Does framing of cancer survival affect perceived value of care? A willingness-to-pay survey of US residents.

AIMS: To investigate the relationship between the framing of survival gains and the perceived value of cancer care. METHODS: Through a population-based survey of 2040 US adults, respondents were randomized to one of the two sets of hypothetical scenarios, each of which described the survival benefit for a new treatment as either an increase in median survival time (median survival), or an increase in the probability of survival for a given length of time (landmark survival). Each respondent was presented with two randomly selected scenarios with different prognosis and survival improvements, and asked about their willingness to pay (WTP) for the new treatments. RESULTS: Predicted WTP increased with survival benefits and respondents' income, regardless of how survival benefits were described. Framing therapeutic benefits as improvements in landmark rather than median time survival increased the proportion of the population willing to pay for that gain by 11-35%, and the mean WTP amount by 42-72% in the scenarios we compared. CONCLUSION: How survival benefits are described may influence the value people place on cancer care.

A randomized controlled trial of darbepoetin alfa administered as a fixed or weight-based dose using a front-loading schedule in patients with anemia who have nonmyeloid malignancies.

BACKGROUND: The effect of using fixed versus weight-based doses for erythropoietic agents has not been reported previously. To investigate this issue, the authors conducted a randomized Phase II study of darbepoetin alfa administered as either a fixed dose or a weight-based dose using an accelerated correction and maintenance dosing regimen (front-loading). METHODS: During the correction phase, patients with anemia (hemoglobin < 11.0 g/dL) who had nonmyeloid malignancies and who were receiving chemotherapy were given darbepoetin alfa at a fixed dose of 325 microg (n = 122) or at a weight-based dose of 4.5 microg/kg (n = 120) once weekly until they achieved a hemoglobin concentration > or = 12.0 g/dL. Patients then received darbepoetin alfa (325 microg or 4.5 microg/kg) once every 3 weeks for the remainder of the 16-week treatment period (maintenance phase). RESULTS: Darbepoetin alfa resulted in high Kaplan-Meier rates of hematopoietic response (> or = 2 g/dL increase from the baseline level or a hemoglobin level > or = 12 g/dL) in both the fixed-dose group (86%; 95% confidence interval [95% CI], 78- 94%) and the weight-based dose group (84%; 95% CI, 76-92%). The median time to hematopoietic response was 34 days (95% CI, 28-44 days) for the fixed-dose group and 36 days (95% CI, 30-45 days) for the weight-based dose group. Hemoglobin concentrations were maintained at target levels for up to 16 weeks in both groups. Darbepoetin alfa was well tolerated, and no clinically significant differences between fixed doses and weight-based doses were observed. CONCLUSIONS: Darbepoetin alfa was effective when administered as either a fixed dose or a weight-based dose using a front-loading approach to rapidly correct anemia and effectively maintain hemoglobin levels in patients with anemia who had malignant disease.

Efficacy and safety of darbepoetin alfa in anaemic patients with lymphoproliferative malignancies: a randomized, double-blind, placebo-controlled study.

This phase 3, randomized, double-blind, placebo-controlled study was designed to evaluate the efficacy and safety of darbepoetin alfa in anaemic patients with lymphoproliferative malignancies. Patients (n = 344) with lymphoma or myeloma received darbepoetin alfa 2.25 microg/kg or placebo s.c., once weekly for 12 weeks. The percentage of patients achieving a haemoglobin response was significantly higher in the darbepoetin alfa group (60%) than in the placebo group (18%) (P < 0.001), regardless of baseline endogenous erythropoietin level. However, increased responsiveness was observed in patients with lower baseline erythropoietin levels. Darbepoetin alfa also resulted in higher mean changes in haemoglobin than placebo from baseline to the last value during the treatment phase (1.80 g/dl vs 0.19 g/dl) and after 12 weeks of treatment (2.66 g/dl vs 0.69 g/dl). A significantly lower percentage of patients in the darbepoetin alfa group received red blood cell transfusions than in the placebo group (P < 0.001). The efficacy of darbepoetin alfa was consistent for patients with lymphoma or myeloma. Improvements in quality of life were also observed with darbepoetin alfa. The overall safety profile of darbepoetin alfa was consistent with that expected for this patient population. Darbepoetin alfa significantly increased haemoglobin and reduced red blood cell transfusions in patients with lymphoproliferative malignancies receiving chemotherapy.

