Purine Analog Therapy Research Articles

Clinical Characteristics and Survival Analysis of Richter Transformation: A Single Center Retrospective Study in China

Introduction: Richter transformation (RT) refers to the progression of an aggressive lymphoma arising on the background of chronic lymphocytic leukemia/small cell lymphoma (CLL/SLL). Despite the incidence of RT among CLL/SLL is low (range 2-10%), the prognosis is very poor. Usually, different clinical and biology characteristics were observed between CLL/SLL and RT stages, and their impacts on disease progression remains unknown. In this report, we investigated the clinical characteristics and outcomes of 37 Chinese patients (pts) in CLL/SLL and in RT stages. This 18-year follow-up retrospective study might serve as a basis for future prospective clinical studies. Methods: From Feb 2004 to Feb 2022, all of the CLL/SLL pts who developed biopsy-proven RT in our institution were enrolled. Clinical characteristics and survival data (treatment course, clinical response to treatment as determined by treating physician, and survival information) were collected by chart review. Overall survival 1 (OS 1) was defined as the time from initial CLL/SLL diagnosis to death. Overall survival 2 (OS 2) was defined as the time from RT to death. Results: A total of 37 Chinese pts with pathological proven RT were enrolled from Feb 2004 to Feb 2022. The median age at CLL/SLL diagnosis and at RT were 60 years (range 29-63 years) and 63 years (range 35-77 years), respectively. Twenty-four pts (64.9%) were male. Frequencies of several adverse clinical/laboratory factors were significantly higher at RT diagnosis compared to at CLL/SLL diagnosis, including elderly age (40.5% vs. 16.2%, p=0.020), bulky disease (45.9% vs. 18.9%, p=0.017), extranodal disease (37.8% vs. 5.4%, p=0.001), B symptoms (67.6% vs. 27.0%, p<0.001) and hypogammaglobulinemia (70.3% vs. 51.4%, p=0.026). The rate of advanced Rai staging was higher in RT stage than in CLL/SLL stage. However, no statistically significant difference was observed in Binet staging or CLL-international prognostic index (CLL-IPI). In CLL/SLL stage, 27 pts (27/37, 73.0%) received at least one line of therapy. The median number of treatment lines was 1 (range: 0-4). Ten pts (27.0%) received BTK inhibitor and 4 pts (10.8%) treated with Bcl-2 inhibitor treatment, 11 pts (29.7%) received purine analogue therapy (i.e. fludarabine) and 9 pts (24.3%) were exposed to anti-CD20 antibody. In our study, the median time from CLL/SLL diagnosis to RT was 45.3 months (95% CI 36.0-54.6 months). In RT stage, the median number of treatment lines was 2 (range: 0-6). Twenty-four pts (64.9%) received BTK inhibitors, 4 pts (10.8%) received Bcl-2 inhibitor treatment, 6 pts (16.2%) received anti-PD1 treatment as part of salvage therapy and 2 pts (5.1%) underwent chimeric antigen receptor T (CAR-T) therapy.The best overall response (BOR) data post RT was collected in our study. Among 36 pts who ever received any anti-cancer treatment and had at least one disease assessment, 1 pt (2.8%) achieved complete response (CR), 19 pts(52.8%) achieved partial response (PR), the rest pts resulted in stable disease (SD) (8/36, 22.2%) and progressive disease (PD)(8/36, 22.2%). The median OS 1 was 119.7 months (95% CI 77.78-161.6 months). Clinically significant difference of OS 1 was observed between salvage therapy responders (CR+PR) compared to non-responders (SD+PD). The estimated median OS 1 was not reached (NR) for responders and 78.8 months (95% CI 30.1-127.5, p=0.001) for non-responders. For OS 1, in the univariate analysis, bulky disease, Eastern Cooperative Oncology Group (ECOG) and TP53 aberration are identified as three prognostic factors. In the multivariate analysis, bulky disease and ECOG were confirmed as independent prognostic factors.(Table 1) The median OS 2 was 39.6 months (95% CI 3.4-75.8 months). Patients who responded to salvage therapy had significantly better OS 2 than non-responders. The median OS 2 was NR vs. 8.3 months (95% CI 0-25.2, p<0.001). For OS 2, in both the univariate analysis and multivariate analysis, bulky disease and treatment response were identified as two prognostic factors in RT stage.(Table 2) Conclusion: In this long-term follow-up study, pts presented more aggressive clinical/laboratory characteristics in RT stage than in CLL/SLL stage. The outcome of Chinese pts with RT was very poor. For OS 1, bulky disease and ECOG are identified as prognostic factors. While, bulky disease and treatment response were confirmed as the indepedent prognostic factors in RT stage.

