Cereblon (CRBN) gene polymorphisms predict clinical response and progression-free survival in relapsed/refractory multiple myeloma patients treated with lenalidomide: a pharmacogenetic study from the IMMEnSE consortium.

Cereblon (CRBN) is crucial for antiproliferative and immunomodulatory properties of immunomodulatory drugs. The objective of this study was to verify whether germline single nucleotide polymorphisms (SNPs) in the CRBN gene may influence response to lenalidomide in multiple myeloma (MM). Fourteen tagging SNPs covering the genetic variability in the CRBN gene region were genotyped in 167 Polish patients with refractory/relapsed MM treated with lenalidomide-based regimens. We found that carriers of minor alleles of two studied CRBN SNPs rs1714327G > C (OR = 0.26; 95% CI = 0.1-0.67; p = .0055, Bonferroni corrected p = .033) and rs1705814T > C (OR = 0.22; 95% CI = 0.07-0.65; p = .0063, Bonferroni corrected p = .037) were significantly associated with lower probability of achievement at least partial remission while treated with lenalidomide-based regimens, using the dominant inheritance model. Moreover, one of these SNPs, namely rs1705814T > C, was correlated with shorter progression-free survival (HR = 2.49; 95%CI = 1.31-4.74, p = .0054, Bonferroni corrected p = .033). It is suggested that selected germline CRBN allelic variants (rs1714327G > C and rs1705814T > C) affect lenalidomide efficacy in patients with relapsed/refractory MM.

A phase III randomized, multicentre, double blind, active controlled trial to compare the efficacy and safety of two different anagrelide formulations in patients with essential thrombocythaemia - the TEAM-ET 2·0 trial.

Anagrelide is an established treatment option for essential thrombocythaemia (ET). A prolonged release formulation was developed with the aim of reducing dosing frequency and improving tolerability, without diminishing efficacy. This multicentre, randomized, double blind, active-controlled, non-inferiority trial investigated the efficacy, safety and tolerability of anagrelide prolonged release (A-PR) over a reference product in high-risk ET patients, either anagrelide-naïve or -experienced. In a 6 to 12-week titration period the individual dose for the consecutive 4-week maintenance period was identified. The primary endpoint was the mean platelet count during the maintenance period (3 consecutive measurements, day 0, 14, 28). Of 112 included patients 106 were randomized. The mean screening platelet counts were 822 × 109 /l (95% confidence interval (CI) 707-936 × 109 /l) and 797 × 109 /l (95% CI 708-883 × 109 /l) for A-PR and the reference product, respectively. Both treatments effectively reduced platelet counts, to mean 281 × 109 /l for A-PR (95% CI 254-311) and 305 × 109 /l (95% CI 276-337) for the reference product (P < 0·0001, for non-inferiority). Safety and tolerability were comparable between both drugs. The novel prolonged-release formulation was equally effective and well tolerated compared to the reference product. A-PR provides a more convenient dosing schedule and will offer an alternative to licensed immediate-release anagrelide formulations.

CEBPA copy number variations in normal karyotype acute myeloid leukemia: Possible role of breakpoint-associated microhomology and chromatin status in CEBPA mutagenesis.

Copy number variations (CNV) in CEBPA locus represent heterogeneous group of mutations accompanying acute myeloid leukemia (AML). The aim of this study was to characterize different CEBPA mutation categories in regard to biological data like age, cytology, CD7, and molecular markers, and identify possible factors affecting their etiology. We report here the incidence of 12.6% of CEBPA mutants in the population of 262 normal karyotype AML (NK-AML) patients. We confirmed that double mutant AMLs presented uniform biological features when compared to single CEBPA mutations and accompanied mostly younger patients. We hypothesized that pathogenesis of distinct CEBPA mutation categories might be influenced by different factors. The detailed sequence analysis revealed frequent breakpoint-associated microhomologies of 2 to 12bp. The analysis of distribution of microhomology motifs along CEBPA gene showed that longer stretches of microhomology at the mutational junctions were relatively rare by chance which suggests their functional role in the CEBPA mutagenesis. Additionally, accurate quantification of CEBPA transcript levels showed that double CEBPA mutations correlated with high-level CEBPA expression, whereas single N-terminal CEBPA mutations were associated with low-level CEBPA expression. This might suggest that high-level CEBPA expression and/or accessibility of CEBPA locus contribute to B-ZIP in-frame duplications.

Real-life comparison of severe vascular events and other non-hematological complications in patients with chronic myeloid leukemia undergoing second-line nilotinib or dasatinib treatment.

We retrospectively analyzed the rates of significant non-hematological adverse events (AEs) in 105 patients with chronic myeloid leukemia (CML) treated with second-generation tyrosine kinase inhibitor (TKIs) dasatinib or nilotinib used as second-line therapy in Polish tertiary care centers. Our analysis revealed that in a "real life setting," nearly half of patients with CML on second-generation TKIs suffer from therapy complications. Grade 2-5 non-hematological AEs were observed in 40% of patients treated with nilotinib and in 42% treated with dasatinib (p=0.83). Severe vascular events including peripheral artery occlusive disease (PAOD) occurred in 11% of patients on nilotinib and 4% on dasatinib (p=0.16). Pleural effusion occurred more often in the dasatinib group (26%) than in the nilotinib group (2%) (p=0.003). Importantly, most AEs occurred late, after more than 1 year of treatment. Since AEs are most often the reason for poor therapy compliance, careful monitoring of tolerability is crucial for an optimal treatment response in CML.

Treatment of elderly patients with acute myeloid leukemia adjusted for performance status and presence of comorbidities: a Polish Adult Leukemia Group study.

This prospective study estimated outcomes in 509 elderly patients with acute myeloid leukemia (AML) with different treatment approaches depending on Eastern Cooperative Oncology Group (ECOG) performance status and Charlson Comorbidity Index (CCI). Patients were stratified into fit (ECOG 0-2 and CCI 0-2) or frail (ECOG>2 and/or CCI>2) groups. Fit patients with CCI 0 received intensive chemotherapy whilst reduced-intensive chemotherapy (R-IC) was given to those with CCI 1-2. Frail patients received best supportive therapy. Fit patients presented a longer overall survival (OS) than frail subjects, but 8-week mortality rates were similar. The complete response (CR) rate between fit CCI 0 and CCI 1-2 subgroups was significantly different. Both of the fit subgroups showed similar 8-week mortality rates and OS probabilities. Allocating fit patients with CCI 1-2 to R-IC enabled an increase in the group of elderly patients who could be treated with the intention of inducing remission.

Long-term results of the Polish Adult Leukemia Group PALG-CLL2 phase III randomized study comparing cladribine-based combinations in chronic lymphocytic leukemia.

Long-term outcomes following newer therapies for chronic lymphocytic leukemia (CLL) have rarely been reported. This article presents the results of the final analysis of the Polish Adult Leukemia Group PALG-CLL2 study performed 10 years from final patient enrollment. With the extended follow-up time, it was found that cladribine (2-CdA)-based combinations CMC (2-CdA, cyclophosphamide, mitoxantrone) and CC (2-CdA, cyclophosphamide) administered as first-line treatment of progressive CLL resulted in significantly longer progression-free survival, but similar overall survival compared to 2-CdA monotherapy. Furthermore, the risk of potentially fatal late adverse events including infections, autoimmune complications and, particularly, secondary neoplasms was comparable among patients treated with CMC, CC or 2-CdA. The results of our analysis support the importance of long-term outcome monitoring of randomized trials in CLL.

Immune thrombocytopenia in patients with chronic lymphocytic leukemia treated with cladribine-based regiments or chlorambucil--follow-up of PALG-CLL randomized trials.