Darbepoetin alfa: a new approach to the treatment of chemotherapy-induced anaemia.

Chemotherapy-induced anaemia has important consequences on the quality of life and social function of cancer patients. The finding of erythropoietin (EPO) deficiency in these patients led to the therapeutic development of erythropoietic proteins. Darbepoetin alfa (Aranesp), Amgen Inc, Thousand Oaks, California), a new erythropoietic growth factor, has eight more sialic acids than epoetin alfa. The increased sialic acid content confers a three-fold longer half-life and allows the drug to be administered less frequently than epoetin alfa. Darbepoetin alfa affects the same early haematopoietic cells as epoetin alfa and the endogenous hormone EPO. Preclinical pharmacokinetic studies suggest that the intrinsic pharmacological properties of darbepoetin alfa are comparable to those of epoetin alfa, but that the increased sialic acid content allows for less-frequent administration with superior performance. Darbepoetin alfa has been shown to have safe clinical efficacy in a variety of tumour settings and with several types of chemotherapy.

A randomized, active-control, pilot trial of front-loaded dosing regimens of darbepoetin-alfa for the treatment of patients with anemia during chemotherapy for malignant disease.

BACKGROUND: Anemia in patients receiving chemotherapy can be ameliorated with recombinant human erythropoietin (rHuEPO), which is administered one to three times per week. Darbepoetin alpha, a new erythropoietic agent, has longer serum residence time, allowing it to be administered less frequently. METHODS: Patients (n = 127) were randomized to receive study drug for 12 weeks: either rHuEPO 40,000 U with escalations to 60,000 U for nonresponders or darbepoetin alpha at doses of 4.5 microg/kg per week until hemoglobin concentration >or= 12 g/dL, then 1.5 microg/kg per week (Group 1); 4.5 microg/kg per week for 4 weeks, then 2.25 microg/kg per week for 8 weeks (Group 2); or 4.5 microg/kg per week for 4 weeks, then 3.0 microg/kg every 2 weeks (Group 3). Efficacy was measured using the mean change in hemoglobin level, the proportion of patients achieving a hemoglobin response, the time to response, and the mean change in Functional Assessment of Cancer Therapy-Fatigue Scale scores. Safety was assessed by reports of adverse events. RESULTS: Overall, after 4 weeks of treatment, the mean change (95% confidence interval [95%CI]) in hemoglobin concentration was 0.53 g/dL (95%CI, 0.05-1.02 g/dL), 0.70 g/dL (95%CI, 0.11-1.29 g/dL), and 0.90 g/dL (95%CI, 0.47-1.33 g/dL) in darbepoetin alpha Groups 1, 2, and 3, respectively, and 0.39 g/dL (95%CI, - 0.22-1.00 g/dL) in the rHuEPO group. By the end of the study, the mean change (95%CI) in hemoglobin concentration was 1.35 g/dL (95%CI, 0.67-2.02 g/dL), 1.35 g/dL (95%CI, 0.57-2.12 g/dL), and 1.28 g/dL (95%CI, 0.84-1.73 g/dL) in darbepoetin alpha Groups 1, 2, and 3, respectively, and 1.03 g/dL (95%CI, 0.53-1.53 g/dL) in the rHuEPO group. The early erythropoietic response in patients who were treated with darbepoetin alpha was associated with an early and maintained reduction in patient-reported fatigue. The adverse event profile was comparable with all doses of darbepoetin alpha and rHuEPO. CONCLUSIONS: Darbepoetin alpha, given as a front-loaded dose for 4 weeks and followed by lower and/or less frequent doses, appears to be efficacious and may decrease the time to response relative to treatment with rHuEPO.

Assessment of hematologic effects and fatigue in cancer patients with chemotherapy-induced anemia given darbepoetin alfa every two weeks.

