Andrea Takeda

Pegaptanib and ranibizumab for neovascular age-related macular degeneration: a systematic review

Aims: To assess the clinical effectiveness of pegaptanib sodium and ranibizumab for neovascular age-related macular degeneration (AMD). Methods: A systematic review of randomised controlled trials (RCTs) identified through searching 12 electronic databases, bibliographies and consultation with experts and manufacturers. RCTs were eligible if they assessed the effects of pegaptanib or ranibizumab with best supportive care, sham injection or photodynamic therapy (PDT) on patients with subfoveal choroidal neovascularisation associated with wet AMD and examined outcomes including visual acuity and adverse events. Results: Three RCTs of ranibizumab (MARINA, ANCHOR, FOCUS) and two of pegaptanib (VISION study) met the inclusion criteria. The RCTs included patients with different lesion types. The studies showed statistically significant benefit on different measures of visual acuity for patients receiving pegaptanib, ranibizumab or ranibizumab with PDT compared to control (sham injection, PDT or sham injection with PDT) after 12 months. These differences appeared to be clinically significant. Although adverse events were common among those receiving pegaptanib or ranibizumab, they were considered mild to moderate in nature. Meta-analysis of ranibizumab trials and indirect comparison of the two drugs were not possible due to differences in the study populations’ lesion types. However, results from the RCTs of ranibizumab tended to show a greater effect on visual acuity than results from the RCT of pegaptanib. Conclusions: Pegaptanib and ranibizumab appear to slow or stop the progression of neovascular AMD. Uncertainty remains over the relative benefits of pegaptanib compared with ranibizumab and other unlicensed drugs (eg, Avastin), due to the nature of the evidence. Head-to-head RCTs and economic evaluations comparing these alternatives are needed.

The Effectiveness of Interventions to Treat Severe Acute Malnutrition in Young Children: A Systematic Review

BACKGROUND Severe acute malnutrition (SAM) arises as a consequence of a sudden period of food shortage and is associated with loss of a persons body fat and wasting of their skeletal muscle. Many of those affected are already undernourished and are often susceptible to disease. Infants and young children are the most vulnerable as they require extra nutrition for growth and development, have comparatively limited energy reserves and depend on others. Undernutrition can have drastic and wide-ranging consequences for the childs development and survival in the short and long term. Despite efforts made to treat SAM through different interventions and programmes, it continues to cause unacceptably high levels of mortality and morbidity. Uncertainty remains as to the most effective methods to treat severe acute malnutrition in young children. OBJECTIVES To evaluate the effectiveness of interventions to treat infants and children aged < 5 years who have SAM. DATA SOURCES Eight databases (MEDLINE, EMBASE, MEDLINE In-Process & Other Non-Indexed Citations, CAB Abstracts Ovid, Bioline, Centre for Reviews and Dissemination, EconLit EBSCO and The Cochrane Library) were searched to 2010. Bibliographies of included articles and grey literature sources were also searched. The project expert advisory group was asked to identify additional published and unpublished references. REVIEW METHODS Prior to the systematic review, a Delphi process involving international experts prioritised the research questions. Searches were conducted and two reviewers independently screened titles and abstracts for eligibility. Inclusion criteria were applied to the full texts of retrieved papers by one reviewer and checked independently by a second. Included studies were mapped to the research questions. Data extraction and quality assessment were undertaken by one reviewer and checked by a second reviewer. Differences in opinion were resolved through discussion at each stage. Studies were synthesised through a narrative review with tabulation of the results. RESULTS A total of 8954 records were screened, 224 full-text articles were retrieved, and 74 articles (describing 68 studies) met the inclusion criteria and were mapped. No evidence focused on treatment of children with SAM who were human immunodeficiency virus sero-positive, and no good-quality or adequately reported studies assessed treatments for SAM among infants < 6 months old. One randomised controlled trial investigated fluid resuscitation solutions for shock, with none adequately treating shock. Children with acute diarrhoea benefited from the use of hypo-osmolar oral rehydration solution (H-ORS) compared with the standard World Health Organization-oral rehydration solution (WHO-ORS). WHO-ORS was not significantly different from rehydration solution for malnutrition (ReSoMal), but the safety of ReSoMal was uncertain. A rice-based ORS was more beneficial than glucose-based ORSs, and provision of zinc plus a WHO-ORS had a favourable impact on diarrhoea and need for ORS. Comparisons of different diets in children with persistent diarrhoea produced conflicting findings. For treating infection, comparison of amoxicillin with ceftriaxone during inpatient therapy, and routine provision of antibiotics for 7 days versus no antibiotics during outpatient therapy of uncomplicated SAM, found that neither had a significant effect on recovery at the end of follow-up. No evidence mapped to the next three questions on factors that affect sustainability of programmes, long-term survival and readmission rates, the clinical effectiveness of management strategies for treating children with comorbidities such as tuberculosis and Helicobacter pylori infection and the factors that limit the full implementation of treatment programmes. Comparison of treatment for SAM in different settings showed that children receiving inpatient care appear to do as well as those in ambulatory or home settings on anthropometric measures and response time to treatment. Longer-term follow-up showed limited differences between the different settings. The majority of evidence on methods for correcting micronutrient deficiencies considered zinc supplements; however, trials were heterogeneous and a firm conclusion about zinc was not reached. There was limited evidence on either supplementary potassium or nicotinic acid (each produced some benefits), and nucleotides (not associated with benefits). Evidence was identified for four of the five remaining questions, but not assessed because of resource limitation. LIMITATIONS The systematic review focused on key questions prioritised through a Delphi study and, as a consequence, did not encompass all elements in the management of SAM. In focusing on evidence from controlled studies with the most rigorous designs that were published in the English language, the systematic review may have excluded other forms of evidence. The systematic review identified several limitations in the evidence base for assessing the effectiveness of interventions for treating young children with severe acute malnutrition, including a lack of studies assessing the different interventions; limited details of study methods used; short follow-up post intervention or discharge; and heterogeneity in participants, interventions, settings, and outcome measures affecting generalisability. CONCLUSIONS For many of the most highly ranked questions evidence was lacking or inconclusive. More research is needed on a range of topic areas concerning the treatment of infants and children with SAM. Further research is required on most aspects of the management of SAM in children < 5 years, including intravenous resuscitation regimens for shock, management of subgroups (e.g. infants < 6 months old, infants and children with SAM who are human immunodeficiency virus sero-positive) and on the use of antibiotics.

Modelling the Cost Effectiveness of Cholinesterase Inhibitors in the Management of Mild to Moderately Severe Alzheimer's Disease

AbstractObjective: To estimate the cost effectiveness (from the UK NHS and personal social services perspective) of the cholinesterase inhibitors donepezil, rivastigmine and galantamine compared with usual care in the treatment of mild to moderately severe Alzheimer’s disease. Patients had a mean age of 74 years, a mean disease duration of 1 year and a mean Alzheimer’s disease assessment scale-cognitive subscale score of 24. Methods: A pharmacoeconomic model was used to predict long-term outcomes over a 5-year time horizon and to estimate the cost effectiveness of cholinesterase inhibitors for the management of Alzheimer’s disease. The model structure is informed by a systematic review of the literature on the clinical and cost effectiveness of cholinesterase inhibitors and a review of the literature on the costs and outcomes associated with treatment for Alzheimer’s disease. The main outcome measure used was the cost per quality-adjusted life-year (QALY) gained. All healthcare costs (excluding cholinesterase inhibitor costs) were indexed to £ (2003 values). Drug costs are 2005 values. Multivariate probabilistic sensitivity analysis and scenario analysis were undertaken to assess uncertainty in the results. Results: The clinical benefits on cognition from treatment with cholinesterase inhibitors resulted in an incremental cost per QALY gained ranging from £53 780 to £74 735, over 5 years (vs usual care). Uncertainty analysis suggests that the probability of any of these treatments having an incremental cost per QALY of <£30 000 is <21%. The key determinants of cost effectiveness were the effectiveness of treatment, the mean treatment cost and the cost savings associated with an expected delay in disease progression. Conclusions: Results presented in this paper suggest that the use of cholinesterase inhibitors may not be a cost-effective use of NHS resources. Guidance from the National Institute for Health and Clinical Effectiveness (NICE) in the UK on their judgements surrounding the acceptability of technologies as an effective use of resources, indicates there would need to be special reasons for accepting cholinesterase inhibitors as a cost-effective use of NHS resources.

Bortezomib for the treatment of multiple myeloma patients.

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of bortezomib for the treatment of multiple myeloma patients at first relapse and beyond, in accordance with the licensed indication, based upon the evidence submission from Ortho Biotech to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The outcomes stated in the manufacturers definition of the decision problem were time to disease progression, response rate, survival and quality of life. The literature searches for clinical and cost-effectiveness studies were adequate and the one randomised controlled trial (RCT) included was of reasonable quality. Results from the RCT suggest that bortezomib increases survival and time to disease progression compared with high-dose dexamethasone (HDD) in multiple myeloma patients who have had a relapse after one to three treatments. Cost-effectiveness analysis based on the same trial and an observational study was reasonable and gave an estimated cost per life-year gained of 30,750 pounds, which ranged from 27,957 pounds to 36,747 pounds on sensitivity analysis. An attempt was made to replicate the results of the manufacturers model and to compare the results to the Kaplan-Meier survival curve presented in the manufacturers submission. In addition, a one-way sensitivity analysis and a probabilistic sensitivity analysis were undertaken, as well as additional scenario analyses. Based on these analyses the ERG suggests that the cost-effectiveness results presented in the manufacturers submission may underestimate the cost per life-year gained for bortezomib therapy (versus high-dose dexamethasone) when potential UK practice and scenarios are considered. The guidance issued by NICE in June 2006 as a result of the STA states that bortezomib monotherapy for the treatment of relapsed multiple myeloma is clinically effective compared with HDD but has not been shown to be cost-effective and is not recommended for the treatment of progressive multiple myeloma in patients who have received at least one previous therapy and who have undergone, or are unsuitable for, bone marrow transplantation.

Ustekinumab for the treatment of moderate to severe psoriasis.

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of ustekinumab for the treatment of moderate to severe psoriasis based upon a review of the manufacturers submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The submissions main evidence came from three randomised controlled trials (RCTs), of reasonable methodological quality and measuring a range of clinically relevant outcomes. Higher proportions of participants treated with ustekinumab (45 mg and 90 mg) than with placebo or etanercept achieved an improvement on the Psoriasis Area and Severity Index (PASI) of at least 75% (PASI 75) after 12 weeks. There were also statistically significant differences in favour of ustekinumab over placebo for PASI 50 and PASI 90 results, and for ustekinumab over etanercept for PASI 90 results. A weight-based subgroup dosing analysis for each trial was presented, but the methodology was poorly described and no statistical analysis to support the chosen weight threshold was presented. The manufacturer carried out a mixed treatment comparison (MTC); however, the appropriateness of some of the methodological aspects of the MTC is uncertain. The incidence of adverse events was similar between groups at 12 weeks and withdrawals due to adverse events were low and less frequent in the ustekinumab than in the placebo or etanercept groups; however, statistical comparisons were not reported. The manufacturers economic model of treatments for psoriasis compared ustekinumab with other biological therapies. The model used a reasonable approach; however, it is not clear whether the clinical effectiveness estimates from the subgroup analysis, used in the base-case analysis, were methodologically appropriate. The base-case incremental cost-effectiveness ratio for ustekinumab versus supportive care was 29,587 pounds per quality-adjusted life-year (QALY). In one-way sensitivity analysis the model was most sensitive to the number of hospital days associated with supportive care, the cost estimate for intermittent etanercept 25 mg and the utility scores used. In the ERGs scenario analysis the model was most sensitive to the price of ustekinumab 90 mg, the proportion of patients with baseline weight > 100 kg and the relative risk of intermittent versus continuous etanercept 25 mg. In the ERGs probabilistic sensitivity analysis ustekinumab had the highest probability of being cost-effective at conventional NICE thresholds, assuming the same price for the 45-mg and 90-mg doses; however, doubling the price of ustekinumab 90 mg resulted in ustekinumab no longer dominating the comparators. In conclusion, the clinical effectiveness and cost-effectiveness of ustekinumab in relation to other drugs in this class is uncertain. Provisional NICE guidance issued as a result of the STA states that ustekinumab is recommended as a treatment option for adults with plaque psoriasis when a number of criteria are met. Final guidance is anticipated in September 2009.

