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.

Long-term Efficacy of Ibrutinib in Relapsed or Refractory Chronic Lymphocytic Leukemia: Results of the Polish Adult Leukemia Study Group Observational Study.

BACKGROUND/AIM: To study the long-term clinical efficacy and tolerability of ibrutinib monotherapy in real-world relapsed and refractory chronic lymphocytic leukemia (RR-CLL) patients outside clinical trials. PATIENTS AND METHODS: Clinical data of 171 RR-CLL patients treated with ibrutinib were collected within the observational study of the Polish Adult Leukemia Study Group. RESULTS: Median patient age was 64 years. Patients were pretreated with 3 (1-10) median lines of therapy, while 42 (24.6%) had 17p deletion. The median observation time was 40 months (range=1-59 months), while median ibrutinib monotherapy reached 37.5 months (range=0.4-59.2 months). Response was noted in 132 (77.2%) patients. The estimated 5-year progression-free survival (PFS) and overall survival (OS) rates were 61.1% (95%CI=49.3-70.9%) and 56.8% (95%CI=45.6-66.6%), respectively. At the time of analysis 97 (56.7%) remained under ibrutinib monotherapy. CONCLUSION: Ibrutinib is clinically effective and tolerable as a monotherapy in real-world RR-CLL patients.

Safety and Efficacy of Bendamustine Monotherapy in the First-Line Treatment of Patients with Chronic Lymphocytic Leukemia: Polish Lymphoma Research Group Real-Life Analysis.

Bendamustine is a cytostatic drug with a unique structure, combining the features of purine nucleoside analogs and alkylating agents. In patients with chronic lymphocytic leukemia (CLL) it is commonly used in combination with rituximab (BR protocol) both in the first-line as well as subsequent lines of therapy, and in clinical trials it is often combined with new targeted therapies. Therefore, the data on its real-life safety and efficacy are of clinical significance. As the Polish Lymphoma Research Group (PLRG), we retrospectively analyzed the efficacy and tolerability of bendamustine monotherapy in 96 patients with CLL. The median number of bendamustine cycles was 5, and 44 patients did not complete the planned 6 cycles (46%). Among the adverse events associated with the earlier termination of bendamustine treatment, infections were the most common (20.5%), followed by neutropenia (15.9%) and thrombocytopenia (15.9%). Dose reductions and/or delays occurred in 31% of treatment cycles (132 of 425) with neutropenia (17.9%) as the most frequent cause. Efficacy analysis showed an overall response rate of 88.2% with complete remission and partial remission achieved in 43.8 and 41.7% of patients, respectively. At the 24th month of follow-up, progression-free survival was 52% and overall survival was 69.7%. Bendamustine in monotherapy was found to be safe and efficacious, at least in terms of early response. Special attention should be paid to infectious complications, and especially that immune disorders are characteristic in the clinical course of CLL. Our observations suggest efforts must be made to ensure the proper timing and proper dose in the administration of the drug, and to avoid the premature termination of the treatment.

The efficacy and safety of pomalidomide in relapsed/refractory multiple myeloma in a "real-world" study: Polish Myeloma Group experience.

BACKGROUND: Patients with relapsed/refractory multiple myeloma (RRMM) have poor prognosis. Pomalidomide is an immunomodulatory compound that has demonstrated activity in MM patients with disease refractory to lenalidomide and bortezomib. OBJECTIVES: Participants of clinical trials are highly selected populations; therefore, the aim of this study was to present observations from real practice that might provide important information for practitioners. PATIENTS AND METHODS: We analyzed retrospectively 50 patients treated with pomalidomide in 12 Polish sites between 2014 and 2017. Median age was 63 years, median time since diagnosis 4.5 years and median number of prior regimens 4. RESULTS: The overall response rate was 39.1%. Median progression-free survival (PFS) and overall survival (OS) were 10.0 and 14.0 months, respectively. Previous treatment with immunomodulatory drugs, bortezomib or stem cell transplant had no impact on PFS and OS. Most frequent grade 3/4 treatment-emergent adverse events were hematologic (neutropenia 24.0%, thrombocytopenia 10.0%, anemia 8.0%). Most common grade 3/4 non-hematologic toxicities were respiratory tract infection (14.0%) and neuropathy (4.0%). CONCLUSIONS: This real-world data have confirmed that pomalidomide is an active drug in RRMM and support results of published clinical trials and other real-world studies.

