Healthcare costs associated with nephrology care in pre-dialysis chronic kidney disease patients

OBJECTIVE

To compare the healthcare costs of pre-dialysis chronic kidney disease (CKD) patients cared for in a nephrology clinic setting versus other care settings.

METHODS

An analysis of health claims between 01/2002 and 09/2007 from the Ingenix Impact Database was conducted. Inclusion criteria were ≥ 18 years of age, ≥ 1 ICD-9 claim for CKD, and ≥ 1 estimated glomerular filtration rate (eGFR) value of < 60 mL/min/1.73 m(2). Patients were classified in the nephrology care cohort if they were treated in a nephrology clinic setting at least once during the study period. Univariate and multivariate analyses were conducted to compare average annualized healthcare costs of patients in nephrology care versus other care settings.

RESULTS

Among the 20,135 patients identified for analysis, 1,547 patients were cared for in a nephrology clinic setting. Nephrology care was associated with lower healthcare costs with an unadjusted cost savings of $3,049 ($11,303 vs. $14,352, p = 0.0014) and a cost ratio of 0.8:1 relative to other care settings. After adjusting for covariates, nephrology care remained associated with lower costs (adjusted cost savings: $2,742, p = 0.006).

LIMITATIONS

Key limitations included potential inaccuracies of claims data, the lack of control for patients' ethnicity in the calculation of eGFR values, and the presence of potential biases due to the observational design of the study.

CONCLUSIONS

The current study demonstrated that pre-dialysis CKD patients treated in nephrology clinics were associated with significantly lower healthcare costs compared with patients treated in other healthcare settings.

Drug utilisation and cost considerations of erythropoiesis stimulating agents in oncology patients receiving chemotherapy: observations from a large managed-care database

OBJECTIVE

Erythropoiesis stimulating agent (ESA) resource utilisation in cancer chemotherapy patients is of importance to managed-care organisations. To understand current real-world utilisation of ESAs, this study examined epoetin alfa (EPO) and darbepoetin alfa (DARB) treatment patterns (dosing and treatment duration), dose ratio and ESA treatment costs.

METHODS

An analysis of medical claims data from January 2006 through to January 2008 was conducted using the PharMetrics Patient-Centric database of over 85 health plans. Patients included in the study were > or =18 years of age, had at least one cancer claim within 90 days prior to ESA treatment initiation, were newly initiated on EPO or DARB, received at least two doses, and were treated with concomitant chemotherapy (at least one chemotherapy claim during ESA treatment). Mean cumulative ESA dose was used to calculate drug cost (based on April 2008 wholesale acquisition cost) and dose ratio (units EPO : microg DARB).

RESULTS

A total of 4,111 EPO patients and 6,817 DARB patients met inclusion criteria and formed the study population. EPO-treated patients were slightly older (mean age: EPO 63.6, DARB 61.8, p<0.0001) with a greater proportion of women in the DARB-treated group (EPO 60.9%, DARB 64.1%, p=0.0007). The mean treatment duration was slightly longer in the EPO group (EPO 58.4 days, DARB 55.4 days, p=0.0019). The mean cumulative ESA dose administered was EPO 329,129 units and DARB 1,289 microg, resulting in a dose ratio of 255:1 (units EPO:microg DARB). Mean drug cost per treatment episode was significantly lower in the EPO group by $1,768 (EPO $4,321, DARB $6,089, p<0.0001). After controlling for covariates, the incremental cost associated with DARB treatment remained stable and statistically significant (adjusted cost difference: $1,806 per treatment episode higher for DARB patients than EPO, p<0.0001).

CONCLUSIONS

This study of 10,928 oncology patients receiving chemotherapy reported a dose ratio of 255:1 (units EPO:microg DARB) with 29% lower treatment cost in the EPO group. These findings are similar to those previously reported from published clinical trials and real-world utilisation studies.

Dosing and Outcomes Study of Erythropoiesis-Stimulating Therapies (DOSE) : a registry for characterizing anaemia management and outcomes in oncology patients

BACKGROUND AND OBJECTIVE

To report the design, methodology, implementation and initial results of the Dosing and Outcomes Study of Erythropoiesis-Stimulating Therapies (DOSE) Registry, the first US patient registry to collect and report on practice patterns and outcomes associated with erythropoiesis-stimulating therapy (EST) for anaemia management in oncology patients.

