title: Prospective phase II study of cisplatin plus pemetrexed with maintenance of pemetrexed for advanced non-squamous cell non-small cell lung cancer in Japan.
abstract: BACKGROUND
  A previous study showed a survival benefit with maintenance therapy with pemetrexed in patients with advanced non-small cell lung cancer (NSCLC). However, it remains unclear whether continuation maintenance therapy with pemetrexed is beneficial in Japanese patients. Here, we present our phase II study that assessed the efficacy and safety of cisplatin plus pemetrexed as induction chemotherapy, followed by maintenance therapy with pemetrexed in advanced NSCLC patients in Japan.
  
  
  METHODS
  Chemotherapy-naïve patients received 500 mg/m(2) pemetrexed and 75 mg/m(2) cisplatin on day one every three weeks for four cycles. In patients who responded to therapy or achieved stable disease, pemetrexed was continued until disease progression. The primary endpoint of this study was the progression-free survival rate at six months (PFS-6).
  
  
  RESULTS
  Of the 35 patients initially enrolled in the study, 18 (51%) received maintenance chemotherapy with pemetrexed. The median PFS was 6.7 months, and the PFS-6 was 60% (95% confidence interval [CI], 42-76%). Median overall survival (OS) was 15.5 months (95% CI, 8.3-22.7 months). The median PFS and OS in patients who received maintenance chemotherapy with pemetrexed were 9.5 months and 25.3 months, respectively. The most frequently noted severe toxicity during induction chemotherapy was neutropenia, which occurred in seven patients. Two patients discontinued maintenance therapy owing to prolonged grade 2 edema in one patient and grade 3 neutropenia in another.
  
  
  CONCLUSIONS
  Continuation maintenance chemotherapy with pemetrexed is associated with a survival benefit in patients who have completed induction chemotherapy for non-squamous NSCLC.
authors.affiliation: Department of Clinical Oncology, National Hospital Organization Kinki-chuo Chest Medical Center Sakai, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Asami
authors.affiliation: Department of Clinical Oncology, Federation of National Public Service Personnel Mutual Aid Associations, Otemae Hospital Osaka, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kawahara
authors.affiliation: Department of Clinical Oncology, Osaka Prefectural Medical Center for Respiratory and Allergic Diseases Habikino, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Hirashima
authors.affiliation: Department of Clinical Oncology, Osaka Prefectural Medical Center for Respiratory and Allergic Diseases Habikino, Japan.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Department of Clinical Oncology, National Hospital Organization Kinki-chuo Chest Medical Center Sakai, Japan.
authors.forename: Kyoichi
authors.initials: K
authors.lastname: Okishio
authors.affiliation: Department of Clinical Oncology, National Hospital Organization Kinki-chuo Chest Medical Center Sakai, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Omachi
authors.affiliation: Department of Clinical Oncology, Osaka Prefectural Medical Center for Respiratory and Allergic Diseases Habikino, Japan.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Tamiya
authors.affiliation: Department of Clinical Oncology, National Hospital Organization Kinki-chuo Chest Medical Center Sakai, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tamiya
authors.affiliation: Department of Clinical Oncology, National Hospital Organization Kinki-chuo Chest Medical Center Sakai, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Hirooka
authors.affiliation: Department of Clinical Oncology, National Hospital Organization Kinki-chuo Chest Medical Center Sakai, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Nakao
authors.affiliation: Department of Clinical Oncology, National Hospital Organization Kinki-chuo Chest Medical Center Sakai, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Tsuji
authors.affiliation: Department of Clinical Oncology, National Hospital Organization Kinki-chuo Chest Medical Center Sakai, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Atagi
keywords: Cisplatin plus pemetrexed; Japanese patients; continuation maintenance; non-small cell lung cancer; non-squamous cell