Results from the Phase 3 DUOTM Trial: A Randomized Comparison of Duvelisib Vs Ofatumumab in Patients with Relapsed/Refractory Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma

Results from the Phase 3 DUOTM Trial: A Randomized Comparison of Duvelisib Vs Ofatumumab in Patients with Relapsed/Refractory Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma

CLL-358: First-Line Treatment of Hairy Cell Leukemia with Cladribine Followed by Rituximab Consolidation Significantly Improves Leukemia-Free Survival

Context Purine analogue therapy remains the standard of care in hairy cell leukemia (HCL) management. Despite high remission rates, many patients subsequently relapse and require re-treatments. Objective The aim of this study is to compare the effectiveness and safety of cladribine vs. cladribine followed by rituximab consolidation as first-line therapy of HCL. Design This is a retrospective study including all consecutive patients with classical HCL treated and followed at the American University of Beirut Medical Center (AUBMC) between 2000 and 2019. Methods We identified 29 HCL patients, with a median age of 50.5 (range: 30–71) years. Patients were divided into two cohorts based on treatment received: cohort A (N=14) received cladribine 5.6 mg/m2 intravenously (IV) for 7 days as a single agent, and cohort B (N=15) received the same dose of cladribine followed by rituximab 375 mg/m2 IV weekly for eight doses. Rituximab consolidation was given after a median time of 33 days (17–60 days) from cladribine completion. Complete remission rates were 64% and 100% in cohorts A and B, respectively. In cohort A, seven (50%) patients relapsed after a median duration of 48 months (range: 1–209 months), requiring second-line treatment with cladribine followed by rituximab. In cohort B, no relapses occurred. After a median follow up of 67 months (range: 1–227 months), the 5-year disease-free survival was significantly better in group B (100%) compared to group A (58%) (HR=0.16, 95% CI: 0.032–0.84, p=0.03). There was no significant difference in overall survival between the two groups. Grade 3/4 adverse events were observed in 92%% and 80% of patients in cohorts A and B, respectively, mainly neutropenia (78.5% vs 66.6%) and febrile neutropenia (71% vs. 40%). One patient in cohort B who received rituximab consolidation too early (day 17) died from febrile neutropenia and septic shock. Conclusion Consolidation rituximab after cladribine in frontline treatment of classical HCL showed high response rate of 100% and translated into a significant improvement in disease-free survival. Cladribine followed by rituximab consolidation may be considered as standard first-line therapy of HCL.

A Characterization of Bridging Therapies Leading up to Commercial CAR T-Cell Therapy

A Characterization of Bridging Therapies Leading up to Commercial CAR T-Cell Therapy

Long Term Follow-up of a Phase II Study of Cladribine with Concurrent Rituximab in Patients with Hairy Cell Leukemia Variant

Background Hairy cell leukemia (HCL) variant (HCLv) is considered a separate, more aggressive entity compared to classic HCL. HCLv responds poorly to single-agent purine analog with complete response (CR) rates below 10% and overall response rates under 50%. Rituximab combined with purine-analog can improve response rate and duration, but long-term data have not been reported for HCLv, particularly regarding minimal residual disease (MRD). We therefore update the results of a phase II trial with cladribine and concurrent rituximab in patients with HCLv, previously reported for 10 of the 20 patients enrolled. Methods Patients with HCLv with 0 to 1 prior courses of cladribine, and/or 0-1 prior courses of rituximab, received cladribine (0.15 mg/kg days 1-5), with 8 weekly doses of rituximab (375 mg/m2) beginning day 1. The primary endpoint was to determine CR rate and secondary endpoints included evaluating minimal residual disease (MRD) by blood and bone marrow aspirate flow cytometry, and bone marrow biopsy immunohistochemistry. Patients were able to receive a 2nd course of rituximab ≥ 6 months after the first, if and when MRD was detected in blood. Results Twenty patients were enrolled. Median age was 67 (range: 42-86) years. No patients had prior concurrent cladribine-rituximab. Eight were previously untreated, 1 had only splenectomy, 6 had prior cladribine, 1 had prior cladribine and splenectomy, 1 had prior rituximab, 1 had prior rituximab and splenectomy, 1 had cladribine, rituximab, and splenectomy, and 1 had combination rituximab-containing chemotherapy followed by cladribine. Out of 20 patients receiving concurrent cladribine-rituximab (CDAR), the CR rate was 95% (95% CI: 75-100%). This CR rate was superior to a historical control group of 3 of 39 HCLv patients who achieved CR to cladribine alone (p<0.0001). Sixteen (80%, 95% CI: 56-94%) of 20 patients became MRD-free at 6 months; median duration of MRD-free CR was 72.0 months, with 9 of 16 still MRD-free at 5-108 (median 29.1) months. With median potential follow up of 88 months (range: 7-123 months), 10 patients received delayed rituximab and 4 re-achieved MRD-free CR. Six patients required alternative treatment and 6 patients died, 5 with HCLv including 1 with HCLv limiting treatment for lung cancer, and 1 with Parkinson's disease but still MRD-free. Time from progression of HCLv to death was 5.9-30.0 (median 28.1) months. Achieving MRD-free CR by 6 months after CDAR (16 vs 4 patients) was important for median progression free survival [PFS, unreached vs 17.4 mo, hazard ratio (HR) 0.031, 95% CI 0.003-0.29, p<0.0001] and overall survival (OS, unreached vs 38.2 months, HR infinite since all 4 MRD+ deaths were prior to deaths of 2 patients who achieved MRD-free CR, p<0.0001). A significant relationship between prior purine analog therapy or unmutated IGHV4-34 (n=7) status and either PFS or OS has not yet been observed. Conclusion Concurrent cladribine with rituximab is highly effective in HCLv irrespective of prior purine-analog treatment or IGHV4-34 status and should replace purine analog monotherapy as treatment. Patients with long-term MRD-free CR are being followed to determine whether concurrent cladribine-rituximab as 1st-3rd line systemic therapy can permanently eradicate HCLv. Patients who progress have limited OS. This provides a rationale for the testing of higher intensity approaches up front and the identification of additional treatment options for HCLv. Disclosures Kreitman: Genentech: Research Funding. OffLabel Disclosure: Rituximab for hairy cell leukemia

Randomized phase II study of cladribine with simultaneous or delayed rituximab in patients with untreated hairy cell leukemia.

