Addition of cladribine to the standard induction treatment improves outcomes in a subset of elderly acute myeloid leukemia patients. Results of a randomized Polish Adult Leukemia Group (PALG) phase II trial.

Intensive induction chemotherapy using anthracycline and cytarabine backbone is considered the most effective upfront therapy in physically fit older patients with acute myeloid leukemia (AML). However, outcomes of the standard induction in elderly AML are inferior to those observed in younger patients, and they are still unsatisfactory. As addition of cladribine to the standard induction therapy is known to improve outcome in younger AML patients. The present randomized phase II study compares efficacy and toxicity of the DAC (daunorubicin plus cytarabine plus cladribine) regimen with the standard DA (daunorubicin plus cytarabine) regimen in the newly diagnosed AML patients over 60 years of age. A total of 171 patients were enrolled in the study (DA, 86; DAC, 85). A trend toward higher complete remission (CR) was observed in the DAC arm compared to the DA arm (44% vs. 34%; P = .19), which did not lead to improved median overall survival, which in the case of the DAC group was 8.6 months compared to in 9.1 months in the DA group (P = .64). However, DAC appeared to be superior in the group of patients aged 60-65 (CR rate: DAC 51% vs. DA 29%; P = .02). What is more, a subgroup of patients, with good and intermediate karyotypes, benefited from addition of cladribine also in terms of overall survival (P = .02). No differences in hematological and nonhematological toxicity between the DA and DAC regimens were observed.

Cytotoxic activity of the amphibian ribonucleases onconase and r-amphinase on tumor cells from B cell lymphoproliferative disorders.

Although major advancements in antitumor treatment have been observed, several B cell-derived malignancies still remain incurable. A promising approach that involves targeting RNA either by the use of specific antisense oligonucleotides or cytostatic/cytotoxic ribonucleases (RNases) is being promoted. Two amphibian RNases, onconase (ONC; ranpirnase) and, more recently, r-amphinase (r-Amph), have already been tested, but thus far, mostly on solid tumors. In this study, for the first time we provide comprehensive data on ex vivo and in vivo cytotoxic activity of ONC or r-Amph against cancer cells from different B cell lymphoid malignancies, together with their detailed mode of antitumor action. Our data revealed strong pro-apoptotic activity of ONC and r-Amph in both chronic lymphocytic leukemia and aggressive B cell lymphomas, with less impact on acute lymphoblastic leukemia or multiple myeloma cells. Moreover, the antitumor action of ONC and r-Amph was markedly selective against neoplastic cells sparing normal, healthy control­derived lymphocytes.

In vitro cytotoxicity of ranpirnase (onconase) in combination with components of R-CHOP regimen against diffuse large B cell lymphoma (DLBCL) cell line.

Ranpirnase (onconase; ONC) is an endoribonuclease obtained from the frog Rana pipiens. This enzyme exhibits anticancer properties mediated by degradation of cellular RNA and induction of apoptosis. In this study we assessed cytotoxicity of ONC in combination with currently used anticancer drugs on a human diffuse large B-cell lymphoma (DLBCL)-derived cell line (Toledo). Cytotoxic activity was measured by the exclusion of propidium iodide assay while apoptosis was assessed using the annexin-V binding method. Additionally, flow cytometry was used to assess the decline of mitochondrial potential and to determine activation of caspases 3, 8 and 9. It was observed that in vitro treatment with ONC in combination with rituximab, mafosfamide, vincristine, doxorubicin, and dexamethasone (drugs corresponding with elements of R-CHOP regimen) resulted in increased cytotoxicity. As a result ONC showed marked cytotoxicity against Toledo cells. Importantly, in combination of ONC with drugs imitating the R-CHOP regimen, this effect was significantly intensified. The main mechanism responsible for this event was induction of apoptosis along a mitochondrial dependent pathway. In conclusion, these data indicate that further preclinical and eventually clinical studies assessing activity of ONC+R-CHOP treatment are warranted.

[Onconase: a ribonuclease with antitumor activity]. / Onkonaza--rybonukleaza o aktywnosci przeciwnowotworowej.

Onconase (ranpirnase) is a homologous protein obtained from Rana pipiens frog eggs. The activity of onconase, and particularly its antitumor effect, is strictly connected with ribonuclease(RN-ase) activity. Onconase induces cell death through the decomposition of inner cellular RNA,inhibition of protein synthesis, and inhibition of cell growth and proliferation and it also specifically triggers tumor cell apoptosis. A very important mechanisms of its cytotoxicity is also its antioxidant activity. The results of preclinical trials demonstrated a high activity of onconase against tumor cells, also those resistant to cytostatics. Moreover, onconase showed synergic activity with other commonly used anticancer drugs. Several clinical trials were performed on patients suffering from kidney, breast, and pancreatic cancers. Most recently a phase III study of onconase in patients with mesothelioma was completed. There are also ongoing phase I and II clinical trials with non-small-cell lung cancer (NSCLC).