding the lungs). Over time, the fibers can cause chronic inflammation and scarring. Occasionally the fibers also cause genetic changes in the cells, which can result in cancerous tumors (pleural mesothelioma). This is a deadly form of cancer. The average life expectancy of a patient diagnosed with pleural mesothelioma is only four to eighteen months.
Part of the difficulty in battling the disease is that many of the symptoms of pleural mesothelioma are not apparent until the cancer is in a later stage (stage III or IV). At this point in the disease’s progression, the tumors and thickening of the membrane around the lungs causes pressure on the lungs. Due to this lung constriction, a patient in this stage of mesothelioma might experience a persistent dry or raspy cough, shortness of breath, severe chest pain, or trouble breathing.
Pleural Mesothelioma Treatment
Historically, upon diagnoses of pleural mesothelioma, doctors have used chemotherapy and radiation treatments to delay the progression of the cancer. Now it’s hoped that Xalkori might offer a better treatment option, with fewer side effects.
To determine whether Xalkori might be beneficial to a patient, doctors first need to identify whether the patient has the abnormal ALK gene. If a genetic test shows the patient has the ALK gene, he or she can be prescribed Xalkori. Only a small percentage of people suffering from non-small cell lung cancer have the ALK gene. More research is needed to show whether the ALK gene is present in some or all mesothelioma sufferers. If so, Xalkori might be a viable mesothelioma treatment option.
Pleural Mesothelioma is an Asbestos Caused Orphan Disease
Because mesothelioma afflicts only a relatively small number of people (about 3,000 per year in the US), and is attributable to basically one key cause, it’s considered an “orphan disease.” To provide an incentive for pharmaceutical companies to research and develop drugs for orphan diseases, the FDA has exempt pharmaceutical companies working on such drugs from paying fees on the drugs for up to seven years. Thanks to these FDA policies and the ongoing research of Pfizer, the development of Xalkori might provide mesothelioma sufferers with a new and better treatment option in the future.