7003 Background: Single-agent purine analog therapy, usually cladribine, has been the standard 1st-line therapy of hairy cell leukemia (HCL) for ~30 years. Relapse is attributed to minimal residual disease (MRD) persisting despite complete remission (CR). Rituximab can clear MRD, but there are no long-term data for how frequently and for how long this happens, or even how frequently MRD remains after cladribine. We therefore conducted a randomized phase II trial of 1st-line cladribine with concurrent vs delayed rituximab. Methods: The primary endpoint was to determine if 8 weekly doses of rituximab (375 mg/m2 iv) begun the same day as 5 daily doses of cladribine (0.15 mg/kg iv) reduce HCL MRD 6 months later compared to cladribine alone. Secondary endpoints included testing delayed rituximab, 8 weekly doses beginning if/when MRD is detected in blood (or if HCL-related cytopenias persist preventing consideration of CR) ≥ 6 months after cladribine. Both groups could receive a 2nd course of rituximab if the same situation recurred ≥ 6 months after starting the 1st course of rituximab. MRD was assessed in blood (PB) and bone marrow (BM) using flow cytometry (FC), consensus PCR, and immunohistochemistry. Results: Sixty-eight patients were randomized 1:1 to concurrent vs delayed arms. At 6 months after cladribine, 97% concurrent vs 24% delayed (p < 0.0001) patients were MRD-free by all tests. 100% concurrent vs 41% delayed patients were MRD-free by all tests except BMA FC (p < 0.0001). At a median follow-up of 87.3 months, delayed rituximab was required by 1 concurrent patient vs 27 courses in 21 delayed patients. MRD-free survival after 1st rituximab was not reached for 34 patients after concurrent rituximab, with 32 still MRD-free after a median of 72 months (94% MRD-free survival), compared to median MRD-free survival 60.1 months after delayed rituximab, with 10 (48%) of 21 remaining MRD-free (p < 0.0001, hazard ratio for concurrent rituximab 0.09). Conclusions: Achievement of MRD-free CR after 1st line cladribine for HCL is greatly enhanced by concurrent rituximab. Use of delayed rather than concurrent rituximab could achieve MRD-free CR but durability was clearly inferior to concurrent rituximab. Longer follow-up will determine if MRD-free survival leads to cures of HCL, increased CR duration, and/or less need for additional therapy. Clinical trial information: NCT00923013.

Open-Label Early-Access Programs (EAPs) for Ibrutinib in Patients with Relapsed/ Refractory Chronic Lymphocytic Leukemia (CLL) or Mantle-Cell Lymphoma (MCL)