The objective of this ongoing trial is to study the ability of darbepoetin alfa to reverse chemotherapy-induced anemia in cancer patients, and to relate improvement in hemoglobin with changes in fatigue and functional capacity. Eligible subjects had a nonmyeloid malignancy, were receiving multicycle chemotherapy, and were anemic, as defined by a screening hemoglobin < or = 11 g/dL. Darbepoetin alfa was administered at a starting dosage of 3 microg/kg every 2 weeks for up to eight doses (16 weeks) in an open-label, noncomparative setting. A total of 194 oncology practices contributed 1,173 subjects to this interim analysis. The mean increase in hemoglobin was 1.7 g/dL (95% CI: 1.6, 1.8) to last value on study (intent-to-treat analysis) and 2.1 g/dL (95% CI: 1.9, 2.2) for those patients receiving the full 16 weeks of therapy. The Kaplan-Meier estimate of the proportion of subjects with a hematopoietic response (increase in hemoglobin > or = 2 g/dL and/or hemoglobin value > or = 12 g/dL) was 84% (95% CI:81,86). Subjects in the lower baseline hemoglobin category (< 10 g/dL) tended to have a greater hemoglobin response during treatment. The Functional Assessment of Cancer Therapy-Fatigue (FACT-Fatigue) subscale score increased by a mean of 6.8 points (26%) during the study, and improvements in fatigue paralleled the increases observed in hemoglobin. Study treatment-related toxicity was minimal, with the most common event being injection-site pain, seen in 2% of subjects. Experience to date with an every-2-week regimen of darbepoetin alfa indicated efficacy comparable to historical experience with weekly and 3-times-weekly regimens of epoetin alfa in treating chemotherapy-induced anemia in cancer subjects.

Every-2-week darbepoetin alfa is comparable to rHuEPO in treating chemotherapy-induced anemia. Results of a combined analysis.

The safety and efficacy of darbepoetin alfa (Aranesp) at 3.0 microg/kg administered every 2 weeks and recombinant human erythropoietin (rHuEPO) given as 40,000 U weekly or 150 U/kg three times weekly were evaluated by pooling data from three darbepoetin alfa clinical studies. All studies enrolled anemic (hemoglobin < or = 11.0 g/dL) patients receiving multicycle chemotherapy. Open-label study drug was administered by subcutaneous injection. Hemoglobin concentrations, red blood cell transfusion requirements, and standard safety parameters were evaluated. Of 260 patients who received darbepoetin alfa at 3.0 microg/kg every 2 weeks and 115 patients who received rHuEPO three times weekly or once weekly, hematopoietic response (change in hemoglobin from baseline of > or = 2 g/dL or hemoglobin concentration of > or = 12 g/dL) was achieved in 71% (95% confidence interval [CI] = 65%-78%) of patients who received darbepoetin alfa every 2 weeks, comparable to the response in patients who received rHuEPO (71%; 95% CI = 61%-81%). The mean increase in hemoglobin concentration over 13 weeks was also similar: 1.48 g/dL (95% CI = 1.28-1.68 g/dL) for darbepoetin alfa and 1.31 g/dL (95% CI = 0.97-1.64 g/dL) for rHuEPO. The proportion of patients in the darbepoetin alfa group requiring transfusions was lower (7%; 95% CI = 4%-11%) than that in the rHuEPO group (14%; 95% CI = 8%-22%). Darbepoetin alfa every 2 weeks was well tolerated with a safety profile comparable to that of rHuEPO. In conclusion, darbepoetin alfa at a dose of 3.0 microg/kg given every 2 weeks safely increases hemoglobin concentration to the same extent as rHuEPO.

Clinical trial simulation of a 200-microg fixed dose of darbepoetin alfa in chemotherapy-induced anemia.

