Letrozole: a review of its use in postmenopausal women with breast cancer

Letrozole (Femara), a nonsteroidal, third-generation aromatase inhibitor administered orally once daily, has shown efficacy in the treatment of postmenopausal women with early-stage or advanced, hormone-sensitive breast cancer. In early-stage disease, extending adjuvant endocrine therapy with letrozole (beyond the standard 5-year period of tamoxifen) improved disease-free survival; compared with placebo there was a 43% relative reduction in disease recurrences or new contralateral breast tumours at a median follow-up of 2.4 years. The results of 4 months' neoadjuvant treatment with letrozole or tamoxifen in postmenopausal women with untreated primary disease favour letrozole. In advanced breast cancer, letrozole was superior to tamoxifen as first-line treatment; time to disease progression was significantly longer (9.4 vs 6.0 months, p < 0.0001) and objective response rate was significantly greater with letrozole, but median overall survival was similar between groups. For second-line therapy of advanced breast cancer that had progressed on antiestrogen therapy, letrozole showed efficacy equivalent to that of anastrozole and similar to or better than that of megestrol acetate. Letrozole is generally well tolerated and has a similar tolerability profile to tamoxifen; the most common treatment-related adverse events were hot flushes, nausea and hair thinning. In patients with tumours that had progressed on antiestrogen therapy, letrozole was tolerated as least as well as, or better than, anastrozole or megestrol acetate. In the trial of extended adjuvant therapy, adverse events reported more frequently with letrozole than placebo were hot flushes, arthralgia, myalgia and arthritis. The long-term effects of letrozole on bone mineral density or lipid profile have not been determined and these parameters may require monitoring. In several pharmacoeconomic modelling studies from various public healthcare system perspectives, letrozole was considered a cost effective choice for first-line (vs tamoxifen) or second-line (vs megestrol acetate) treatment for advanced breast cancer in postmenopausal women. In conclusion, letrozole 2.5 mg/day is effective in the treatment of postmenopausal women with early-stage or advanced breast cancer. The efficacy, cost effectiveness and favourable tolerability profile of letrozole are reflected in current treatment guidelines recommending the drug as first-line therapy for advanced breast cancer. Letrozole is superior to tamoxifen for first-line treatment and is at least as effective as standard second-line treatments in disease that has progressed on antiestrogen therapy. For early-stage disease, letrozole is superior to tamoxifen in the neoadjuvant setting, and prolongs disease-free survival when administered after the standard 5-year period of adjuvant tamoxifen therapy.     

Anastrozole: a review of its use in postmenopausal women with early-stage breast cancer

Anastrozole (Arimidex) is an aromatase inhibitor approved in the EU, the US and in other countries worldwide for use as an adjuvant treatment in postmenopausal women with early-stage, hormone receptor-positive breast cancer. It is also approved in the EU and other countries worldwide for continuing adjuvant treatment in women who have already had 2-3 years of adjuvant tamoxifen treatment for breast cancer.Anastrozole is an effective primary adjuvant treatment for postmenopausal women with early-stage breast cancer. In patients with hormone receptor-positive tumours, 5 years of anastrozole treatment was more efficacious in reducing breast cancer recurrence than 5 years of tamoxifen, both in a head-to-head comparison and in switching trials when given after 2-3 years of tamoxifen treatment. The treatment benefits have now been shown to extend to 100 months following breast surgery. To date, overall survival was better in anastrozole than tamoxifen recipients in one switching trial and in a meta-analysis of three switching trials. There was no increased benefit in health-related quality of life with anastrozole over tamoxifen. In women who had received 5 years of tamoxifen treatment, continuation of treatment with anastrozole further reduced the risk of breast cancer recurrence. Ongoing head-to-head trials against other third-generation aromatase inhibitors will provide data as to its relative efficacy against these agents. Anastrozole is a generally well tolerated treatment for early-stage breast cancer. Like other aromatase inhibitors, its most important adverse effect was an increased risk of bone fractures, which for anastrozole was restricted to the treatment period. It is still unclear whether primary adjuvant treatment extended beyond 5 years is of benefit and whether primary adjuvant treatment with anastrozole for 5 years is preferable to switching to anastrozole after 2-3 years of tamoxifen treatment. However, the evidence to date establishes anastrozole as a valuable adjuvant and extended adjuvant treatment for postmenopausal women with hormone receptor-positive, early-stage breast cancer.     