Background:Treatment options for patients with relapsed/refractory chronic lymphocytic leukemia (CLL) or mantle cell lymphoma (MCL) are limited. Ibrutinib is a first-in-class small-molecule inhibitor of Bruton's tyrosine kinase. These extended access programs (EAP) provided patient access to ibrutinib in Brazil and real-world safety data was collected, at a time when the medication was not commercially available in Brazil.Methods:These two prospective, multicenter, open-label EAPs of single-agent ibrutinib were conducted between April 2013 and August 2017, and enrolled Brazilian patients with relapsed/refractory CLL or MCL. Eligible patients must have progressive disease after at least one prior therapy and not suitable for retreatment with purine analogue therapy. After a 30-day screening, eligible patients received once-daily oral ibrutinib 420 mg (CLL) or 560 mg (MCL) continuously until disease progression, unacceptable toxicity, absence of clinical benefit, or end of EAP, whichever occurred first. Doses could be withheld or reduced based on toxicity. Patients were monitored for safety and disease evaluations were conducted per routine local standard of care practices.Results:Of 33 CLL patients enrolled, 32 received one dose of drug or more and were included in the safety analysis. Median age was 62.5 years, and most patients were male (n=24; 75%) and white (n=27; 84.4%). The median time from CLL diagnosis to study inclusion was 83.8 months and from diagnosis to relapsed/refractory state, 42.0 months. The median number of ibrutinib cycles was 12.0 (1.0-16.0) with a median treatment duration of 11.1 (0.9-11.6) months. Eight patients discontinued due to adverse event (AE; n = 4; 12.5%), consent withdrawal (n = 2; 6.3%), death (n = 1; 3.1%), or disease progression (n = 1; 3.1%). AEs leading to treatment discontinuation were intestinal bleeding, neutropenia, infection, and gastric tumor (one patient each). Three (9.4%) patients had dose reductions: one (3.1%) for neutropenia, febrile neutropenia with pneumonia, or worsening fatigue. 21 patients (65.6%) had at least one Grade ≥3 (G3) AE or serious AE (SAE). The most frequent G3 or SAEs included neutropenia in 8 (25.0%), fatigue (1), leukocytosis (1), and pneumonia (3). No atrial fibrillation or bleeding AEs were reported. Among the 47 G3 or SAEs, 17 (36.2%) were serious, 38 (80.9%) were suspected to be related to ibrutinib, and 39 (83.0%) were resolved without sequelae.All 13 MCL patients enrolled in the study were included in the safety analysis. The median age was 60.0 years, and most patients were male (n=9; 69.2%) and white (n=9; 69.2%). The median number of prior treatment regimens were 3. The median time from diagnosis to the first dose of ibrutinib was 20.4 months. The median number of ibrutinib cycles was 19 (4.0-34.0) with a median treatment duration of 16.8 (3.6-30.5) months. Eight patients discontinued because of either death (n=3; 23.1%) or disease progression (n=5; 38.5%). The three patients died with treatment-emergent G4 or higher AEs, including pneumonia (G5; probably treatment-related [TR]), sepsis (G5; not TR), and dyspnea (G4; doubtful TR); 8 patients (61.5%) had at least one G3 or higher treatment-emergent AE. The most frequent AE was diarrhea (n=3; 23.1%), and other AEs were reported in one patient each (i.e. abdominal hernia, anemia, appendicitis, dyspnea, febrile neutropenia, influenza, leukocytosis, neutropenia, pneumonia, productive cough, renal failure/insufficiency, retroperitoneal abscess, thrombocytopenia). Three (23.1%) patients had ibrutinib dose modifications: one (7.7%) each because of appendicitis/tuberculosis, thrombocytopenia, and diarrhea/retroperitoneal abscess/dyspnea. No atrial fibrillation or bleeding AEs were reported. Among the 20 G3 or higher treatment-emergent AEs, 14 (70%) were suspected to be related to ibrutinib and 15 (75%) were resolved.Conclusions: This is the first real-world experience with ibrutinib monotherapy for CLL and MCL in Brazil. Overall, treatment was well tolerated with no unexpected toxicities. No atrial fibrillation or bleeding AEs were reported. Of 32 patients with relapsed/refractory CLL, 24 (80%) remained on therapy, 4 (12.5%) discontinued due to AEs, 1 (3.1%) each died or experienced disease progression. Among 13 patients with relapsed/refractory MCL, 5 (38.5%) remained on the therapy, 3 (23.1%) died and 5 (38.5%) experienced disease progression. DisclosuresChiattone:Janssen: Honoraria, Research Funding. Fogliatto:Novartis: Consultancy; Janssen: Honoraria, Research Funding; Roche: Consultancy, Speakers Bureau. Scheinberg:Novartis: Consultancy, Speakers Bureau; Janssen: Honoraria, Research Funding; Pfizer: Speakers Bureau. Bigni:Janssen: Honoraria, Research Funding. Rodrigues:Janssen: Honoraria, Research Funding. Garicochea:Janssen: Honoraria, Research Funding. Pimenta:Janssen: Honoraria, Research Funding. Boechat:Janssen: Honoraria, Research Funding. Musacchio:Janssen: Honoraria, Research Funding. Goncalves:Janssen: Honoraria, Research Funding. Vieira:Janssen: Honoraria, Research Funding. Santos:Janssen: Employment. Grings:Janssen: Employment. Parisi:Janssen: Employment. Barreyro:Janssen: Employment.

Coexistence of chronic myeloid leukemia and diffuse large B-cell lymphoma with antecedent chronic lymphocytic leukemia: a case report and review of the literature

BackgroundChronic lymphocytic leukemia and chronic myeloid leukemia are the most common types of adult leukemia. However, it is rare for the same patient to suffer from both. Richter’s transformation to diffuse large B-cell lymphoma is frequently observed in chronic lymphocytic leukemia. Purine analog therapy and the presence of trisomy 12, and CCND1 gene rearrangement have been linked to increased risk of Richter’s transformation. The coexistence of chronic myeloid leukemia and diffuse large B-cell lymphoma in the same patient is extremely rare, with only nine reported cases. Here, we describe the first reported case of concurrent chronic myeloid leukemia and diffuse large B-cell lymphoma in a background of chronic lymphocytic leukemia.Case presentationA 60-year-old Saudi man known to have diabetes, hypertension, and chronic active hepatitis B was diagnosed as having Rai stage II chronic lymphocytic leukemia, with trisomy 12 and rearrangement of the CCND1 gene in December 2012. He required no therapy until January 2016 when he developed significant anemia, thrombocytopenia, and constitutional symptoms. He received six cycles of fludarabine, cyclophosphamide, and rituximab, after which he achieved complete remission.One month later, he presented with progressive leukocytosis (mostly neutrophilia) and splenomegaly. Fluorescence in situ hybridization from bone marrow aspirate was positive for translocation (9;22) and reverse transcription polymerase chain reaction detected BCR-ABL fusion gene consistent with chronic myeloid leukemia. He had no morphologic or immunophenotypic evidence of chronic lymphocytic leukemia at the time. Imatinib, a first-line tyrosine kinase inhibitor, was started. Eight months later, a screening imaging revealed new liver lesions, which were confirmed to be diffuse large B-cell lymphoma.ConclusionsIn chronic lymphocytic leukemia, progressive leukocytosis and splenomegaly caused by emerging chronic myeloid leukemia can be easily overlooked. It is unlikely that chronic myeloid leukemia arose as a result of clonal evolution secondary to fludarabine treatment given the very short interval after receiving fludarabine. It is also unlikely that imatinib contributed to the development of diffuse large B-cell lymphoma; rather, diffuse large B-cell lymphoma arose as a result of Richter’s transformation. Fludarabine, trisomy 12, and CCND1 gene rearrangement might have increased the risk of Richter’s transformation in this patient.