OBJECTIVES: The relationship between treatments of chronic lymphocytic leukemia (CLL) with cladribine (2-CdA) or chlorambucil and immune thrombocytopenia (IT) has not been yet determined. METHODS: The records of 777 patients in two randomized Polish Adult Leukemia Group (PALG)-CLL programs treated with these agents were retrospectively analyzed. RESULTS: Immune thrombocytopenia occurred in 55 of 777 (7.1%) patients. No significant differences in IT prevalence were seen between patients on chlorambucil or 2-CdA-based regiments (P = 0.33). IT developed at a median time of 0.499 yr (0.06-4.8) from the start of CLL therapy. This time was significantly longer in patients treated with chlorambucil (2.03 yr, 95% CI: 0.06-4.22) in relation to patients treated with 2-CdA-based regiments (0.52 yr, 95%CI: 0.34-0.69, P = 0.049). Overall survival (OS) of patients with IT and those without IT were similar (2.65 yr vs. 3.2 yr P = 0.23) but the severity of bleeding was more pronounced in the 2-CdA group. The responses to IT therapy were 35%, 54% and 75% for steroids, chemotherapy and splenectomy, respectively. CONCLUSIONS: In this study, an unexpectedly high percentage of IT incidence was demonstrated in patients with CLL requiring chemotherapy. Although no marked differences were seen in IT frequency in patients treated with 2-CdA-based regiments compared to chlorambucil regimen, the clinical course of hemorrhagic diathesis was more severe in 2-CdA group. Also, the time elapsed from study screening to IT diagnosis was significantly shorter in the 2-CdA group than in the chlorambucil group suggesting a causative relationship. The appearance of IT did not influence the median time of OS.

A risk of essential thrombocythemia in carriers of constitutional CHEK2 gene mutations.

Germline mutations of the CHEK2 gene have been reported in some myeloid and lymphoid malignancies, but their impact on development of essential thrombocythemia has not been studied. In 16 out of 106 (15.1%) consecutive patients, newly diagnosed with essential thrombocythemia, we found one of four analyzed CHEK2 mutations: I157T, 1100delC, IVS2+1G>A or del5395. They were associated with the increased risk of disease (OR=3.8; P=0.002). The median age at ET diagnosis among CHEK2+/JAK2V617F+ patients was seven years lower than that among CHEK2-/JAK2V617F+ (52 vs. 59 years; P=0.04), whereas there was no difference in the medians of hematologic parameters between these groups. The results obtained suggest that CHEK2 mutations could potentially contribute to the susceptibility to essential thrombocythemia. The germline inactivation of CHEK2, as it seems, has no direct impact on the development of disease, but it could cause disruption of cell cycle checkpoints and initiate or support the cancerogenic process of essential thrombocythemia at a younger age.

The early reduction of leukemic blasts in bone marrow on day 6 of induction treatment is predictive for complete remission rate and survival in adult acute myeloid leukemia; the results of multicenter, prospective Polish Adult Leukemia Group study.

The aim of this study was to prospectively evaluate the impact of early bone marrow response on complete remission (CR) rate and long-term outcome in adults with acute myeloid leukemia. Bone marrow cytology was assessed on day 6 of induction treatment in 164 patients, revealing the presence of ≥5% blasts in 61 cases. In this subgroup the CR rate was significantly lower compared to the remaining patients (P < 0.00001) resulting in decrease of the overall survival (P = 0.002). Persistence of ≥5% blasts in bone marrow on day 6 of induction is an easily available surrogate marker to be used for treatment decisions.

Comparison of cladribine plus cyclophosphamide with fludarabine plus cyclophosphamide as first-line therapy for chronic lymphocytic leukemia: a phase III randomized study by the Polish Adult Leukemia Group (PALG-CLL3 Study).

PURPOSE Little is known about comparison of the activity of different purine nucleoside analogs in chronic lymphocytic leukemia (CLL). We conducted a randomized phase III trial to compare efficacy and safety of cladribine and fludarabine, each combined with cyclophosphamide, in previously untreated progressive CLL. PATIENTS AND METHODS Patients received cladribine at 0.12 mg/kg combined with cyclophosphamide at 250 mg/m(2) for 3 days intravenously (CC regimen) or fludarabine at 25 mg/m(2) combined with cyclophosphamide at 250 mg/m(2) for 3 days intravenously (FC regimen), every 28 days for up to six cycles. The primary end point was complete response (CR) rate. Secondary end points included overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and treatment-related toxicity. RESULTS Of 423 randomly assigned patients (211 to CC and 212 to FC), 395 were evaluated in the final analysis. The CR and ORR reached 47% and 88% in the CC arm and 46% and 82% in the FC arm (P = .25 and P = .11, respectively). The median PFS was 2.34 years with CC and 2.27 years with FC (P = .51). OS and grade 3/4 treatment-related toxicity were also comparable. Moreover, we did not observe any significant differences in CC and FC efficacy across different patient prognostic subgroups that included patients with 17p13 (TP53 gene) deletion who had poor survival in both study arms. CONCLUSION Cladribine and fludarabine in combination with cyclophosphamide are equally effective and safe first-line regimens for progressive CLL. Both combinations have unsatisfactory activity in patients with 17p13 (TP53 gene) deletion.

Clinical characteristics of patients with chronic eosinophilic leukaemia (CEL) harbouring FIP1L1-PDGFRA fusion transcript--results of Polish multicentre study.

A small subgroup of patients with hypereosinophilic syndrome (HES) demonstrates imatinib-sensitive fusion transcript-the FIP1L1-PDGFRA (F/P+). These cases are currently diagnosed as chronic eosinophilic leukaemia (CEL). In this paper, we screened 77 patients to estimate the frequency of FIP1L1-PDGFRA transcript among patients with unexplained, long-term hypereosinophilia exceeding 1.5 x 10(9)/L and to analyse the clinical and serological features in F/P+ CEL population. The FIP1L1-PDGFRA chimeric protein was detectable in 16 (14 males and 2 females) out of 77 examined HES patients (20%) by RT-PCR. Two patients suffered from cough at diagnosis. Three out of 16 (18%) patients had no organ involvements, in 5-one organ was affected and in the remaining eight cases-at least two. Eosinophilic organ damage/dysfunction identified splenomegaly in the majority of studied patients. We compared clinical and serological features between CEL F/P+ (n = 16) and HES (n = 61) patients. F/P+ cases had significantly increased WBC and absolute eosinophil count (AEC) at diagnosis (p = 0.008 and 0.02), whereas platelet count was decreased in this population (p = 0.03). Serum B12 and tryptase levels were increased (p = 0.002 and 0.004) in CEL F/P+ patients when compared to HES cases whereas serum IL-5 levels were significantly increased in the latter group (p = 0.01). Male gender and splenomegaly occurred more frequent in CEL F/P+ population (p = 0.002 and 0.0007, respectively). Additionally, patients with F/P+ CEL (n = 16) were compared with F/P- CEL (n = 8). The latter group, was significantly older, had lower AEC and higher platelet count. In conclusion, significant clinical symptoms are infrequent present and splenomegaly remains the most common organ involvement in patients with CEL expressing F/P fusion transcript. Our study confirmed the long-term remission on imatinib in this patient population.

CD38 gene polymorphisms contribute to genetic susceptibility to B-cell chronic lymphocytic leukemia: evidence from two case-control studies in Polish Caucasians.

Given the recent findings on the importance of CD38 signaling in the pathogenesis of B-cell chronic lymphocytic leukemia (B-CLL), we hypothesized that single nucleotide polymorphisms (SNP) in the CD38 gene may be related to B-CLL risk. We evaluated two potentially functional CD38 SNPs, intronic rs6449182 (184C>G) and missense rs1800561 (418C>T, Arg140Trp) in two hospital-based case-control studies (study A and validation study B). Genotyping was done using PCR-based assays in a total of 460 Polish Caucasian patients with B-CLL and 503 age-matched and gender-matched controls. We found that frequencies of both variant alleles (rs6449182 G and rs1800561 T) were significantly higher in B-CLL. In study A, logistic regression analysis revealed an association between B-CLL and genotypes: rs6449182 CG [odds ratio (OR), 3.57; 95% confidence interval (95% CI), 2.4-5.3], rs6449182 GG (OR, 5.2; 95% CI, 2.36-11.5), and rs1800561 CT (OR, 6.72; 95% CI, 1.5-30.1), although no homozygous rs1800561 TT genotype was detected in either study. These results were confirmed in study B, which showed an association between B-CLL and genotypes rs6449182 CG (OR, 4.00; 95% CI, 2.7-6.0), rs6449182 GG (OR, 12.84; 95% CI, 4.3-38.7), and rs1800561 CT (OR, 10.12; 95% CI, 1.3-81.6), and in the combined analysis of both studies. We also observed that rs6449182 G carriers had more advanced clinical stage (P=0.002) and tended to be younger at diagnosis (P=0.056). Furthermore, we found higher CD38 transcript levels and higher proportions of CD38-positive cells in carriers of rs6449182 G and rs1800561 T alleles (P<0.05 for all comparisons). In conclusion, our data show that CD38 SNPs may affect CD38 expression and contribute to the increased risk of B-CLL carcinogenesis.

