A phase II study of pemetrexed and carboplatin in patients with locally advanced or metastatic breast cancer

BACKGROUND

Pemetrexed and carboplatin have demonstrated activity in breast cancer. Their potential synergism in experimental models and the proven efficacy of pemetrexed/platinum in other indications make pemetrexed/carboplatin an attractive combination in breast cancer. Thus, this two-stage, sequential, open-label, multicenter, phase II study assessed the efficacy and safety of pemetrexed plus carboplatin as first-line therapy in patients with locally advanced breast cancer (LABC) or metastatic breast cancer (MBC).

PATIENTS AND METHODS

Patients >or= 18 years with a histologic/cytologic diagnosis and no prior chemotherapy for LABC or MBC received pemetrexed 600 mg/m(2) and carboplatin AUC 5.0 on day 1 every 21 days with folic acid and vitamin B(12) supplementation.

RESULTS

From June 2003 to April 2005, 50 patients with stage IIIB (30.0%) and stage IV (70.0%) disease were enrolled at 3 study centers. Twenty-eight percent of patients previously received adjuvant chemotherapy, 46.0% had visceral metastases, and 36.0% had >or=3 organs involved. Partial responses (RECIST criteria) were achieved in 27 (54.0%) patients (ORR = 54.0%; 95% CI, 39.3-68.2%). The median response duration was 11.1 months (95% CI, 6.5-14.0 months) and the median time to disease progression was 10.3 months (95% CI, 8.3-14.6 months). CTC hematologic toxicities were grade 3/4 neutropenia (58.0%/28.0%) and grade 3 thrombocytopenia (10.0%) and anemia (18.0%). Two (4.0%) patients had febrile neutropenia, 1 of whom died. No grade 4 non-hematologic toxicities occurred. Grade 3 non-hematologic toxicities were ALT (4.0%) and AST elevation, and edema, fatigue, pruritus, rash/desquamation, and renal toxicity (2.0% each).

CONCLUSIONS

Results of this study suggest that the combination of pemetrexed and carboplatin has promising efficacy and an acceptable safety profile. Further assessment of this combination in a randomized trial of various breast cancer patient populations is warranted.

Phase I and Pharmacokinetic Study of Pemetrexed with High-Dose Folic Acid Supplementation or Multivitamin Supplementation in Patients with Locally Advanced or Metastatic Cancer

PURPOSE

This phase I study evaluated the effect of folate supplementation on the toxicity, tolerability, and pharmacokinetics of pemetrexed in patients with locally advanced or metastatic cancer. It also examined two different types of vitamin supplementation and whether the extent of prior myelosuppressive therapy affected pemetrexed tolerability.

PATIENTS AND METHODS

Patients received a 10-min infusion of 600 to 14,00 mg/m(2) pemetrexed every 3 weeks. Patients were stratified into cohorts by pretreatment status [lightly pretreated (LPT) or heavily pretreated (HPT)] and were supplemented with intermittent high-dose folic acid (HDFA) or with continuous daily multivitamins (MVI) containing nutritional doses of folic acid. Pemetrexed plasma pharmacokinetics were evaluated for cycle 1.

RESULTS

Sixty-two HDFA patients (28 HPT and 34 LPT) were treated with 204 cycles of pemetrexed, and 43 MVI patients (20 HPT and 23 LPT) were treated with 182 cycles. Hematologic dose-limiting toxicities included grade 4 neutropenia (5 of 105 patients), grade 4 thrombocytopenia (4 of 105 patients), and febrile neutropenia (3 of 105 patients). Nonhematologic toxicities included fatigue, vomiting, diarrhea, and nausea. Pemetrexed doses of 800 and 1,050 mg/m(2) were well tolerated when administered with vitamin supplementation to HPT and LPT patients, respectively. There were no clinically relevant differences in toxicities or pemetrexed pharmacokinetics for LPT versus HPT patients or for patients receiving HDFA versus daily MVI supplementation.

CONCLUSIONS

The pemetrexed doses tolerated in this study with vitamin supplementation were significantly higher than those tolerated in earlier studies without supplementation, and toxicities were independent of the type of vitamin supplementation or prior myelosuppressive treatment. The recommended dose of pemetrexed is 1,050 mg/m(2) in LPT patients and 800 mg/m(2) in HPT patients, irrespective of the type of vitamin supplementation.