What is Chemotherapy?
Chemotherapy is a group of toxic drugs that kill cells (mesothelioma, other cancers, and healthy cells) by damaging their DNA. Chemotherapy is a cytotoxic therapy, meaning it kills cells. Chemo drugs target rapidly growing cancer cells, but they can also affect healthy cells that grow rapidly such as blood cells. The effect of these drugs on both cancer and normal cells often causes chemo side effects.
Alimta (Pemetrexed) and Cisplatin
As of this writing, the only FDA approved chemotherapy for mesothelioma is a combination of Alimta (pemetrexed) and cisplatin. In February 2004, the Food and Drug Administration approved pemetrexed for the treatment of malignant pleural mesothelioma in combination with cisplatin for patients whose disease is either inoperable or who are not otherwise candidates for curative surgery. Patients who take this chemo regimen are often prescribed folic acid and vitamin B12 supplement to help reduce side effects from the chemotherpay. Patients are usually prescribed corticosteroids to reduce the risk of skin rashes as well.
The recommended dose of pemetrexed is 500 mg/m administered as an intravenous infusion over 10 minutes on day 1 of each 21-day cycle together with cisplatin at a dose of 75 mg/m infused over 2 hours beginning 30 minutes after the pemetrexed infusion.
The Clinical Trial that Approved Alimta (Pemetrexed) and Cisplatin
There was one key clinical trial that led to the FDA approval of this regimen for mesothelioma. Two hundred twenty-six pleural mesothelioma patients were randomized to receive pemetrexed and cisplatin, while 222 patients were randomized to receive cisplatin alone. The primary study end point was survival. Median survival times were 12.1 months for the pemetrexed plus cisplatin treatment group and 9.3 months for the cisplatin alone group.
Median time to progression (regrowth of tumor) was longer in the pemetrexed/cisplatin arm of the study, 5.7 months versus 3.9 months. This means that the mesothelioma patients who received both drugs had their tumors return a median of 1.8 months longer versus those who only got one drug.
Like most chemo drugs, pemetrexed kills blood cells so the most common adverse events were neutropenia, fatigue, leukopenia, nausea, dyspnea, and vomiting.
On February 4, 2004, pemetrexed was approved by the FDA in combination with cisplatin for the treatment of patients with malignant pleural mesothelioma whose disease is inoperable or who are otherwise not candidates for curative surgery.