A single weekly dose of imatinib is sufficient to induce and maintain remission of chronic eosinophilic leukaemia in FIP1L1-PDGFRA-expressing patients.

Hypereosinophilic syndrome (HES) is defined as chronic, unexplained hypereosinophilia with organ involvement. A subset of HES patients presents an interstitial deletion in chromosome 4q12, which leads to the expression of an imatinib-responsive fusion gene, FIP1L1-PDGFRA. These patients are diagnosed as chronic eosinophilic leukaemia (CEL). We treated seven CEL and HES patients, six of which expressed FIP1L1-PDGFRA, with imatinib using initial daily doses ranging from 100 to 400 mg. In a remission maintenance phase, the patients were treated with imatinib once weekly. All imatinib-treated patients achieved a complete haematological remission (CHR), and five of the six patients with FIP1L1-PDGFRA expression exhibited molecular remission. The decreased imatinib doses were as follows: 200 mg/week in three patients, 100 mg/week in two patients and 100 mg/d in the remaining two patients. For remission maintenance, imatinib doses were set at 100 mg/week in five patients and 200 mg/week in two patients. At a median follow-up of 30 months all patients remained in CHR and FIP1L1-PDGFRA expression was undetectable in five of the six FIP1L1-PDGFRA-expressing patients. These data suggest that a single weekly dose of imatinib is sufficient to maintain remission in FIP1L1-PDGFRA- positive CEL patients.

Cladribine in a weekly versus daily schedule for untreated active hairy cell leukemia: final report from the Polish Adult Leukemia Group (PALG) of a prospective, randomized, multicenter trial.

Cladribine (2-chlorodeoxyadenosine, 2-CdA) treatment-associated infections may shorten potentially long-term survival in hairy cell leukemia (HCL). In search of the optimal mode of 2-CdA administration, 132 patients with untreated HCL were randomized to receive either standard 5-day 2-CdA protocol or a novel schedule of 6 weekly 2-CdA infusions suggested to be less toxic. Analysis of treatment response confirmed similar complete remission rates, overall response rates, progression-free survival, and overall survival in both 2-CdA protocols. However, we did not observe lower toxicity in the weekly schedule. Of special interest, no significant differences were found in the rate of grade 3/4 infections (18% for daily and 26% for weekly protocol, difference -8.2%; 95% confidence interval [CI] -23.2% to 6.9%; P = .28) and the rate of septic deaths (3% for daily and 2% for weekly protocol, difference 1.4%; 95% CI -4.3% to 7.0%; P = .64). In conclusion, HCL treatment with weekly 2-CdA infusions is equally effective but no safer than the standard 5-day 2-CdA protocol.

Cladribine alone and in combination with cyclophosphamide or cyclophosphamide plus mitoxantrone in the treatment of progressive chronic lymphocytic leukemia: report of a prospective, multicenter, randomized trial of the Polish Adult Leukemia Group (PALG CLL2).

In this prospective randomized trial, we compared the efficacy and toxicity of cladribine (2-CdA) alone to 2-CdA combined with cyclophosphamide (CC) or cyclophosphamide and mitoxantrone (CMC) in untreated progressive chronic lymphocytic leukemia (CLL). Study end points were complete response (CR), overall response, minimal residual disease (MRD), progression-free survival, overall survival, and toxicity. From January 1, 1998 to December 31, 2003, 508 patients from 15 hematology departments were randomized. Compared with 2-CdA, CMC induced higher CR rate (36% vs 21%, P = .004), and a trend for higher CR rate with CC was observed (29% vs 21%, P = .08). Furthermore, the percentage of patients who were in CR and were MRD negative was higher in CMC compared with 2-CdA (23% vs 14%, P = .042). There were no differences in overall response, progression-free survival, and overall survival among treatment groups. Grade 3/4 neutropenia occurred more frequently in CC (32%) and CMC (38%) than in 2-CdA (20%) (P = .01 and P = .004, respectively). Infections were more frequent in CMC compared with 2-CdA (40% vs 27%, P = .02). In conclusion, CMC used in first-line treatment of CLL results in a higher CR rate and suppresses MRD more efficiently than 2-CdA monotherapy, although associates with increased toxicity. No important differences in efficacy and toxicity were found between CC and 2-CdA regimens.