Inhibition of B Cell Receptor Signaling by Ibrutinib in Primary CNS Lymphoma

Publication date: Available online 25 May 2017
Source:Cancer Cell
Author(s): Michail S. Lionakis, Kieron Dunleavy, Mark Roschewski, Brigitte C. Widemann, John A. Butman, Roland Schmitz, Yandan Yang, Diane E. Cole, Christopher Melani, Christine S. Higham, Jigar V. Desai, Michele Ceribelli, Lu Chen, Craig J. Thomas, Richard F. Little, Juan Gea-Banacloche, Sucharita Bhaumik, Maryalice Stetler-Stevenson, Stefania Pittaluga, Elaine S. Jaffe, John Heiss, Nicole Lucas, Seth M. Steinberg, Louis M. Staudt, Wyndham H. Wilson
Primary CNS lymphoma (PCNSL) harbors mutations that reinforce B cell receptor (BCR) signaling. Ibrutinib, a Bruton's tyrosine kinase (BTK) inhibitor, targets BCR signaling and is particularly active in lymphomas with mutations altering the BCR subunit CD79B and MYD88. We performed a proof-of-concept phase Ib study of ibrutinib monotherapy followed by ibrutinib plus chemotherapy (DA-TEDDi-R). In 18 PCNSL patients, 94% showed tumor reductions with ibrutinib alone, including patients having PCNSL with CD79B and/or MYD88 mutations, and 86% of evaluable patients achieved complete remission with DA-TEDDi-R. Increased aspergillosis was observed with ibrutinib monotherapy and DA-TEDDi-R. Aspergillosis was linked to BTK-dependent fungal immunity in a murine model. PCNSL is highly dependent on BCR signaling, and ibrutinib appears to enhance the efficacy of chemotherapy.

Teaser

Primary CNS lymphoma (PCNSL) harbors mutations that reinforce B cell receptor signaling. In a phase 1b study, Lionakis et al. observe promising therapeutic effects of the BTK inhibitor ibrutinib in PCNSL but also increased aspergillosis, which they show is linked to BTK-dependent fungal immunity in a mouse model.


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