Treatment of Richter's Transformation with Novel Therapies

PURPOSE OF REVIEW

This review presents recently published clinical trial data and ongoing investigations regarding the treatment of Richter's transformation (RT).

RECENT FINDINGS

Recently, numerous approaches have been investigated for the treatment of RT including: traditional chemoimmunotherapy regimens combined with targeted agents such as BTKi and BCL2i; immunotherapy combined with targeted agents; non-covalent BTKis; bispecific T cell engagers; and CART therapy. In addition, various novel targeted agents are currently being studied for the treatment of RT in phase 1 and 2 clinical trials. Standard of care treatment with chemoimmunotherapy for RT has limited efficacy in achieving durable remissions. Here, we review recent data on the use of combination treatments and targeted agents in RT. Although some progress has been made in the investigation to optimize treatment of RT, further study is needed to evaluate long term outcomes of recently published trials and test efficacy of upcoming novel agents.

An experience with ibrutinib monotherapy for Richter's syndrome isolated in the central nervous system

Richter's syndrome (RS) of the central nervous system (CNS) is known to have an extremely poor prognosis. Ibrutinib has been reported to have some activity in patients with RS, despite its poor prognosis. Although ibrutinib crosses the blood-brain barrier, its efficacy in RS patients with CNS involvement remains unknown. Here, we report a case of RS isolated in the CNS that was confirmed to be clonally related to chronic lymphocytic leukemia (CLL) by immunoglobulin heavy chain gene analysis. Although the median survival of patients with RS clonally related to CLL was significantly shorter than that of patients with RS clonally unrelated to CLL, the patient received ibrutinib monotherapy without experiencing any significant adverse events, and the disease remained stable with ibrutinib until 6 weeks later. Following whole-brain radiation therapy (40 Gy in 20 fractions) with dexamethasone, the patient has survived for five months after diagnosis. Thus, ibrutinib may be a safe and effective therapeutic option for patients with RS and CNS involvement.

Case Report: Sequential Development of Three Mature Lymphoid Neoplasms in a Single Patient: Clonal Relationship and Molecular Insights

Two main variants of Richter syndrome (RS) are recognized, namely, the diffuse large B-cell lymphoma (DLBCL) and the Hodgkin’s lymphoma (HL) variant. Clonal relationship, defined as an identity of the immunoglobulin heavy chain variable (IGHV) region sequence between chronic lymphocytic leukemia (CLL) and RS clones, characterizes patients with a poor prognosis. Due to method sensitivity, this categorization is performed without considering the possibility of small-size ancillary clones, sharing the same phenotype with the preexisting predominant CLL clone, but with different IGHV rearrangements. Here we describe and molecularly profile the peculiar case of a patient with a CLL-like monoclonal B-cell lymphocytosis (MBL), who sequentially developed a DLBCL, which occurred concomitantly to progression of MBL to CLL, and a subsequent HL. Based on standard IGHV clonality analysis, DLBCL was considered clonally unrelated to the concomitantly expanded CLL clone and treated as a de novo lymphoma, achieving a persistent response. Three years later, the patient further developed a clonally unrelated HL, refractory to bendamustine, which was successfully treated with brentuximab vedotin and radiotherapy, and later with pembrolizumab. We retrospectively performed additional molecular testing, by applying next-generation sequencing (NGS) of immunoglobulin repertoire (Ig-rep) techniques and a more sensitive allele-specific oligonucleotide-droplet digital PCR (ASO-ddPCR) strategy, in order to quantitatively investigate the presence of the rearranged IGHV genes in tumor specimens collected during the disease course. In this highly complex case, the application of modern and sensitive molecular technologies uncovered that DLBCL, initially considered as a de novo lymphoma, was instead the result of the transformation of a preexisting ancillary B-cell clone, which was already present at the time of first MBL diagnosis. A similar approach was also applied on the HL sample, showing its clonal unrelatedness to the previous MBL and DLBCL.

Novel Approaches for the Treatment of Patients with Richter's Syndrome

In the last 10–15 years, the way to treat cancers has dramatically changed towards precision medicine approaches. These treatment options are mainly based on selective targeting against signaling pathways critical for or detrimentally activated in cancer cells in cancer cells, as well as exploiting molecules that are specifically expressed on neoplastic cells, also known as tumor-associated antigens. These considerations hold true also in the hematological field where a plethora of novel targeted agents have reached patients’ bedside, significantly improving clinical responses. Chronic lymphocytic leukemia (CLL) is an example of how targeted therapies, such as BTK, PI3K, or Bcl-2 inhibitors as well as anti-CD20 antibodies, have improved patients’ management, even when adopted as frontline treatment. However, these advancements do not apply to Richter’s syndrome (RS), the transformation of CLL into a very aggressive and fatal lymphoma, occurring in 2–10% of patients. RS is usually a fast-growing lymphoma of the diffuse large B cell or the Hodgkin’s variant, with a dismal prognosis. Despite advancements in depicting and understanding the genetic background of RS and its pathogenesis, no significant clinical results have been registered. In the last couple of years, several studies have started to investigate the impact of novel drugs or drug combinations and some of them have opened for clinical trials, currently in phase I or II, whose results will be soon available. This review will present an overview of current and most recent therapeutic options in RS, discussing also how results coming from xenograft models may help in designing and identifying novel treatment opportunities to overcome the lack of effective therapies.

Outcomes of Richter's transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL): an analysis of the SEER database

Richter's transformation (RT) is a rare complication arising in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and is associated with an overall dismal outcome. The rarity of this entity poses many challenges in understanding its biology and outcomes seen and the optimal treatment approach. We utilized the SEER (Surveillance, Epidemiology and End Results) database to identify patients diagnosed with CLL/SLL between 2000 and 2016 and subsequently had a diagnosis of diffuse large B-cell lymphoma (DLBCL) or Hodgkin lymphoma (HL), thus capturing those who experienced an RT event. We compared the outcomes of those patients to those of patients in the database diagnosed with DLBCL without a preceding CLL/SLL diagnosis. We identified 530 patients who developed RT out of 74,116 patients diagnosed with CLL/SLL in the specified period. The median age at RT diagnosis was 66 years, and the median time from CLL/SLL diagnosis to RT development was roughly 4 years. Patients with RT had a dismal outcome with median overall survival of 10 months. We identified advanced Ann Arbor stage (III/IV) and prior treatment for CLL as predictors of worse outcome in patients with RT. Our study represents the largest dataset of patients with CLL/SLL and RT and adds to the existing literature indicating the poor outcomes for those patients.

Non-Coding RNAs: The "Dark Side Matter" of the CLL Universe

For many years in the field of onco-hematology much attention has been given to mutations in protein-coding genes or to genetic alterations, including large chromosomal losses or rearrangements. Despite this, biological and clinical needs in this sector remain unmet. Therefore, it is not surprising that recent studies have shifted from coded to non-coded matter. The discovery of non-coding RNAs (ncRNAs) has influenced several aspects related to the treatment of cancer. In particular, in chronic lymphocytic leukemia (CLL) the knowledge of ncRNAs and their contextualization have led to the identification of new biomarkers used to follow the course of the disease, to the anticipation of mechanisms that support resistance and relapse, and to the selection of novel targeted treatment regimens. In this review, we will summarize the main ncRNAs discovered in CLL and the molecular mechanisms by which they are affected and how they influence the development and the progression of the disease.

Cutaneous manifestations of B-cell chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a malignant lymphoproliferative disease characterized by the accumulation of immature monoclonal B lymphocytes in blood cells, bone marrow, spleen and lymph nodes. This is the most common type of leukemia among the Caucasoid race. When CLL skin lesions occur in about 25% of patients, they are extremely diverse. These lesions can be divided into specific, including infiltration of the skin by leukemic cells and the skin form of Richter's syndrome, secondary skin tumors, nonspecific lesions and associated skin diseases.Leukemic infiltration of the skin in patients with leukemia is called specific skin lesions (SSL). Many authors associate the unfavorable prognosis with the transformation of CLL with specific infiltration of the skin into Richter syndrome, as well as the appearance of SSL before the diagnosis of CLL. The risk of developing various cancer pathologies in patients with CLL is three times higher than in healthy people identical in sex and age. It was found that the risk of skin cancer in these patients is eight times higher than in the healthy population. The most common secondary skin tumors in CLL are basal-cell carcinoma, squamous-cell carcinoma, melanoma, and Merkel tumor.Nonspecific skin changes are extremely diverse and occur in patients with CLL in 30-50% of cases. The most common secondary changes in the skin in CLL are those of infectious nature. There are also increased reactions to insect bites, generalized itching, exfoliative erythroderma, nodular erythema, paraneoplastic pemphigoid, bullous pemphigoid, drug eruption. Concomitant dermatoses in these patients are more severe and often torpid to the previously conducted therapy. There is no doubt that together with the clarification of the etiology and pathogenesis of CLL, particular issues related to the study of clinical and morphological changes in individual organs and systems, in particular the skin, formed at various stages of the development of this disease should be studied in detail. This can not only expand and clarify our understanding of this pathology, but also can help to clarify the essence of the disease.

Rare case of Richter's syndrome localization in liver and thyroid of a patient with a chronic lymphocytic leukemia (CLL) - Case report and literature

Richter's syndrome (RS) is a rare complication in which chronic lymphocytic leukaemia (CLL) or small lymphocytic lymphoma (SLL) transforms into a more aggressive type of lymphoma - diffuse large B cell lymphoma (DLBCL), or Hodgkin's lymphoma (HL). The review describes the clinical case of a patient with CLL and RS diagnosis. A computed tomography (CT) scan of the abdominal cavity detected numerous normodense areas in the liver. Simultaneously, ultrasound examination (USG) of the thyroid revealed the presence of a solid hypoechogenic lump. The material sampled from closed biopsies of liver and thyroid in both cases allowed the diagnosis of diffuse large B cell lymphoma (DLBCL). The liver and the thyroid are particularly rare locations of RS. However, those cases allowed the conclusion that RS may occur even in a very unexpected and less probable location.

Richter's syndrome of T-cell lineage (T rex lymphoma)

By definition, Richter's syndrome represents the transformation of low-grade B-cell lymphoma into high-grade B-cell lymphoma, usually refractory to treatment. Exceptional cases of transformation into very aggressive mature T-cell lymphomas have been described as an unusual manifestation of the syndrome in patients died after few months from the diagnosis, despite chemotherapy. The time is ripe to regroup these T lymphomas under a new pathological subset, through the unequivocal alternate naming of 'T rex lymphoma', by analogy with the aggressive behavior of the famous dinosaur (T. rex). In practice, it represents the transformation of low-grade B-cell lymphoma into high-grade T-cell lymphoma, burdened by a very poor prognosis, because of the underlying B-cell lymphoma, which negatively interferes with the immune response of the patient. Against this distinct lymphomatous T clone, the major therapeutic efforts should be addressed.

Is percutaneous computed tomography-guided biopsy sufficient to establish indolent lymphoma transformation?

INTRODUCTION

The aim of the study was to retrospectively evaluate the technical features, efficacy, accuracy, and relevant complications of computed tomography-guided biopsies in various anatomical localizations when diagnosing indolent lymphoma transformations, relapses, duplicate malignant diseases or benign processes.

MATERIAL AND METHODS

From December 2007 to December 2017, 81 percutaneous biopsy procedures in 72 patients for tumors, sizes 17-232 mm in diameter (median length: 39 mm), were performed in patients with known indolent lymphomas in their clinical history. The patients were men in 41 cases and women in 31 cases, aged 36 to 86 years.

RESULTS

In 79 cases (97.5%; 95% CI: 91.3-99.7) results were true positive or true negative; only 2 interventions (2.5%; 95% CI: 0.3-8.6) were histologically false negative. Transformation was verified in 29 cases (35.8%; 95% CI: 25.4-47.2), relapses in 30 cases (37%; 95% CI: 26.6-48.5), duplicate malignancy in 15 cases (18.5%; 95% CI: 10.8-28.7) and benign processes in 7 cases (8.7%; 95% CI: 3.5-17.0). Eight complications in total were revealed, 7 of which were in consequence of thoracic cavity biopsy. A statistically significant relationship between the complication incidence and anatomical localization in the thoracic cavity was identified (p = 0.0104).

CONCLUSIONS

Percutaneous CT guided biopsy performed in patients with a history of indolent lymphoma had high accuracy in establishing the correct diagnosis regarding transformation, relapse, duplicate malignancy or a benign process. Simultaneously, the complication rate was low.

CD5-negative chronic lymphocytic leukemia/small lymphocytic lymphoma in a patient with gastrointestinal mantle cell lymphoma: an unusual case report

Richter’s syndrome, the development of high-grade non-Hodgkin lymphoma in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), may be triggered by viral infections (eg, Epstein–Barr virus infection). Herein, we report an unusual case of CD5-negative CLL/SLL patient with gastrointestinal mantle cell lymphoma (MCL) and hepatitis B virus infection. CLL/SLL was diagnosed based on lymph node immunohistochemistry and bone marrow pathology. This patient was treated with seven cycles of multi-agent chemotherapy. During treatment, the hepatitis B viruses were activated. Then, after 20 months of antiviral treatment with entecavir, he developed abdominal discomfort and abdominal lymphadenopathy and was diagnosed with MCL based on intestinal biopsy. This work indicates that the hepatitis B virus in patients with CLL/SLL may accelerate the progress or transformation to MCL.

Richter syndrome: A rare complication of chronic lymphocytic leukemia or small lymphocytic lymphoma

BACKGROUND

Richter's syndrome (RS) is a rare complication with an unfavorable prognosis, in which chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) transform into a more aggressive type of lymphoma, most commonly into diffuse large B cell lymphoma (DLBCL) or less often into Hodgkin's lymphoma (HL).

OBJECTIVES

The objective of this research paper was to present a retrospective analysis of patients with CLL/SLL whose disease transformed into RS.

MATERIAL AND METHODS

The study included 217 patients (100 women and 107 men) with CLL/SLL diagnosed in the years 2006-2015 at the Department of Hematooncology and Bone Marrow Transplantation of the Medical University of Lublin, which transformed into RS. We analyzed clinical, laboratory, immunophenotypic (ZAP-70 and CD38 expression), histopathological, and genetic data (del(17p), del(11q)), which was collected at the time of CLL/SLL diagnosis, and some which was collected at the time of transformation.

RESULTS

Richter's syndrome was diagnosed in 4.6% of all CLL and SLL patients. The group of patients with RS consisted of 9 patients with primary CLL and 1 patient with a diagnosis of SLL (8 patients with transformation into DLBCL and 2 patients with transformation into HL). Leukemic lymphocytes showed evidence of peripheral blood lymphocyte membrane expression of ZAP70+/CD38+ (1 patient), of ZAP-70+/CD38- (3 patients), of ZAP-70-/CD38- (1 patient), and of ZAP-70-/CD38+ (5 patients). The deletion of 11q (del(11q)) was documented in 2 patients. In 4 cases, the location of RS was extremely rare (the thyroid gland, liver, skin, bladder, and central nervous system).

CONCLUSIONS

Richter's syndrome is a rare, but probable complication of CLL/SLL with an unfavorable prognosis, and it should be taken into account at every stage of the disease, particularly when the course of the disease is aggressive.

B-chronic lymphocytic leukemia showed triple transformation, to diffuse large B cell, CD20-negative, and T-cell neoplasm during ofatumumab treatment: a case report

Background

Chronic lymphocytic leukemia (CLL) is a mature lymphoid neoplasm currently categorized as an indolent type of malignant lymphoma. CLL progresses slowly over years, but it eventually transforms to a more aggressive lymphoma such as the diffuse large B-cell (DLBCL) type, also known as Richter's syndrome.

Case presentation

We treated a 69-year-old Japanese male who was histologically diagnosed with Richter's syndrome after 6 years of CLL. His lymphadenopathy had systemically progressed for years, with lymphocyte counts of less than 10,000 cells/μL and a disease status of Rai classification stage I and Binet classification B. He had high fever and hepatosplenomegaly upon Richter's transformation. The patient was treated with ofatumumab for refractory CLL, which relieved his febrile lymphadenopathy. He received a total of 11 ofatumumab courses and achieved partial remission. On the day of the 12th course of ofatumumab, his disease relapsed with febrile lymphadenopathy. Computed tomography revealed multiple liver masses and systemic lymphadenopathy, while a liver biopsy confirmed T-cell lymphoma. Concomitantly, CD20-lacking CLL cells were detected in his peripheral blood and bone marrow, and pathological examination of his left cervical lymph node biopsy showed CD20-positive DLBCL. The final diagnosis was three different types of lymphoma pathologies: (1) CD20-positive DLBCL of the lymph nodes, (2) CD20-lacking CLL of the peripheral blood and bone marrow, and (3) peripheral T-cell lymphoma (PTCL) of the liver. He received intravenous and oral dexamethasone therapy as palliative care. He died because of the rapid progression of abdominal masses 2 months after the diagnosis of triple transformation CLL. An autopsy revealed aggressive PTCL with aggressive systemic involvement of the liver, spleen, gall bladder, pericardium, bone marrow, and mediastinal-paraaortic-intraceliac lymph nodes. T-cell receptor study of an autopsy specimen supported the diagnosis of PTCL that spread to the intraceliac organs and lymph nodes. We concluded that his pathogenicity progressed to a mixture of triple lymphoma as a result of double malignant transformations, which included PTCL from CLL, CD20-negative CLL, and CD20-positive DLBCL by Richter's transformation.

Conclusions

Our case provides information on the biology of CLL, to transform from a low-grade chemosensitive status to a malignant chemoresistant status.