Germline HLA-DQ genotype influences response to CAR T-cell therapy in patients with large B-cell lymphoma

CD19-directed chimeric antigen receptor (CAR) T cells have greatly improved the prognosis of relapsed/refractory large B-cell lymphoma (rrLBCL), yet treatment failure occurs in more than half of patients, usually in the first 3 months after treatment. While they primarily act through CAR-dependent, HLA-independent recognition of tumor targets, CAR-T cells may also indirectly contribute to long-term tumor immunosurveillance by stimulating endogenous immunity. We hypothesized that HLA diversity, measured by the HLA evolutionary divergence (HED) metric which reflects the breadth of the immunopeptidome presented to host T cells, could influence antitumor response after CAR T-cell therapy, as seen after immune chekpoint inhibitor treatment. We studied 127 rrLBCL patients treated with commercial CAR-T cells in our center, of whom 50 % achieved durable response. We observed no impact of diversity at any HLA locus, except for HED-DQA1 that was surprisingly negatively associated with response. Analysis of the distribution of HLA-DQ alleles according to clustering of HED values pointed to the DQ1/DQ1 genotype as an independent predictor of durable response and lower incidence of relapse/progression. These findings highlight the unsuspected role of germline HLA-DQ molecules in the response to CAR-T cells and suggest an important contribution of cross-talk between CAR-T cells and endogenous immune cells. Key Points ### Competing Interest Statement R. Di Blasi: Scientific Advisory Board of Novartis, Gilead, Janssen and BMS. C. Thieblemont: Scientific Advisory Board of AstraZeneca, Beigene, Abbvie, Takeda, Roche, Novartis, Kyte/Gilead and Bristol Myers Squibb. ### Funding Statement This work was funded by Fondation ARC pour la recherche sur le cancer (PREDICARTe ARCTHEM2021010002907). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study was approved by the review board of Saint-Louis hospital, Assistance Publique-Hopitaux de Paris (BIOCART-CPP 2019-77) and all patients signed informed consent prior to treatment. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors