Christian Buske

Ibrutinib for patients with rituximab-refractory Waldenström's macroglobulinaemia (iNNOVATE): an open-label substudy of an international, multicentre, phase 3 trial

BACKGROUNDnIn the era of widespread rituximab use for Waldenströms macroglobulinaemia, new treatment options for patients with rituximab-refractory disease are an important clinical need. Ibrutinib has induced durable responses in previously treated patients with Waldenströms macroglobulinaemia. We assessed the efficacy and safety of ibrutinib in a population with rituximab-refractory disease.nnnMETHODSnThis multicentre, open-label substudy was done at 19 sites in seven countries in adults aged 18 years and older with confirmed Waldenströms macroglobulinaemia, refractory to rituximab and requiring treatment. Disease refractory to the last rituximab-containing therapy was defined as either relapse less than 12 months since last dose of rituximab or failure to achieve at least a minor response. Key exclusion criteria included: CNS involvement, a stroke or intracranial haemorrhage less than 12 months before enrolment, clinically significant cardiovascular disease, hepatitis B or hepatitis C viral infection, and a known bleeding disorder. Patients received oral ibrutinib 420 mg once daily until progression or unacceptable toxicity. The substudy was not prospectively powered for statistical comparisons, and as such, all the analyses are descriptive in nature. This study objectives were the proportion of patients with an overall response, progression-free survival, overall survival, haematological improvement measured by haemoglobin, time to next treatment, and patient-reported outcomes according to the Functional Assessment of Cancer Therapy-Anemia (FACT-An) and the Euro Qol 5 Dimension Questionnaire (EQ-5D-5L). All analyses were per protocol. The study is registered at ClinicalTrials.gov, number NCT02165397, and follow-up is ongoing but enrolment is complete.nnnFINDINGSnBetween Aug 18, 2014, and Feb 18, 2015, 31 patients were enrolled. Median age was 67 years (IQR 58-74); 13 (42%) of 31 patients had high-risk disease per the International Prognostic Scoring System Waldenström Macroglobulinaemia, median number of previous therapies was four (IQR 2-6), and all were rituximab-refractory. At a median follow-up of 18·1 months (IQR 17·5-18·9), the proportion of patients with an overall response was 28 [90%] of 31 (22 [71%] of patients had a major response), the estimated 18 month progression-free survival rate was 86% (95% CI 66-94), and the estimated 18 month overall survival rate was 97% (95% CI 79-100). Baseline median haemoglobin of 10·3 g/dL (IQR 9·3-11·7) increased to 11·4 g/dL (10·9-12·4) after 4 weeks of ibrutinib treatment and reached 12·7 g/dL (11·8-13·4) at week 49. A clinically meaningful improvement from baseline in FACT-An score, anaemia subscale score, and the EQ-5D-5L were reported at all post-baseline visits. Time to next treatment will be presented at a later date. Common grade 3 or worse adverse events included neutropenia in four patients (13%), hypertension in three patients (10%), and anaemia, thrombocytopenia, and diarrhoea in two patients each (6%). Serious adverse events occurred in ten patients (32%) and were most often infections. Five (16%) patients discontinued ibrutinib: three due to progression and two due to adverse events, while the remaining 26 [84%] of patients are continuing ibrutinib at the time of this report.nnnINTERPRETATIONnThe sustained responses and median progression-free survival time, combined with a manageable toxicity profile observed with single-agent ibrutinib indicate that this chemotherapy-free approach is a potential new treatment choice for patients who had heavily pretreated, rituximab-refractory Waldenströms macroglobulinaemia.nnnFUNDINGnPharmacyclics LLC, an AbbVie Company.

Treatment recommendations from the Eighth International Workshop on Waldenström’s Macroglobulinemia

Waldenström macroglobulinemia (WM) is a distinct B-cell lymphoproliferative disorder for which clearly defined criteria for the diagnosis, initiation of therapy, and treatment strategy have been proposed as part of the consensus panels of the International Workshop on Waldenströms Macroglobulinemia (IWWM). At IWWM-8, a task force for treatment recommendations was impanelled to review recently published and ongoing clinical trial data as well as the impact of new mutations (MYD88 and CXCR4) on treatment decisions, indications for B-cell receptor and proteasome inhibitors, and future clinical trial initiatives for WM patients. The panel concluded that therapeutic strategies in WM should be based on individual patient and disease characteristics. Chemoimmunotherapy combinations with rituximab and cyclophosphamide-dexamethasone, bendamustine, or bortezomib-dexamethasone provide durable responses and are still indicated in most patients. Approval of the BTK inhibitor ibrutinib in the United States and Europe represents a novel and effective treatment option for both treatment-naive and relapsing patients. Other B-cell receptor inhibitors, second-generation proteasome inhibitors (eg, carfilzomib), and mammalian target of rapamycin inhibitors are promising and may increase future treatment options. Active enrollment in clinical trials whenever possible was endorsed by the panel for most patients with WM.

Age-dependent frequencies of NPM1 mutations and FLT3-ITD in patients with normal karyotype AML (NK-AML)

Prognosis of AML in elderly patients is poor due to adverse patient characteristics and comorbidities. In addition, disease-associated parameters reveal differences between older and younger patients with AML. Survival in normal karyotype AML (NK-AML) is influenced by different clinical and molecular markers. The aim of this work was to investigate the frequencies of molecular markers in patients with NK-AML with a focus on NPM1 mutations and FLT3-ITD in different age groups. In the present study, we analyzed the frequencies of mutations of NPM1 and FLT3-ITD in a cohort of 1,321 adult patients and 148 children with AML treated within the AMLCG99, the AML98, and AML04 trials and their distribution in different age groups. Additionally, the frequencies of mutations in CEBPA genes, FLT3-TKD, and MLL-PTD were analyzed in the cohort with NK-AML (nu2009=u2009729). Our data show that the presence of mutations of NPM1 (from 60% to 40%) and FLT3-ITD (from 50% to 20%) significantly decreased with age in adult AML. Consequently, the proportion of NPM1−/FLT3-ITD− patients increased with age. The decreasing frequency of NPM1 mutations in elderly patients was paralleled by a reduced complete remission (CR) rate in the elderly of 55% compared to 80% in the younger patients. By contrast, the frequencies of other gene mutations, like FLT3-TKD and MLL-PTD, and mutations in CEBPA were not age-dependent. The decreasing frequency of the favorable NPM1 mutations with increasing age may partially explain the worse outcome in the elderly patients. Furthermore, the increasing amount of elderly patients without NPM1 mutations or FLT3-ITD suggests that other molecular and clinical risk factors may influence prognosis in this age group.

Concise Review: The Piwi‐piRNA Axis: Pivotal Beyond Transposon Silencing

Piwi proteins and their associated piRNAs are essential for preserving the self‐renewal property of mammalian germ stem cells. Their highly conserved role in CpG island DNA methylation and chromatin modifications in germ stem cells has long been associated with transposon silencing but recent reports hint at protein coding regions being targets for Piwi‐mediated epigenetic changes as well. Interestingly, the expression of PIWI family members is not restricted to the germline, and certain members have also been implicated in tumorigenesis in cases of adenocarcinomas, gliomas, and sarcomas. The following review discusses our knowledge of the function of Piwi proteins and piRNAs in suppressing transposable elements while maintaining the self‐renewing population of germ stem cells. We also highlight the somatic function of Piwi as an epigenetic modifier. Furthermore, we summarize the recently uncovered involvement of Piwi proteins and piRNAs in various cancers. STEM CELLS 2012;30:2603–2611

An eight-gene expression signature for the prediction of survival and time to treatment in chronic lymphocytic leukemia

An eight-gene expression signature for the prediction of survival and time to treatment in chronic lymphocytic leukemia

Hairy cell leukaemia: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up

T. Robak1, E. Matutes2, D. Catovsky3, P. L. Zinzani4 & C. Buske5, on behalf of the ESMO Guidelines Committee* Department of Hematology, Medical University of Lodz, Lodz, Poland; Haematopathology Unit, Hospital Clinic, Barcelona University, Barcelona, Spain; Haemato-Oncology Research Unit, The Institute of Cancer Research, Sutton, Surrey, UK; Seràgnoli Institute of Hematology, University of Bologna, Bologna, Italy; Comprehensive Cancer Center Ulm, Institute of Experimental Cancer Research, University Hospital, Ulm, Germany

Expression analysis of genes located in the minimally deleted regions of 13q14 and 11q22-23 in chronic lymphocytic leukemia-unexpected expression pattern of the RHO GTPase activator ARHGAP20.

In chronic lymphocytic leukemia (CLL), 13q14 and 11q22‐23 deletions are found in 2/3 of the cases. 11q22‐23 deletions are associated with poor survival, whereas 13q14 deletions as single abnormality are often found in indolent disease forms. The molecular basis for this difference in prognosis is not known. We examined the 13q14 and 11q22‐23 minimally deleted regions (MDRs) for differentially expressed genes by analyzing 154 microarray CLL gene expression data sets. We were able to generate a detailed gene expression map of the MDRs demonstrating a gene dosage effect. Surprisingly, ARHGAP20 encoding the RHO GTPase activating protein 20, which is located in the 11q22‐23 MDR, showed—counterintuitively—a significantly higher expression in cases with 11q22‐23 deletions compared with cases with no detectable genetic lesion or trisomy 12. Interestingly, cases with 13q14 deletions also had higher ARHGAP20 expression. These expression level changes were confirmed by quantitative PCR in 110 additional CLL samples. The ARHGAP20 gene encodes an evolutionarily conserved protein. In the zebra fish (Danio rerio) genome the syntenic regions of human chromosomal bands 13q14 and 11q22‐23 are juxtaposed. The similar expression profiles of ARHGAP20 in 13q14 and 11q22‐23 deleted CLL cases suggest a molecular connection and an intriguing mechanism of regulation.

Efficacy, pharmacokinetics, and safety of the biosimilar CT-P10 compared with rituximab in patients with previously untreated advanced-stage follicular lymphoma: a randomised, double-blind, parallel-group, non-inferiority phase 3 trial

BACKGROUNDnStudies in patients with rheumatoid arthritis have shown that the rituximab biosimilar CT-P10 (Celltrion, Incheon, South Korea) has equivalent efficacy and pharmacokinetics to rituximab. In this phase 3 study, we aimed to assess the non-inferior efficacy and pharmacokinetic equivalence of CT-P10 compared with rituximab, when used in combination with cyclophosphamide, vincristine, and prednisone (CVP) in patients with newly diagnosed advanced-stage follicular lymphoma.nnnMETHODSnIn this ongoing, randomised, double-blind, parallel-group, active-controlled study, patients aged 18 years or older with Ann Arbor stage III-IV follicular lymphoma were assigned 1:1 to CVP plus intravenous infusions of 375 mg/m2 CT-P10 or rituximab on day 1 of eight 21-day cycles. Randomisation was done by the investigators using an interactive web or voice response system and a computer-generated randomisation schedule, prepared by a clinical research organisation. Randomisation was balanced using permuted blocks and was stratified by country, gender, and Follicular Lymphoma International Prognostic Index score (0-2 vs 3-5). Study teams from the sponsor and clinical research organisation, investigators, and patients were masked to treatment assignment. The study was divided into two parts: part 1 assessing equivalence of pharmacokinetics (in the pharmacokinetics subset), and part 2 assessing efficacy in all randomised patients (patients from the pharmacokinetics subset plus additional patients enrolled in part 2). Equivalence of pharmacokinetics was shown if the 90% CIs for the geometric mean ratio of CT-P10 to rituximab in AUCτ and CmaxSS were within the bounds of the equivalence margin of 80% and 125%. Non-inferiority of response was shown if the one-sided 97·5% CI lay on the positive side of the -7% margin, using a one-sided test done at the 2·5% significance level. The primary efficacy endpoint was the proportion of patients who had an overall response over eight cycles and was assessed in the efficacy population (all randomised patients). The primary pharmacokinetic endpoints were area under the serum concentration-time curve at steady state (AUCτ) and maximum serum concentration at steady state (CmaxSS) at cycle 4, assessed in the pharmokinetic population. This trial is registered with ClinicalTrials.gov, number NCT02162771.nnnFINDINGSnBetween July 28, 2014, and Dec 29, 2015, 140 patients were enrolled. Here we report data for the eight-cycle induction period, up to week 24. The proportion of patients with an overall response in the efficacy population was 64 (97·0%) of 66 patients in the CT-P10 treatment group and 63 (92·6%) of 68 patients in the rituximab treatment group (4·3%; one-sided 97·5% CI -4·25), which lay on the positive side of the predefined non-inferiority margin. The ratio of geometric least squares means (CT-P10/rituximab) was 102·25% (90% CI 94·05-111·17) for AUCτ and 100·67% (93·84-108·00) for CmaxSS, with all CIs within the bioequivalence margin of 80-125%. Treatment-emergent adverse events were reported for 58 (83%) of 70 patients in the CT-P10 treatment group and 56 (80%) of 70 in the rituximab treatment group. The most common grade 3 or 4 treatment-emergent adverse event in each treatment group was neutropenia (grade 3, 15 [21%] of 70 patients in the CT-P10 group and seven [10%] of 70 patients in the rituximab group). The proportion of patients who experienced at least one treatment-emergent serious adverse event was 16 (23%) of 70 patients in the CT-P10 group and nine (13%) of 70 patients in the rituximab group.nnnINTERPRETATIONnIn this study, we show that CT-P10 exhibits non-inferior efficacy and pharmacokinetic equivalence to rituximab. The safety profile of CT-P10 was comparable to that of rituximab. CT-P10 might represent a new therapeutic option for advanced-stage follicular lymphoma.nnnFUNDINGnCelltrion, Inc.

Phase 3 Trial of Ibrutinib plus Rituximab in Waldenström’s Macroglobulinemia

Background Single‐agent ibrutinib has shown substantial activity in patients with relapsed Waldenströms macroglobulinemia, a rare form of B‐cell lymphoma. We evaluated the effect of adding ibrutinib to rituximab in patients with this disease, both in those who had not received previous treatment and in those with disease recurrence. Methods We randomly assigned 150 symptomatic patients to receive ibrutinib plus rituximab or placebo plus rituximab. The primary end point was progression‐free survival, as assessed by an independent review committee. Key secondary end points were response rates, sustained hematologic improvement from baseline, and safety. The mutational status of MYD88 and CXCR4 was assessed in bone marrow samples. Results At 30 months, the progression‐free survival rate was 82% with ibrutinib–rituximab versus 28% with placebo–rituximab (hazard ratio for progression or death, 0.20; P<0.001). The benefit in the ibrutinib–rituximab group over that in the placebo–rituximab group was independent of the MYD88 or CXCR4 genotype. The rate of major response was higher with ibrutinib–rituximab than with placebo–rituximab (72% vs. 32%, P<0.001). More patients had sustained increases in hemoglobin level with ibrutinib–rituximab than with placebo–rituximab (73% vs. 41%, P<0.001). The most common adverse events of any grade with ibrutinib–rituximab included infusion‐related reactions, diarrhea, arthralgia, and nausea. Events of grade 3 or higher that occurred more frequently with ibrutinib–rituximab than with placebo–rituximab included atrial fibrillation (12% vs. 1%) and hypertension (13% vs. 4%); those that occurred less frequently included infusion reactions (1% vs. 16%) and any grade of IgM flare (8% vs. 47%). The major hemorrhage rate was the same in the two trial groups (4%). Conclusions Among patients with Waldenströms macroglobulinemia, the use of ibrutinib–rituximab resulted in significantly higher rates of progression‐free survival than the use of placebo–rituximab, both among those who had received no previous treatment and among those with disease recurrence. Atrial fibrillation and hypertension were more common with ibrutinib–rituximab, whereas infusion reactions and IgM flare were more common with placebo–rituximab. (Funded by Pharmacyclics and Janssen Research and Development; ClinicalTrials.gov number, NCT02165397.)

An introduction to biosimilar cancer therapeutics: definitions, rationale for development and regulatory requirements

Monoclonal antibodies and other biologic drugs play important roles in the treatment of various hematological malignancies and solid tumors. However, such drugs are intrinsically more expensive to develop than small molecules and their clinical benefits are often accompanied by challenges relating to affordability and access. Patent expiry for originator biologics is providing opportunities for a new generation of biosimilar drugs, potentially capable of relieving pressure on healthcare budgets. This article discusses key characteristics of biosimilars, distinguishes them from generics and noncomparable biologics and outlines the robust regulatory requirements that must be followed to establish biosimilarity with a reference product. The path to approval is discussed with reference to the rituximab biosimilar CT-P10, the first licensed monoclonal antibody biosimilar cancer therapeutic.