PharmacoEconomics & Outcomes News 394 - 11 Jan 2003 1

PharmacoEconomics & Outcomes News 11 Jan 2003 No. 3941173-5503/10/0394-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved

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Anti-infectives news from the 5th Annual European ISPOR CongressTheeconomic impact of anti-infective agents was the focus of several studies presented at the 5th Annual EuropeanCongress of the International Society for Pharmacoeconomics and Outcomes Research (ISPOR). This report highlightsa selection of these studies.

Lamivudine potentially cost saving in ChinaLamivudine has the potential to provide cost savings following one year of treatment for patients with chronic

hepatitis B infection, say researchers from Fudan University Department of Health Economic Institute and ShanghaiInfectious Hospital, China, and GlaxoSmithKline Pharmaceuticals.1 This is particularly of interest as the burden ofhepatitis B infection and its complications is high in China, with treatment accounting for 160% of per-capita annualincome.

The researchers conducted interviews with 1396 Asian patients with chronic hepatitis B infection at secondary andtertiary hospitals in Shanghai.* Direct medical costs were calculated based on mean patient expenses for eachoutpatient visit and hospitalisation, and rates of outpatient care and hospitalisation facility use and the intensity ofmedical services use. Expenses associated with health products, nutrition and transportation comprised the directnonmedical costs, while mean indirect economic loss per patient-year was assessed in terms of average work-days lostfor patients and family members (2000 values). The total per-patient annual cost associated with hepatitis B in Chinawas estimated at $US2368 in year 1. Direct medical costs accounted for $US1463, indirect costs for $US787 and directnonmedical costs for $US118.

The researchers used clinical data from an Asian multicentre study and three international multicentre studies toevaluate the potential cost savings of lamivudine [‘Heptodin’; GlaxoSmithKline] treatment for chronic hepatitis B inChina. The cost associated with lamivudine treatment was $US75 639 annually per 100 patients treated. In year 2,lamivudine would potentially lead to healthcare cost savings of $US80 759 per 100 patients treated, compared with notreatment, representing a cost saving of 106.8% per 100 patients, or healthcare cost offsets of 6.8% or $US51 perpatient, in year 2. The potential for cost savings was attributed to a reduction in the rate of progression to cirrhosis, notethe researchers. Among patients with Asian ethnicity and high serum ALT levels, the clinical benefits of lamivudinetreatment are "enhanced", they add.

Linezolid warranted for MRSA infectionsCurrently, an important consideration in Spanish hospitals is the prevalence of methicillin-resistant Staphylococcus

aureus (MRSA) infections, ranging from 20–30% at different centres and accounting for a substantial proportion ofhospital infections in the country. A second study presented at the meeting was conducted by a group of researchersfrom Spain,** and comprised an economic evaluation of linezolid versus teicoplanin for the treatment of Gram-positivebacterial infections, using a decision-analysis model based on resource-use data from a clinical trial and expertopinion.2 Therapeutic failures were assumed to be treated with linezolid in the teicoplanin arm and with quinupristin/dalfopristin in the linezolid arm. Linezolid recipients required fewer days of IV administration and fewer days inhospital than teicoplanin recipients (6 vs 9 and13 vs 14 days, respectively). Linezolid treatment resulted in a lower totalper-patient cost (5463 euros vs 5740 euros),† and greater effectiveness (95.5% vs 86.7% of patients cured) thanteicoplanin, leading to a lower cost-effectiveness ratio (5720 vs 6552 euros per successfully cured patient).

Sensitivity analysis showed that linezolid had a more favourable cost-effectiveness ratio than teicoplanin, even in theworst scenarios. Moreover, linezolid treatment would "also increase the Quality of Life of patients as it will permit themto finalize their treatment at home", given its 100% oral bioavailability, note the researchers. Linezolid would thereforebe a "recommended choice" for treating Gram-positive infections in a hospital setting, they conclude.

Linezolid vs vancomycin for MRSS infections in the USIn a third study, Dr Henry Glick from the University of Pennsylvania Health Systems, Philadelphia, US, and

colleagues compared costs among patients receiving linezolid or vancomycin for methicillin-resistant Staphylococcispecies (MRSS) infections‡ as part of a phase II, open-label, multinational clinical trial primarily assessing the safety andefficacy of linezolid compared with vancomycin.3 Patients with MRSS infections were randomised to receive IV or orallinezolid (n = 240) or oral vancomycin (220) for up to 4 weeks, with up to 4 weeks of post-treatment observation. Only254 of the 460 intent-to-treat patients were clinically evaluable.

"Several important imbalances" were observed between the treatment groups, "indicating greater severity of illnessamong linezolid patients", note the researchers. Compared with patients in the vancomycin group, patients in thelinezolid group were, on average, older, less likely to begin treatment on the general ward, had more past and currentcomorbid conditions, greater severity scores, and were more likely to have at least one severe sign or symptom.

