Tumor vasculature-targeted recombinant mutated human TNF-α enhanced the antitumor activity of doxorubicin by increasing tumor vessel permeability in mouse xenograft models.

OBJECTIVE: Increasing evidence suggests that, when used in combination, tumor necrosis factor-α (TNF-α) synergizes with traditional chemotherapeutic drugs to exert a heightened antitumor effect. The present study investigated the antitumor efficacy of recombinant mutated human TNF-α specifically targeted to the tumor vasculature (RGD-rmhTNF-α) combined with the chemotherapeutic agent doxorubicin in 2 murine allografted tumor models. METHODS: Mice bearing hepatoma or sarcoma allografted tumors were treated with various doses of RGD-rmhTNF-α alone or in combination with doxorubicin (2 mg/kg). We then evaluated tumor growth and tumor vessel permeability as well as intratumoral levels of RGD-rmhTNF-α and doxorubicin. RESULTS: RGD-rmhTNF-α treatment enhanced the permeability of the tumor vessels and increased intratumoral doxorubicin levels. In addition, intratumoral RGD-rmhTNF-α levels were significantly higher than that of rmhTNF-α. In both of the tested tumor models, administering RGD-rmhTNF-α in combination with doxorubicin resulted in an enhanced antitumor response compared to either treatment alone. Double-agent combination treatment of doxorubicin with 50,000 IU/kg RGD-rmhTNF-α induced stronger antitumor effects on H22 allografted tumor-bearing mice than the single doxorubicin agent alone. Moreover, doxorubicin with 10,000 IU/kg RGD-rmhTNF-α synergized to inhibit tumor growth in S180 allografted tumor-bearing mice. CONCLUSIONS: These results suggest that targeted delivery of low doses of RGD-rmhTNF-α into the tumor vasculature increases the antitumor efficacy of chemotherapeutic drugs

Effect of RGD-rmhTNF-α on tumor vessel permeability, and the effect of doxorubicin combined with RGD-rmhTNF-α on the tumor-growth inhibition rate when administered via different routes.

<p>(A) RGD-rmhTNF-α increases tumor-vessel permeability. Mice-bearing S180 cells (n = 8/group) were treated with or without RGD-rmhTNF-α (0.1 mL, i.m.), followed 2 h later by administration of Evans Blue dye (0.1%, 0.2 mL, i.v.) or doxorubicin (2 mg/kg, i.p.). After 2 h, mice were sacrificed, tumors were excised, and the concentration of Evans blue or doxorubicin was measured within the tumor (µg/g tumor tissue). The relative increase in concentration was calculated and statistically analyzed (*<i>p</i><0.05, RGD-rmhTNF-α+Evans Blue or RGD-rmhTNF-α+doxorubicin compared with Evans Blue or doxorubicin alone, respectively). (B) The effect of RGD-rmhTNF-α combined with doxorubicin on tumor-growth inhibition rate was similar between the i.m. and i.p. administration routes of RGD-rmhTNF-α. Animals bearing S180 allografted tumors (n = 16/group,n = 24 in DOX alone group) were i.m. or i.p. treated every 2 days with various doses of RGD-rmhTNF-α combined with doxorubicin starting on day 10 after tumor implantation. Saline was used as negative control. Mice received a total of 6 consecutive treatments and were sacrificed; tumors were immediately excised and weighed. The inhibition rate was calculated based on the tumor growth of mice in the saline-treated group. Data are represented as the mean (%) ± SD from 3 experiments. (C) Picture showing tumors excised from mice used to calculate the data shown in B. 1, Saline; 2, DOX alone (2 mg/kg); 3–7, DOX+RGD-rmhTNFα (10,000, 22,360, 50,000, 111,800, and 250,000 IU/kg, respectively), i.m.; 8–12, DOX+RGD-rmhTNFα (10,000, 22,360, 50,000, 111,800, and 250,000 IU/kg, respectively), i.p.</p

Distribution of RGD-rmhTNF-α and rmhTNF-α in tumors and serum of S180-bearing ICR mice.

<p>Equimolar amounts of RGD-rmhTNF-α (5.89 µg/kg weight) and rmhTNF-α (5.52 µg/kg weight) were i.v. injected into the tail vein of S180 hepatoma-bearing ICR mice. TNF-α levels were detected in serum and tumor homogenates by ELISA at 5, 20, and 60 min post-dosing (n = 6 mice/time point. Data are represented as the mean ± SD from 3 experiments. Numbers above bars indicate relative fold changes between the groups.</p

Effect of rmhTNF-α or RGD-rmhTNF-α alone or in combination with doxorubicin on tumor growth in S180 sarcoma-bearing mice.

