Pharmacological restoration and therapeutic targeting of the B-cell phenotype in classical Hodgkin lymphoma.

Classical Hodgkin lymphoma (cHL), although originating from B cells, is characterized by the virtual lack of gene products whose expression constitutes the B-cell phenotype. Epigenetic repression of B-cell-specific genes via promoter hypermethylation and histone deacetylation as well as compromised expression of B-cell-committed transcription factors were previously reported to contribute to the lost B-cell phenotype in cHL. Restoring the B-cell phenotype may not only correct a central malignant property, but it may also render cHL susceptible to clinically established antibody therapies targeting B-cell surface receptors or small compounds interfering with B-cell receptor signaling. We conducted a high-throughput pharmacological screening based on >28 000 compounds in cHL cell lines carrying a CD19 reporter to identify drugs that promote reexpression of the B-cell phenotype. Three chemicals were retrieved that robustly enhanced CD19 transcription. Subsequent chromatin immunoprecipitation-based analyses indicated that action of 2 of these compounds was associated with lowered levels of the transcriptionally repressive lysine 9-trimethylated histone H3 mark at the CD19 promoter. Moreover, the antileukemia agents all-trans retinoic acid and arsenic trioxide (ATO) were found to reconstitute the silenced B-cell transcriptional program and reduce viability of cHL cell lines. When applied in combination with a screening-identified chemical, ATO evoked reexpression of the CD20 antigen, which could be further therapeutically exploited by enabling CD20 antibody-mediated apoptosis of cHL cells. Furthermore, restoration of the B-cell phenotype also rendered cHL cells susceptible to the B-cell non-Hodgkin lymphoma-tailored small-compound inhibitors ibrutinib and idelalisib. In essence, we report here a conceptually novel, redifferentiation-based treatment strategy for cHL.

Ibrutinib- and bortezomib-extended R-CHOP induction in elderly higher-risk patients newly diagnosed with diffuse large B-cell lymphoma - first analysis of toxicity and efficacy signals.

Diffuse large-cell B-cell lymphoma (DLBCL) is the most common lymphoid malignancy. About 30-40% of the patients will not be cured by standard Rituximab (R)-CHOP-like immune-chemotherapy, and many of them experience relapse and eventually succumb to their disease. Enhancing first-line efficacy in patients at higher risk, among them many elderly, is key to improve long-term outcomes. Numerous attempts to combine R-CHOP with targeted agents failed in large randomized phase III trials. The addition of Ibrutinib enhanced survival in younger patients, but increased toxicity across all age groups, especially in the elderly. Older DLBCL patients impose particular challenges, since they often present with more advanced disease, and exhibit treatment-relevant comorbidities. ImbruVeRCHOP trial aims at identifying patients who need that benefit from rationally augmented first-line regimens without experiencing overt toxicity and detecting their molecular signatures of response. This first analysis presents encouraging feasibility, safety, and preliminary response data in elderly high-risk DLBCL patients.

A Phase I/II first-line study of R-CHOP plus B-cell receptor/NF-κB-double-targeting to molecularly assess therapy response.

The ImbruVeRCHOP trial is an investigator-initiated, multicenter, single-arm, open label Phase I/II study for patients 61-80 years of age with newly diagnosed CD20+ diffuse large B-cell lymphoma and a higher risk profile (International Prognostic Index ≥2). Patients receive standard chemotherapy (CHOP) plus immunotherapy (Rituximab), a biological agent (the proteasome inhibitor Bortezomib) and a signaling inhibitor (the Bruton's Tyrosine Kinase-targeting therapeutic Ibrutinib). Using an all-comers approach, but subjecting patients to another lymphoma biopsy acutely under first-cycle immune-chemo drug exposure, ImbruVeRCHOP seeks to identify an unbiased molecular responder signature that marks diffuse large B-cell lymphoma patients at risk and likely to benefit from this regimen as a double, proximal and distal B-cell receptor/NF-κB-co-targeting extension of the current R-CHOP standard of care. EudraCT-Number: 2015-003429-32; ClinicalTrials.gov identifier: NCT03129828.