Researchers affiliated with a multicenter U.S. trial have reported that the combination of Alimta® (pemetrexed) and Gemzar® (gemcitabine) was active in patients with peritoneal mesothelioma. The details of this study appeared in the July 20, 2008 issue of the Journal of Clinical Oncology.¹

Peritoneal mesothelioma is much less common than pleural mesothelioma, making up less than 20% of all cases. The latency period for abdominal mesothelioma appears to be 20-30 years, which is shorter than the latent period for pleural mesothelioma. Controlled trials of various treatment options are not available for peritoneal mesothelioma due to the relative rarity of this disease. The most common treatment strategy for peritoneal mesothelioma involves a multimodality approach with surgical debulking followed by systemic and/or intraperitoneal chemotherapy. The role of radiation therapy is not well documented. Researchers from Columbia University have recently reported that combined resection, intraperitoneal chemotherapy, and whole abdominal radiation therapy may be the most effective strategy for palliative therapy for malignant peritoneal mesothelioma (see first item of related news).

Because there have been few studies of chemotherapy for peritoneal mesothelioma, treatment regimens are derived from studies in patients with pulmonary mesothelioma. All chemotherapy for mesothelioma is palliative. Therefore, identification of a chemotherapy regimen that can improve quality of life or survival is essential for improving care in this population. The most active agents for the treatment of mesothelioma include the following: Platinol® (cisplatin), Paraplatin® (carboplatin), Alimta, Tomudex® (raltitrexed), and Gemzar. Alimta is usually combined with Platinol or Paraplatin, and there are no reports of Alimta and Gemzar.

The current study involved 20 patients treated between 2002 and 2004. Patients received Alimta and Gemzar every 21 days. Patients also received folic acid, vitamin B12, and dexamethasone.

• The overall response rate was 15%.
• The disease control rate was 50%.
• The median time to disease progression was 10.4 months.
• The median survival time was 26.8 months.
• Toxicities appeared to be tolerable but with a grade 3-4 neutropenia rate of 60%.

These authors concluded that Gemzar and Alimta was an active regimen that was an alternative to standard therapies.

Comments: This is one of the first studies devoted to systemic chemotherapy treatment of peritoneal mesothelioma and provides important baseline information.

Related News:

Comprehensive Approach to Peritoneal Mesothelioma Described (3/26/2008)

Chemotherapy May Not Affect Survival or Quality of Life for Patients with Advanced Mesothelioma (5/21/2008)

Results of Alimta® for Treatment of Malignant Pleural Mesothelioma Reported (10/31/2007)

Reference:

¹ Simon GR, Verschraegen CF, Janne PA, et al. Pemetrexed plus gemcitabine as first-line chemotherapy for patients with peritoneal mesothelioma: Final report of a phase II trial. Journal of Clinical Oncology. 2998;26:3567-3572.