<p>(A) Low doses of RGD-rmhTNF-α most significantly enhanced the therapeutic effects of doxorubicin on allografted S180 sarcomas in mice. Animals bearing tumors (n = 8/group) were i.m. treated every 2 days with various doses of rmhTNF-α alone, RGD-rmhTNF-α alone, rmhTNF-α combined with doxorubicin, or RGD-rmhTNF-α combined with doxorubicin starting on day 10 after tumor implantation. Saline and doxorubicin (doxorubicin, 2 mg/kg weight, i.p.) were used as negative and positive controls, respectively. Mice received a total of 6 consecutive treatments and were sacrificed before tumors in the saline control group reached 2.0 to 3.0 cm³; tumors were immediately excised and weighed. Tumor weights are shown as the mean ± SD. (DOX: doxorubicin; *: vs. the saline group; §: vs. the DOX group). (B) Picture showing tumors excised from selected groups used to calculate the data shown in A. 1, Saline; 2, DOX alone (2 mg/kg); 3–5, DOX+rmhTNFα (10,000, 50,000, and 250,000 IU/kg, respectively); 6–8, DOX+RGD-rmhTNFα (10,000, 50,000, and 250,000 IU/kg, respectively).</p

Efficacy and safety of darbepoetin alfa injection replacing epoetin alfa injection for the treatment of renal anemia in Chinese hemodialysis patients: A randomized, open‐label, parallel‐group, noninferiority phase III trial

Abstract Background This study was to explore the clinical efficacy and safety of darbepoetin alfa injection replacing epoetin alfa injection (recombinant human erythropoietin injection, rHuEPO) for the treatment of anemia associated with chronic kidney failure in Chinese patients undergoing hemodialysis. Method This study was a multicenter, randomized, open‐label, intergroup parallel control phase III noninferiority trial from April 19, 2013 to September 9, 2014 at 25 sites. In this study, the members of the darbepoetin alfa group underwent intravenous administration once per week or once every two weeks. The members of the control drug epoetin alfa group underwent intravenous administration two or three times per week. All subjects underwent epoetin alfa administration during the 8‐week baseline period. After that, subjects were randomly assigned to the darbepoetin alfa group or epoetin alfa group. The noninferiority in the changes of the average Hb concentrations from the baseline to the end of the evaluation period (noninferiority threshold: −1.0 g/dl) was tested between the two treatments. The time‐dependent hemoglobin (Hb) concentration and the maintenance rate of the target Hb concentration (the proportion of subjects with Hb concentrations between 10.0 and 12.0 g/dl) were also evaluated. Iron metabolism, including changes in the serum iron, total iron‐binding capacity, ferritin, transferrin saturation, and comparisons of the dose adjustments between the two groups during the treatment period were analyzed further. Adverse events (AEs) were also observed and compared, and the safety was analyzed between the two treatment groups. The conversion rate switching from epoetin alfa to darbepoetin alfa was also discussed. SAS® software version 9.2 was used to perform all statistical analyses. Descriptive statistics were used for all efficacy, safety, and demographic variable analyses, including for the primary efficacy indicators. Results Four hundred and sixty‐six patients were enrolled in this study, and ultimately 384 cases were analyzed for safety, including 267 cases in the darbepoetin alfa group and 117 cases in the epoetin alfa group. There were 211 cases in the per‐protocol set, including 152 cases in the darbepoetin alfa group and 59 cases in the epoetin alfa group. The changes in the average Hb concentrations from the baseline to the end of the evaluation period were −0.07 and −0.15 g/dl in the darbepoetin alfa group and epoetin alfa group respectively. The difference between the two groups was 0.08 g/dl (95% confidence interval [CI]: −0.22 to 0.39), and the lower limit of the 95% CI was −0.22 > −1.0 g/dl. The average Hb concentrations of the two groups were 10.88–11.43 g/dl (darbepoetin alfa) and 10.91–11.38 g/dl (epoetin alfa) during the study period of Weeks 0–28, with the maintenance rates of the target Hb concentration ranging within 71%–87% and 78%–95% in the darbepoetin alfa group and epoetin alfa group respectively. During the period of comparison between the two groups, the incidence of AEs in the darbepoetin alfa group was 61.42%, while in the epoetin alfa group it was 56.41%. All of the adverse events and reactions in the study were those commonly associated with hemodialysis. Conclusion The overall efficacy and safety of darbepoetin alfa for the treatment of Chinese renal anemia patients undergoing hemodialysis are consistent with those of epoetin alfa