Total mean and log costs were greater in the linezolid, than in the vancomycin, group ($US14 185 vs $US11 944 and$US8957 vs $US8794 per patient, respectively), although the between-group differences were not statisticallysignificant.†† A "substantial skewness of total costs" was suggested by the much lower between-group median costdifference compared with the mean cost difference ($US239 vs $US2241), say the researchers. Statistically confirmednon-normality of total costs was observed in each treatment group, while the log of total costs was "marginally non-normal", they note. Only study medication costs were found to be significantly higher for linezolid (+$US802) thanvancomycin upon examination of total cost components. However, this increase in costs was nearly equal to theestimated savings in hospital length-of-stay costs associated with linezolid, compared with vancomycin (–$US741).

In conclusion, the researchers note that, due to the "variability inherent in both costs themselves and the specificationused in analysis", they could not estimate the incremental cost of linezolid compared with vancomycin "with sufficientprecision to be of definitive use in decision-making".

Moxifloxacin for CAP cost effective for Spanish NHS

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1173-5503/10/0394-0002/$14.95 Adis © 2010 Springer International Publishing AG. All rights reservedPharmacoEconomics & Outcomes News 11 Jan 2003 No. 394

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Dr Michael Drummond from the University of York and Innovus Research (UK) Ltd, UK, and colleagues conducted acost-effectiveness analysis of moxifloxacin versus standard comparators in patients hospitalised with community-acquired pneumonia (CAP) from the perspective of the Spanish NHS.4

Patients were randomised to receive sequential IV/oral monotherapy with moxifloxacin 400mg once daily or IV/oralamoxicillin/clavulanic acid 1.2g IV/625mg oral with or without clarithromycin 500mg twice daily for 7–14 weeks. Costsand outcomes were evaluated over 21 days using clinical cure rates 5–7 days post-treatment, and resource dataobtained from the multinational, randomised open-label TARGET trial. Data from all centres were pooled for analysis asthe effect of treatment on resource use was similar across countries.

For all clinical measures (clinical success rates at test-of-cure and late follow-up visits, time to first return to apyrexia,and number of adverse events, serious adverse events and deaths), moxifloxacin was shown to be more effective thanthe comparator therapy. Moreover, compared with amoxicillin/clavulanic acid with or without clarithromycin,moxifloxacin resulted in per-patient savings of 281 euros to the Spanish NHS, "primarily due to a shorter length ofhospital stay", note the researchers [see table].‡‡ Despite the fact that between-group cost and efficacy differences "didnot reach traditional levels of significance", upon bootstrap analysis, the results suggested that "the probability of MXF[moxifloxacin] being cost saving was 90%", they add. The probability of moxifloxacin being cost effective relative to thecomparator therapy rose to 94% assuming a decision-makers’ willingness to pay up to 2000 euros per additionalpatient cured, the researchers state.

Table. Cost effectiveness of moxifloxacin vs amoxicillin/clavulanic acid ± clarithromycin in patients with CAPPer-patient costs and outcomes Amoxicillin/clavulanic acid ± Moxifloxacin

clarithromycin

Patients cured (%) 75.4 80.7Costs (euros):study medication 87 185hospitalisation 2472 2853outpatient carea 7 9Total costs to the Spanish NHS (euros) 2666 2947Incremental cost per additional patient cured . dominant b

(euros)a including those related to radiological procedures, therapeutic adjuncts, concomitant antimicrobials and other concomitant medicationsb less costly and more efficacious than alternative therapy

* The study was sponsored by GlaxoSmithKline, with which three of the researchers were affiliated.** Two of the researchers were affiliated with Pharmacia, S.A. Barcelona, Spain.† Costs were those related to drug acquisition, hospitalisation, administration, diagnostic tests and therapeutic failure, and were assessed from theperspective of the hospital assistance.‡ including bacteraemia or right-sided endocarditis, pneumonia, complicated skin and soft tissue infections and urinary tract infections†† Costs (2001 values) were those associated with antibacterials, hospitalisation, noninvestigational therapies and medications, and outpatientservice use, and were assessed from a societal perspective.‡‡ Costs included those related to radiological procedures, therapeutic adjuncts, concomitant antimicrobials and other concomitant medications.

1. Chen X, et al. Economic burden of chronic hepatitis B virus infection and potential cost savings with lamivudine. Value in Health 5: 567 (plus poster), Nov-Dec 2002.2. Grau S, et al. Cost-effectiveness analysis of linezolid versus teicoplanin in the treatment of infections caused by Gram-positive bacteria in Spain. Value in Health 5: 563

(plus poster) abstr. PIN6, No. 6, Nov-Dec 2002.3. Glick HA, et al. Comparing hospital costs between linezolid and vancomycin in the treatment of methicillin-resistant staphylococcal species infections: a randomized multi-

center clinical trial. Value in Health 5: 565-566 (plus poster), Nov-Dec 2002.4. Drummond M, et al. Economic evaluation demonstrates that moxifloxacin IV/PO monotherapy is cost-effective to the Spanish national healthcare system when compared to

IV/PO amoxicillin/clavulanate +- clarithromycin in the treatment of community-acquired pneumonia. Value in Health 5: 565 (plus poster) abstr. PIN10, No. 6, Nov-Dec2002.

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PharmacoEconomics & Outcomes News 11 Jan 2003 No. 3941173-5503/10/0394-0003/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved