Phase II study of pemetrexed disodium, a multitargeted antifolate, and cisplatin as first-line therapy in patients with advanced nonsmall cell lung carcinoma: a study of the National Cancer Institute of Canada Clinical Trials Group.

BACKGROUND

Pemetrexed disodium (Alimta [Eli Lilly and Company, Indianapolis, IN], LY231514, multitargeted antifolate) is a new multitargeted antifolate agent that inhibits multiple enzymes in the folate pathway. Phase II trials showed single-agent response rates of 16% and 23% in untreated patients with nonsmall cell lung carcinoma (NSCLC). This study was undertaken to determine the response to pemetrexed disodium given in combination with cisplatin.

METHODS

Previously untreated patients were eligible if they had Stage IIIB or IV NSCLC, performance status 0, 1, or 2, adequate hematology and biochemistry and bidimensionally measurable lesions. Patients with brain metastases or neuropathy higher than Grade 2 were excluded. Pemetrexed disodium 500 mg/m(2) was given over 10 minutes, and cisplatin 75 mg/m(2) with hydration and mannitol diuresis was administered on Day 1 of each 21-day cycle. Dexamethasone 4 mg was taken orally once every 12 hours starting 24 hours before treatment and continuing for 6 doses after treatment. Four patients had detailed pemetrexed disodium pharmacokinetic analysis performed.

RESULTS

Between May 1998 and June 1999, 31 patients were treated on the study. There were 20 males and 11 females; median age was 60 years (range, 35-75 years); there were 5 Stage IIIB, 26 Stage IV, 26 performance status 0 or 1, and 5 performance status 2. In 29 patients evaluable for response, there were 13 partial responses (PRs; overall response rate [ORR], 95%; confidence interval [CI]: 26-64%) of median duration 6.1 months (1.6-7.8 months). Three of four evaluable patients with performance status 2 achieved PR, and 11 of 24 evaluable Stage IV patients responded (ORR, 45.8% in Stage IV). Eighteen patients died. The median survival rate was 8.9 months (range, 1-15+ months). A total of 160 courses were delivered (median, 6 for both cisplatin and pemetrexed disodium). Grade 3 and 4 anemia was observed in 5 and 1 patients, respectively, and Grade 3 and 4 granulocytopenia in 7 and 4 patients, respectively. Grade 3 nausea and emesis occurred in only 2 patients, Grade 3/4 diarrhea in 3 patients, and 2 patients had Grade 3 motor neuropathy. Nine patients had Grade 2 infections, and there was one case of febrile neutropenia. Pharmacokinetic results showed C(max), clearance and V(ss) values to be similar to data from single-agent pemetrexed disodium given in the same dose.

CONCLUSIONS

The combination of pemetrexed disodium and cisplatin is active against advanced NSCLC and is a well-tolerated convenient outpatient regimen. It deserves further study to compare it with other standard regimens for NSCLC.