513PPhase II study of vitamin B12 and folate supplementation for patients undergoing chemotherapy with pemetrexed

Abstract Background To assess the safety and efficacy of vitamin B12 and folic acid starting 24 to 48 hours before the chemotherapy including pemetrexed (PEM). Methods Patients with advanced non-squamous non-small cell lung cancer or malignant pleural mesothelioma diagnosed and scheduled for chemotherapy including PEM were enrolled. Vitamin B12 and folic acid were administered 24-48 hours before the initiation of chemotherapy and we assessed the safety and efficacy of chemotherapy prospectively. As hematologic toxicity by this method has been confirmed in previous study, the primary endpoint was the incidence of non-hematologic toxicity grade 3 or worse during treatment and the secondary endpoint was hematologic toxicity, response rate, progression-free survival, and homocysteine concentration. Results 103 patients were enrolled. The median age was 67 years (range 31-84 years), the gender was 59 male and 44 female and PS 0/1/2 were 33/69/1. Histological types were 96 cases of advanced non-squamous non-small cell lung cancer and 7 cases of malignant pleural mesothelioma. The regimens were CDDP+PEM 80 cases, PEM single agent 11 cases, CBDCA+PEM 7 cases, CDDP+PEM+BEV 3 cases, CBDCA+PEM+BEV 2 cases. The incidence of nonhematologic toxicity at grade 3 or worse was 11 cases (10.7%), achieving the primary endpoint. The incidence of hematologic toxicity at grade 3 or worse was 25 cases (24.3%). The response rate for CDDP+PEM in advanced non-squamous non-small cell lung cancer was 51.4% and a median progression-free survival was 4.8 months. Conclusions The method of administering vitamin B12 and folic acid 24 to 48 hours before initiation of chemotherapy including PEM was safe and there was no problem in efficacy. Clinical trial identification UMIN000010570. Legal entity responsible for the study Yukio Hosomi. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.