RecruitingPhase 2Drug trialItacitinib Pre-modulation in DLBCL Receiving CAR T Cell TherapyThe purpose of the study is to assess the safety and efficacy of once daily itacitinib oral administration in participants with diffuse large B-cell lymphoma (DLBCL) who will receive CAR-T cell therapy with axicabtagene ciloleucel (axi-cel).