Exemestane: a review of its use in postmenopausal women with advanced breast cancer

Exemestane is an orally active irreversible steroidal aromatase inactivator that effectively suppresses in vivo aromatase activity and circulating estrogen levels in postmenopausal women with advanced breast cancer. In clinical trials, tumour responses were elicited by exemestane regardless of disease site, importantly, in patients with visceral disease. In patients with disease refractory to tamoxifen, once daily exemestane 25 mg produced objective response rates of 15 to 28% that were sustained for a median duration of 69 to 76 weeks. In a large comparative study, exemestane and megestrol showed similar clinical efficacy according to objective response and overall success rates. However, the duration of overall success and times to disease progression and treatment failure were significantly prolonged with exemestane compared with megestrol. Additionally, a significant survival advantage for exemestane over megestrol was reported. Exemestane retains efficacy in patients refractory to multiple hormonal therapies. In patients whose disease had progressed after tamoxifen and megestrol, objective response rates of 11 and 13% were reported, and responses were similar regardless of whether megestrol resistance was de novo or acquired. Objective responses also occurred in studies that explored sequential use of exemestane after failure of aminoglutethimide (26% with exemestane 200 mg/day) or other nonsteroidal aromatase inhibitors (6.6% with exemestane 25 mg/day). Additionally, tumour responses (objective response 6.1%, overall success rate 24.7%) were reported in patients who had not responded to their last hormonal treatment. As first-line treatment, once daily exemestane 25 mg elicited objective and overall success rates of 42 and 58%, compared with 16 and 31% for once daily tamoxifen 20 mg. Exemestane was generally well tolerated in clinical trials at once daily dosages up to 600 mg. At the 25 mg recommended once daily dosage, the most commonly occurring adverse events were nausea, hot flushes, fatigue, increased sweating and dizziness. Weight gain occurred in significantly more patients receiving megestrol than among those treated with exemestane. Androgenic events have been reported in a small number of patients receiving once daily exemestane 200 mg, but were rarely reported at the recommended dosage. Conclusions: Exemestane is effective in postmenopausal patients with tamoxifen-refractory advanced breast cancer, prolonging time to disease progression and treatment failure and improving survival compared with megestrol treatment. Moreover, exemestane has an acceptable tolerability profile and a convenient once daily oral dosage regimen. Available data indicate that exemestane maintains its efficacy in patients with visceral metastases and does not show cross-resistance with nonsteroidal aromatase inhibitors. Preliminary data indicate that exemestane is also effective as first-line therapy for advanced breast cancer.     

Trastuzumab: a pharmacoeconomic review of its use in early breast cancer

Trastuzumab (Herceptin) is a monoclonal antibody approved for the treatment of breast cancer that overexpresses human epidermal growth factor receptor 2 (HER2). Well designed clinical trials in women with early breast cancer have demonstrated that 1 years' therapy with adjuvant intravenous trastuzumab (a loading dose followed by 6 mg/kg every 3 weeks or 2 mg/kg weekly) significantly improves disease-free survival and overall survival compared with observation (subsequent to chemotherapy) or chemotherapy alone in women with HER2-positive disease. In the HERA trial, disease-free survival was estimated to improve by 6.3% at 3 years in the trastuzumab group compared with the observation group. Trastuzumab is generally well tolerated. The most common adverse events are infusion-related symptoms, such as fever and chills, which usually occur with administration of the first dose. Cardiotoxicity occurs in a small proportion of patients receiving trastuzumab, particularly when coadministered with anthracyclines, and cardiac assessment is recommended for all patients at baseline and at 3-monthly intervals. In modelled cost-effectiveness analyses based on data from clinical trials in patients with HER2-positive early breast cancer, adjuvant trastuzumab was predicted to be cost effective from a healthcare payer or societal perspective in several countries. Incremental costs per QALY or life-year gained with trastuzumab administered subsequent to or concurrent with chemotherapy compared with chemotherapy alone were consistently within accepted local thresholds for cost effectiveness. Sensitivity analyses demonstrated that these results remained generally robust to plausible changes in key model assumptions. In conclusion, in patients with HER2-positive early breast cancer, the addition of adjuvant trastuzumab is clinically effective in improving disease-free survival. Available pharmacoeconomic data from several countries, despite some inherent limitations, support the use of adjuvant trastuzumab for 1 year as a cost-effective treatment relative to chemotherapy alone in this patient population.     

