The Outcomes of Ponatinib Therapy in Patients With Chronic Myeloid Leukemia Resistant or Intolerant to Previous Tyrosine Kinase Inhibitors, Treated in Poland Within the Donation Program.

INTRODUCTION: Tyrosine kinase inhibitors (TKIs) have greatly improved the treatment outcome for most patients with chronic myeloid leukemia (CML). Ponatinib is a new pan-inhibitor of TK active in resistant CML. This study aimed to evaluate the efficacy and safety of ponatinib in patients suffering from CML. PATIENTS AND METHODS: This multicenter, non-randomized, observational, retrospective study evaluated the efficacy and safety of ponatinib administered in adult CML patients in any disease phase, including those with a detected ABL T315I mutation, which were resistant or intolerant to previous-generation TKIs. The study comprised 43 patients benefiting from the ponatinib donation program who were treated in 16 Polish centers. RESULTS: For patients who started treatment with ponatinib in chronic phase (CP) (n = 23) and in accelerated phase (AP) (n = 3) the median time on ponatinib was 19.5 months (range: 1.0-35.4), and 31.7 months (range: 31.0-34.1), respectively. All these patients were in CP after 1 month of treatment and at the end of observation - none of them progressed to AP or blastic phase (BP) during the study, meaning that progression-free survival was 100% at the end of observation (35.4 months). The estimated 2-year survival in this group of patients was 84%. For all 43 patients, median survival was not reached (lower quartile 6.3 months), and estimated 2-year survival was 60%. CONCLUSION: Our analysis confirmed ponatinib efficacy in a significant proportion of patients heavily pre-treated with TKIs achieving durable responses in both CP and AP/BP CML groups.

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.

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.

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.

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.