Development of an erythropoietin prescription simulator to improve abilities for the prescription of erythropoietin stimulating agents: Is it feasible?

BACKGROUND: The increasing use of erythropoietins with long half-lives and the tendency to lengthen the administration interval to monthly injections call for raising awareness on the pharmacokinetics and risks of new erythropoietin stimulating agents (ESA). Their pharmacodynamic complexity and individual variability limit the possibility of attaining comprehensive clinical experience. In order to help physicians acquiring prescription abilities, we have built a prescription computer model to be used both as a simulator and education tool. METHODS: The pharmacokinetic computer model was developed using Visual Basic on Excel and tested with 3 different ESA half-lives (24, 48 and 138 hours) and 2 administration intervals (weekly vs. monthly). Two groups of 25 nephrologists were exposed to the six randomised combinations of half-life and administration interval. They were asked to achieve and maintain, as precisely as possible, the haemoglobin target of 11-12 g/dL in a simulated naïve patient. Each simulation was repeated twice, with or without randomly generated bleeding episodes. RESULTS: The simulation using an ESA with a half-life of 138 hours, administered monthly, compared to the other combinations of half-lives and administration intervals, showed an overshooting tendency (percentages of Hb values > 13 g/dL 15.8 ± 18.3 vs. 6.9 ± 12.2; P < 0.01), which was quickly corrected with experience. The prescription ability appeared to be optimal with a 24 hour half-life and weekly administration (ability score indexing values in the target 1.52 ± 0.70 vs. 1.24 ± 0.37; P < 0.05). The monthly prescription interval, as suggested in the literature, was accompanied by less therapeutic adjustments (4.9 ± 2.2 vs. 8.2 ± 4.9; P < 0.001); a direct correlation between haemoglobin variability and number of therapy modifications was found (P < 0.01). CONCLUSIONS: Computer-based simulations can be a useful tool for improving ESA prescription abilities among nephrologists by raising awareness about the pharmacokinetic characteristics of the various ESAs and recognizing the factors that influence haemoglobin variability

Phase II study of two dose schedules of C.E.R.A. (Continuous Erythropoietin Receptor Activator) in anemic patients with advanced non-small cell lung cancer (NSCLC) receiving chemotherapy

BACKGROUND: C.E.R.A. (Continuous Erythropoietin Receptor Activator) is an innovative agent with unique erythropoietin receptor activity and prolonged half-life. This study evaluated C.E.R.A. once weekly (QW) or once every 3 weeks (Q3W) in patients with anemia and advanced non-small cell lung cancer (NSCLC) receiving chemotherapy. METHODS: In this Phase II, randomized, open-label, multicenter, dose-finding study, patients (n = 218) with Stage IIIB or IV NSCLC and hemoglobin (Hb) ≤ 11 g/dL were randomized to one of six treatment groups of C.E.R.A. administered subcutaneously for 12 weeks: 0.7, 1.4, or 2.1 μg/kg QW or 2.1, 4.2, or 6.3 μg/kg Q3W. Primary endpoint was average Hb level between baseline and end of initial treatment (defined as last Hb measurement before dose reduction or transfusion, or the value at week 13). Hematopoietic response (Hb increase ≥ 2 g/dL or achievement of Hb ≥ 12 g/dL with no blood transfusion in the previous 28 days determined in two consecutive measurements within a 10-day interval) was also measured. RESULTS: Dose-dependent Hb increases were observed, although the magnitude of increase was moderate. Hematopoietic response rate was also dose dependent, achieved by 51% and 62% of patients in the 4.2 and 6.3 μg/kg Q3W groups, and 63% of the 2.1 μg/kg QW group. In the Q3W group, the proportion of early responders (defined as ≥ 1 g/dL increase in Hb from baseline during the first 22 days) increased with increasing C.E.R.A. dose, reaching 41% with the highest dose. In the 6.3 μg/kg Q3W group, 15% of patients received blood transfusion. There was an inclination for higher mean Hb increases and lower transfusion use in the Q3W groups than in the QW groups. C.E.R.A. was generally well tolerated. CONCLUSION: C.E.R.A. administered QW or Q3W showed clinical activity and safety in patients with NSCLC. There were dose-dependent increases in Hb responses. C.E.R.A. appeared to be more effective when the same dose over time was given Q3W than QW, with a suggestion that C.E.R.A. 6.3 μg/kg Q3W provided best efficacy in this study. However, further dose-finding studies using higher doses are required to determine the optimal C.E.R.A. dose regimen in cancer patients receiving chemotherapy