Tamoxifen: a review of pharmacoeconomic and quality-of-life considerations for its use as adjuvant therapy in women with breast cancer

Extensive clinical experience, summarised in the recent overview of the Early Breast Cancer Trialists' Collaborative Group (EBCTCG), have confirmed that tamoxifen reduces the rate of both disease recurrence and mortality when administered as adjuvant therapy in women with early breast cancer. Tamoxifen is now established as the preferred adjuvant agent in postmenopausal women; in particular, patients with node-positive, estrogen receptor-positive breast cancer have the most to gain from tamoxifen therapy. Data from a decision-analysis model indicated that tamoxifen monotherapy had a cost-utility ration {$US6000 per additional quality-adjusted life-year (QALY), in 1989 dollars} 5 to 6 times lower than that cited as the cost-acceptability cut-off point in the US. While tamoxifen monotherapy is effective in postmenopausal women, the EBCTCG overview findings indicate that a combined regimen of tamoxifen and antineoplastic chemotherapy has superior efficacy in the same patient group. An issue of current interest is whether the added benefit offered by such a regimen can be justified in terms of added toxicity and cost. Data from a decision-analysis model indicate that combined therapy has a high incremental cost-utility ratio ($US58 000 per additional QALY, in 1989 dollars) compared with no therapy in postmenopausal women. However, the quality-of-life measures TWiST (Time Without Symptoms and Toxicity) and Q-TWiST (quality-adjusted TWiST) indicate that the early toxicity associated with a combined regimen appears to be justified given the superior long term benefits. Patient preference data from 1 study further indicate that the degree of benefit offered by a combined regimen would be acceptable to the majority (73%) of patients. Other areas where pharmacoeconomic analyses may help define more closely the optimal use of adjuvant tamoxifen is in patients at low risk of developing metastatic disease and in determining the optimal duration of therapy. Both areas require further clinical data. In conclusion, tamoxifen adjuvant monotherapy has a low cost-utility ratio in postmenopausal women with node-positive, estrogen receptor-positive breast cancer. Combined therapy in the same patient group has a high cost-utility ratio compared with no therapy but quality-of-life and patient preference data suggest that the costs may be justified. Firm conclusions relating to the use of the drug in other patient subgroups and the optimal duration of therapy await further research.     

Letrozole : in postmenopausal hormone-responsive early-stage breast cancer

Letrozole is a highly selective, nonsteroidal, third-generation aromatase inhibitor approved for first-line and extended adjuvant therapy in postmenopausal women with hormone-responsive, early-stage breast cancer. Binding of letrozole to the haeme component of the cytochrome P450 subunit of aromatase inhibits estrogen biosynthesis throughout the body. As first-line adjuvant therapy in approximate, equals 8000 postmenopausal women with hormone-responsive, early-stage breast cancer, once-daily letrozole 2.5mg significantly prolonged disease-free survival (DFS; primary endpoint) and reduced the risk of relapse at distant sites relative to once-daily tamoxifen 20mg in the ongoing Breast International Group 1-98, double-blind, multinational trial. The median duration of follow-up for this primary core analysis was 25.8 months. Extended adjuvant therapy with once-daily letrozole 2.5mg significantly prolonged DFS relative to placebo treatment at a median follow-up of 30 months (primary endpoint) in the MA-17 trial in approximate, equals 5000 postmenopausal women who were disease free after 4.5-6 years of tamoxifen therapy for hormone-responsive, early-stage breast cancer. Letrozole treatment for up to 5 years was generally well tolerated in this clinical setting. As first-line treatment, relative to tamoxifen, letrozole was associated with a significantly lower incidence of venous thromboembolitic events, vaginal bleeding, hot flushes and night sweating, whereas the incidence of cardiac failure, bone fractures and arthralgia was higher in letrozole recipients.     

Fulvestrant: a review of its use in the management of hormone receptor-positive metastatic breast cancer in postmenopausal women

Fulvestrant (Faslodex?) is an intramuscularly administered steroidal estrogen receptor antagonist that is devoid of any known estrogen agonist effects. It is indicated as second-line therapy for the treatment of postmenopausal women with hormone receptor-positive advanced breast cancer who have progressed following prior endocrine therapy. In well designed, randomized clinical trials, regimens of fulvestrant 250 and 500 mg provided effective second-line therapy for postmenopausal women with advanced breast cancer who had progressed following prior endocrine therapy. Moreover, fulvestrant 250 mg monthly (with or without a loading dose) was as effective as aromatase inhibitor therapy. However, fulvestrant is absorbed slowly, and greater steady-state concentrations are achieved more rapidly when using a higher dosage with a loading dose regimen. Consequently, a regimen of fulvestrant 500 mg monthly with a loading dose was significantly more effective than a regimen of 250 mg monthly in postmenopausal women with disease progression. Limited data also indicate a potential role for the fulvestrant 500 mg regimen as first-line therapy. Fulvestrant is generally well tolerated with no additional adverse events noted with the high-dose regimen compared with the 250 mg regimens. Furthermore, the incidence of joint disorders was shown to be significantly lower with fulvestrant 250 mg monthly than with anastrozole. Treatment with fulvestrant is not associated with any clinically significant effects on endometrial thickening, bone-specific turnover markers or sex hormone levels. In conclusion, a monthly regimen of intramuscular fulvestrant 500 mg with a loading dose provides effective and well tolerated second-line therapy for postmenopausal women with advanced breast cancer who have progressed following prior endocrine therapy and is now the approved optimal dose.     

