Phase I Trial Of Ibrutinib, Lenalidomide And Dexamethasone In Patients With Relapsed And/Or Refractory Multiple Myeloma (Rrmm)

Background: Ibrutinib (ibr) is a small-molecular inhibitor of Bruton's Tyrosine Kinase (BTK), active in the treatment of various B-cell malignancies. B-cell receptor signaling blockade by BTK inhibition using ibr down regulates IRF4 (survival transcription factor) which is down regulated by lenalidomide (R) as well, suggesting possible synergistic effect on cell death. Higher doses of ibr (560-840 mg daily) have been used in combination regimens for MM with no significant dose-limiting toxicities (DLTs) but the combination of ibr and len has not been previously tested. We present safety and preliminary efficacy of the combination ibr, R, and dexamethasone (d) in RRMM patients.