METHODS

DOSE is a prospective ongoing registry of oncology patients treated with epoetin-alpha or darbepoetin-alpha. Patients from either community or academic centres who meet prespecified entry criteria are eligible for inclusion in the registry. Data collected include patient demographic and clinical characteristics, EST administration, haematological parameters, patient-reported outcomes and medical resource utilization. Patients are followed from EST initiation through to the end of therapy or 16 weeks, whichever is earlier.

RESULTS

Initial results from 45 sites for 861 patients (epoetin-alpha, n = 312; darbepoetin-alpha, n = 549) showed that baseline demographic and disease characteristics were similar between the two treatment groups. Administration of EST at both weekly and > or =2-weekly intervals was observed in both groups, with similar numbers of haemoglobin determinations. However, the mean number of office visits was higher in the darbepoetin-alpha group despite more frequent administration of therapy at > or =2-weekly intervals in this group. Mean treatment duration was approximately 8 weeks for both groups. Mean post-baseline haemoglobin levels of 11-12 g/dL were achieved and maintained at all timepoints assessed with epoetin-alpha but not with darbepoetin-alpha. Both groups had similar rates of packed red blood cell transfusions.

CONCLUSIONS

The DOSE Registry is a valuable source of data relating to anaemia management, practice patterns and outcomes in oncology patients from the perspective of actual clinical practice. Results from this registry should provide patients, clinicians and healthcare decision makers with a better understanding of the relationship between EST dosage and outcomes in the clinical setting.

Dose and cost comparison of erythropoietic agents in the inpatient hospital setting

PURPOSE

The inpatient dosing patterns and treatment costs in cancer and predialysis chronic kidney disease (CKD) patients treated with erythropoietic agents from a hospital pharmacy perspective were studied.

METHODS

An analysis of electronic inpatient records from the Premier Perspective comparative hospital database was conducted. Study participants were identified through hospitalizations recorded between July 2002 and March 2005 from over 500 hospitals nationwide. Adult patients with an admitting diagnosis of cancer or predialysis CKD and treated with epoetin alfa or darbepoetin alfa during hospitalization were included. Patients who had received renal dialysis or both agents during a hospitalization were excluded. Wholesale acquisition costs from September 2006 were used to calculate drug costs.

RESULTS

A total of 25,645 hospitalized patients with cancer (22,873 received epoetin alfa; 2,772 received darbepoetin alfa) and 66,822 hospitalized patients with CKD (60,079 received epoetin alfa; 6,743 received darbepoetin alfa) were identified. The mean cumulative dose per hospitalization resulted in dose ratios of 245:1 and 242:1 (units epoetin alfa:micrograms darbepoetin alfa) for cancer and CKD patients, respectively. On the basis of the cumulative dose per hospitalization, drug costs for darbepoetin alfa-treated patients were approximately 50% higher than drug costs for epoetin alfa-treated patients for both oncology and CKD patients.

CONCLUSION

Epoetin alfa was associated with less cost compared with darbepoetin alfa for treating inpatients with cancer or CKD. Further research including the patients' clinical outcomes is necessary to determine the true pharmacoeconomic differences between the two agents.

Dosing patterns, hematologic outcomes, and costs of erythropoietic agents in anemic predialysis chronic kidney disease patients from an observational study

INTRODUCTION

Epoetin alfa (EPO) and darbepoetin alfa (DARB) are two erythropoietic agents currently available in the United States for the treatment of anemia in patients with pre-dialysis chronic kidney disease (CKD). The goal of this study was to assess and compare EPO- and DARB-treated CKD patients with respect to dosing patterns, hematologic outcomes, and associated costs.

