Pemetrexed Becomes Recommended Combined Chemotherapy Drug

For years the primary chemotherapy drug used in mesothelioma treatments has been cisplatin. However, a relatively new drug has proven that, when given with cisplatin, it can reduce tumor size up to 40% in some patients.  Pemetrexed, also known as Alimta when delivered via injection, has become the primary drug of choice for many oncologists.

Pemetrexed is approved for treating various forms of lung cancer in addition to malignant forms of pleural mesothelioma (nicknamed asbestos cancer since exposure to asbestos is the primary cause.)  It gained the FDA’s stamp of approval in 2004 and became the first drug approved specifically for malignant pleural mesothelioma. 

The drug works by blocking enzymes that are necessary during tumor development. This can effectively halt tumor growth and, as clinical trials have shown, actually decrease tumor size by up to 40%.

The drug has also been shown to have a rather remarkable effect on the longevity of mesothelioma patients. Those patients receiving cisplatin alone lived, on average, just 9.3 months after diagnosis. Patients receiving both cisplatin and pemetrexed in the form of Alimta survived, on average, 12.1 months. That’s a 130% improvement with the addition of a single chemotherapy drug. That figure doesn’t take into account patients who undergo additional forms of treatment such as cytoreductive surgery or pleurectomies. 

The Alimta injection form of pemetrexed is delivered intravenously every 21 days. The injections are followed with a cisplatin infusion after about 30 minutes. The recommended course of treatment is 6 injections over time but doctors have leeway in determining how many is right for each individual patient. 

While pemetrexed does have a long list of side effects, they are very similar in both type and severity to other already available chemotherapy drugs. These include digestive problems and decreased white blood cell count, which may lead to decreased ability to fight infections. In addition, Alimta can have adverse reactions with NSAIDs so the manufacturer recommends discontinuing their usage at least five days before pemetrexed injections and for at least two days afterward. 

The most significant side effect of pemetrexed is reduced renal function. This means that patients with deficient kidneys may not be suitable for treatment with this mesothelioma chemotherapy drug. In addition, taking drugs such as NSAIDs which reduce the kidney’s functionality or interfere with “clearing” of pemetrexed from the bloodstream may lead to significant complications.

While pemetrexed isn’t a cure, it is a step ahead of many of more traditional treatments for asbestos related diseases. More and more mesothelioma specialists and oncologists are using this drug in combination with others to tailor specific treatment regimens for their patients.