Abstract 2710: Molecular and clinical characteristics of IGHV4-34 expressing classic and variant HCL

Abstract Classic hairy cell leukemia (HCLc) is a B-cell malignancy with distinctive immunophenotype, typically expressing CD20, CD22, CD25, CD11c, CD103, CD123, annexin A1, tartrate-resistant acid phosphatase (TRAP), and BRAF V600E mutation. Purine analog therapy is highly effective with complete remission rates of approximately 85% in first line. HCL variant (HCLv) is recognized as a distinct entity, lacking CD25 and usually lacking annexin A1, tartrate-resistant acid phosphatase expression, CD123, and also lacks the BRAF V600E mutation. Patients respond poorly to purine analogs, with partial response in less than 50% and relatively poor overall survival from diagnosis. HCLc expressing B-cell receptor (BCR) with the IGHV4-34 immunoglobulin rearrangement has a poor prognosis like HCLv, whether immunophenotypically consistent with HCLv or HCLc, and also lacks BRAF V600E. We previously reported a series of 17 patients expressing IGHV4-34, immunophenotypically resembling HCLc in 7 and HCLv in 10 cases. Using routine deep sequencing of patient samples for immunoglobulin rearrangements, we have been able to accumulate 42 IGHV4-34 expressing cases including 23 classic HCL and 19 HCLv. Six (26%) of 23 HCLc vs 12 (63%) of 19 HCLv were truly unmutated, with VH gene germline identity (GI) 100%. Eleven (48%) of 23 HCLc and 7 (37%) of 19 HCLv were borderline-mutated (97≤GI<100), and 6 (26%) of 23 HCLc were significantly mutated (97<GI). There was no significant difference between the 5 groups with respect to either IGHD or IGHJ genes usage, or CDR3 length. However, we found a significant restriction of IGHD genes between 12 HCLv truly unmutated and 6 HCLc truly unmutated cases, in that there was no overlap of any IGHD genes between these 2 groups (p<0.0001). Of 28 cases test for BRAF V600E, only 5 were positive, all HCLc with GI 93.18-97.49%. The 23 BRAF wild-type (WT) cases included one with only one with GI=93.64%, but GI was >98.7% for the remaining 22 cases (p<0.0001). Of the 23 BRAF WT cases, 9 patients died of disease, 9 have active disease, and only 2 are in remission. Patients commonly had highly aggressive courses, with infiltration of HCLc/HCLv into spinal cord and cranial nerves, cardiac muscle, lungs, and cervical lymph nodes. Complete remission was achieved only through either recombinant immunotoxin therapy of combination purine analog and rituximab, but not by purine analogs alone. Additional clinical and genetic studies are ongoing to better characterize this poor-prognosis syndrome and determine if therapy can be optimized. Citation Format: Evgeny Arons, Katherine Potocka, Maryalice Stetler-Stevenson, Hong Zhou, Mark Raffeld, Mark Sokolsky, Sarah Davies, Robert J. Kreitman. Molecular and clinical characteristics of IGHV4-34 expressing classic and variant HCL [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2710. doi:10.1158/1538-7445.AM2017-2710

Abstract 4682: Genomic profiles in gene expression and methylation help define the molecular characteristics of hairy cell leukemia subtypes

Abstract Hairy cell leukemia (HCL) until recently was characterized as a single blood and bone marrow malignancy, even though clinically at least two pathologies seemed to be at work. This study sought to confirm the clinical observations using genomic evidence. HCL is a chronic mature B-cell malignancy with distinctive immunophenotype, typically expressing CD20, CD22, CD25, CD11c, CD103, CD123, annexin A1 (ANXA1), and tartrate-resistant acid phosphatase (TRAP). Purine analog therapy is highly effective, with most patients achieving durable remissions. HCL- variant (HCLv) was first identified by Cawley et al. (1980) and recently recognized by the World Health Organization as a separate cancer. HCLv lacks CD25, ANXA1, TRAP, and BRAF V600E expression, and patients respond poorly to purine analogs. In order to find detailed biological information involving these two diseases, we studied the genome-wide gene expression and methylation profiles of 75 HCL patient samples; 67 were tested by both methods. Our study results indicate that HCL and HCLv show very distinct gene expression and methylation patterns. Many genes that are differentially expressed are involved in immunological and inflammatory response pathways. Several cancer associated genes such as ANXA1 and FLT3 are down-regulated in HCLv compared to HCL. Correlation patterns between methylation and gene expression for many genes such as ANXA1 suggest that methylation plays an import role in gene expression regulation for these malignancies. This study has begun the process of identifying better biomarkers for disease discrimination between HCL and HCLv and providing potential new targets for strongly needed therapies for HCLv. Citation Format: Daniel C. Edelman, Holly S. Stevenson, Yonghong Wang, Evgeny Arons, Joshua J. Waterfall, David Petersen, Hong Zhou, Paul S. Meltzer, Robert J. Kreitman. Genomic profiles in gene expression and methylation help define the molecular characteristics of hairy cell leukemia subtypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4682. doi:10.1158/1538-7445.AM2017-4682

How I manage patients with hairy cell leukaemia.