MATERIALS AND METHODS

In this multicenter, retrospective chart review, 400 charts of anemic predialysis CKD patients (200 treated with EPO and 200 treated with DARB) were sequentially selected from a large self-insured employer health insurance database. The database included both employees and their dependents. Selection criteria included patients newly initiated on EPO or DARB between July 2002 and December 2003 who had at least 24 weeks of dosing and hematologic laboratory data available. Patients with a diagnosis of malignancy or on dialysis were excluded. Dosing frequency was categorized as once weekly (QW), once every 2 weeks (Q2W), every 3 weeks (Q3W), or every 4 weeks (Q4W). Hemoglobin (Hb) levels and dates/doses of EPO and DARB administrations were recorded. Costs were calculated using 2005 wholesale acquisition costs.

RESULTS

Baseline demographics were similar in the EPO and DARB groups with respect to race, sex, renal function, and Hb. Extended dosing (defined as > or =Q2W) was common in both groups. The predominant dosing frequency was Q2W (59.5% of patients) for EPO and Q3W (68.0% of patients) for DARB. Hematologic response (defined as Hb > or = 11 g/dL) was significantly greater in the EPO group at early time points (week 4: EPO 28%, DARB 12%; week 8: EPO 39%, DARB 21%; week 12: EPO 98%, DARB 89%). In both groups, 99% of patients achieved hematologic response by week 24. The mean cumulative dose during the first 12 weeks (initiation phase) was EPO 141,481 +/- 32,426 units and DARB 499 +/- 152 microg. The 24 week mean cumulative dose (initiation and maintenance phase) was EPO 243,715 +/- 39,264 units and DARB 902 +/- 265 microg, corresponding to a drug cost of EPO $2,966 and DARB $3,933 and a dose ratio of 270:1 (units EPO:microg DARB).

CONCLUSION

Extended dosing frequency (> or = Q2W) was common in both groups. EPO treatment was associated with a significantly greater hematologic response at early time points (weeks 4, 8, and 12). Erythropoietic agent cost was 33% higher in the DARB group.

Dosing patterns and costs of erythropoietic agents in patients with chronic kidney disease not on dialysis in managed care organizations

BACKGROUND

Epoetin alfa (EPO) and darbepoetin alfa (DARB) are erythropoietic agents indicated in the United States for the treatment of anemia in chronic kidney disease (CKD).

OBJECTIVE

This study investigated dosing patterns and costs associated with the use of erythropoietic-stimulating therapy (EST) in patients with CKD not on dialysis who were newly starting EPO or DARB therapy in managed care organizations.

METHODS

This was a retrospective analysis of medical claims data from >30 health plans for the period from July 2002 to February 2005. Patients were included if they were aged > or =18 years, had > or =1 claim for CKD within 90 days before the initiation of treatment, had newly started therapy with EPO or DARB, and had received > or =2 doses of treatment. If a patient was undergoing renal dialysis, data were censored 30 days before the first date of dialysis. Patients with a diagnosis of cancer or who had undergone chemotherapy were excluded from the analysis. The mean dosing interval was determined for both groups. Mean weekly doses and costs (using 2005 wholesale acquisition costs), weighted by the treatment duration, were calculated. The frequency of outpatient nephrologist visits was described and included in cost considerations.

RESULTS

The study population consisted of 595 patients who received EPO and 260 who received DARB. The EPO group was significantly older than the DARB group (mean age, 63.5 vs 61.2 years, respectively; P = 0.020). The proportion of women was similar between the 2 groups (51.6% and 50.4%). Use of extended dosing (> or =q2wk) was common in both groups (63.2% and 90.8%). The weighted mean weekly dose was 11,536 U for EPO and 42.5 mug for DARB. The mean number of outpatient nephrologist visits during treatment was similar between the 2 groups (3.9 and 3.5). Mean weekly costs (EST drug cost plus cost of nephrologist visits) were significantly lower for EPO compared with DARB (159 dollars vs 205 dollars; P < 0.001).

CONCLUSIONS

The majority of these CKD patients newly started on EST in managed care organizations received extended dosing regimens (> or =q2wk) of EPO or DARB. EPO treatment was associated with significantly lower mean weekly costs compared with DARB. The number of outpatient nephrology visits did not differ significantly between groups.

Drug administration frequency and provider office visit patterns for oncology patients during treatment with erythropoietic agents: An analysis of four observational studies

BACKGROUND

Several drug administration regimens of epoetin alfa (EPO) and darbepoetin alfa (DARB) are used for the management of anemia in cancer patients in the clinical practice setting.

OBJECTIVE

The purpose of the present analysis was to assess whether drug administration regimens were associated with differences in the number of provider office visits and hemoglobin assessments during treatment with these agents.

METHODS

Data from 4 observational studies that examined treatment patterns of EPO and DARE and health care resource utilization were analyzed. These studies, selected based on the availability of office visit and/or hemoglobin determination data during the course of treatment, included a retrospective chart review, 2 retrospective claims analyses, and an ongoing prospective patient registry. The treatment patterns and oncology-related provider visits and/or the frequency of hemoglobin evaluations among the studies were reported.

RESULTS

Data from 15,845 cancer patients were included in the analysis. The patient demographic and baseline characteristics were similar across all 4 studies; patients were predominantly women (62%-71%) with a mean age range of 56 to 63 years. Mean treatment duration ranged from 7.1 to 8.4 weeks without significant differences between EPO and DARE in any study. Weekly and extended (at least every 2 weeks [> or =Q2W]) drug administration frequencies were observed in both treatment groups. The most frequent drug administration schedule for EPO was once weekly (53%-75% of patients), and for DARE Q2W (67%-73%). Despite the difference in erythropoietic agent administration frequency, no significant differences were observed between EPO and DARB for either the number of oncology-related provider visits or the number of hemoglobin assessments.

CONCLUSIONS

The frequency of oncology-related provider visits and hemoglobin assessments appears to be independent of the EPO and DARB administration frequency. These findings might provide useful information for health care providers and oncology patients in understanding patterns of care during treatment with erythropoietic agents.

Dosing patterns, treatment costs, and frequency of physician visits in adults with cancer receiving erythropoietic agents in managed care organizations

OBJECTIVE

To investigate the dosing patterns and treatment costs of erythropoietic agents in adult (>or= 18 years of age) cancer patients newly initiated on epoetin alfa (EPO) or darbepoetin alfa (DARB) in managed care organizations.

METHODS

An analysis of US medical claims (30 million lives in over 35 health plans) in the period July 1, 2002-February 28, 2005 was conducted. Patients with >or= 1 cancer claim within 90 days prior to initiating EPO or DARB, and who received at least two doses of the same erythropoietic agent, were included in this analysis. Weighted average weekly dosing, cumulative treatment dose, associated drug cost, dosing frequency patterns, and the frequency of outpatient visits were evaluated. The EPO:DARB dose ratio, based on average cumulative treatment doses, was assessed.

RESULTS

5639 EPO and 2166 DARB patients met the inclusion and exclusion criteria. The EPO group was older (EPO 59.1 years; DARB 57.6 years; p < 0.001) with a higher proportion of men (EPO 38.1%; DARB 33.1%; p < 0.001). Variable dosing frequency was observed with similar treatment durations for the two groups (days: EPO 55.6; DARB 57.7; p = 0.122). A dose ratio of 236:1 was observed (average cumulative dose: EPO 252 856 U; DARB 1072 mcg). Average drug cost was significantly higher in the DARB group (drug cost: EPO 3077 dollars; DARB 4674 dollars; p < 0.001). The average number of hematology/oncology outpatient visits per patient (visits: EPO 7.4; DARB 7.3; p = 0.676) and outpatient visits for hemoglobin determination (visits: EPO 6.7; DARB 6.4; p = 0.093) during treatment was similar between the two groups.

LIMITATIONS

The results were based on medical claims only. The absence of information on actual injection dates in pharmacy claims prevented their incorporation in the analysis.

CONCLUSIONS

Based on the average cumulative doses, the EPO:DARB dose ratio was 236:1 (Units EPO: mcg DARB) with 52% greater drug cost in the DARB group. Despite the variable administration frequency observed between the two agents, the number of hematology/oncology outpatient visits was not different.

