This is a multicenter, open-label, Phase 1b/2 study to evaluate the safety, tolerability and potential clinical benefits of maplirpacept (PF-07901801), an anti-CD47 molecule, in combination with standard doses of tafasitamab and lenalidomide in participants with relapsed/refractory (R/R) DLBCL not eligible for or unwilling to undergo high dose chemotherapy and subsequent autologous stem cell transplantation (ASCT) or unable to receive approved chimeric antigen receptor T-cell (CAR-T) therapy (for example, due to logistical limitations).
For Phase 1b, participants must have previously received at least 1 prior systemic treatment regimen. For Phase 2, participants must have received at least 1 but no more than 2 prior systemic treatment regimens. All participants must have previously received an anti-CD20 containing regimen.
Phase 1b will assess dose-limiting toxicities of maplirpacept (PF-07901801) when administered in combination with tafasitamab and lenalidomide, to select up to 2 doses for the Phase 2 part of the study. Phase 2 will evaluate safety and efficacy to determine the recommended Phase 3 dose of Maplirpacept (PF-07901801) to be administered in combination with tafasitamab and lenalidomide.