Exemestane in postmenopausal women with early or advanced breast cancer: a review

Importance of the field: Inhibition of the aromatase enzyme in postmenopausal women reduces levels of estrogens, which is of therapeutic value in hormone-sensitive breast cancer. Exemestane is a third-generation steroidal irreversible inactivator of the aromatase enzyme used in early and advanced breast cancer for the treatment of postmenopausal women with estrogen-receptor-positive disease.

Areas covered in this review: The scientific literature on exemestane, including published articles and abstracts, was searched from 1988 to the present, and the most significant results are included in the review.

What the reader will gain: The review outlines the pharmacological characteristics of exemestane and the evidence supporting its use in the treatment of postmenopausal women with early or advanced estrogen-receptor-positive breast cancer.

Take home message: Exemestane is an effective and well-tolerated aromatase inhibitor with a defined role in early-stage breast cancer following 2 – 3 years of adjuvant treatment with tamoxifen. Exemestane also has a role in the sequence of hormonal agents employed to control advanced hormone-sensitive breast cancer, in which clinicians may exploit its partial lack of cross-resistance with nonsteroidal aromatase inhibitors.     

Escitalopram: a pharmacoeconomic review of its use in depression

Escitalopram (Cipralex), a new highly selective serotonin reuptake inhibitor (SSRI), is the active S-enantiomer of RS-citalopram. It is effective in the treatment of patients with major depressive disorder (MDD) and may have a faster onset of therapeutic effect than citalopram. It has also been shown to lead to improvements in measures of QOL. Escitalopram is generally well tolerated, with nausea being the most common adverse event associated with its use. Modelled pharmacoeconomic analyses found escitalopram to have a cost-effectiveness and cost-utility advantage over other SSRIs, including generic citalopram and fluoxetine and branded sertraline, and also over the serotonin-noradrenaline reuptake inhibitor (SNRI) venlafaxine extended-release (XR). These studies used a decision-analytic approach with a 6-month time horizon and were performed in Western Europe (year of costing 2000 or 2001). Cost-effectiveness ratios for escitalopram, in terms of cost per successfully treated patient over 6 months, ranged from Euro 871 to Euro 2598 in different countries, based on direct costs and remission rates, and were consistently lower (i.e. more favourable) than the ratios for comparators (Euro 970 to Euro 3472). Outcomes similarly favoured escitalopram when indirect costs (represented by those associated with sick leave and loss of productivity) were included. The results of comparisons with citalopram, fluoxetine and sertraline were not markedly affected by changes to assumptions in sensitivity analyses, although comparisons with venlafaxine XR were sensitive to changes in the remission rate. The mean number of QALYs gained during the 6-month period was similar for all drugs evaluated, but direct costs were lower with escitalopram, leading to lower cost-utility ratios than for comparators. Incremental analyses performed in two of the studies confirmed the cost-effectiveness and cost-utility advantage of escitalopram. A prospective, 8-week comparative pharmacoeconomic analysis found that escitalopram achieved similar efficacy to venlafaxine XR, but was associated with 40% lower direct costs (Euro 85 vs Euro 142 per patient over 8 weeks; 2001 costs), although this difference did not reach statistical significance. In both the modelled and prospective analyses, the differences in overall direct costs were mainly due to lower secondary care costs (in particular those related to hospitalisation) with escitalopram. In the prospective analysis, escitalopram had lower estimated drug acquisition costs than venlafaxine XR. CONCLUSION: Escitalopram, the S-enantiomer of RS-citalopram and a highly selective SSRI, is an effective antidepressant in patients with MDD, has a favourable tolerability profile, and, on the basis of available data, appears to have a rapid onset of therapeutic effect. Modelled pharmacoeconomic analyses from Western Europe suggest that it may be a cost-effective alternative to generic citalopram, generic fluoxetine and sertraline. Although the available data are less conclusive in comparison with venlafaxine XR, escitalopram is at least as cost effective as the SNRI based on a prospective study, and potentially more cost effective based on modelled analyses. Overall, clinical and pharmacoeconomic data support the use of escitalopram as first-line therapy in patients with MDD.     

Paclitaxel: a pharmacoeconomic review of its use in non-small cell lung cancer.

