Combination of Ibrutinib and Nivolumab Overcomes Ibrutinib Resistance in a Novel Patient-Derived Mantle Cell Lymphoma 3D Model

Mantle cell lymphoma (MCL) is a rare and aggressive B cell non-Hodgkin lymphoma subtype which arises from mature B cells and mainly develops in the lymph node (LN) microenvironment, with a significant proportion of cases showing peripheral blood (PB) dissemination. However, the LN is the organ where MCL creates a protective and immunosuppressive tumor microenvironment (TME), including tumor-associated macrophages that induce tumor survival, proliferation and chemoresistance.

To capture disease heterogeneity and microenvironment cues, we have developed the first MCL Patient-derived lymphoma spheroid (MCL-PDLS) model culturing lymphoma cells from PB in 96-well ultra-low attachment plates with a cytokine cocktail that mimics LN stimuli. Remarkably, our model recapitulates MCL tumor oncogenic pathways. Moreover MCL-PDLS shows immune profile in a multiplexed system that allows easy drug screening including immunotherapies.

MCL-PDLS include tumor B cells and autologous T cells obtained from patients' PB samples, together with healthy donors' monocytes to complete the LN immune microenvironment. These populations self-organize in disc-shaped structures, as determined by light sheet microscopy, where B and T cells maintain viability and proliferate, and monocytes differentiate into M2-like macrophages. Interestingly, RNA-seq analysis demonstrated that tumor cells in MCL-PDLS recapitulate fundamental hallmarks of MCL-LN (Saba et al, Blood 2015), such as proliferation, BCR, NF-kB, antigen presentation and DNA repair, among others.

Using public data basis we have determined by differential expression analysis (MCL-LN vs normal tonsils) a immune profile characteristic of MCL-LN. Flow cytometry analysis of MCL-PDLS determined that immune exhaustion profile is recapitulated in our model, including high expression of PD1, TIM-3 and TIGIT, and their corresponding ligands, together with the expression of other immune regulators such as CD70, CD27, CD47 and SIRPα.

Noteworthy, we have validated that MCL-PDLS reproduce in vivo responses to the first-in-class Bruton's tyrosine kinase inhibitor ibrutinib, setting the basis for the discovery of novel combinatorial approaches. In this regard, we have demonstrated that the combination of ibrutinib with Nivolumab (anti-PD1), may be efficacious in ibrutinib-resistant cases and induces a Th1-polarized response and cytotoxic activity, as demonstrated by an increased IFNγ and granzyme B release, respectively.

In conclusion, MCL-PDLS recapitulates specific LN features and in vivo responses to ibrutinib, representing a robust tool to study the pathogenesis of MCL, its interaction with the TME, and to perform drug screening in a patient-derived system, thus advancing towards personalized therapeutic approaches.

López-Guillermo:Roche: Research Funding; Hospital Clinic de Barcelona: Current Employment; Roche, Kite/Gilead, Celgene, Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees. Giné:Kite, a Gilead Company: Consultancy, Honoraria; Genmab: Honoraria; Janssen: Honoraria, Research Funding.