Dosing patterns, hematologic outcomes, and costs of erythropoietic agents in predialysis chronic kidney disease patients with anemia

OBJECTIVE

Few observational studies have evaluated the use of epoetin alfa (EPO) and darbepoetin alfa (DARB) in chronic kidney disease (CKD) patients with anemia. The objective of this study was to investigate dosing patterns, hematologic outcomes, and intervention costs with EPO and DARB in anemic CKD patients treated in an ambulatory care setting.

METHODS

This was a multicenter, retrospective, chart review of predialysis CKD patients with anemia treated with EPO or DARB. Charts were sequentially selected from 435 EPO and 432 DARB patients naive to erythropoietic therapy and treated for > or = 24 weeks. Hemoglobin (Hb) levels, dates, and EPO/DARB doses were recorded. Drug costs using 2005 wholesale acquisition costs (WAC) and Federal Supply Schedule (FSS) pricing were based on the mean cumulative drug dose over the 24-week study period.

RESULTS

A total of 393 EPO and 396 DARB charts met all criteria with predominantly male subjects (EPO: 94%; DARB: 96%). Mean baseline GFR and Hb levels were similar. Once-weekly and extended dosing (> or = Q2W) was common in both groups. At Weeks 4, 8, and 12 following initiation of therapy, a greater proportion of EPO than DARB patients reached target Hb levels (> or = 11 g/dL) (p < 0.0001); at Week 24, all patients reached target Hb levels. Mean 24-week cumulative doses were EPO 279 336 +/- 68 302 units and DARB 1084 +/- 246 microg. Drug cost was higher for DARB independent of pricing utilized (WAC: EPO = 3400 US dollars, DARB = 4726 US dollars; FSS: EPO = 1528 US dollars, DARB = 2379 US dollars).

CONCLUSIONS

Extended dosing (Q2W) was common in EPO- and DARB-treated patients with CKD-related anemia, with EPO-treated patients experiencing a significantly greater hematologic response (at Weeks 4, 8, and 12). In addition, drug cost was 39-56% higher in the DARB group. The male predominance may limit generalizability, warranting further research in other populations.

Economic evaluation of weekly epoetin alfa versus biweekly darbepoetin alfa for chemotherapy-induced anaemia: evidence from a 16-week randomised trial

INTRODUCTION

A 16-week, open-label, multicentre, randomised trial of weekly epoetin alfa 40 000 units versus biweekly darbepoetin alfa 200microg among 358 patients with solid-tumour cancers and chemotherapy-induced anaemia demonstrated superior haematological outcomes with epoetin alfa. We sought to compare resource use, costs and clinical outcomes between treatment groups and report the results using a cost-consequences framework.

METHODS

Pre-specified methods were used to assign costs (US dollars, year 2004-5 values) to medical resources and patient time using a societal perspective. Costs for inpatient care, outpatient care and physician services were based on US Medicare reimbursement rates. Indirect costs assigned to patient time spent receiving study medication were based on the mean hourly wage in the US. In the base-case analysis, the average wholesale price was used to assign costs to medications. Clinical outcomes included all haemoglobin levels and transfusions recorded throughout the trial. Sensitivity analyses were performed to evaluate the impact of different costing methods, cost sources, perspectives and methods to assign haemoglobin values following a blood transfusion.

RESULTS

Over a mean follow-up duration of 11.8 weeks, the average cost of study medications and their administration was the single largest component of total costs and was similar between groups (epoetin alfa 5979 US dollars and darbepoetin alfa 5935 US dollars, difference 44 US dollars; 95% CI -590, 692). There were no significant differences in the proportions of patients hospitalised (epoetin alfa 24.6%, darbepoetin alfa 22.0%; p = 0.57). Patients randomised to epoetin alfa experienced more inpatient days, on average, than patients randomised to darbepoetin alfa (2.6 vs 1.6, 95% CI for the difference, 0.07, 2.27). However, with regard to transfusions, patients in the epoetin alfa arm required fewer units of blood than patients in the darbepoetin alfa arm (0.46 vs 0.88, 95% CI for the difference -0.77, -0.08). Mean total costs, comprising costs for study medications and their administration, inpatient care, transfusions, unplanned radiation therapy, haematology and laboratory services, chemotherapy and non-chemotherapy drugs and indirect costs were 14,976 US dollars in the epoetin alfa arm compared with 14,101 US dollars in the darbepoetin alfa arm, a difference of 875 US dollars (95% CI for difference -849, 2607), of which 98% of the difference was attributable to higher inpatient costs in the epoetin alfa arm (2374 US dollars vs 1520 US dollars; 95% CI for difference -33, 1955). Assessments of multiple clinical measures demonstrated improved outcomes with epoetin alfa relative to darbepoetin alfa.