A number of first-line chemotherapy options for patients with advanced non-small cell lung cancer (NSCLC) are advocated in treatment guidelines and/or by various clinical investigators. Platinum-based chemotherapy has clearly demonstrated efficacy in patients with advanced NSCLC and is generally recommended as first-line therapy, although there is increasing interest in the use of non-platinum chemotherapy regimens. Among the platinum-based combinations currently used in clinical practice are regimens such as cisplatin or carboplatin combined with paclitaxel, vinorelbine, gemcitabine, docetaxel or irinotecan. The particular combinations employed may vary between institutions and geographical regions. Several pharmacoeconomic analyses have been conducted on paclitaxel in NSCLC and most have focused on its use in combination with cisplatin. In terms of clinical efficacy, paclitaxel-cisplatin combinations achieved significantly higher response rates than teniposide plus cisplatin or etoposide plus cisplatin (previously thought to be among the more effective regimens available) in two large randomised trials. One of these studies showed a survival advantage for paclitaxel plus cisplatin [with or without a granulocyte colony-stimulating factor (G-CSF)] compared with etoposide plus cisplatin. A Canadian cost-effectiveness analysis incorporated data from one of the large randomised comparative trials and showed that the incremental cost per life-year saved for outpatient administration of paclitaxel plus cisplatin versus etoposide plus cisplatin was $US 22181 (30619 Canadian dollars; $Can) [1997 costs]. A European analysis incorporated data from the other large randomised study and showed slightly higher costs per responder for paclitaxel plus cisplatin than for teniposide plus cisplatin in The Netherlands ($US 30769 vs $US 29592) and Spain ($US 19 923 vs $US 19724) but lower costs per responder in Belgium ($US 22852 vs $US 25000) and France ($US28 080 vs $US 34747) [1995/96 costs]. In other cost-effectiveness analyses, paclitaxel plus cisplatin was associated with a cost per life-year saved relative to best supportive care of approximately $US 10000 in a US study (year of costing not reported) or $US 11200 in a Canadian analysis ($Can 15400; 1995 costs). Results were less favourable when combining paclitaxel with carboplatin instead of cisplatin and particularly when G-CSF was added to paclitaxel plus cisplatin. The Canadian study incorporated the concept of extended dominance in a threshold analysis and ranked paclitaxel plus cisplatin first among several comparator regimens (including vinorelbine plus cisplatin) when the threshold level was $Can 75000 ($US 54526) per life-year saved or per quality-adjusted life-year gained (1995 values). CONCLUSION: Current treatment guidelines for advanced NSCLC recognise paclitaxel-platinum combinations as one of the first-line chemotherapy treatment options. In two large head-to-head comparative clinical trials, paclitaxel plus cisplatin was associated with significantly greater response rates than cisplatin in combination with either teniposide or etoposide, and a survival advantage was shown for paclitaxel plus cisplatin (with or without G-CSF) over etoposide plus cisplatin. There are limitations to the currently available pharmacoeconomic data and further economic analyses of paclitaxel-carboplatin regimens are warranted, as this combination is widely used in NSCLC and appears to have some clinical advantages over paclitaxel plus cisplatin in terms of ease of administration and tolerability profile. Nevertheless, results of various cost-effectiveness studies support the use of paclitaxel-platinum combinations, particularly paclitaxel plus cisplatin, as a first-line chemotherapy treatment option in patients with advanced NSCLC.     

Quetiapine: a pharmacoeconomic review of its use in bipolar disorder

This article briefly summarizes the burden of bipolar disorder and the clinical profile of quetiapine (Seroquel?) in the management of bipolar disorder, followed by a detailed review of pharmacoeconomic analyses. Quetiapine is an atypical antipsychotic that is available in numerous countries as immediate-release and extended-release tablets for the treatment of major psychiatric disorders, including bipolar disorder. Randomized, double-blind, placebo-controlled trials with quetiapine have demonstrated its efficacy in bipolar I and II disorders, and the drug has been generally well tolerated in clinical trials. Three cost-effectiveness analyses of maintenance therapy in bipolar I disorder, which used similar Markov models and incorporated data from key clinical trials and a number of other sources, showed that quetiapine, as adjunctive therapy with mood stabilizers (lithium or divalproex), was a cost-effective treatment option from the healthcare payer perspective in the UK and the US. Quetiapine either dominated comparators (typically mood stabilizers alone) or was associated with incremental cost-effectiveness ratios that were usually well below widely accepted thresholds of cost effectiveness. One of the studies evaluated extended-release quetiapine, although clinical efficacy data used in the Markov model were for the immediate-release formulation. In another analysis, which used a discrete-event simulation model and was conducted from the perspective of the UK healthcare payer, quetiapine monotherapy was cost effective compared with olanzapine monotherapy as maintenance treatment for all phases of bipolar I or II disorder. In this model, favourable results were also shown for quetiapine (with or without mood stabilizers) compared with a wide range of maintenance therapy regimens. Another modelled analysis conducted from the UK healthcare payer perspective showed that quetiapine was dominated by haloperidol in the short-term treatment of a manic episode in patients with bipolar I disorder. Both favourable and unfavourable results have been reported in cost analyses of quetiapine in bipolar disorder (type I or type not specified). Possible explanations for some of the variability in results of the pharmacoeconomic analyses include heterogeneity among the models in terms of input parameters or assumptions in the base-case analyses, country- or region-specific differences in estimates of healthcare resource use and associated costs, variability in treatment alternatives, and differences in the year of costing and discounting used in the analyses. In addition, some of the studies had short time horizons and focused on acute manic episodes only, whereas others were longer-term analyses that considered the full spectrum of health states in patients with bipolar disorder. Various limitations of the studies have been recognized, and results from one country may not be applicable to other countries. In conclusion, results of available pharmacoeconomic analyses provide evidence of the cost effectiveness of quetiapine as an adjunct to mood stabilizers for maintenance therapy in (primarily type I) bipolar disorder from a healthcare payer perspective in the UK and the US. Some evidence is available to support the cost effectiveness of quetiapine monotherapy or the use of extended-release quetiapine as adjunctive therapy with mood stabilizers in this setting, although further analyses appear to be warranted. Whether these findings apply to other geographical regions requires further study. Evidence for the long-term (>2-year) cost effectiveness of quetiapine in bipolar disorder is currently limited and further studies are also needed to address the cost effectiveness of quetiapine from a societal perspective and in bipolar II disorder.     

