Radiation with Pemetrexed a Possibility
Geneva—Combining high-dose pemetrexed (Alimta, Eli Lilly) with concurrent radiation for lung cancer is feasible, according to results of a phase 1 study presented at the 2nd European Lung Cancer Conference. Administering pemetrexed at high doses with radiation may increase the effectiveness of treatment.
Prof Françoise Mornex, head of the Department of Radiotherapy Oncology at Centre Hospitalier Lyon Sud, and colleagues conducted the first trial of the drug in combination with radiotherapy and cisplatin chemotherapy in patients with stage III (locally advanced, but not metastatic) lung cancer.
Nine patients with unresected stage III non–small-cell lung cancer (NSCLC) were first given 2 cycles of chemotherapy, 3 weeks apart, with 500 mg/m2 of pemetrexed plus 75 mg/m2 of cisplatin. This was followed by 2 cycles of combined chemotherapy and radiotherapy, where doses of pemetrexed began at 400 mg/m2 and were then escalated to 500 mg/m2 and 600 mg/m2. Cisplatin and radiotherapy at 66 Gy/33 Gy fractions over 7 weeks remained constant.
Of 10 patients initially treated, 1 dropped out due to disease progression; 7 completed all 4 cycles of chemotherapy and 8 completed the radiotherapy.
In a press release discussing the study, Prof Mornex said that pemetrexed “appears to be the only thirdgeneration agent that can likely be recommended safely at full dose in trials with concurrent radiotherapy.” This is important, because concurrent radiation and chemotherapy often necessitates lowering the chemotherapy dose because of excessive toxicity. The higher tolerance afforded by pemetrexed allows the patient to receive higher cytotoxic doses during radiation, which increases the chance of killing cancerous cells.
Pemetrexed is currently indicated for the treatment of pleural mesothelioma and already has an established role in treating metastatic NSCLC.
Prof Mornex suggested that the findings “will have an impact on clinical practice in the near future. This regimen is already being studied in several ongoing clinical trials around the world; it may become the treatment of choice in the future for concurrent chemoradiation schemes.”