Our objective was to assess, using clinical trial simulation, the feasibility of a fixed 200-microg dose of darbepoetin alfa (Aranesp) administered every 2 weeks in chemotherapy-induced anemia. A pharmacokinetic/pharmacodynamic model was developed using clinical data from 547 cancer patients who received darbepoetin alfa at various doses and schedules. Monte Carlo simulations were performed for weight-based (3 microg/kg every 2 weeks) and fixed-dose (200 microg every 2 weeks) regimens and were compared with observed clinical data. Mean hemoglobin changes from baseline to end of treatment were +1.61 g/dL, +1.83 g/dL, and +1.79 g/dL for observed data, the weight-based simulation, and the fixed-dose simulation, respectively. The rates of required transfusions (hemoglobin < or = 8 g/dL) were also similar between groups. For patients between 45 and 95 kg (over 90% of the population), the impact of a fixed dose on mean hemoglobin change was negligible. There was a slight weight effect at body weight extremes (< 45 kg and > 95 kg). Clinical outcomes from simulations of weight-based andfixed dosing of darbepoetin alfa were similar to those of observed weight-based data. Given the weight distribution of a typical cancer population, the majority would be expected to benefit equally from weight-based and fixed-dose darbepoetin alfa in the amelioration of chemotherapy-induced anemia.

Darbepoetin alfa: impact on treatment for chemotherapy-induced anemia and considerations in special populations.

Our objective was to evaluate the effects of darbepoetin alfa (Aranesp) on hemoglobin and transfusions in anemic patients with cancer undergoing chemotherapy, and the impact of age, sex, baseline hemoglobin, chemotherapy type, and tumor type. Patients were randomized to one of three darbepoetin alfa groups based on average weekly dose (< 1.5 microg/kg, 1.5 to 2.25 microg/kg, and > 2.25 microg/kg) or to placebo. Dose response was evaluated for change in hemoglobin, hemoglobin and hematopoietic responses, and red blood cell transfusion rates. Hazard ratios for the incidence of hemoglobin response and transfusions were calculated. Adverse events and antibody formation were assessed. Treatment effects were observedfor all hemoglobin end points and incidence of transfusion. The incidence of hematopoietic response among the darbepoetin alfa dose groups ranged from 46% (95% confidence interval [CI] = 33%-60%) to 74% (95% CI = 66%-81%) and increased with higher darbepoetin alfa dose. Patients receiving darbepoetin alfa were more likely to exhibit a hemoglobin response and less likely to require a transfusion, compared with placebo, irrespective of the patient characteristics examined. No increased risk of adverse events and no development of neutralizing antibodies were observed with darbepoetin alfa use. Darbepoetin alfa increased the likelihood of a hemoglobin response and decreased the need for transfusions in cancer patients with chemotherapy-induced anemia.

Randomized, dose-finding study of darbepoetin alfa in anaemic patients with lymphoproliferative malignancies.

Darbepoetin alfa is a novel erythropoiesis-stimulating protein with a prolonged serum half-life. This randomized, double-blind, placebo-controlled, dose-finding study investigated the efficacy and safety of darbepoetin alfa in anaemic patients with lymphoproliferative malignancies who were receiving chemotherapy. Patients were randomized in a 1:2:2:1 ratio to receive darbepoetin alfa 1.0 microg/kg (n = 11), 2.25 microg/kg (n = 22), 4.5 microg/kg (n = 22) or placebo (n = 11), administered subcutaneously once weekly for 12 weeks. No dose increases were allowed during the study. A higher proportion of patients achieved a haemoglobin response (defined as a >/= 2.0 g/dl increase from baseline) in the darbepoetin alfa 1.0 microg/kg (45%), 2.25 microg/kg (55%) and 4.5 microg/kg (62%) groups than in the placebo group (10%; P < 0.01). The mean change in haemoglobin from baseline to week 13 was 1.56 g/dl in the 1.0 microg/kg group, 1.64 g/dl in the 2.25 microg/kg group and 2.46 g/dl in the 4.5 microg/kg group, compared with a mean change of 1.00 g/dl in the placebo group. The overall safety profile of darbepoetin alfa in this study was similar to that of placebo. These results show that darbepoetin alfa effectively and safely increased haemoglobin concentrations in patients with lymphoproliferative malignancies. Confirmative studies at doses of 2.25 and/or 4.5 microg/kg/week in this population are warranted.