The purpose of this study is to learn about the effects of two study medicines (maplirpacept \[PF-07901801\] and glofitamab) when given together for the treatment of diffuse large B-cell lymphoma (DLBCL) that is relapsed or is refractory. Relapsed means has returned after last treatment. Refractory means that it has not responded to last treatment. The two study medicines are given after a single dose of obinutuzumab which is the third study medicine. DLBCL is a type of non-Hodgkin lymphoma (NHL). NHL is a cancer of the lymphatic system. It develops when the body makes abnormal B lymphocytes. These lymphocytes are a type of white blood cell that normally help to fight infections. This study is seeking adult participants who: * Have histologically confirmed diagnosis of DLBCL * Have received at least two first lines of treatment for NHL. * Are unable or unwilling to undergo a stem cell transplant or CAR-T cell therapy. Stem cell transplant is a procedure in which a patient receives healthy blood-forming cells to replace their own stem cells that have been destroyed by treatment. A CAR-T therapy is a type of treatment in which a patient's T cells are changed in the laboratory so they will attack cancer cells. Everyone in this study will receive all three medicines at the study site by intravenous (IV) infusion which is given directly into a vein. The two study medicines (maplirpacept \[PF-07901801\] and glofitamab) will be given in 21-day cycles. At Cycle 0, participants will receive a single dose of obinutuzumab pre-treatment followed by two step-up doses of glofitamab. The combination of maplirpacept (PF-07901801) with glofitamab full dose will be administered for the first time at Cycle 1 Day 1. Maplirpacept (PF-07901801) will be given weekly for the first three cycles and then every three weeks. Glofitamab will be given every 3 weeks for approximately 9 months. Thereafter participants will continue to receive maplirpacept alone. Maplirpacept (PF-07901801) will be given at different doses to different participants. Everyone taking part will receive the same fixed doses of glofitamab and obinutuzumab studied in patients with DLBCL. The study will compare the experiences of people receiving different doses of maplirpacept (PF-07901801). This will help to determine what dose is safe and effective when given with the other 2 study medicines.
Phase 1 trials primarily test safety and dosing in a small number of participants (typically 20–100). Results do not yet speak to efficacy. FDA approval is typically many years away from this stage.
Phase 2 trials begin testing efficacy in a larger patient group (100–300). This is often where biotech binary events occur — positive Phase 2 data can significantly advance a company's pipeline narrative, while failures can be terminal for a program.
Enrollment is complete. The trial is in its follow-up or data collection phase — a readout may occur on or near the primary completion date.
Pfizer Inc (PFE) is the sponsoring company for this trial. BiotechSign currently grades this company F (33/100) based on composite catalyst signals across its full pipeline. This trial is one data point in that overall catalyst picture.