Mechanisms of resistance to chimeric antigen receptor-T cells in haematological malignancies

Chimeric antigen receptor (CAR)-T cells have recently emerged as a powerful therapeutic approach for the treatment of patients with chemotherapy-refractory or relapsed blood cancers, including acute lymphoblastic leukaemia, diffuse large B cell lymphoma, follicular lymphoma, mantle cell lymphoma and multiple myeloma. Nevertheless, resistance to CAR-T cell therapies occurs in most patients. In this Review, we summarize the resistance mechanisms to CAR-T cell immunotherapy by analysing CAR-T cell dysfunction, intrinsic tumour resistance and the immunosuppressive tumour microenvironment. We discuss current research strategies to overcome multiple resistance mechanisms, including optimization of the CAR design, improvement of in vivo T cell function and persistence, modulation of the immunosuppressive tumour microenvironment and synergistic combination strategies.

Lisocabtagene maraleucel in the treatment of relapsed/refractory large B-cell lymphoma

Lisocabtagene maraleucel (liso-cel) is one of the three US FDA-approved chimeric antigen receptor T-cell therapies for the treatment of relapsed/refractory (R/R) large B-cell lymphoma (LBCL). TRANSCEND is the landmark trial that led to the approval of liso-cel in the third-line setting for R/R diffuse LBCL, primary mediastinal B-cell lymphoma, follicular lymphoma grade 3B and transformed lymphoma. The TRANSFORM and PILOT studies evaluated the use of liso-cel in the second-line treatment of R/R LBCL. This review details the structure and manufacturing process of liso-cel that make it distinct from other approved chimeric antigen receptor constructs, outlines results from landmark trials of liso-cel in LBCL and discusses liso-cel toxicity.

Top advances in lymphoma for 2021

Chimeric antigen receptor (CAR) T-cell therapy, antibody-drug conjugates, bispecific T-cell redirectors, and agents targeting tonic B-cell receptor signaling have altered the paradigm for three of the most common lymphomas in the year 2021. For diffuse large B-cell lymphoma, the POLARIX study has shown improvement on the standard backbone of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone in the frontline setting, a feat that had not been achieved despite great efforts over the past 20 years. In the relapsed and refractory setting, two unique CAR T-cell products have displaced autologous transplantation to the third line, and they allow patients with chemotherapy-resistant disease to receive approved therapy earlier. CAR T-cell products, once used exclusively in the aggressive lymphoma arena, are now showing high response rates and durable activity against indolent lymphomas. The investigation of mosunetuzumab in indolent lymphomas offers another option for patients who have received multiple lines of cytotoxic drugs. On the basis of these trends, PI3K inhibitors are being displaced in favor of safer and more durable constructs. In addition, within the past year, the approval and implementation of zanubrutinib for marginal zone lymphoma have filled a need for later line therapy, especially for less fit and elderly patients.