Abstract Background: Glioblastoma multiforme (GBM) is the most aggressive malignant brain tumor in humans. In spite of advances in treatment strategies, survival rate of GBM remains poor. We have recently reported a novel anti-cancer compound with intrinsic magnetism(EI236). In addition to its anti-cancer effect, EI236 generates a large amount of heat upon an alternating magnetic field (AMF) application because of its magnetism, i.e., hyperthermic effect. In this study, we have examined the effect of EI236 on human GBM in vitroand vivo. Materials and Methods: Human GBM cell lines, U251MG, YKG-1, and U87, were used in this study. Cell proliferation was assessed by methyl thiazolyl tetrazorium (MTT) assays in the presence of EI236, in comparison to temozolomide (TMZ) and calmustine (BCNU), i.e. the clinical standard drugs for GBM. Apoptosis was analyzed by fluorescence activated cells sorting. In addition, we have examined whether EI236 inhibited the tumor growth with/without AMF application in animal models. Tumors were induced by implantation of U251MG cells into the hip of female Balb-c mice. Seven days after the implantation of GBM cells, EI236, BCNU or normal saline (control) was injected respectively into the tumors and mice were exposed to an AMF application(330.8A, 280kHz) for 30 minutes. Therefore, we calculated the tumor volume and the regression rate of tumors twice a week. Result: EI236 inhibited the proliferation of all cell lines and increased apoptosis in a dose dependent manner. Moreover, we found that EI236 had much greater anti-cancer effect than the clinical standard drugs. Mice bearing GBM cancer cells in their hip were then subjected to a double combination therapy, consisting of local injection of EI236 and hyperthermic treatment by AMF application. Tumor sizes in both drug stimulation groups were reduced, especially that in EI236 with AMF application group was highly reduced, while that in control group was increased. Conclusion: EI236 has greater anti-cancer effect than TMZ and BCNU, i.e. the clinical standard drugs. Besides this strong anti-cancer effect, EI236 has hyperthermic effect upon an AMF application because of heat generation. Accordingly, EI236 may enable us to develop novel strategies in GBM treatment, i.e. hyperthermic-chemotherapy with a single-drug compound. Note: This abstract was not presented at the meeting. Citation Format: Makoto Ohtake, Masanari Umemura, Itaru Sato, Kayoko Oda, Akane Nagasako, Ayako Makino, Haruki Aoyama, Mayumi Katsumata, Haruki Eguchi, Nobutaka Kawahara, Yoshihiro Ishikawa. Simultaneous hyperthermic-chemotherapy for glioblastoma using a single anti-cancer compound with intrinsic magnetism. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4548. doi:10.1158/1538-7445.AM2015-4548