Radiotherapy in Combination With Glofitamab in Relapsed/Refractory Diffuse Large B Cell Lymphoma

Clinical trial looking at Radiotherapy in combination with glofitimab in relapsed/refractory Diffuse Large B Cell lymphoma. Where Relapsed/refractory diffuse large B-cell lymphoma after ≥ 2 therapies OR after 1 line AND transplant or CAR-T ineligible. The primary end points is to see what proportion of patients who achieve a complete metabolic response in the absence of prohibitive toxicity following radiotherapy (25Gy in 5 fractions) plus 12 cycles of glofitamab therapy with each cycle delivered every 3 weeks. The secondary endpoints are to assess overall toxicity, to evaluate overall response rates, duration of Response (DOR), time to treatment failure, progression free survival, overall survival, patient report outcome measure - Using EORTC QLD-C30, EORTC IL46 and PRO-CTCAE. Additional PET imaging studies will be performed in a cohort of patients (up to 6) who are willing to undergo infusions of 89Zr-Df-Crefmirlimab and for evaluation of the impact of radiotherapy plus glofitamab on CD8+ T cell biodistribution in the body and in relapsed diffuse large B-cell lymphoma. Additional PET imaging studies will be performed in a cohort of patients (up to 6) who are willing to undergo infusions of 18F-Granzyme B to image active immune responses to treatment with radiotherapy plus glofitamab in patients with relapsed diffuse large B-cell lymphoma.