A systematic review and economic evaluation of adefovir dipivoxil and pegylated interferon-alpha-2a for the treatment of chronic hepatitis B

Summary.  Standard treatments for chronic hepatitis B (CHB) include interferon‐alpha (IFN‐α) and lamivudine (LAM), but these are associated with adverse effects and viral resistance, respectively. The aim of this systematic review and economic evaluation was to assess the clinical effectiveness and cost‐effectiveness of two alternative drugs for the treatment of adults with CHB: adefovir dipivoxil (ADV) and pegylated IFN‐α‐2a. We searched electronic databases, including Cochrane Systematic Reviews and Medline, for literature that met criteria defined in a research protocol. Retrieved articles were independently assessed for inclusion by two reviewers. We developed a Markov state transition model to estimate the cost‐effectiveness (cost‐utility) of pegylated IFN‐α‐2a and of ADV compared with nonpegylated IFN‐α‐2a, LAM and best supportive care. Seven randomized controlled trials and two systematic reviews met the inclusion criteria for our review of clinical effectiveness. ADV was significantly more effective than placebo or ongoing LAM in reducing levels of hepatitis B virus (HBV) DNA. Rates of hepatitis B e antigen (HBeAg) seroconversion were higher among patients receiving ADV than either placebo or ongoing LAM. Patients treated with pegylated IFN‐α‐2a, either as monotherapy or in combination with LAM, showed significantly reduced HBV DNA levels compared with patients treated with LAM monotherapy. HBeAg seroconversion rates at follow‐up were significantly higher for pegylated IFN‐α‐2a patients than for those receiving LAM monotherapy. Results of our cost‐effectiveness analysis demonstrate that incremental costs per quality adjusted life year (QALY) for a range of comparisons were between £5994 and £16 569, and within the range considered by NHS decision‐makers to represent good value for money.

Gemcitabine for the treatment of metastatic breast cancer.

This paper presents a summary of the evidence review group (ERG) report into the evidence for the clinical effectiveness and cost-effectiveness of gemcitabine with paclitaxel for the first-line treatment of metastatic breast cancer (MBC) in patients who have already received chemotherapy treatment with an anthracycline, compared with current standard of care, based upon the manufacturers submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The clinical evidence for gemcitabine as a treatment for MBC comes from the unpublished JHQG trial (some data commercial-in-confidence): overall survival was 3 months longer for the gemcitabine/paclitaxel arm (18.5 months) than for the paclitaxel arm (15.8 months) (p = 0.0489); gemcitabine/paclitaxel also improved tumour response and time to documented progression of disease compared with paclitaxel monotherapy, but haematological serious adverse events were more common. In the absence of any formal methods of indirect comparison there is insufficient robust evidence to compare the relative effectiveness of gemcitabine/paclitaxel with docetaxel monotherapy or docetaxel/capecitabine combination therapy. The manufacturers used a Markov state transition model to estimate the effect of treatment with five different chemotherapy regimes, adopting a 3-year time horizon with docetaxel monotherapy as the comparator. Health state utilities for different stages of disease progression and for patients experiencing treatment-related toxicity are used to derive quality-adjusted life expectancy with each treatment. The base-case cost-effectiveness estimate for gemcitabine/paclitaxel versus docetaxel is 17,168 pounds per quality-adjusted life-year (QALY). When longer survival with docetaxel is assumed in a sensitivity analysis, the incremental cost-effectiveness ratio (ICER) is 30,000 pounds per QALY. Probabilistic sensitivity analysis estimates a 70% probability of gemcitabine/paclitaxel being cost-effective relative to docetaxel at a willingness-to-pay threshold of 35,000 pounds. There is considerable uncertainty over the results because of the lack of formal quality assessment or assessment of the comparability of the 15 trials included in the input data, and the questionable validity of the indirect comparison method adopted. An illustrative analysis using a different method for indirect comparison carried out by the ERG produces an ICER of 45,811 pounds per QALY for gemcitabine/paclitaxel versus docetaxel. The guidance issued by NICE in November 2006 as a result of the STA states that gemcitabine in combination with paclitaxel, within its licensed indication, is recommended as an option for the treatment of MBC only when docetaxel monotherapy or docetaxel plus capecitabine is also considered appropriate.