Randomised cross-over comparison of intravenous and subcutaneous darbepoetin dosing efficiency in haemodialysis patients

Copyright © 2005 Asian Pacific Society of Nephrology.Background: Studies have consistently shown the superior dosing efficiency of subcutaneous (s.c.) compared to intravenous (i.v.) erythropoietin (r-HuEPO). Unlike r-HuEPO, data from pivotal darbepoetin trials support s.c. and i.v. dosing equivalence, however, no blinded cross-over randomized studies of s.c. and i.v. dose efficiency or intra-patient variability in response have been published. Methods: During this 12-month study, 53 haemodialysis patients were randomized to s.c. or i.v. darbepoetin for a 6-month period and then switched to the alternative route for a second 6-month period. Darbepoetin dose was titrated during the first 4-months of each period to acheive a stable haemoglobin during the final 2-month observation period of each arm. Results: Twenty-four patients were included in analysis. No significant difference between s.c. and i.v. administration was observed for any measured parameter. Patients acheived a non-significantly higher haemoglobin (123.6 ± 3.76 vs 120.9 ± 4.42 g/L, P = 0.11) from a non-significantly lower darbepoetin dose (40.8 ± 10.7 vs 42.5 ± 11.0 mcg/week, P = 0.23) with i.v. administration. The population-based weight normalized s.c./i.v. dose ratio was 1.04 (0.97–1.11). Despite no significant overall difference, some patients experienced changes in individual dose efficiency response. Three of 24 patients recorded a greater than 30% change, four of 24 recorded between a 20 and 30% change, and five of 24 patients recorded between a 10 and 20% change relative to i.v. dose efficiency. Conclusions: This study further supports s.c. and i.v. dosing equality and that overall the more convenient i.v. route can be used with equal dosing efficiency. However, patients switching routes of administration should be monitored due to the wide range in individual response.Matthew J. Cervelli, Nicholas Gray, Stephen McDonald, Melanie G. Gentgall and Alex PS Disne

Detection of EPO injections using a rapid lateral flow isoform test

Misuse of recombinant human erythropoietin (rhEPO) is a major concern in competitive sports, and the implementation of tests allowing for higher detection rates than what current tests are capable of is required. In this study, a novel lateral flow EPO isoform test kit, EPO WGA MAIIA, is evaluated on the basis of plasma and urine samples obtained from eight healthy males in connection with a 28-day rhEPO injection period. rhEPO was injected every other day during the first 14 days of the study, and the method proved to be 100 % effective in detecting rhEPO in the concomitantly obtained samples. Seven days after the last injection, three positive (>99.99 % confidence limit (CL)) subjects were found. When using 99 % CL as the cut-off limit, six of the eight subjects (75 %) were found to be suspected of doping. Samples obtained 14 and 21 days after the last injection showed no detectable trace of rhEPO. A previous study using indirect methods to determine EPO doping on the same samples indicated only that two of the subjects had suspicious values 7-21 days after the last injection. We propose implementing the easy to-use EPO WGA MAIIA test as an initial screening procedure in anti-doping work to (1) increase the detection rate of potential rhEPO doping athletes and (2) allow for a 10- to 20-fold higher analytical rate than what is possible today

Detection of EPO injections using a rapid lateral flow isoform test

Misuse of recombinant human erythropoietin (rhEPO) is a major concern in competitive sports, and the implementation of tests allowing for higher detection rates than what current tests are capable of is required. In this study, a novel lateral flow EPO isoform test kit, EPO WGA MAIIA, is evaluated on the basis of plasma and urine samples obtained from eight healthy males in connection with a 28-day rhEPO injection period. rhEPO was injected every other day during the first 14 days of the study, and the method proved to be 100 % effective in detecting rhEPO in the concomitantly obtained samples. Seven days after the last injection, three positive (>99.99 % confidence limit (CL)) subjects were found. When using 99 % CL as the cut-off limit, six of the eight subjects (75 %) were found to be suspected of doping. Samples obtained 14 and 21 days after the last injection showed no detectable trace of rhEPO. A previous study using indirect methods to determine EPO doping on the same samples indicated only that two of the subjects had suspicious values 7-21 days after the last injection. We propose implementing the easy to-use EPO WGA MAIIA test as an initial screening procedure in anti-doping work to (1) increase the detection rate of potential rhEPO doping athletes and (2) allow for a 10- to 20-fold higher analytical rate than what is possible today