Risk factors associated with Richter's transformation in patients with chronic lymphocytic leukaemia: protocol for a retrospective population-based cohort study

Richter Transformation: Clinical Manifestations, Evaluation, and Management

Richter transformation is a devastating and rare but not uncommon development of an aggressive B-cell lymphoma in patients with chronic lymphocytic leukemia or small lymphocytic lymphoma. Prognosis is dismal, with survival generally in the realm of months to a couple of years. Many patients progress quickly after traditional first-line immunochemotherapy. Nonetheless, novel therapies are on the horizon. It is important that the advanced practitioner have awareness and knowledge of this condition in order to furnish a crucial timely diagnosis and to provide appropriate treatment.

Revisiting Richter transformation in the era of novel CLL agents

Richter transformation (RT) is the development of aggressive lymphoma - most frequently diffuse large B-cell lymphoma (DLBCL) and rarely Hodgkin lymphoma (HL) - arising on the background of chronic lymphocytic leukaemia (CLL). Despite recent advances in CLL treatment, RT also develops in patients on novel agents, usually occurring as an early event. RT incidence is lower in CLL patients treated with novel agents in the front line compared to relapsed/refractory cases, with a higher incidence in patients with TP53 disruption. The genetic heterogeneity and complexity are higher in RT-DLBCL than CLL; the genetics of RT-HL are largely unknown. In addition to TP53, aberrations in CDKN2A, MYC, and NOTCH1 are common in RT-DLBCL; however, no distinct RT-specific genetic aberration is recognised yet. RT-DLBCL on ibrutinib is frequently associated with BTK and PLCG2 mutations. Here, we update on genetic analysis, diagnostics and treatment options in RT in the era of novel agents.

U-RT1 - A new model for Richter transformation

The advent of highly effective treatments targeting the disease biology of chronic lymphocytic leukemia (CLL) has transformed the therapeutic field tremendously. However, transformation into an aggressive B-cell lymphoma, called Richter syndrome (RS), remains highly challenging since the treatment options for this condition are still insufficient. Exploratory drug testing and experimental studies are restricted by the lack of satisfactory models. We have established U-RT1, a cell line derived from a highly proliferating RS clonally related to the patient's underlying CLL. The cell line shows morphological features and an immunophenotype of RS-DLBCL (non-GCB). Molecular analysis revealed a complex karyotype with driver aberrations characteristic for RS such as loss of TP53 and CDKN2A. Furthermore, U-RT1 displays a chromosomal gain of the NOTCH1 gene locus and strong immunoreactivity for BCL-2. These features suggest that U-RT1 is the first eligible model system for investigations on the pathogenesis of RS and novel treatment options.

Ibrutinib in Chronic Lymphocytic Leukemia: Clinical Applications, Drug Resistance, and Prospects

Bruton’s tyrosine kinase (BTK), a pivotal component of B-cell receptor (BCR) signaling, has been recognized as an important driver of the pathogenesis of chronic lymphocytic leukemia. Ibrutinib is a highly active and selectively irreversible inhibitor of BTK, which has been approved to be effective in both frontline and recurrent therapy of CLL. Acquired resistance has become a greater problem than initially anticipated with the widespread use of ibrutinib. An ongoing exploration of the mechanisms of ibrutinib resistance (IR) in CLL has revealed potentially useful therapeutic targets. New drugs expected to overcome IR in CLL are in the early stages of clinical development. This study aimed to summarize the possible mechanisms of IR and retrospectively analyze promising therapies that might have superior efficacy in overcoming IR.

Tumor Lysis Syndrome Caused by Unrecognized Richter's Transformation of Chronic Lymphocytic Leukemia: Treatment With Venetoclax for Suspected Disease Progression

Richter’s transformation (RT) is defined as the transition of chronic lymphocytic leukemia (CLL) or small lymphocytic leukemia (SLL) into an aggressive lymphoma. The conversion generally leads to diffuse large B-cell lymphoma (DLBCL), but more aggressive forms such as Hodgkin lymphoma (HL) can also occur. RT is a rare complication of CLL. RT can be confused with CLL progression. Its identification is crucial because the management of lymphoma and CLL differ from each other. Furthermore, the use of certain agents for CLL such as venetoclax increases the risk of tumor lysis syndrome (TLS) in neoplasms with rapid replication such as DLBCL or CLL with hyperleukocytosis (blast crisis). We present the case of a 76-year-old man with a history of CLL on chemotherapy who developed fatigue, malaise, night sweats, chills, and unintentional weight loss for which he was started on treatment with venetoclax due to suspected clinical progression of his disease. The patient developed TLS, requiring hospitalization, and he was found to have an acute blast crisis. Also, his CLL was found to have been transformed into an aggressive DLBCL. This case highlights the importance of differentiating a true progression of CLL from RT into an aggressive lymphoma given that treatment would be different for the two and the prognosis with the transformation is worse.

Richter's transformation in patients with chronic lymphocytic leukaemia: a Nationwide Epidemiological Study

Richter's transformation (RT) refers to the development of an aggressive lymphoma in patients with chronic lymphocytic leukemia (CLL). Approximately, 2-10% of patients with CLL develop RT, most often as diffuse large B-cell lymphoma. To assess the incidence of RT, we examined risk factors for RT and death among patients with RT in a nationwide CLL cohort (from 2008 to 2016). Among 3772 patients, 113 had biopsy-proven RT. With a median follow-up of 4.3 years, the 5-year cumulative incidence of RT was 2.8%. Advanced Binet stage (B/C) (p<.001), unmutated IGHV (p<.001), and del(17p) (p<.001) were independently associated with risk of developing RT. Half of the patients with RT (49%) were treatment-naïve prior to transformation and demonstrated longer survival after RT compared to patients previously treated for CLL (6.1 vs. 2.8 years, p=.03). Whether this finding could be explained by a higher proportion of clonally unrelated RT among treatment-naïve patients, remain to be addressed.