Pemetrexed (Alimta®) Is a Less-Toxic Alternative for Recurrent Lung Cancer
Key words
Pemetrexed, Alimta, non-small cell lung cancer. (Definitions of many terms related to cancer can be found in the Cancer.gov Dictionary 4.)
Summary
The experimental drug pemetrexed (Alimta®) was as effective as the current standard therapy for recurrent non-small cell lung cancer (NSCLC) and caused fewer side effects.
Source
American Society of Clinical Oncology (ASCO) annual meeting, Chicago, June 2, 2003. [Note: The final results from this study were subsequently published in the May 1, 2004, issue of the Journal of Clinical Oncology. See the journal abstract.)
Background
Non-small cell lung cancer (NSCLC) accounts for about 80 percent of all lung cancer cases. The average five-year survival rate is about 50 percent for patients whose NSCLC is found early and treated with surgery, before it has spread to other organs. In advanced-stage disease, chemotherapy offers modest improvements in median survival, although overall survival is poor.
The drug docetaxel is the current standard treatment for NSCLC that recurs after chemotherapy. In two previous studies, docetaxel improved survival compared with other chemotherapy drugs or observation. However, docetaxel causes severe side effects, such as fever and infections, in many patients.
Previous studies have suggested that the experimental drug pemetrexed might be an effective alternative to docetaxal. Pemetrexed interferes with the body’s production of nucleotides, which are the building blocks of DNA. Because cancer cells grow more rapidly than normal cells, they have a greater need for nucleotides.
The earlier studies, however, did not assign patients at random to receive either pemetrexed or standard therapy, so their results were considered less than definitive. (See “What is Randomization? 5” and “Which Study Results Are the Most Helpful in Making Cancer Care Decisions? 6” for more information about the importance of randomization.)
The Study
Between March 2001 and February 2002, the new study enrolled 571 patients with recurrent NSCLC, making it the largest-yet phase III clinical trial to evaluate treatments for patients at this stage of the disease. Patients were randomly assigned to treatment with either docetaxel, the current standard of care, or pemetrexed.
Results
As of May 2003, the median survival for patients treated with pemetrexed was 8.3 months, compared with 7.9 months for patients treated with docetaxel. However, the apparent slight advantage with pemetrexed was not statistically significant; that is, the difference could have occurred by chance. Patients in both treatment groups had about a 30 percent chance of surviving for one year.
While survival was no different between the two groups of patients, those treated with pemetrexed were significantly less likely to suffer from fever and infections caused by low levels of white blood cells. They were also less likely to be hospitalized for fever or other side effects, or to need treatment to stimulate production of white blood cells. In addition, patients treated with pemetrexed suffered less hair loss and numbness in the arms and legs.
These results show that “pemetrexed is an effective chemotherapy agent” for patients with recurrent NSCLC, said Nasser Hanna, M.D., of Indiana University in Indianapolis, the lead investigator for the study. “Survival was equivalent for patients treated with either pemetrexed or docetaxel, and pemetrexed had a more favorable toxicity profile.”
Limitations
Pemetrexed therapy for recurrent NSCLC, while less toxic, didn’t improve overall outcome compared to the standard drug, which itself has a modest impact on survival. Clearly, said Scott Saxman, M.D., of the National Cancer Institute’s Clinical Investigations Branch, better therapies are still needed for this patient population. |
