Testing the Addition of a New Anti-cancer Drug, M3814 (Peposertib), to the Usual Radiotherapy in Patients With Locally Advanced Pancreatic Cancer

PRIMARY OBJECTIVES: I. To evaluate the safety and tolerability of M3814 (peposertib) in combination with hypofractionated radiotherapy in patients receiving treatment for locally advanced pancreatic adenocarcinoma (LAPC). (Phase I) II. To determine the difference in progression free survival (PFS) between patients with LAPC treated with hypofractionated radiotherapy in combination with M3814 (peposertib) as compared to patients treated with hypofractionated radiotherapy alone. (Phase II) SECONDARY OBJECTIVES: I. To observe and record anti-tumor activity. (Phase I) II. To evaluate plasma pharmacokinetic (PK) profiles of M3814 (peposertib) in patients receiving hypofractionated radiotherapy. (Phase I) III. To compare the 2-year overall survival (OS) rate of patients treated with hypofractionated radiotherapy plus M3814 (peposertib) to that of those treated with hypofractionated radiotherapy alone. (Phase II) IV. To compare the objective response rate (ORR) by imaging of patients treated with hypofractionated radiotherapy plus M3814 (peposertib) to that of those treated with hypofractionated radiotherapy alone. (Phase II) V. To compare the disease control rate in patients treated with hypofractionated radiotherapy plus M3814 (peposertib) as compared to those patients treated with hypofractionated radiotherapy alone. (Phase II) VI. To explore gene signature patterns in baseline patient tumor tissues that may suggest response to the combination of M3814 (peposertib) and radiotherapy, as identified on whole exome sequencing and ribonucleic acid (RNA) sequencing (seq). (Phase II) EXPLORATORY OBJECTIVE: I. To explore changes in gene signature induced by M3814 (peposertib) and hypofractionated radiotherapy treatment as identified in analysis of cell-free deoxyribonucleic acid (DNA) from the peripheral blood. (Phase II) OUTLINE: This is a phase I, dose-escalation study of M3814 followed by a phase II study. PHASE I: Patients undergo hypofractionated radiation therapy for 5 fractions every other day (QOD) over 2 weeks and receive M3814 orally (PO) once daily (QD) for 14 days in the absence of disease progression or unacceptable toxicity. PHASE II: Patients are randomized to 1 of 2 groups. GROUP I: Patients undergo hypofractionated radiation therapy for 5 fractions QOD over 2 weeks and receive M3814 PO QD for 14 days in the absence of disease progression or unacceptable toxicity. GROUP II: Patients undergo hypofractionated radiation therapy for 5 fractions QOD over 2 weeks and receive placebo PO QD for 14 days in the absence of disease progression or unacceptable toxicity. Patients undergo blood sample collection and tissue biopsy on study. Patients also undergo computed tomography (CT) and magnetic resonance imaging (MRI) during screening and on study. After completion of study treatment, patients are followed up at 30, 60, and 90 days, and then every 3 months for up to 2 years.