Comparative efficacy evaluation of catheter intraperitoneal chemotherapy, normothermic and hyperthermic chemoperfusion in a rat model of ascitic ovarian cancer.

OBJECTIVES: The choice of an optimal administration route for intraperitoneal (IP) chemotherapy and a suitable chemotherapeutic regime in the treatment of ovarian cancer remains a controversy. We investigated survival outcomes according to catheter intraperitoneal chemotherapy (CIPC), normothermic and hyperthermic chemoperfusion (NIPEC and HIPEC) with cytostatic drugs dioxadet and cisplatin in rats with transplantable ascitic ovarian cancer. METHODS: Ascitic liquid containing 1 × 107 tumour cells was inoculated to female Wistar rats and 48 hours after rats received dioxadet and cisplatin at the maximum tolerated doses. Dioxadet at doses 1.5, 30 and 15 mg/kg and cisplatin at doses 4, 40 and 20 mg/kg body weight were administered for CIPC, NIPEC and HIPEC, respectively. Rats in the control groups received physiological saline and CIPC with physiological saline was regarded as the untreated control. The antitumor activity of the drugs was evaluated as an increase in average life expectancy (ALE). Analysis of the data was based primarily on Bayesian statistics and included Kaplan-Meier method, log-rank test and hazard ratio (HR) estimation. RESULTS: Compared to the untreated control CIPC, NIPEC and HIPEC with dioxadet significantly increased ALE by 101316, 61524 and 1.71735 days, whereas with cisplatin by 61013, 122437 and -13523 days, respectively. CONCLUSIONS: Dioxadet and cisplatin show similar efficacy in the CIPC route. Compared with CIPC IP chemotherapy by chemoperfusions is more effective for both the drugs. Dioxadet in HIPEC showed highest survival benefit whereas largest effect during NIPEC is achieved with cisplatin.

Both heat and new chemotherapeutic drug dioxadet in hyperthermic intraperitoneal chemoperfusion improved survival in rat ovarian cancer model.

BACKGROUND AND OBJECTIVES: Hyperthermic Intraperitoneal Chemotherapy (HIPEC) at the time of Cytoreductive Surgery (CRS) is an actively researched treatment in patients with advanced ovarian cancer. Relative contribution of heat and chemotherapeutic agents during HIPEC as well as efficacy of a new agent dioxadet for regional chemotherapy in a rat model of ovarian cancer was studied. METHODS: Sixty rats were divided into three groups: no treatment control group (n = 19), hyperthermia without chemotherapy (HIPEP) (n = 14), HIPEC + cisplatin (n = 14), HIPEC + dioxadet (n = 13). The intra-abdominal tumor was not resected. End points were: median survival (primary), cause of death (secondary). RESULTS: The median survival of the animals in the control group, HIPEP group, HIPEC + cisplatin, HIPEC + dioxadet were 9 (CI; 8-23), 22.5 (CI; 12-43), 25.5 (CI; 13-62), 49 (Cl; 28-70) days, respectively. The P-values control versus HIPEP, HIPEC + cisplatin versus HIPEC + dioxadet were 0.006, 0.002, and 0.001, respectively. CONCLUSION: During HIPEC both the heat and the cytotoxic drug had antitumor effects in a rat ovarian cancer model. Dioxadet showed potential as a drug for regional chemotherapy. J. Surg. Oncol. 2016;113:438-442. © 2015 Wiley Periodicals, Inc.

Nanomedicines Bearing an Alkylating Cytostatic Drug from the Group of 1,3,5-Triazine Derivatives: Development and Characterization.

Cancer is still one of the major diseases worldwide. The discovery of new drugs and the improvement of existing ones is one of the areas of priority in the fight against cancer. Dioxadet ([5-[[4,6-bis(aziridin-1-yl)-1,3,5-triazin-2-yl]amino]-2,2-dimethyl-1,3-dioxan-5-yl]methanol) represents one of the promising 1,3,5-triazine derivatives and has cytostatic activity towards ovarian cancer. In this study, we first report the development of dioxadet-bearing nanomedicines based on block-copolymers of poly(ethylene glycol) monomethyl ether (mPEG) and poly(D,L-lactic acid) (PLA)/poly(ε-caprolactone) (PCL) and then conduct an investigation into their characteristics and properties. The preparation of narrow-sized nanoparticles with a hydrodynamic diameter of 100−120 nm was optimized using a nanoprecipitation approach. Thoughtful optimization of the preparation of nanomedicines was carried out through adjustments to the polymer's molecular weight, the pH of the aqueous medium used for nanoprecipitation, the initial drug amount in respect to the polymer, and polymer concentration in the organic phase. Under optimized conditions, spherical-shaped nanomedicines with a hydrodynamic diameter of up to 230 nm (PDI < 0.2) containing up to 592 ± 22 µg of dioxadet per mg of polymer nanoparticles were prepared. Study of the drug's release in a model medium revealed the release up to 64% and 46% of the drug after 8 days for mPEG-b-PLA and mPEG-b-PCL, respectively. Deep analysis of the release mechanisms was carried out with the use of a number of mathematical models. The developed nanoparticles were non-toxic towards both normal (CHO-K1) and cancer (A2780 and SK-OV-3) ovarian cells. A cell cycle study revealed lesser toxicity of nanomedicines towards normal cells and increased toxicity towards cancer cells. The IC50 values determined for dioxadet nanoformulations were in the range of 0.47−4.98 µg/mL for cancer cells, which is close to the free drug's efficacy (2.60−4.14 µg/mL). The highest cytotoxic effect was found for dioxadet loaded to mPEG-b-PCL nanoparticles.

Experimental study of antitumour activity and effects on leukocyte count of intraperitoneal administration and hyperthermic intraperitoneal chemoperfusion (HIPEC) with dioxadet in a rat model of ovarian cancer.

Survival of rats with advanced ovarian cancer after intraperitoneal (i.p.) administration and hyperthermic intraperitoneal chemoperfusion (HIPEC) with dioxadet and effects of these treatment modalities on leukocyte count were evaluated in two independent series of experiments. Hyperthermic intraperitoneal chemoperfusion with dioxadet (15 mg/kg) provided median survival of rats of 49 days (95% CI 28-70), i.p. administration of dioxadet (1.5 mg/kg) of 28 days (95% CI 16-36; P = 0.020). Single i.p. injection of dioxadet caused a significant decrease in total number of leukocytes (17-52%), granulocytes (18-75%), lymphocytes (18-62%) and monocytes (12-46%) in the peripheral blood of tumour-bearing rats compared to untreated animals. After HIPEC with dioxadet, the total number of leukocytes, granulocytes, lymphocytes and monocytes in peripheral blood of rats remained significantly higher than the corresponding values in the group with dioxadet.