CONCLUSION

Most clinical outcome measures suggested greater improvement with epoetin alfa relative to darbepoetin alfa, but most costs for both agents appeared similar. Decision makers must evaluate the differences in costs and efficacy measures that are most relevant from their perspectives.

Dosing Patterns and Treatment Costs of Erythropoietic Agents in Elderly Patients with Pre-Dialysis Chronic Kidney Disease in Managed Care Organisations

OBJECTIVES

To investigate dosing patterns and drug costs of erythropoietic agents and assess the frequency of outpatient nephrologist visits in an elderly population with pre-dialysis chronic kidney disease (pCKD) newly initiated on epoetin alfa (EPO) or darbepoetin alfa (DARB).

METHODS

An analysis of medical claims from more than 30 healthcare plans covering all census regions of the US in the period July 2002 through February 2005 was conducted. Patients were included if they were > or = 65 years of age, had at least one claim for CKD within 90 days prior to the initiation of any erythropoietic agent, were newly commenced on either EPO or DARB, and had received at least two treatment doses. If a patient received renal dialysis, data were censored 30 days prior to the first date of dialysis. Patients diagnosed with cancer or those who had undergone chemotherapy were excluded from the analysis. The average dosing interval for both EPO and DARB was calculated and classified as once weekly (qw), every 2 weeks (q2w) or every 3 weeks or less frequently (> or = q3w). Weighted average weekly doses were scaled based on treatment duration. The frequency of outpatient nephrologist visits was analysed. Average weekly treatment costs were calculated and presented using the May 2005 Wholesale Acquisition Costs.

RESULTS

A total of 293 EPO and 102 DARB patients met the inclusion criteria. The two groups of patients had similar mean age (74.4 years for EPO vs 74.3 years for DARB) and gender distribution (47.4% female for EPO vs 51.0% for DARB). Extended dosing (every 2 weeks or less frequently: > or = q2w) during treatment was observed in both groups (EPO: qw 49.8%, q2w 31.7%, > or = q3w 18.4%; DARB: qw 19.6%, q2w 52.9%, > or = q3w 27.5%). The average dosing interval between injections was 13.6 days for the EPO group and 17.3 days for the DARB group. The weighted average weekly dose was 12,748 units for EPO and 43.5 microg for DARB. The average weekly erythropoietic treatment cost was significantly greater for DARB compared with EPO (190 US dollars vs 155 US dollars per week [2005 values]; p = 0.028). After controlling for covariates, the cost difference between the two groups was more pronounced and remained statistically significant (adjusted cost difference 41 US dollars/week higher for DARB patients; p = 0.013). The frequency of outpatient nephrologist visits during treatment was similar between the two groups (EPO 3.4 vs DARB 3.0 visits).

CONCLUSIONS

Based on this analysis of claims data from more than 30 US healthcare plans, extended dosing (> or = q2w) of EPO and DARB was common in elderly pCKD patients treated with erythropoietic agents, with significantly higher weekly drug costs observed in the DARB group compared with the EPO group. The number of outpatient nephrologist visits was not significantly different between EPO and DARB patients. This study was the first to evaluate the dosing patterns of EPO and DARB in elderly pCKD patients in a large managed care population.

The cost-effectiveness of weekly epoetin alfa relative to weekly darbepoetin alfa in patients with chemotherapy-induced anemia

OBJECTIVE

To compare the cost-effectiveness of epoetin alfa (EPO) and darbepoetin alfa (DARB) for the treatment of chemotherapy-induced anemia (CIA), using dosing regimens approved by the FDA (EPO 40,000 U once weekly and DARB 2.25 U once weekly and DARB 2.25 mcg/kg once weekly).