Patients with hairy cell leukaemia (HCL) have highly favourable outcomes after purine analogue therapy. However, most patients subsequently relapse and require re-treatment. A minority of patients develop purine analogue-refractory disease. Targeted therapies have improved outcomes for such patients. Recently, the BRAF V600E mutation was identified in most patients with classical HCL, resulting in constitutive mitogen-activated protein kinase pathway activation; impressive responses are achieved in heavily pre-treated patients with BRAF inhibition. The CD22-targeted immunoconjugate moxetumomab pasudotox and BTK inhibitor ibrutinib also achieve responses in relapsed and refractory patients. HCL variant and the IGHV4-34 molecular variant of HCL lack BRAF mutation and have inferior outcomes with standard purine analogue therapy. The addition of rituximab to purine analogues achieves very high rates of minimal residual disease-negative complete remission and improves outcomes for patients with HCL variant. Given the rarity of HCL, optimal integration of novel therapies into treatment algorithms will require well-designed, collaborative studies.

Melanoma and non-melanoma skin cancers in hairy cell leukaemia: a Surveillance, Epidemiology and End Results population analysis and the 30-year experience at Memorial Sloan Kettering Cancer Center.

Few studies have examined melanoma and non-melanoma skin cancer (NMSC) incidence rates after a diagnosis of hairy cell leukaemia (HCL). We assessed 267 HCL patients treated at Memorial Sloan Kettering Cancer Center (MSKCC) and Surveillance, Epidemiology and End Results (SEER) data for melanoma and NMSC incidence rates after HCL. Incidence data from MSKCC patients demonstrated a 10-year combined melanoma and NMSC skin cancer rate of 11·3%, melanoma 4·4% and NMSC 6·9%. Molecular analysis of skin cancers from MSKCC patients revealed activating RAS mutations in 3/9 patients, including one patient with melanoma. Of 4750 SEER patients with HCL, 55 (1·2%) had a subsequent diagnosis of melanoma. Standardized incidence ratios (SIRs) did not show that melanoma was more common in HCL patients versus the general population (SIR 1·3, 95% CI 0·78-2·03). Analysis of SEER HCL patients diagnosed before and after 1990 (approximately before and after purine analogue therapy was introduced) showed no evidence of an increased incidence after 1990. A better understanding of any potential association between HCL and skin cancer is highly relevant given ongoing trials using BRAF inhibitors, such as vemurafenib, for relapsed HCL, as RAS-mutant skin cancers could be paradoxically activated in these patients.

Advances in the Treatment of Hairy Cell Leukemia

Hairy cell leukemia is relatively rare, chronic low grade B-cell leukemia. It is characterized morphologically by cells with abundant cytoplasm and “hair”-like projections that can be found within the peripheral blood, bone marrow or splenic pulp. Like many cancers, the treatment for hairy cell leukemia has evolved considerably in the last several years. In the mid 1980s, the acceptable treatment was splenectomy and later interferon therapy, which is quickly falling out of favor with the advent and acceptance of purine analog therapy. In addition, we now have several biologic agents that are coming into favor based on their improved success and favorable toxicity. In addition, several studies are currently looking into the efficacy of purine analogs in conjunction with biologic agents. Rituximab, alemtuzumab and recombinant immunotoxins are being studied with limited success in hairy cell leukemia. The use of kinase inhibition is also being studied at this time. Advances in understanding the biology of hairy cell leukemia could potentially increase more treatment options.

SL-401, a Targeted Therapy Directed to the Interleukin-3 Receptor (IL-3R), Shows Cytotoxic Activity Against Hairy Cell Leukemia

Background: Hairy cell leukemia (HCL) is a rare B-lymphocyte disorder that is characterized by abnormal lymphoproliferation, cytoplasmic villous “hairy” projections, and infiltration of the bone marrow and spleen. These cellular changes lead to peripheral cytopenia and splenomegaly. HCL cases comprise approximately 2% of all leukemias, with an incidence of approximately 600-800 and prevalence of approximately 6,000 cases annually in the U.S. The purine analogs Leustatin® (cladribine) and Nipent® (pentostatin) induce high complete remission (CR) rates (70-95%), with most patients remaining in CR after 10+ years. However, there is an increasing number of patients who either relapse or become refractory to each successive purine analog therapy given, and for these patients there are currently no approved therapies. Since HCL is known to express high levels of the interleukin-3 receptor (IL-3R) α-chain (CD123), we tested the cytotoxic activity of SL-401, a novel targeted therapy directed to CD123, against HCL cells.Methods: Expression of CD123 on a human cell lines obtained from an HCL patient (MoB and MoT) was determined by flow cytometry. Cells were washed with phosphate-buffered saline (PBS) and stained with anti-CD123 PE (BD Biosciences) and control IgG for 20 minutes at 4oC and then washed with PBS again. Stained cells were acquired using the LSR II (BD) cytometer and data were analyzed using Flow Jo software (Tree Star). The sensitivity of the cells to SL-401 was assessed using a CellTiter Glo in vitro cytotoxicity assay. A CD123 positive leukemia cell line (TF-1-HRas), which is known to be sensitive to SL-401, was used as a positive control. The cells were cultured in the presence of absence of SL-401 for 48 hours and assessed for viability at concentrations ranging from (0.087 pM to 368 nM).Results: The HCL cell lines MoB and MoT were found to express moderate to high levels of IL-3R (45% and 84%, respectively). Based on the IL-3R expression pattern, the sensitivity of these cells to SL-401 was then tested. Cells were shown to be markedly sensitive to SL-401 in a concentration-dependent manner after 48 hours of incubation, with IC50 values in the low nanomolar range from triplicate experiments. Cell viability was also reduced by 80% after 48 hours of treatment with SL-401 at a concentration of 35 nM.Conclusion: Our results indicate that SL-401 possesses strong in vitro anti-cancer activity against HCL, which expresses high levels of the IL-3R. Studies testing SL-401 against additional HCL samples are ongoing. Given the current unmet medical need for new therapies to treat relapsed/refractory HCL patients, our findings support the further investigation of SL-401 in HCL. DisclosuresBrooks:Stemline Therapeutics: Employment, Equity Ownership. Chen:Stemline Therapeutics: Employment, Equity Ownership. Bergstein:Stemline Therapeutics: Employment, Equity Ownership. Rowinsky:Stemline Therapeutics: Consultancy, Employment, Equity Ownership.