Parallel numerical modelling of the antarctic ice sheet

The Antarctic Ice Sheet comprises the West Antarctic Ice Sheet and the much larger East Antarctic Ice Sheet. Fast flowing ice streams and outlet glaciers are important dynamic components of the ice sheet system, and a grid resolution of at least 20 km is required to identify many of these areas. Previous fine resolution numerical models have focussed on ice flow in West Antarctica or on fine resolution modelling of subsections of the ice sheet, since the size of East Antarctica has generally precluded studies of the whole ice sheet at a resolution adequate to identify complex flow features.The equations describing ice flow are highly non-linear, making this a computationally intensive problem. We use a staggered grid for calculation of ice diffusivity to overcome numerical instability, and a sparse packing scheme to take account of the irregular boundary of Antarctica. We have developed an efficient parallel temperature-dependent ice flow model of the entire grounded portion of the Antarctic Ice Sheet at a resolution of 20 km. The model was primarily written to run on a commodity cluster of workstations, and performance results for this and other systems are presented. Ice flow patterns at steady state compare well with recently published balance velocity calculations.

Evaluation of the cost-effectiveness of drotrecogin alfa (activated) for the treatment of severe sepsis in the United Kingdom

OBJECTIVES The aim of this study was to assess the cost-effectiveness of drotrecogin alfa (activated) compared with best supportive care in a UK cohort of adult intensive-care patients with severe sepsis. METHODS A systematic review of evidence on the clinical- and cost-effectiveness of drotrecogin alfa (activated) was undertaken, and a decision-analytic model was developed to estimate the cost-effectiveness of treatment in the United Kingdom. Trial data from the Recombinant Human Activated Protein C Worldwide Evaluation in Severe Sepsis (PROWESS) study have been synthesized with other data, including UK data on severe sepsis, to estimate the costs and consequences of treatment over time. RESULTS For patients with severe sepsis and multiple organ dysfunction, the estimates of cost per life year and cost per quality-adjusted life year (QALY) are pounds 4931 and pounds 8228, respectively. For patients with severe sepsis alone, the cost per life-year and cost per QALY are pouhds 5495 and pounds 9161, respectively. CONCLUSIONS Whereas the therapeutic cost for drotrecogin alfa (activated) appears high (at around pounds 5000 per patient) and the potential impact on the provider budget is considerable, drotrecogin alfa (activated) is clinically effective, represents a cost-effective use of resources, and is a significant advance in the treatment of severe sepsis in patients requiring intensive care.

A systematic review of the clinical and cost-effectiveness of memantine in patients with moderately severe to severe Alzheimer's disease.

Alzheimer’s disease (AD) is the most common form of dementia and is characterised by a worsening of cognition, functional ability, and behaviour and mood. The objective of this study was to review the clinical and cost-effectiveness of memantine for the treatment of patients with moderately severe to severe AD. To achieve this, a systematic search and review of the clinical and cost effectiveness literature for memantine was undertaken. The literature search covered the period from the inception of MEDLINE, Cochrane Library, EMBASE and other electronic databases until July 2004. The search included randomised controlled trials (RCTs) and full economic evaluations that assessed the use of memantine in patients with moderately severe to severe AD.Two published RCTs were included in this review; in one of these trials the participants were already being treated with donepezil. The two RCTs showed benefit for patients receiving memantine compared with placebo on the outcome measures of the Alzheimer’s Disease Cooperative Study Activities of Daily Living Inventory modified for severe dementia, the Clinician’s Interview-Based Impression of Change Plus Caregiver Input, and the Severe Impairment Battery, and that memantine appeared to be slightly more effective in patients already receiving a stable dose of donepezil. Five cost-effectiveness studies were included in the review. Although these studies reported cost reductions and improved outcomes with memantine, the evaluations were based on a number of assumptions.In conclusion, memantine appears to be beneficial when assessed using functional and global measurements. However, the effect of memantine on cognitive scores and behaviour and mood outcomes is less clear. Cost-effectiveness is dependent upon assumptions surrounding clinical effect and context-specific cost data.