A Clinical Trial Testing the Safety of the Investigational Drug Pumitamig (BNT327) and How Well it Works in Patients With Recurrent Glioblastoma

Key Inclusion Criteria: * Adults, aged 18-75 years inclusive at the time of giving informed consent. Local laws will be followed if the age at consent is older. * Have a histologically confirmed diagnosis of WHO Grade IV GBM, IDH-wildtype consistent with WHO CNS 2021 criteria. * Have recurrent supratentorial GBM who have received prior treatment with at least radiotherapy and temozolomide. * Have first recurrence documented by magnetic resonance imaging (MRI), with an interval of at least 12 weeks after the end of prior radiotherapy unless there is either: i) histopathologic confirmation of recurrent tumor, or ii) new enhancement on MRI outside of the radiotherapy treatment field. * Have been clinically evaluated as having relapsed or progressed disease with at least one measurable lesion as the targeted lesion based on RANO 2.0 criteria. * Have KPS ≥60. * Can swallow the medication and maintain oral administration. * Have a baseline brain MRI, not more than 14 days before starting the study treatment. * Have a stable dose of steroids ≥7 days before the contrast-enhanced scan. * Have adequate organ function, as defined in the protocol. Key Exclusion Criteria: * Have received any of the following therapies or drugs before study enrollment: * Any anticancer therapies, including systemic, palliative, biologic, immunostimulatory, or immunosuppressive treatment within 4 weeks (or five half-lives, whichever is longer) before starting the study treatment. * PD(L)-1/VEGF bisp…