Hairy cell leukemia - immunotargets and therapies.

Hairy cell leukemia (HCL) is an indolent low-grade B-cell lymphoproliferative disorder that is reasonably sensitive to standard first-line purine analog therapy. However, in many cases, repeat relapses occur, requiring multiple courses of purine analog therapy, promoting eventual drug resistance. This, coupled with the concerning side effects of repeated purine analog exposure, has prompted the search for alternative targets and therapies that may provide deeper remissions. Novel strategies employing immune-mediated targeting via monoclonal antibody therapies and recombinant immunotoxins appear promising in HCL and are currently under investigation. More recently, the concept of targeted kinase inhibition using small-molecule inhibitors in HCL has emerged as another potentially viable option. As a deeper understanding of the aberrant molecular pathways contributing to the pathogenesis of HCL develops, the landscape of management for HCL, particularly in the relapse setting, may change significantly in the future as a result of these promising immunotargets and therapies.

Hodgkin Transformation Of Chronic Lymphocytic Leukemia (CLL): Mayo Clinic Experience

▪ BackgroundAlthough its prevalence is not well defined, transformation to Hodgkin lymphoma (HL) is a rare but well recognized complication in patients with CLL. Prior studies have reported a median survival of 0.8-1.7 years in these patients. Prior therapy of CLL, especially with purine analogs, has been shown to have adverse impact on survival after development of HL. We used the Mayo Clinic CLL database to describe outcomes of CLL patients seen at our institution who developed HL. MethodsThe Mayo Clinic CLL database includes all consenting patients with a pathologic diagnosis of CLL. Patients who developed biopsy-proven HL were included in this analysis. For patients referred from an outside institution, pathology review at Mayo Clinic was mandatory to be included. Clinical characteristics, therapy and overall survival (OS) were analyzed for all HL patients. ResultsAmong 3124 CLL patients seen at Mayo Clinic from 1/1995 to 7/2011, 26 developed HL. In a nested cohort of 1644 patients who were seen within 12 months of CLL diagnosis and followed prospectively, the prevalence of HL was 0.05%/year (10 year risk=0.5%). All 26 patients had classical HL. The median duration between CLL diagnosis and development of HL was 6.2 years (range, 0-24.5 years). The median age at diagnosis of HL was 68 years (range, 45-88 years) and 21 (81%) were male. At the time of HL diagnosis, the median WBC count was 7.8 x 109/L (range, 1.3-87.3), median hemoglobin was 11 gm/dL (range, 7.2-13), median platelet count was 220x109/L (range, 53-627), median serum lactate dehydrogenase was 249 U/L (range, 133-658), and median serum albumin was 3.4 gm/dL (range, 2.6-4.2). According to the Ann Arbor staging system for HL, 10 (38%) were Stage II, 2 (8%) were Stage III, 11 (42%) were Stage IV, and undetermined in 3 (12%) patients. Sixteen patients (61%) received HL therapy with doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD), seven (27%) received other chemotherapy, and treatment was unknown in 3 (12%) patients. No patient underwent stem cell transplantation as therapy for HL.After a median follow-up of 8.7 years from CLL diagnosis date, 16 (61%) patients have died. The median OS from date of HL diagnosis was 3.9 years (95% CI, 1.0 – 5.0 years). The International Prognostic score (IPS) for HL, originally proposed by Hasenclever in 1998, identified seven prognostic factors: serum albumin <4 gm/dL, hemoglobin <10.5 gm/dL, male sex, age >45 years, stage IV disease, WBC≥15 x 109/L, and lymphocytopenia in patients with newly diagnosed HL. When we applied these prognostic parameters (available in 22/26 patients, 85% in our cohort), the IPS score predicted median survival as follows: score of ≤2 (18% of the patients), median survival not reached; score of 3 (23% of the patients), 6.2 years; score of 4 (36% of the patients), 2.4 years; and score ≥5 (23% of the patients), 0.3 years (p-value=0.005, Figure 1). In contrast, the Richter syndrome prognostic score developed for CLL patients who transform to diffuse large B-cell lymphoma failed to predict survival in these patients (Tsimberidou, JCO, 2006). [Display omitted] Of the 26 patients with HL, 16 (61%) had received therapy for their CLL prior to developing HL, including 12 (46%) who had received more than one line of therapy. Purine analogs had been administered for treatment of CLL prior to development of HL in 13/26 (50%) patients. The median survival of HL patients who had previously received CLL therapy was significantly worse compared to those who were untreated for CLL (2.8 years vs. 7.6 years, p-value=0.02). There was a trend toward shorter survival for HL patients who had received previous purine analog therapy for CLL compared to those who received alternate therapies (1.8 years vs. 5 years, p-value: p-value=0.07).Of the 9 HL biopsy samples in which Epstein Barr virus (EBV) in-situ hybridization studies were performed, EBV was detected in 6 (67%) patients. No association was observed between prior purine analog therapy and EBV status (p-value=1.0). There was no difference in survival according to the EBV status of HL (p-value=0.33). ConclusionThe 10 year incidence of transformation to Hodgkin transformation among patients with newly diagnosed CLL is 0.5% (∼1/200 CLL patients). In this single-institution analysis, median survival of CLL patients who developed Hodgkin transformation of CLL was approximately 4 years after HL diagnosis. The IPS accurately predicted survival in our cohort of HL patients. Disclosures:Zent:Novartis: Research Funding; GlaxSmithKline: Research Funding; Biothera: Research Funding; Genzyme: Research Funding; Genentech : Research Funding. Shanafelt:Glaxo-Smith-Kline: Research Funding; Cephalon: Research Funding; Hospira: Research Funding; Celgene: Research Funding; Polyphenon E International: Research Funding; Genentech: Research Funding.

