By Jill Stein
BARCELONA, SPAIN — September 24, 2007 — Pemetrexed alone or in tandem with a platinum agent shows good overall response and disease control rates in patients with peritoneal mesothelioma (PM), according to data presented here at the 14th European Cancer Conference (ECCO).
The study enrolled 109 patients with a histologic or cytologic diagnosis of peritoneal mesothelioma that was not amenable to curative surgery and was treated with pemextrexed alone or in combination with a platinum agent.
“Malignant peritoneal mesothelioma is a rare cancer, with a yearly incidence of about one or two cases per million in the U.S. and Europe, while the incidence of pleural mesothelioma is 3- to 30-fold higher in different countries, said study presenter Giacomo Carteni, MD, Director, Oncology Division, Cardarelli Hospital, Naples, Italy.
Few large studies have examined peritoneal mesothelioma, so treatment has largely been based on protocols used in patients with pleural mesothelioma, Dr. Carteni said in his poster presentation on September 24th.
The international Expanded Access Program (EAP) for pemetrexed in mesothelioma provided access to the drug before and during review by regulatory agencies.
In the trial, pemetrexed 500 mg/m2 alone or in combination with cisplatin 75 mg/m2 or carboplatin AUC 5 was given on day 1 of each 21-day treatment cycle as part of the EAP. All patients received standard supplementation with vitamin B12 and folic acid, and dexamethasone for prophylaxis.
Patients were treated until they developed progressive disease or unacceptable toxicity, or until the investigator or patient decided to halt treatment.
Pemetrexed and platinum combination was associated with a 20% or greater response rate and a 76% or greater disease control rate.
Patients in the single-agent platinum group had a 12.5% overall response rate, a 50% disease control rate, and a 41.5% survival rate at 1 year. “This is in line with their worse prognostic factors like higher median age, higher percent of patients who had undergone prior chemotherapy, and lower performance status at baseline,” Dr. Carteni said.
Hematologic toxicity was manageable in all groups and in agreement with earlier phase 3 findings, he said.
These results reported for peritoneal mesothelioma are comparable to the pemetrexed EAP in the U.S., which involved 98 patients with peritoneal mesothelioma. In that report, the overall response rate was 26% and median survival exceeded 13 months.
The study was sponsored by Eli Lilly and Company.
[Presentation title: Open-Label Study of Pemetrexed (P) Alone or in Combination With a Platinum in Patients With Peritoneal Mesothelioma (PM): Results From the International Expanded Access Program. Abstract P-6571]