METHODS

The study compared published results of two double-blind, randomized, phase III trials one utilizing EPO (N = 166) and the other, DARB (N = 367). Patients in both trials similar baseline characteristics. Effectiveness was measured as the proportion of EPO or DARB patients who were successfully treated (i.e., did not require blood transfusion) during weeks 0-16 and 5-16, respectively. Estimated drug costs were presented in 2005 USD based on wholesale acquisition cost (WAC) and average drug utilization over 16 weeks. Cost-effectiveness was calculated as the estimated drug costs divided by transfusion effectiveness. Threshold analysis was used to determine the break-even point at which EPO and DARB had the same drug costs.

RESULTS

Estimated drug costs over 16 weeks were $9,039 for EPO and $13,555 for DARB. During weeks 5-16, 85% of EPO patients and 73% of DARB patients were successfully treated, resulting in average cost-effectiveness ratios of $106 for EPO and $186 for DARB per one per cent of successfully treated patients. A 33% reduction in DARB WAC was required to achieve the same drug costs as for EPO.

CONCLUSIONS

Utilizing FDA-approved doses, EPO was found to result in lower drug costs and better treatment success when compared to DARB. Hence, EPO is a dominant alternative compared to DARB for the treatment of CIA. The analyses presented here are not without limitations. Specifically, although the studies were comparable, patients were ultimately drawn from different populations.

Retrospective observational study of patients with chemotherapy-related anemia receiving erythropoietic agents

OBJECTIVE

Epoetin alfa (EPO) and darbepoetin alfa (DARB) are approved for the treatment of chemotherapy-related anemia (CRA) in patients with nonmyeloid malignancies. This study examined dosing and hematologic outcomes with these agents in community oncology clinics.

METHODS

Medical charts were abstracted retrospectively for 1005 patients (527 EPO, 478 DARB) with CRA (hemoglobin [Hb] < or = 11 g/dL) who received EPO or DARB at 10 U.S. oncology clinics between January 2002 and March 2003.

MAIN OUTCOME MEASURES

Outcome measures included dose and frequency of erythropoietic therapy, change in Hb at 4, 8, and 12 weeks after initiation of therapy, and transfusion of packed red blood cells.

RESULTS

Baseline characteristics were generally similar between groups. Most EPO-treated patients received EPO once weekly, but 25% received EPO every 2-3 weeks, with 40,000 U the predominant dose. DARB was usually given every 1-2 weeks in doses ranging from 200-400 mcg/injection. Mean treatment duration was relatively short (< 8 weeks) in both groups, with a similar number of Hb determinations and similar incidence of red blood transfusion between groups. Hb increased from baseline in the EPO and DARB groups at 4 weeks (0.99 vs. 0.69 g/dL, p = 0.003), 8 weeks (1.39 vs. 1.06 g/dL, p = 0.011), and 12 weeks (1.43 vs. 1.11 g/dL, p = 0.055). Early Hb response (> or = 1 g/dL increase by 4 weeks) was more common with EPO than DARB (48% vs. 38%, p = 0.008).

CONCLUSIONS

EPO was superior to DARB for early hematologic outcomes in patients with CRA in community oncology clinics. Retrospective data collection and relative inexperience with DARB at the time of the study may limit the generalization of these results. Randomized, controlled trials comparing EPO and DARB are warranted.

Spiral CT during arterial portography

Spiral computed tomography (CT) performed during arterial portography offers several advantages compared with portographic studies based on conventional CT technique. Because all hepatic images are derived from a volume data set acquired during a single 24-32-second breath hold timed to coincide with the phase of peak hepatic enhancement, motion artifacts and section misregistration are eliminated and high liver-to-lesion attenuation value differences are present on all sections. These factors, in conjunction with the ability to retrospectively acquire thin, overlapping axial sections, result in improved lesion detection. The ability to produce high vein-to-liver attenuation value differences and two-dimensional multiplanar reconstructions simplifies the identification of hepatic segments and therefore lesion localization. A limitation of all CT portographic methods is the frequent occurrence of nontumorous perfusion defects that, in most cases, demonstrate characteristic locations and appearances. Performing delayed CT following portography is one method by which such pseudolesions may be characterized and differentiated from focal pathologic entities.