Docetaxel. A pharmacoeconomic review of its use in the treatment of metastatic breast cancer.

Advanced breast cancer has a poor prognosis (median duration of survival about 2 years); thus, treatment options are largely palliative. Recent studies with the taxoids docetaxel and paclitaxel suggest that these agents are effective second-line therapy in patients with metastatic breast cancer. Objective response rates range from 30 to 57% with docetaxel monotherapy in clinical trials in patients with advanced disease who had failed to respond to previous therapy, and the median time to disease progression ranges from 17 to 20 weeks. Currently available pharmacoeconomic data relating to docetaxel in the treatment of women with metastatic breast cancer include a cost-minimisation study and 3 cost-utility studies which relate to the UK, French and US healthcare systems. All analyses compared docetaxel with paclitaxel. Since no direct clinical comparisons of these 2 agents have been performed, model assumptions were based on available, rather than comparative, clinical data. The French model also considered vinorelbine monotherapy as a comparator. Considering direct costs only, costs associated with docetaxel ranged from < 0.3% less to 13% more than those of paclitaxel. When utilities were evaluated, docetaxel was associated with incremental gains versus paclitaxel of 33 and 75 additional days of quality-adjusted health in the UK and US studies, respectively, and 22 additional days of quality-adjusted progression-free survival (QPFS) in the French analysis. Thus, the incremental cost utility of docetaxel versus paclitaxel was an estimated Pounds 2431 per quality-adjusted life-year (QALY) in the UK analysis (1994 values) and US$8615 per QALY in the US analysis (1997 values). The French model found that docetaxel cost 700 French francs less for the extra days of QPFS (1993 costs). CONCLUSIONS: Cost-utility analyses, compiled in the absence of direct comparative data, show that docetaxel offers utility gains versus paclitaxel in the treatment of metastatic breast cancer. The incremental cost for these gains is within the accepted range for healthcare interventions.     

Paclitaxel: a pharmacoeconomic review of its use in the treatment of ovarian cancer.

Paclitaxel belongs to the group of antitumour agents called the taxanes. Its efficacy in advanced ovarian cancer has been established in large, randomised phase III clinical trials. When used in combination with cisplatin for first-line treatment of advanced ovarian cancer, it is superior to cyclophosphamide/cisplatin, with gains in median survival of around 1 year. Paclitaxel plus carboplatin has similar efficacy to paclitaxel plus cisplatin. There is now consensus that paclitaxel plus either carboplatin or cisplatin is the recommended first-line therapy for patients with advanced ovarian cancer. The particular combination employed may vary between institutions and geographical regions, although paclitaxel plus carboplatin is generally better tolerated (i.e. lower incidence of non-haematological adverse events) than paclitaxel plus cisplatin and is widely used in many countries. Paclitaxel is also used as monotherapy in second-line (salvage) treatment of ovarian cancer. Pharmacoeconomic analyses performed to date have primarily focused on first-line therapy comparing the combination of paclitaxel/cisplatin with cyclophosphamide/cisplatin. All studies incorporated clinical outcomes data, most commonly from the Gynecologic Oncology Group (GOG) 111 trial, showing a survival advantage for paclitaxel/cisplatin. These studies report incremental cost-effectiveness ratios (ICERs) ranging from $US 6395 per additional life-year gained (LYG) in Spain (1995/96 values) to $US 44,690 per additional progression-free LYG in France (year of costs not reported). Five studies were based in the US and Canada and these reported very similar ICERs of $US 13,135 (year of costs not reported) to $US 25,131 (1993 costs) per additional LYG. In all of these studies the incremental costs of paclitaxel/cisplatin therapy fall well within the commonly cited threshold limit of $US 50,000 for new therapies and compare well with incremental costs reported for other oncological and life-saving therapies. Patient preferences and quality of life are important issues due to the short survival of patients with advanced ovarian cancer. Two cost-utility studies reported similar incremental cost-utility ratios (ICURs). In the study based on US costs, the ICUR of paclitaxel/cisplatin treatment was US $18,200 per additional quality-adjusted life-year (QALY) [1995 drug costs]. In a Canadian study the ICUR ranged from 11,600 Canadian dollars ($Can) to $Can 24,200 (1996 costs) per additional progression-free QALY depending on the choice of second-line treatment. CONCLUSIONS: Paclitaxel used in combination with cisplatin offers survival and utility gains versus cyclophosphamide plus cisplatin, when used as first-line treatment in patients with stage III or IV ovarian cancer. The incremental cost for these gains is within the accepted range for healthcare interventions. However, pharmacoeconomic analyses of paclitaxel plus carboplatin--a combination widely accepted for use in women with advanced ovarian cancer and with clinical advantages over paclitaxel plus cisplatin in terms of ease of administration and tolerability profile--are currently lacking. Nevertheless, results of available pharmacoeconomic data support the clinical use of paclitaxel/platinum combinations, particularly paclitaxel plus cisplatin, as a first-line chemotherapy treatment option in patients with advanced ovarian cancer.     

