Phase II study of fludarabine, cytarabine (Ara-C), cyclophosphamide, cisplatin and GM-CSF (FACPGM) in patients with Richter's syndrome or refractory lymphoproliferative disorders

Are we closer to a standard of care for Richter's syndrome? Novel treatments on the horizon

INTRODUCTION

The therapeutic landscape for chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) has significantly evolved over the past decade with dramatically improved outcomes with the introduction of targeted therapies. This unfortunately has not been the case for Richter transformation (RT), the histologic transformation to a more aggressive lymphoma, most typically diffuse large B-cell lymphoma (DLBCL). As such, RT continues to be one of the most challenging complications of CLL/SLL. Historically, RT has a poor response to treatment, with a minority reaching complete remission (CR) and overall survival (OS) being less than a year.

AREAS COVERED

The focus of this review is to discuss the effectiveness of commonly used regimens, and review existing data for emerging regimens being examined in ongoing clinical trials to improve prognosis and outcomes in patients with RT. Despite extensive efforts to optimize therapies for RT, there is still no generalized consensus on either first-line treatment regimens or regimens in the relapsed/refractory setting. RT continues to carry a high mortality rate without durable response to current therapeutic agents.

EXPERT OPINION

Ongoing and future research may identify novel treatment approaches that will eventually improve outcomes for patients with RT. The optimal care for RT patients is a clinical trial, when feasible.

Richter transformation-is there light at the end of this tunnel?

Richter transformation (RT) represents an uncommon (2% to 10%) but feared complication of chronic lymphocytic leukemia (CLL). The disease is characterized by rapid disease kinetics, a high-risk genetic mutational profile, chemoimmunotherapy resistance, and consequent poor survival. The typical overall survival (OS) from the pre-Bruton tyrosine kinase (BTK)/B-cell lymphoma 2 (BCL2) inhibitor CLL era is 6-12 months, and recent series of RT complicating progression on a BTK or BCL2 inhibitor in heavily pretreated relapsed CLL patients suggests an OS of only 3-4 months. Despite these sobering survival statistics, novel agents have the potential to impact the natural RT disease course. This article reviews recent therapeutic developments, focusing on inhibitors of BTK, BCL2, the PD1-PDL1 axis, and T-cell-activating/engaging therapies. Herein, I discuss the importance of randomized clinical trials in a disease where small single-arm studies dominate; industry engagement, including the role of registrational studies; and the need to integrate prospectively planned correlative biological studies embedded within future clinical trials to help discover which patient benefits most from each class or combination of novel targets.

Response to therapy in Richter syndrome: a systematic review with meta-analysis of early clinical trials

Introduction and aims

Richter syndrome (RS) represents the clonal evolution of chronic lymphocytic leukemia with histological transformation into a high-grade B cell lymphoma (diffuse large B cell lymphoma - DLBCL) or Hodgkin lymphoma. Considering that RS is an uncommon condition with poor prognosis, few high-quality evidence is available. To overcome this unmet need, this meta-analysis aimed to pool efficacy of early clinical trials in Richter syndrome (DLBCL subtype).

Methods

MEDLINE, Scopus and Web of Science were searched up to May of 2023 to identify clinical trials decoying efficacy. The pooled complete response, objective response and intension-to-treat failure rates were calculated by pharmacological categories (classical chemotherapy, immunochemotherapy, immunotherapy, Bruton-tyrosine kinase inhibitors, targeted approaches, cell-based therapies and combinatorial regimens) using the Der-Simonian and Laird random-effects model. The Freeman-Tukey double arcsine method was used to estimate variance and confidence intervals. Heterogeneity was assessed using the I2 method.

Results

Overall, from 1242 studies identified, 30 were included, pooling data from 509 patients. The higher efficacy rates when, cell-based therapies were excluded, were achieved by immunochemotherapeutic regimens followed by combinatorial regimens, with complete response rates of 21.54% (IC95%14.93-28.87) and 23.77% (IC95% 8.70-42.19), respectively. Bispecific antibodies (alone or coupled with a chemotherapy debulking strategy) overtook Bruton tyrosine kinase inhibitors response rates. The latter, although achieving objective response rates above average, presented scarce complete response rates. Checkpoint inhibitors alone usually do not lead to complete responses, but their effectiveness may improve when combined with other agents, unveiling the importance of immune microenvironmental modulation.

Conclusion

This is the first meta-analysis of early clinical trials assessing the impact of different therapeutics in RS. By analyzing the pooled efficacy estimates, our work suggests the role of a tailor-made bridging therapy for young patients with RS eligible for allogeneic hematopoietic stem cell transplantation (alloSCT), formally the only curative strategy.

SOHO State of the Art Updates and Next Questions | Treatment of Richter's Transformation

Richter's transformation (RT) is a rare condition, represented by the development of an aggressive lymphoma arising from underlying chronic lymphocytic leukemia/small lymphocytic lymphoma. The management of RT remains challenging, necessitating combined therapeutic strategies to achieve favorable outcomes. Traditional treatment options for RT have involved intensive chemotherapy regimens, often with limited success due to the high-risk nature of the disease. However, recent advances in the understanding of RT pathogenesis have led to the emergence of novel targeted therapies that show promising results. Noncovalent Bruton tyrosine kinase inhibitors, T-cell-engaging bispecific antibodies, chimeric antigen receptor T-cells, and conjugated monoclonal antibodies may hold promise for improved outcomes in RT, especially when combined in a multitargeted fashion. Further prospective randomized trials and collaborative efforts are warranted to optimize treatment algorithm and ultimately improve patient outcomes in this dismal condition. This review provides a comprehensive overview of the current treatment options for RT.

Accelerated Chronic Lymphocytic Leukemia and Richter Transformation in the Era of Novel Agents

BACKGROUND

Tremendous developments in the field of chronic lymphocytic leukemia (CLL) in recent years have led to a revolutionary change in the treatment approach, which today is based on targeted treatments with a good response and optimal prognosis. Nevertheless, CLL can present or progress to "accelerated CLL" (A-CLL) or to "Richter transformation" (RT) and these two entities have a more aggressive course and are still characterized by challenges in the fields of diagnosis and therapy. In the current review, we summarized the latest knowledge in terms of diagnostic approaches to A-CLL, available treatments and clinical trials, for both A-CLL and RT which still pose an unmet need and require additional basic and clinical investigations.

SUMMARY

A-CLL is a rare and underdiagnosed entity that probably stands in the "gray zone" between CLL and RT, generally holding an intermediate prognosis. Its diagnosis is mainly based on histological findings including expanded proliferation centers, increased mitotic activity, and/or high Ki-67 index. Due to its rarity, its treatment approach has still not been defined, but it seems that novel agents, especially Bruton tyrosine kinase inhibitors (BTKi), are effective. As for RT, the standard therapy still consists of chemo-immunotherapy followed by stem-cell transplantation for fit responders with a dismal prognosis. New approaches are recently adopted including B-cell inhibition via novel agents (BTKi, venetoclax), T-cell engagers (checkpoint inhibitors, bispecific antibodies [BiTe] or the chimeric antigen receptor [CAR] technology), antibody-drug conjugates, or drug combinations. Although both CAR-T and BiTe seem promising, especially when combined with BTKi, evidence is still insufficient, and patients should generally be recruited in clinical trials.

KEY MESSAGES

The field of CLL has been a subject of major advances in recent years, but A-CLL and RT remain topics of "unmet need" and require further studies to identify the best diagnostic approach and a more effective treatment.

Treatment of Richter Transformation of Chronic Lymphocytic Leukemia in the Modern Era

Richter Transformation (RT) refers to the development of an aggressive lymphoma in the setting of chronic lymphocytic leukemia (CLL). While many variants of RT are recognized, diffuse large B-cell lymphoma (RT-DLBCL) is the most common (80%), followed by Hodgkin’s lymphoma (RT-HL, 19%). Diagnosis is based upon histologic evaluation of clinically suspicious lymph nodes. Positron emission tomography (PET) may be used to select the node of interest for biopsy. Although clonality testing is not a prerequisite of RT diagnosis, it has significant implications for survival. Clonally related DLBCL carries the worst prognosis with a median overall survival (OS) of less than one year in the era of combination chemotherapies with or without anti-CD20 antibodies. Prognosis has improved with the use of stem cell transplant and newer agents such as targeted therapy and newer forms of immunotherapy. Consideration of a clinical trial is encouraged. This review describes our current understanding of RT and focuses on treatment of RT-DLBCL, including clinical trials in progress and new therapies in development. We also report an illustrative example of a patient with clonally related DLBCL who survived two years after diagnosis without the use of combination chemotherapy.

Treatment of Richter's syndrome

Richter's syndrome (RS) is an aggressive histologic transformation of chronic lymphocytic leukemia (CLL), most commonly to diffuse large B-cell lymphoma (DLBCL). Outcomes are generally poor, with complete remission (CR) rates of only about 20% and less than 20% long-term survival with chemoimmunotherapy (CIT). RS is biologically heterogeneous, and in 80% of patients with CLL who develop DLBCL, the disease is clonally related to the CLL. Clonally unrelated cases are genetically and immunologically distinct from clonally related DLBCL-RS, have more favorable responses to CIT, and are best treated as de novo DLBCL. Relatively favorable outcomes with CIT are also seen in patients who have never previously received treatment for CLL and who lack TP53 mutation or deletion. For the remaining patients, treatment on a clinical trial is optimal. Fortunately, numerous agents are now in clinical development that show encouraging results. Here we review clinical data for some of the most promising approaches. DLBCL-RS tumor cells frequently express programmed cell death 1 protein (PD-1), and several studies have demonstrated activity for PD-1 inhibitors, especially in combination with ibrutinib. The BCL2 inhibitor venetoclax in combination with R-EPOCH CIT achieved CR in 50% of patients, and a study of venetoclax-R-CHOP is ongoing. The noncovalent Bruton's tyrosine kinase inhibitor pirtobrutinib has achieved responses in approximately two-thirds of heavily pretreated patients and, given its favorable toxicity profile, appears ideally suited to combining with other active agents. Finally, we review available data for bispecific antibodies, antibody-drug conjugates, and chimeric antigen receptor T-cell therapy, which, after revolutionizing the treatment of DLBCL, are now being evaluated in RS.

[Richter Syndrome: Diagnostic and Therapeutic Management]

Richter syndrome (RS) is defined as the occurrence of an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (DLBCL) and rarely Hodgkin lymphoma (HL), in a patient with prior or concomitant chronic lymphocytic leukemia (CLL). RS is estimated to occur in 0.5-1 % per year and is associated with adverse outcome. In the vast majority of patients (80 %), RS is clonally related to the prior CLL. Those with unrelated RS appear to have better outcome. The therapeutic approach is based on those of de novo DLBCL or HL. However, even with modern immunochemotherapy regimens, response rate remains low. In eligible patients with related RS, a consolidation by autologous or allogeneic stem-cell transplantation must be proposed. Combinations including therapies targeting BCR or BCL2 and effective in CLL are currently being evaluated in RS. Novels immunotherapies could be promising approaches based on preliminary results.

Electrolyte Disorders Induced by Antineoplastic Drugs

The use of antineoplastic drugs has a central role in treatment of patients affected by cancer but is often associated with numerous electrolyte derangements which, in many cases, could represent life-threatening conditions. In fact, while several anti-cancer agents can interfere with kidney function leading to acute kidney injury, proteinuria, and hypertension, in many cases alterations of electrolyte tubular handling and water balance occur. This review summarizes the mechanisms underlying the disturbances of sodium, potassium, magnesium, calcium, and phosphate metabolism during anti-cancer treatment. Platinum compounds are associated with sodium, potassium, and magnesium derangements while alkylating agents and Vinca alkaloids with hyponatremia due to syndrome of inappropriate antidiuretic hormone secretion (SIADH). Novel anti-neoplastic agents, such as targeted therapies (monoclonal antibodies, tyrosine kinase inhibitors, immunomodulators, mammalian target of rapamycin), can induce SIADH-related hyponatremia and, less frequently, urinary sodium loss. The blockade of epidermal growth factor receptor (EGFR) by anti-EGFR antibodies can result in clinically significant magnesium and potassium losses. Finally, the tumor lysis syndrome is associated with hyperphosphatemia, hypocalcemia and hyperkalemia, all of which represent serious complications of chemotherapy. Thus, clinicians should be aware of these side effects of antineoplastic drugs, in order to set out preventive measures and start appropriate treatments.

PD-1 Expression in Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL) and Large B-cell Richter Transformation (DLBCL-RT): A Characteristic Feature of DLBCL-RT and Potential Surrogate Marker for Clonal Relatedness

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is a low-grade B-cell neoplasm and ∼2% to 9% patients develop an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (Richter transformation, DLBCL-RT). Programmed death-1 (PD-1) pathway plays a crucial role in tumor host immunity evasion and its blockade has emerged as an effective anti-cancer immunotherapy. PD-L1 and PD-1 expression has shown predictive value in anti-PD cancer immunotherapy; however, it has not been well documented in CLL/SLL and DLBCL-RT. We evaluated PD-1 and PD-L1 expression by immunohistochemistry in 39 CLL/SLL, 15 DLBCL-RT, and 26 other DLBCL. In CLL/SLL, neoplastic B-cell PD-1 expression was weak and restricted to prolymphocytes/paraimmunoblasts within proliferation centers (PCs) and accentuated PCs of all sizes. Neoplastic B-cell PD-1 expression was highly prevalent and demonstrated increased intensity in DLBCL-RT, but in contrast was only rarely seen in other DLBCL (12/15 vs. 1/26; P<0.0001). An excellent correlation (90% concordance) was observed between neoplastic B-cell PD-1 immunohistochemistry positivity and molecularly defined CLL/SLL clonal relatedness in DLBCL-RT. PD-L1 expression was observed on the neoplastic B cells in rare DLBCL-RT and other DLBCL cases (1/15 vs. 1/26; P>0.05) as well as background histiocytes and dendritic cells. Overall survival of DLBCL-RT was significantly inferior to that of the other DLBCL (median, 16.9 vs. 106.1 mo; P=0.002). Our findings suggest a biological continuum from prolymphocytes/paraimmunoblasts in CLL/SLL PCs to the neoplastic B-cells in DLBCL-RT. The characteristic PD-1 expression in DLBCL-RT makes it a potential surrogate marker for determining clonal relatedness to CLL/SLL, which may have important prognostic and therapeutic implications.

Utility of positron emission tomography-computed tomography in patients with chronic lymphocytic leukemia following B-cell receptor pathway inhibitor therapy

The utility of positron emission tomography-computed tomography (PET-CT) in distinguishing Richter’s transformation versus chronic lymphocytic leukemia (CLL) progression after ibrutinib and/or idelalisib was assessed in a post hoc analysis of a phase II study of venetoclax. Patients underwent PET-CT at screening and were not enrolled/treated if Richter’s transformation was confirmed pathologically. Of 167 patients screened, 57 met criteria for biopsy after PET-CT. Of 35 patients who underwent biopsy, eight had Richter’s transformation, two had another malignancy, and 25 had CLL. A PET-CT maximum standardized uptake value (SUVmax) ≥10 had 71% sensitivity and 50% specificity for detecting Richter’s transformation [Odds Ratio (OR): 2.5, 95%CI: 0.4-15; P=0.318]. Response rate to venetoclax was similar for screening SUVmax <10 versus ≥10 (65% vs. 62%) (n=127 enrolled), though median progression-free survival was longer at <10 months (24.7 vs. 15.4 months; P=0.0335). Six patients developed Richter’s transformation on venetoclax, of whom two had screening biopsy demonstrating CLL (others did not have a biopsy) and five had screening SUVmax <10. We have defined the test characteristics for PET-CT to distinguish progression of CLL as compared to Richter’s transformation when biopsied in patients treated with B-cell receptor signaling pathway inhibitors. Overall diminished sensitivity and specificity as compared to prior reports of patients treated with chemotherapy/chemoimmunotherapy suggest it has diminished ability to discriminate these two diagnoses using a SUVmax ≥10 cutoff. This cutoff did not identify venetoclax-treated patients with an inferior response but may be predictive of inferior progression-free survival. (Registered at clinicaltrials.gov identifier: 02141282)

The involvement of microRNA in the pathogenesis of Richter syndrome

Richter syndrome is the name given to the transformation of the most frequent type of leukemia, chronic lymphocytic leukemia, into an aggressive lymphoma. Patients with Richter syndrome have limited response to therapies and dismal survival. The underlying mechanisms of transformation are insufficiently understood and there is a major lack of knowledge regarding the roles of microRNA that have already proven to be causative for most cases of chronic lymphocytic leukemia. Here, by using four types of genomic platforms and independent sets of patients from three institutions, we identified microRNA involved in the transformation of chronic lymphocytic leukemia to Richter syndrome. The expression signature is composed of miR-21, miR-150, miR-146b and miR-181b, with confirmed targets significantly enriched in pathways involved in cancer, immunity and inflammation. In addition, we demonstrated that genomic alterations may account for microRNA deregulation in a subset of cases of Richter syndrome. Furthermore, network analysis showed that Richter transformation leads to a complete rearrangement, resulting in a highly connected microRNA network. Functionally, ectopic overexpression of miR-21 increased proliferation of malignant B cells in multiple assays, while miR-150 and miR-26a were downregulated in a chronic lymphocytic leukemia xenogeneic mouse transplantation model. Together, our results suggest that Richter transformation is associated with significant expression and genomic loci alterations of microRNA involved in both malignancy and immunity.

Successful Treatment of Richter Transformation with Ibrutinib in a Patient with Chronic Lymphocytic Leukemia following Allogeneic Hematopoietic Stem Cell Transplant

Patients with chronic lymphocytic leukemia (CLL) who progress to Richter transformation (RT) have a poor prognosis. Multi-agent chemotherapy regimens do not have good response rates. There are few case reports on the use of ibrutinib in RT. Here, we present a patient who was heavily pretreated for CLL, including allogeneic stem cell transplant, and progressed to RT. She had a mixed response to multi-agent chemotherapy and was started on ibrutinib. She had a complete response for 16 months on single-agent ibrutinib with minimal toxicity.

Richter Syndrome in Chronic Lymphocytic Leukemia

The term Richter syndrome (RS) indicates the transformation of chronic lymphocytic leukemia (CLL) into an aggressive lymphoma. RS is a rare complication with an aggressive clinical course, bearing an unfavorable prognosis. In the majority of cases, CLL transforms into RS as diffuse large B cell lymphoma (DLBCL), and a clonal relation between the two processes can be found. However, clonally unrelated RS can occur and transformations to other histologies beside DLBCL have been described. Recent data have shed some light on genetic characteristics that can influence and drive the transformation from CLL to RS. This molecular information has not been translated yet into significant treatment advances, and currently the therapy regimens for RS continue to rely on intensive chemotherapy combinations followed by stem cell transplant in suitable candidates. Based on the rapid pace of discoveries in the field of hematological malignancies and on the recent revolution in the therapeutic landscape for CLL and B cell lymphomas, new therapeutic options for RS might be available in the upcoming years.

NCRI phase II study of CHOP in combination with ofatumumab in induction and maintenance in newly diagnosed Richter syndrome

Richter syndrome (RS) is associated with chemotherapy resistance and a poor historical median overall survival (OS) of 8-10 months. We conducted a phase II trial of standard CHOP-21 (cyclophosphamide, doxorubicin, vincristine, prednisolone every 21 d) with ofatumumab induction (Cycle 1: 300 mg day 1, 1000 mg day 8, 1000 mg day 15; Cycles 2-6: 1000 mg day 1) (CHOP-O) followed by 12 months ofatumumab maintenance (1000 mg given 8-weekly for up to six cycles). Forty-three patients were recruited of whom 37 were evaluable. Seventy-three per cent were aged >60 years. Over half of the patients received a fludarabine and cyclophosphamide-based regimen as prior CLL treatment. The overall response rate was 46% (complete response 27%, partial response 19%) at six cycles. The median progression-free survival was 6·2 months (95% confidence interval [CI] 4·9-14·0 months) and median OS was 11·4 months (95% CI 6·4-25·6 months). Treatment-naïve and TP53-intact patients had improved outcomes. Fifteen episodes of neutropenic fever and 46 non-neutropenic infections were observed. There were no treatment-related deaths. Seven patients received platinum-containing salvage at progression, with only one patient obtaining an adequate response to proceed to allogeneic transplantation. CHOP-O with ofatumumab maintenance provides minimal benefit beyond CHOP plus rutuximab. Standard immunochemotherapy for RS remains wholly inadequate for unselected RS. Multinational trials incorporating novel agents are urgently needed.

Richter syndrome: pathogenesis and management

Richter syndrome (RS) is the development of an aggressive lymphoma in patients with a previous or concomitant diagnosis of chronic lymphocytic leukemia (CLL). The incidence rate RS is ~0.5% per year of observation. Two biomarkers (NOTCH1 mutations and subset 8 configuration of the B-cell receptor) may help identifying CLL patients at risk of RS to be considered for close monitoring and a careful biopsy policy. In the presence of clinical features suspicious of RS, diagnosis of transformation and choice of the site of biopsy may take advantage of fluorine 18 fluorodeoxyglucose ((18)FDG) positron emission tomography (PET)/computed tomography (CT). Molecular lesions of regulators of tumor suppression (TP53), cell cycle (CDKN2A), and cell proliferation (NOTCH1, MYC) overall account for ~90% of RS and may be responsible for the aggressive clinical phenotype observed in this disease because of the combined effect of chemoresistance and rapid disease kinetics. The prognosis of RS is generally highly unfavorable. However, the pattern of survival is not homogeneous and the most important prognostic factor is the clonal relationship between the CLL and the aggressive lymphoma clones. Rituximab-containing polychemotherapy represents the backbone for induction treatment in RS. Younger patients who respond to induction therapy should be offered stem cell transplant (SCT) to prolong survival.

A Rare Cause of Cavitary Lesion in the Lung: Richter's Transformation

Richter's transformation (RT) refers to the development of aggressive lymphoma during the course of CLL. Clinically, patients with RT present with an aggressive disease course with rapidly enlarging lymph nodes, hepatosplenomegaly, and elevated serum lactate dehydrogenase levels. But rarely it presents with extra nodal organ involvement at the beginning. Common sites of extra nodal involvement are the gastrointestinal tract, eye, central nervous system, lung, and kidney. We are reporting this case that was presented with RT in the lung involvement diagnosed while researching cavitary lesion etiology.

Single arm NCRI phase II study of CHOP in combination with Ofatumumab in induction and maintenance for patients with newly diagnosed Richter's syndrome

BACKGROUND

Transformation of B-cell chronic lymphocytic leukaemia (B-CLL) to diffuse large B cell lymphoma (DLBCL) (Richter's syndrome (RS)) is a rare (2-15% of patients) but catastrophic complication of B-CLL. Dose-intense chemotherapy regimens investigated in small single institution trials, but with the exception of bone marrow transplantation for a minority of patients, little has improved the median overall survival of patients with RS beyond eight months. Patients are often elderly, immunosuppressed, possess co-morbidities and have a deteriorating performance status. TP53 disruption is a common molecular abnormality noted in RS and contributes to the tumour's chemotherapy resistance. Ofatumumab is a fully human anti-CD20 monoclonal IgG1κ antibody that targets a unique epitope on B lymphocytes. It has displayed increased binding affinity and a longer dissociation time when compared to rituximab resulting in improved complement dependent cellular cytotoxicity (CDCC); a mechanism with the potential to overcome apoptosis-resistance in TP53 disruption. Given the prevalence of TP53 disruption in RS, Ofatumumab was considered a relatively non-toxic agent with a sound rationale to test in a prospective multicentre trial as an adjunct to CHOP induction and subsequent ofatumumab maintenance therapy in responding patients.

METHODS/DESIGN

The CHOP-OR study is a prospective phase II study to evaluate the safety, feasibility and activity of a CHOP chemotherapy in combination with ofatumumab in induction and subsequent maintenance for patients with newly diagnosed RS. The primary objective will be the overall response rate (ORR) in patients with RS after six cycles of CHOP-O. The secondary objectives include feasibility of recruitment, progression free survival (PFS), overall survival (OS) and toxicity. The study will be accompanied by exploratory analysis of the genomic landscape of RS in newly diagnosed patients.

DISCUSSION

The CHOP-OR trial evaluates the safety, feasibility and activity of CHOP plus Ofatumumab induction and Ofatumumab maintenance in new RS patients. The study is currently recruiting and has met the interim analysis criteria, with more than 7 of the first 25 participants achieving a CR or PR after six cycles of CHOP-O. The study has the potential to identify predictive biomarkers for this treatment modality.

TRIAL REGISTRATION

NCT01171378.

How we treat Richter syndrome

Richter syndrome (RS) is defined as the transformation of chronic lymphocytic leukemia (CLL) into an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (DLBCL). RS occurs in approximately 2% to 10% of CLL patients during the course of their disease, with a transformation rate of 0.5% to 1% per year. A combination of germline genetic characteristics, clinical features (eg, advanced Rai stage), biologic (ζ-associated protein-70(+), CD38(+), CD49d(+)) and somatic genetic (del17p13.1 or del11q23.1) characteristics of CLL B cells, and certain CLL therapies are associated with higher risk of RS. Recent studies have also identified the crucial role of CDKN2A loss, TP53 disruption, C-MYC activation, and NOTCH1 mutations in the transformation from CLL to RS. An excisional lymph node biopsy is considered the gold standard for diagnosis of RS; a (18)F-fluorodeoxyglucose positron emission tomography scan can help inform the optimal site for biopsy. Approximately 80% of DLBCL cases in patients with CLL are clonally related to the underlying CLL, and the median survival for these patients is approximately 1 year. In contrast, the remaining 20% of patients have a clonally unrelated DLBCL and have a prognosis similar to that of de novo DLBCL. For patients with clonally related DLBCL, induction therapy with either an anthracycline- or platinum-based regimen is the standard approach. Postremission stem cell transplantation should be considered for appropriate patients. This article summarizes our approach to the clinical management of CLL patients who develop RS.

Correlation between FDG/PET, histology, characteristics, and survival in 332 patients with chronic lymphoid leukemia

Richter syndrome (RS) is associated with poor outcome. The prognosis of patients with histologically aggressive chronic lymphocytic leukemia (CLL), or HAC, has not been studied. We aimed to correlate 2-deoxy-2-[(18)F]fluoroglucose/positron emission tomography (FDG/PET) data, histological diagnosis, clinical characteristics, and survival in patients with CLL. A total of 332 patients with CLL were histologically classified as: 95 RS, 117 HAC, and 120 histologically indolent CLL (HIC). HAC and RS patients had higher maximum standardized uptake value (SUVmax), more frequent constitutional symptoms, poorer performance status (PS), lower hemoglobin and platelets, and higher lactate dehydrogenase and β-2-microglobulin. An SUVmax ≥10 strongly correlated with mortality (overall survival [OS], 56.7 vs 6.9 months in patients with SUVmax <10 vs ≥10). Survival of patients with RS and HAC was similar among patients with SUVmax <10 or ≥10. SUVmax ≥10, PS ≥2, bulky disease, and age ≥65 were independently associated with shorter OS. In patients undergoing both fine-needle aspiration and biopsy, the former proved diagnostically inadequate in 23%, 29%, and 53% of HIC, HAC, and RS, respectively. FDG/PET is a useful diagnostic tool in patients with CLL and suspected transformation. Patients with HAC show different characteristics and worse prognosis compared with those with HIC. Patients with different CLL phases, but similar SUVmax have similar outcome. Tissue biopsy should be preferred for diagnosing RS.

Fludarabine, cyclophosphamide and rituximab plus granulocyte macrophage colony-stimulating factor as frontline treatment for patients with chronic lymphocytic leukemia

Fludarabine, cyclophosphamide and rituximab (FCR), the standard of care for the frontline treatment of patients with chronic lymphocytic leukemia (CLL), is associated with a high rate of neutropenia and infectious complications. Granulocyte macrophage colony-stimulating factor (GM-CSF) reduces myelosuppression and can potentiate rituximab activity. We conducted a clinical trial combining GM-CSF with FCR for frontline treatment of 60 patients with CLL. Eighty-six percent completed all six courses and 18% discontinued GM-CSF for toxicity: grade 3-4 neutropenia was observed in 30% of cycles, and severe infections in 16% of cases. The overall response rate was 100%. Both median event-free survival (EFS) and overall survival (OS) have not been reached. Longer EFS was associated with favorable cytogenetics. GM-CSF led to a lower frequency of infectious complications than in the historical FCR group, albeit similar EFS and OS.

Severe hypophosphatemia induced after first cycle of the ESHAP protocol for Hodgkin's lymphoma: a case report

The effect of the ESHAP (etoposide, methylprednisolone, cytarabine, cisplatin) salvage protocol on serum electrolytes has been previously reported by individual observational studies. The most commonly described electrolyte affected by the ESHAP protocol is magnesium. In addition, hypophosphatemia has been studied and reported as a complication of cisplatin therapy, although it is usually asymptomatic. This is a case report of a 51-year-old woman with relapsed Hodgkin's lymphoma who developed severe hypophosphatemia following administration of the first cycle of the ESHAP protocol. The patient started to develop gradually decreasing phosphate levels 2 weeks after receiving chemotherapy, which needed to be corrected by phosphate supplementation. This case report raises concern regarding hypophosphatemia as a possible side effect of the ESHAP protocol and points to a need for close monitoring, taking into consideration vitamin D levels, urinary phosphate excretion, parathyroid hormone levels, and arterial blood gas analysis to rule out other contributing factors. Health care providers should be made aware of this possible toxicity. Critical monitoring of phosphate levels and considering supplementation is warranted with the ESHAP protocol, especially when it is used in combination with granulocyte colony-stimulating factor and diuretics, to prevent such possible hypophosphatemia. Further investigations may be required to confirm and evaluate the significance of this type of toxicity.

Richter syndrome

Transformation of chronic lymphocytic leukemia (CLL) to aggressive lymphoma is known as Richter syndrome (RS). In the CLL population considered as a whole, the prevalence of RS development ranges from 2 to 7 %. The most common pathologic phenotype at the time of RS transformation is diffuse large B-cell lymphoma (DLBCL), while, in a small fraction of cases, the transformed phase shows pathologic features mimicking Hodgkin lymphoma. TP53 disruption and MYC activation cooperate as dual hits in driving DLBCL transformation. Two biomarkers (NOTCH1 mutations and usage of the immunoglobulin VH CDR3 subset 8) may help in identifying CLL patients at risk of DLBCL transformation to be considered for close monitoring and a careful biopsy policy. In the presence of clinical features suspicious of RS, diagnosis of transformation and choice of the site of biopsy may take advantage of (18)FDG PET/CT. The prognosis of RS transformation is generally highly unfavorable. However, the pattern of survival is not homogeneous and may be predicted on clinical and biological grounds. RS that are clonally unrelated to the paired CLL phase are biologically and clinically different from clonally related cases, and should be considered, and probably managed, as a de novo DLBCL arising in the context of CLL. Rituximab-containing polychemotherapy represents the backbone for induction treatment in patients with clonally related DLBCL transformation. Younger patients who respond to induction therapy should be offered stem cell transplant to prolong survival.

State-of-the-Art Management of Patients Suffering from Chronic Lymphocytic Leukemia

The management of chronic lymphocytic leukemia (CLL) has evolved dramatically in the last decade. For the first time, clinical intervention has been shown to alter the natural history of the disease. Considerable efforts are focussing on better patient selection and response prediction, and it is expected that the publication of the first 200 CLL genomes will spark new insights into risk stratification of CLL patients. Besides, many new agents are being evaluated on their own and in combination therapy in early and late Phase clinical studies. Here, we provide a general clinical introduction into CLL including diagnosis and prognostic markers followed by a summary of the current state-of-the-art treatment. We point to areas of continued clinical research in particular for patients with co-morbidities and highlight the challenges in managing refractory disease.

Richter transformation in 16 of 149 Chinese patients with chronic lymphocytic leukemia

No confirmed risk factors are known to predict Richter syndrome (RS), and the value of clinical prognosticators conventionally applied to chronic lymphocytic leukemia (CLL) is not firmly established in this setting. The objective of this study was to present evidence for RS in Chinese patients with CLL and risk factors for CLL transformation to Richter syndrome. With a median follow-up of 43 months from CLL diagnosis in 149 Chinese patients, 16 (10.7%) patients progressed to diffuse large B-cell lymphoma (DLBCL). According to correlation analysis, a high level of lactate dehydrogenase (LDH) and CD38 positivity were found to be independent predictors of transformation to RS. Survival analysis showed that presence of RS, advanced Binet stage, high level of LDH, high level of β(2)-microglobulin, high concentration of thymidine kinase (TK), ZAP-70 and CD38 expression, unmutated immunoglobulin heavy chain variable (IGHV) gene status and del(17p13) were adverse factors in determining overall survival (OS). Only del(17p13) was strongly associated with survival by multivariate Cox regression analysis. Median OS after transformation was 16 months (95% confidence interval, 5.6-26.4 months). The results support that RS is associated with a poor outcome, and a policy of close monitoring and careful biopsy is needed in patients carrying transformation risk factors.

The spectrum of use of rituximab in chronic lymphocytic leukemia

The monoclonal chimeric anti-CD20 antibody, rituximab, has considerably improved therapeutic outcome in B-cell chronic lymphocytic leukemia. Rituximab has limited clinical activity when used as a single agent. The combination of the monoclonal antibody with fludarabine-based regimens clearly demonstrated, in Phase II and randomized trials, an increase in clinical efficacy in previously untreated and pretreated patients. Furthermore the addition of rituximab enabled the eradication of minimal residual disease, which is correlated with the prognosis in a high proportion of patients. Although the combination of rituximab with fludarabine-based regimens increased myelosuppression and immunosuppression, incidence of infections did not increase. The benefit of adding rituximab to other purine analogs or other chemotherapeutic combination regimens has also been explored. Moreover there could be a role for achieving better quality of responses with the combination of different monoclonal antibodies, considering that they target different antigens and exert different mechanism of action. Although the role of rituximab as maintenance therapy in low grade non-Hodgkin's lymphomas has been determined, the benefit and optimal schedule in chronic lymphocytic leukemia are still under investigation. This review brings together knowledge of the pharmacokinetics, mechanism of action and clinical use of rituximab in chronic lymphocytic leukemia.

Medication-induced hypophosphatemia: a review

Hypophosphatemia (serum phosphorus concentration <2.5 mg/dl, 0.8 mmol/l), although rare in the general population, is commonly observed in hospitalized patients and may be associated with drug therapy. In fact, hypophosphatemia frequently develops in the course of treatment with drugs used in every-day clinical practice including diuretics and bisphosphonates. Proper diagnostic approach of patients with low serum phosphorus concentrations should involve a detailed medical history with special attention to the recent use of medications. The clinical manifestations of drug-induced hypophosphatemia are usually mild but might also be severe and potentially life-threatening. This review aims at a thorough understanding of the underlying pathophysiological mechanisms and risk factors of drug therapy-related hypophosphatemia thus allowing prevention and effective intervention strategies.

Chest Wall Swelling, A Rare Presentation of Richter's Transformation

A large cell lymphoma develops in approximately 1-10% of chronic lymphocytic leukemia (CLL). This is known as Richter's syndrome. Chest wall swelling is a very unusual presentation of this syndrome. Here we report another such case of chest wall swelling, a very rare presentation of Richter's syndrome.

Richter syndrome: molecular insights and clinical perspectives

Richter syndrome (RS) represents the clinico-pathologic transformation of chronic lymphocytic leukaemia (CLL) to an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (DLBCL). The clinical definition of RS is heterogeneous, and encompasses at least two biologically different conditions: (i) CLL transformation to a clonally related DLBCL, that accounts for the majority of cases; (ii) development of a DLBCL unrelated to the CLL clone. In clonally related RS, the pathogenetic link between the CLL and the DLBCL phases is substantiated by the acquisition of novel molecular lesions at the time of clinico-pathologic transformation. RS is not a rare event in the natural history of CLL, since the cumulative incidence of RS at 10 years exceeds 10%. Prompt recognition of RS is known to be clinically useful, and may be favoured by close monitoring of CLL patients harbouring clinical and/or biological risk factors of RS development. Conventional risk factors that are independent predictors of RS development at the time of CLL diagnosis include: (i) expression of CD38; (ii) absence of del13q14 and (iii) lymph node size > or =3 cm. Other risk factors of RS development include CD38 genotype and usage of specific immunoglobulin variable genes. The molecular pathogenesis of RS has been elucidated to a certain extent. Acquisition of TP53 mutations and/or 17p13 deletion is a frequent molecular event in RS, as it is in other types of transformation from indolent to aggressive B-cell malignancies. Additional molecular alterations are being revealed by genome wide studies. Once that transformation has occurred, RS prognosis may be predicted by the RS score, based on performance status, LDH, platelet count, tumour size and number of prior therapies. Depending on patient's age and RS score, the therapeutic options for RS may range from conventional immunochemotherapy to allogeneic bone marrow transplantation.

Phase I-II Study of Oxaliplatin, Fludarabine, Cytarabine, and Rituximab Combination Therapy in Patients With Richter's Syndrome or Fludarabine-Refractory Chronic Lymphocytic Leukemia

Purpose

Richter's syndrome (RS) and fludarabine-refractory chronic lymphocytic leukemia (CLL) are associated with poor clinical outcomes. We conducted a phase I-II trial of oxaliplatin, fludarabine, cytarabine, and rituximab (OFAR) in these diseases.

Patients and Methods

The OFAR regimen consisted of increasing doses of oxaliplatin (17.5, 20, or 25 mg/m2/d) on days 1 to 4 (phase I), fludarabine 30 mg/m2 on days 2 to 3, cytarabine 1 g/m2 on days 2 to 3, rituximab 375 mg/m2 on day 3 of cycle 1 and day 1 of subsequent cycles, and pegfilgrastim 6 mg on day 6, every 4 weeks for a maximum of six courses. Dose-limiting toxicity (DLT) was defined as any nonhematologic, treatment-related toxicity ≥ grade 3.

Results

Fifty patients were treated (20 patients had RS, and 30 had CLL). The highest tolerated oxaliplatin dose was 25 mg/m2, which was the highest dose tested. DLT was not observed. Pharmacodynamic analyses demonstrated enhanced leukemia cell killing by oxaliplatin in the presence of fludarabine and cytarabine. The overall response rates were 50% in RS and 33% in fludarabine-refractory CLL. The overall response rate in 14 patients with age ≥ 70 years was 50%. Responses were achieved in seven (35%) of 20 patients with 17p deletion, two (29%) of seven patients with 11q deletion, all four patients with trisomy 12, and two (40%) of five patients with 13q deletion. The median response duration was 10 months. Toxicities were mainly hematologic; prolonged myelosuppression was not observed.

Conclusion

The OFAR regimen is highly active in RS and has activity in fludarabine-refractory patients with CLL. This regimen warrants further investigation in the treatment of these disorders.

The role of DNA repair in chronic lymphocytic leukemia pathogenesis and chemotherapy resistance

Front-line therapy for chronic lymphocytic leukemia (CLL) with alkylating agents is associated with low rates of complete remission and no improvement in overall survival. The ability of CLL cells to efficiently repair alkylator-induced damage to DNA might explain this lack of response. Novel strategies that inhibit DNA repair, such as combinations of alkylating agents, purine nucleoside analogues, and immunotherapy, have produced durable clinical and molecular remission in both untreated and relapsed CLL. This review evaluates the contribution of DNA repair processes in the development of resistance to chemotherapy and the impact of therapies that exploit the DNA repair capacity of CLL cells to therapeutic advantage.

Recent advances in the diagnosis and therapy of richter’s syndrome

Richter's syndrome (RS) denotes the development of aggressive lymphoma that arises in patients with chronic lymphocytic leukemia (CLL). Presenting features typically include a rapid clinical deterioration with fever in the absence of infection, progressive lymph node enlargement, and an elevation in serum LDH. Diagnostic biopsy of affected sites usually reveals large cell lymphomas; however, Hodgkin variant cases have been described. Richter's transformation occurs in approx 5% of CLL patients and may be associated with infection with Epstein-Barr virus (EBV). Chromosome 11 and 14 abnormalities have also been described as well as tumor suppressor gene defects involving p53, p21, and p27. Treatment options for these patients are limited and include combination chemotherapy with or without the addition of monoclonal antibodies and stem cell transplantation. Response to therapy is variable and generally short-lived. Median survival is usually in the order of 5-8 mo. More effective management for RS is needed as well as prognostic models that will identify CLL patients at risk of transformation. This review will address the current status of RS and deal with the pathophysiology, diagnostic approach, and treatment of this challenging disease.

Richterʼs Syndrome

Richter's syndrome, that is, transformation of chronic lymphocytic leukemia to a large cell or immunoblastic lymphoma, occurs in up to 10% of patients with chronic lymphocytic leukemia. The onset of Richter's syndrome is characterized by worsening systemic symptoms, rapid tumor growth, and/or extranodal involvement. Median survival with conventional chemotherapy is less than 6 months. Therapy with more recent therapeutic regimens, such as hyperCVXD (fractionated cyclophosphamide, vincristine, liposomal daunorubicin, and dexamethasone), augmented hyperCVXD, and yttrium-90 ibritumomab tiuxetan, has not produced major improvements in response rates or overall survival. Improvement in the outcome of patients with Richter's syndrome may be aided by a more comprehensive understanding of the pathogenesis of Richter's syndrome; therapy could then be targeted against specific abnormalities. Current data indicate that the transformation of chronic lymphocytic leukemia to a large-cell or immunoblastic lymphoma is associated with abnormalities in cell cycle regulation (e.g., loss of the cell cycle inhibitors p16(INK4a) and p27(KIP1) ) and DNA repair (e.g., mutations and/or deletions of the p53, ATM, and p14(ARF) genes and epigenetic silencing of the MLH1 gene). However, the critical event leading to transformation is unclear. Given the poor prognosis of patients with Richter's syndrome, every effort should be made to enroll these patients into clinical trials evaluating novel agents with the appropriate correlative studies.

Richter syndrome: biology, incidence, and therapeutic strategies

Richter's transformation denotes the development of high-grade non-Hodgkin lymphoma, prolymphocytic leukemia, Hodgkin disease, or acute leukemia in patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma. A search of published articles in Medline (PubMed) and abstracts from professional meetings was performed. An electronic database search of patients with CLL at The University of Texas M. D. Anderson Cancer Center (Houston, TX) determined the incidence of Richter syndrome (RS) in patients with CLL between 1992 and 2002. RS occurs in approximately 5% of patients with CLL. The large cells of RS may arise through transformation of the original CLL clone or represent a new neoplasm. RS may be triggered by viral infections, such as Epstein-Barr virus. Trisomy 12 and chromosome 11 abnormalities are more frequent in patients with RS than in the overall population of patients with CLL. Multiple genetic defects, such as mutations of the p53 tumor suppressor gene, p16INK4A, and p21, loss of p27 expression, deletion of retinoblastoma, increased copy number of C-MYC, and decreased expression of the A-MYB gene, have been described. These abnormalities may cause CLL cells to proliferate and-by facilitating the acquisition of new genetic abnormalities-to transform into RS cells. Therapeutic strategies include intensive chemotherapy, monoclonal antibodies, and stem cell transplantation. The response rates range from 5% to 43% (complete response, 5-38%), and the median survival duration ranges from 5 months to 8 months. In conclusion, RS may be triggered by viral infections or by genetic defects. Current treatments are aggressive, but prognosis is poor. Novel curative treatment strategies are needed.

Yttrium-90 ibritumomab tiuxetan radioimmunotherapy in Richter syndrome

BACKGROUND

(90)Y ibritumomab tiuxetan is a radioimmunotherapeutic construct that is reported to be an effective treatment for patients with lymphoma. The aim of the current analysis was to evaluate retrospectively the efficacy and safety of (90)Y ibritumomab tiuxetan in patients with Richter syndrome (RS).

METHODS

Patients with histologically proven CD20-positive RS and < 25% lymphoma and/or chronic lymphocytic leukemia in the bone marrow were treated. Patients received an imaging dose of (111)In-labeled ibritumomab tiuxetan of 1.6 mg (5.0 mCi of (111)In) intravenously. One week later, they received 0.3 or 0.4 mCi/kg of (90)Y ibritumomab tiuxetan. Rituximab, at a dose of 250 mg/m(2) intravenously, was given immediately before ibritumomab tiuxetan on Days 1 and 8.

RESULTS

Seven patients were treated. Their median age was 56 years (range, 44-70 years). The median time to transformation was 7.9 years (range, 0.7-28.4 years). The median number of previous therapies received was five (range, one to seven previous therapies). The median number of previous therapies received for RS was one (range, none to three previous therapies). Six patients were treated previously with hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone alternating with methotrexate and cytosine arabinoside. No patient responded to (90)Y ibritumomab tiuxetan therapy. All patients developed disease progression. The median time to disease progression was 41 days (range, 39-89 days). Side effects included hematologic toxicity. Grade 3-4 (according to the second version of the National Cancer Institute Common Toxicity Criteria) thrombocytopenia and neutropenia occurred in 5 patients (71%) and 2 patients (29%), respectively. There was one episode of septic shock in a patient with Grade 4 neutropenia.

CONCLUSIONS

(90)Y ibritumomab tiuxetan had no significant antitumor activity and hematologic toxicity was severe in these heavily pretreated patients with RS.

Fractionated cyclophosphamide, vincristine, liposomal daunorubicin, and dexamethasone plus rituximab and granulocyte-macrophage-colony stimulating factor (GM-CSF) alternating with methotrexate and cytarabine plus rituximab and GM-CSF in patients with Richter syndrome or fludarabine-refractory chronic lymphocytic leukemia

BACKGROUND

Therapy for patients with Richter syndrome (RS) or fludarabine-refractory chronic lymphocytic leukemia (CLL) is unsatisfactory. A Phase II study was conducted to evaluate an alternating combination cytotoxic regimen given with rituximab and granulocyte-macrophage-colony stimulating factor (GM-CSF) in these patients.

METHODS

Fludarabine-refractory CLL was defined as failure to respond to most recent prior fludarabine-containing regimen. Patients received up to six cycles of fractionated cyclophosphamide, vincristine, liposomal daunorubicin, and dexamethasone (hyper-CVXD) plus rituximab and GM-CSF alternating with methotrexate and cytarabine plus rituximab and GM-CSF. Response, toxicity, and survival data were compared with data from prior therapy with hyper-CVXD alone in this patient group.

RESULTS

Forty-nine patients with RS (n = 30 patients) or refractory CLL (n = 19 patients) were treated on study. Nine patients (18%) achieved a complete remission, and 11 patients achieved a partial remission (22%), for an overall objective response (OR) rate of 41%. With a median follow-up of 7.5 months and a maximum follow-up of 15.2 months, the 12-month failure free survival (FFS) rate was 27%, and the overall survival (OS) rate was 39%. Nine patients (18%) died during the first cycle of therapy, and two patients (4%) died during the second cycle. There were no significant differences between the rates of OR, OS, and FFS in the current study and those obtained with hyper-CVXD alone on a prior study.

CONCLUSIONS

The study regimen had activity and significant toxicity in patients with RS or fludarabine-refractory CLL. It was not clearly better compared with hyper-CVXD alone in this patient population.