piperidines and Lymphoma--T-Cell--Cutaneous

Ibrutinib has previously been shown to inhibit Bruton's tyrosine kinase (BTK) and interleukin-2-inducible T-cell kinase (ITK), which mediate B-cell and T-cell receptor signaling, respectively. BTK inhibition with ibrutinib has demonstrated impressive clinical responses in a variety of B-cell malignancies. Whether ibrutinib inhibition of ITK can lead to clinical response in T-cell malignancies is unknown. We hypothesized that ibrutinib-mediated ITK inhibition in T-cell lymphoma would result in decreased signaling through the T-cell receptor pathway and promote antitumor immune response by driving selective cytotoxic Th1 CD4 effector T-cell differentiation. This pilot clinical trial evaluated 2 dose levels of ibrutinib: 560 and 840 mg orally daily. Fourteen patients with relapsed, refractory peripheral T-cell lymphoma and cutaneous T-cell lymphoma were enrolled. Both dose levels were safe and well tolerated, and no dose-limiting toxicities were observed. One patient achieved a partial response (overall response rate, 8% [1/13]). ITK occupancy studies demonstrated a mean occupancy of 50% (range, 15%-80%). Higher ITK occupancy of more than 50% correlated with higher serum levels of tumor necrosis factor-α and interferon-γ and favored a Th1 phenotype. Our data suggest that ibrutinib inhibition of ITK has limited clinical activity in T-cell lymphoma. This study is registered at www.clinicaltrials.gov as #NCT02309580.

Topics: Adenine; Adult; Aged; Aged, 80 and over; Female; Humans; Lymphoma, T-Cell; Lymphoma, T-Cell, Cutaneous; Lymphoma, T-Cell, Peripheral; Male; Middle Aged; Pilot Projects; Piperidines; Protein Kinase Inhibitors; Pyrazoles; Pyrimidines; Salvage Therapy; Treatment Outcome

Topics: Acrylamides; Adult; Aged; Child; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Humans; Infusions, Intravenous; Lymphoma, T-Cell, Cutaneous; Male; Middle Aged; Neoplasm Invasiveness; Neoplasm Recurrence, Local; Neoplasm Staging; Patient Safety; Piperidines; Prognosis; Risk Assessment; Skin Neoplasms; Survival Analysis; Treatment Outcome

Aberrant activation of Janus kinase-3 (Jak3) and its key down-stream effectors, Signal Transducer and Activator of Transcription-3 (STAT3) and STAT5, is a key feature of malignant transformation in cutaneous T-cell lymphoma (CTCL). However, it remains only partially understood how Jak3/STAT activation promotes lymphomagenesis. Recently, non-coding microRNAs (miRNAs) have been implicated in the pathogenesis of this malignancy. Here, we show that (i) malignant T cells display a decreased expression of a tumor suppressor miRNA, miR-22, when compared to non-malignant T cells, (ii) STAT5 binds the promoter of the miR-22 host gene, and (iii) inhibition of Jak3, STAT3, and STAT5 triggers increased expression of pri-miR-22 and miR-22. Curcumin, a nutrient with anti-Jak3 activity and histone deacetylase inhibitors (HDACi) also trigger increased expression of pri-miR-22 and miR-22. Transfection of malignant T cells with recombinant miR-22 inhibits the expression of validated miR-22 targets including NCoA1, a transcriptional co-activator in others cancers, as well as HDAC6, MAX, MYCBP, PTEN, and CDK2, which have all been implicated in CTCL pathogenesis. In conclusion, we provide the first evidence that de-regulated Jak3/STAT3/STAT5 signalling in CTCL cells represses the expression of the gene encoding miR-22, a novel tumor suppressor miRNA.

Topics: Cell Line, Tumor; Genes, Tumor Suppressor; Humans; Janus Kinase 3; Lymphoma, T-Cell, Cutaneous; MicroRNAs; Piperidines; Protein Kinase Inhibitors; Pyrimidines; Pyrroles; Signal Transduction; Skin Neoplasms; STAT3 Transcription Factor; STAT5 Transcription Factor; Transfection