Bendamustine plus alemtuzumab is safe and feasible treatment for fludarabine refractory chronic lymphocytic leukaemia (CLL)

Bendamustine plus alemtuzumab is safe and feasible treatment for fludarabine refractory chronic lymphocytic leukaemia (<scp>CLL</scp>)

Epstein-Barr Virus–Induced CD30-Positive Diffuse Large B-Cell Lymphoma in a Patient With Mixed-Phenotypic Leukemia Treated With Clofarabine

Lymphoproliferative disorders (LPD) have been reported in several clinical settings associated with immunosuppression such as primary immune deficiency, HIV infection, bone marrow or solid organ transplantation, methotrexate or tumor necrosis factor-therapy, and aging.1,2 A significant number of these cases are associated with EBV. While EBV-positive LPD have been documented in patients with low grade lymphoma’s treated with purine analogues including cladribine 3,4 or fludarabine,5,6 we could not identify any reports of EBV-positive LPD after purine analogue (including clofarabine) therapy for AML or MPAL. As clofarabine is being used with increasing frequency in AML therapy 7,8 such phenomenon may be noted with increasing frequency in the future. In our patient R-CHOP (rituximab, cyclophosphamide, his-adriamycin, vincristine, prednisone) therapy 9,10 effectively treated the EBV-positive LPD and this may help guide treatment in future occurrences of a similar nature.

Immunoconjugates and new molecular targets in hairy cell leukemia

Abstract Hairy cell leukemia (HCL) is a B-cell malignancy that in its classic form is exquisitely sensitive to single-agent purine analog therapy, but that is associated in many patients with late relapse and eventual purine analog resistance. Minimal residual disease, which is present in most patients achieving complete remission with purine analogs, retains Ags that are ideal for targeted therapy. Rituximab, which targets CD20, is active as a single agent, particularly if combined with purine analogs. Recombinant immunotoxins targeting either CD25 or CD22 and containing truncated Pseudomonas exotoxin have achieved major responses in relapsed/refractory HCL. Moxetumomab pasudotox in phase 1 testing achieved responses in 86% of such patients (complete in 46%) without dose limiting toxicity and often without MRD. Soluble CD22 has been used for improved detection and monitoring of HCL, particularly the poor-prognosis variant that lacks CD25. Ig rearrangements unique for each HCL patient have been cloned, sequenced, and followed by real-time quantitative PCR using sequence-specific reagents. Analysis of these rearrangements has identified an unmutated IGVH4-34–expressing poor-prognosis variant with immunophenotypic characteristics of either classic or variant HCL. The BRAF V600E mutation, reported in 50% of melanomas, is present in &gt; 85% of HCL cases that are both classic and express rearrangements other than IGVH4-34, making HCL a potential target for specific inhibitors of BRAF V600E. Additional targets are being defined in both classic and variant HCL, which should improve both detection and therapy.

Guidelines on the diagnosis, investigation and management of chronic lymphocytic leukaemia

Royal Bournemouth Hospital, Bournemouth, 2 Royal Marsden Hospital, London, 3 Southampton General Hospital, Southampton, Cardiff and Vale NHS Trust, Cardiff Cambridge University Hospitals NHS Foundation Trust, Cambridge UK; St. James's Institute of Oncology, Leeds, Christie Hospital NHS Trust, Manchester Royal Marsden Hospital London; Heart of England NHS Foundataion Trust, Birmingham; 10 Royal Liverpool University Hospital, Liverpool; Churchill Hospital, Headington, Oxford, Norfolk and Norwich University Hospital, Norwich