Phase I clinical and pharmacokinetic study of high-dose mitoxantrone combined with carboplatin, cyclophosphamide, and autologous bone marrow rescue: high response rate for refractory ovarian carcinoma

PURPOSE

To develop an active high-dose chemotherapy regimen for the treatment of ovarian carcinoma. Due to the rapid development a drug resistance, conventional chemotherapy cures only 20% of patients with advanced disease. However, in vitro data demonstrate a steep dose-response curve to a variety of agents, most notably mitoxantrone.

PATIENTS AND METHODS

A phase I study of escalated bolus mitoxantrone (10 to 25 mg/m2 x 3) and cyclophosphamide (30 to 50 mg/kg x 3) with a 5-day infusion of carboplatin (1,500 mg/m2) and an autologous bone marrow transplant (ABMT) was performed. Mitoxantrone pharmacokinetics were performed to document levels required to kill platinum-resistant ovarian carcinoma in vitro.

RESULTS

We treated 25 patients; the maximum-tolerated total doses (MTD) were 75 mg/m2 for mitoxantrone, 120 mg/kg for cyclophosphamide, and 1,500 mg/m2 for carboplatin. The dose-limiting toxicity was gastrointestinal, with severe diarrhea, ileus, and resulting sepsis. Transient partial deafness was seen in four patients, and acute renal failure (ARF) occurred in one patient at the first dose level, but was eliminated in subsequent patients with aggressive hydration. There were four early deaths due to ARF (n = 1), Legionella pneumonia (n = 1), and sepsis (n = 2). Peak mitoxantrone levels at the MTD were 623 to 2,810 ng/mL, and the area under the curve (AUC) values of the concentration versus time measurements were 560 to 1,700 ng/mL/h. Of 20 assessable patients, 65% responded, with a 45% complete remission (CR) rate. All six of the assessable patients with ovarian cancer responded: CR in five (83%) and partial remission (PR) in one (17%); the CRs have lasted 7 to 30+ months. Responses were also seen in testicular and breast carcinoma.

CONCLUSION

This regimen was well tolerated at the MTD and appears promising for relapsed/refractory ovarian carcinoma, with mitoxantrone levels achieved that are active in vitro against platinum-resistant ovarian carcinoma cells.

Identification of a novel CD56- lymphokine-activated killer cell precursor in cancer patients receiving recombinant interleukin 2

Circulating lymphokine-activated killer (LAK) cell activity in cancer patients receiving recombinant interleukin 2 (rIL-2) therapy is confined to cells expressing the CD56- surface marker. However, CD56- cells from these patients but not normal individuals have been reported to exhibit LAK cytotoxicity only following in vitro activation with rIL-2. Studies were performed to document the existence of CD56- LAK precursor cells and to phenotypically characterize this population in patients receiving rIL-2 therapy using fluorescence-activated cell sorter-purified CD56- cell subsets. Initial studies confirmed that CD56- cells exhibit NK activity [20 +/- 7 (SE) LU/10(6) cells] but not LAK activity (0 +/- 0 LU/10(6) cells) when evaluated directly from peripheral blood of patients receiving rIL-2. CD56- cells from patients but not normal individuals developed significant LAK cytolytic activity against NK-resistant COLO 205 targets (16 +/- 3 LU/10(6) cells) when cultured for 3 days with 1500 units/ml rIL-2. The CD56- LAK precursor activity was confined to cells expressing a CD56-CD16+ phenotype and a large granular lymphocyte morphology; little or no NK or LAK precursor activity was detectable in CD56-CD5+ T-cells from patients. Phenotypic characterization of CD16+CD56- cells revealed that this population is uniformly CD11a+,CD18+, and CD38+ and is heterogeneous in its expression of CD11b, CD11c, and CD16/Leu 11c. These results indicate that rIL-2 administration induces enhanced LAK precursor activity in a novel population of CD5-CD16+CD56- cells.