Infliximab: a pharmacoeconomic review of its use in rheumatoid arthritis

Infliximab (Remicade), a biological disease-modifying antirheumatic drug (DMARD), binds to and inhibits the activity of tumour necrosis factor-alpha, which is thought to play an important role in the pathophysiology of rheumatoid arthritis. Intravenous infliximab plus methotrexate is recommended in patients with rheumatoid arthritis who have not achieved satisfactory disease control with adequate courses of other DMARDs. Pharmacoeconomic analyses have been based on efficacy data from the pivotal placebo-controlled Anti-Tumour Necrosis Factor Trial in Rheumatoid Arthritis with Concomitant Therapy (ATTRACT) trial in patients with active, refractory rheumatoid arthritis. Infliximab every 8 weeks plus methotrexate demonstrated rapid and sustainable improvements in clinical response, delayed radiographic progression, and/or improved functional status and health-related QOL compared with placebo plus methotrexate at weeks 30, 54 and 102. In cost-utility analyses of infliximab plus methotrexate conducted from a healthcare payer and/or societal perspective in the US, Europe, Portugal, Sweden and the UK, infliximab 3 mg/kg every 8 weeks plus methotrexate was associated with acceptable (<$US50,000 per discounted QALY gained) cost-utility ratios relative to methotrexate alone in patients with active, refractory rheumatoid arthritis. When only direct costs were considered, the lifetime incremental cost per discounted QALY gained with infliximab plus methotrexate relative to methotrexate alone was $US30,500-38,700 (year of costing 1998 or not reported; treatment duration 54 or 102 weeks or lifelong) in the US and Europe analyses, and euro39 500 (year of costing not reported; lifelong treatment) in the Portuguese analysis. The cost-utility ratios were more favourable when lost productivity costs or the additional benefit of infliximab on radiographic stabilisation were considered. In the Swedish and UK analyses with a 10-year time horizon, infliximab plus methotrexate for 1 or 2 years was associated with cost-utility ratios of euro28 600-56 100 (year of costing not reported) when direct costs were considered, and euro3440-48 200 when direct costs plus loss-of-productivity costs were considered. In conclusion, cost-utility analyses, which were based on modelling of data from the pivotal clinical trial of infliximab plus methotrexate, indicate that infliximab plus methotrexate is associated with acceptable cost-effectiveness ratios (<$US50,000 per discounted QALY gained) relative to methotrexate monotherapy in patients with active rheumatoid arthritis who have not responded to previous methotrexate or other DMARD therapy. The cost effectiveness of infliximab versus other DMARDs is at present unclear, but will be clarified when appropriate data from directly comparative clinical and/or pharmacoeconomic studies become available. In patients in whom adequate courses of other DMARDs have failed to achieve satisfactory disease control, infliximab plus methotrexate may prevent or delay disability, which may produce reductions in nondrug costs that can help offset its acquisition cost.     

Etanercept: a pharmacoeconomic review of its use in rheumatoid arthritis

Etanercept (Enbrel), which inhibits the activity of tumour necrosis factor-alpha, is indicated in the treatment of patients with active rheumatoid arthritis (RA). A lifetime cost-utility analysis in patients with severe disease-modifying antirheumatic drug (DMARD)-resistant RA in the UK suggested that etanercept is associated with acceptable cost-utility ratios relative to traditional nonbiological DMARDs. In a 12-month cost-utility study in Spain, etanercept was predicted to be dominant over infliximab plus methotrexate in patients with active, refractory RA with regards to the cost per QALY gained and cost per American College of Rheumatology (ACR) 20 response achieved. In short-term cost-effectiveness analyses conducted in the US, the cost effectiveness of etanercept relative to other treatments in patients with methotrexate-naive or -resistant RA depends on whether predicted incremental cost-effectiveness ratios of at least USD 41,900 per ACR 20 response or USD 34,800 per ACR 70 weighted response over a 6-month period are considered acceptable (1999 values). The relative efficacy and cost effectiveness of etanercept and other biological DMARDs will be clarified when appropriate data from directly comparative clinical and/or long-term pharmacoeconomic studies become available. Etanercept may prevent or delay disability, which may produce reductions in nondrug costs that could help offset its acquisition cost.     

Adjuvant use of aromatase inhibitors in postmenopausal women with breast cancer.

PURPOSE: Emerging data from clinical trials on the use of aromatase inhibitors in the management of early-stage, hormone-dependent breast cancer in postmenopausal women are reviewed. SUMMARY: Aromatase is the enzyme responsible for the conversion of androgens to estrogens and the only source of estrogens in postmenopausal women. Clinical trials using aromatase inhibitors in the adjuvant treatment of postmenopausal women with breast cancer are few but significant because of their comparative design with tamoxifen given for five years, long regarded as the gold standard for breast cancer treatment. Data from the Anastrozole, Tamoxifen and Combination trial, the MA-17 trial (letrozole compared with placebo), the Italian Tamoxifen Arimidex trial (anastrozole following tamoxifen), and the Intergroup Exemestane Study have shown promising efficacy and safety in the use of these agents. While the optimal aromatase inhibitor for use in the adjuvant setting has not been elucidated, current evidence-based recommendations include using (1) anastrozole as the first adjuvant therapy for five years, (2) tamoxifen for two to three years, then exemestane or anastrozole for the remainder of the five years, and (3) tamoxifen for five years, then letrozole for another five years. CONCLUSION: While their impact on survival has not been determined, aromatase inhibitors are slowly changing the management of early-stage, hormone-dependent breast cancer in postmenopausal women because of improved disease-free survival rates. Their ultimate role in therapy is unknown, but educating patients about the potential risks and benefits will allow them to make informed decisions regarding these data and their breast cancer care.     

Galantamine: a pharmacoeconomic review of its use in Alzheimer's disease

Galantamine is one of several orally administered cholinesterase inhibitors that improve cognition in patients with mild to moderate Alzheimer's disease. Compared with placebo, galantamine 16 or 24 mg/day improved cognition and activities of daily living, delayed emergence of behavioural symptoms and reduced caregiver burden in three pivotal randomised studies of 5 or 6 months' duration. Galantamine may reduce the considerable economic burden of Alzheimer's disease by delaying the need for full-time care (FTC) in patients with mild to moderate Alzheimer's disease. In pharmacoeconomic analyses with a time horizon of 10 years conducted in Canada, Sweden, The Netherlands and the US, data from the pivotal trials were incorporated into a model to examine economic implications associated with galantamine treatment. FTC was defined in the model as the consistent requirement for caregiving and supervision for the greater part of each day regardless of the location of care and the identity of caregiver. When the effect of galantamine 16 or 24 mg/day was analysed from the perspective of a comprehensive healthcare payer, treatment was associated with cost savings (inclusive of drug costs) relative to no treatment, regardless of country for which the model was customised. Cost savings resulted from the delay in the time until FTC was required in patients with mild to moderate disease. In sensitivity analyses, cost savings were most sensitive to the cost of institutional care. In the analyses that considered the effect of galantamine 24 mg/day solely on cognition, galantamine was predicted to reduce the time FTC was required by approximately 10% in patients with mild to moderate Alzheimer's disease compared with no pharmacological treatment. Greater reductions in the time that FTC was required were predicted when the effects of galantamine 16 or 24 mg/day on behavioural symptoms in addition to cognition were considered in the US analysis or in sensitivity analyses in studies in other countries. In conclusion, pharmacoeconomic analyses, which were based on modelling of data from pivotal clinical trials with galantamine and included drug costs, indicate that galantamine treatment may result in cost savings from a healthcare payer perspective. The effects of galantamine on cognition and behavioural symptoms in patients with mild to moderate Alzheimer's disease are predicted to delay the need for FTC, which may result in cost savings. From a societal perspective, the caregiver burden of caring for a patient with Alzheimer's disease in the community may be decreased and the time that patients have without severe disease may be prolonged.