 This is a single-center, open-label, non-randomized, Phase IIIa study to investigate the safety, tolerability, and antitumor efficacy of AXL1717 picropodophyllin as active agent formulated in an oral suspension; PPP in patients with recurrent malignant astrocytomas glioblastoma, gliosarcoma, anaplastic astrocytoma, anaplastic oligodendroglioma, anaplastic oligoastrocytoma, and anaplastic ependymoma. Patients will be treated for up to 5 cycles. A treatment cycle is defined as 28 days7 days rest 287 days during cycle 1 to 4, and 28 days during cycle 5. The following cycle will not be started until the treatment continuation criteria are fulfilled. Concomitant supportive therapies will be allowed. 