Polish experience of lenalidomide in the treatment of lower risk myelodysplastic syndrome with isolated del(5q).

BACKGROUND: Lenalidomide has been approved for the treatment of lower-risk myelodysplastic syndrome (MDS) with 5q deletion (del(5q)). We present for the first time a retrospective analysis of low-risk MDS with isolated del5q treated with lenalidomide, outside the clinical trials. METHODS: 36 red blood cell (RBC) transfusion-dependent patients have been included in the study. Patients received lenalidomide 10 mg/day on days 1-21 of 28-day cycles. RESULTS: 91.7 % of patients responded to lenalidomide treatment: 72.2 % achieved erythroid response, 19.4 % achieved minor erythroid response and 8.4 % of patients did not respond to treatment. Response depended on number of previous treatment lines (p = 0.0101), International Prognostic System Score (IPSS; p = 0.0067) and RBC transfusion frequency (p = 0.0139). Median duration of response was 16 months (range 6-60 months). Treatment was well tolerated. We observed hematological toxicity (grade 3 and 4): neutropenia in 16 (44.4 %) patients and thrombocytopenia in 9 (25 %) patients. Two patients (5.5 %) progressed to high-risk MDS and two subsequent progressed to acute myeloid leukemia. A Kaplan-Meier estimate for overall survival at 5 years in the study group was 79.0 ± 8.8 %. CONCLUSIONS: Lenalidomide in this group of patients was beneficial for the treatment of RBC transfusion-dependency with well-known safety profile.

Occurrence of secondary malignancies in chronic myeloid leukemia during therapy with imatinib mesylate-single institution experience.

INTRODUCTION: Imatinib mesylate (IM) remains the treatment of choice for chronic myeloid leukemia (CML) showing a remarkable efficacy and offers a perspective for long disease-free survival. Due to prolonged administration of IM, the questions about the possible impact on the development of secondary malignancies (SM) are raised. OBJECTIVE: To investigate the incidence and clinical outcome of secondary malignancies during IM therapy for CML. MATERIAL AND METHODS: The records of 221 CML patients treated with IM between 2003-2013 in a single institution were reviewed. The Poisson regression model was used to estimate the relative risks for SM and death in CML patients. RESULTS: Secondary malignancies developed in eight out of the 221 patients (3.6%) receiving IM for a median of 61 months (range, 10-137 months). Female/male ratio was 5/3. Two patients were diagnosed with their CML at accelerated phase whereas 6 had chronic phase. The median age at IM initiation was 58 years (range, 31-72 years). Five of these 8 SM patients received IM after other treatments failure: interferon α (n=5), hydroxyurea (n=4) and cytarabine (n=1). Three patients received IM as a frontline therapy. All patients were on IM at 400mg daily at SM occurrence. The therapy for SM included surgery (n=3), chemotherapy only (n=3), and chemotherapy followed by radiotherapy (n=1). One patient did not receive treatment due to disseminated disease. All CML patients were in hematologic and complete cytogenetic response (CCR) at the time of SM development. All of them also met the criteria for major molecular response (BCR-ABL(IS) ≤0.1%). They continued their IM while receiving treatment for SM. Among eight patients with SM, five patients are alive and remain in CCR on IM whereas three patients died due to SM. The risks for SM development as well as death due to SM in CML patients were not statistically increased if compared to age-adjusted population. CONCLUSIONS: The association between IM therapy for CML and SM development has not been found.