The clinical effectiveness and cost-effectiveness of topotecan for small cell lung cancer: a systematic review and economic evaluation

Abstract

To assess the clinical effectiveness and cost-effectiveness of topotecan as second-line treatment for small cell lung cancer (SCLC). Bibliographic databases were searched from 1990 to February 2009, including the Cochrane library, MEDLINE (Ovid), EMBASE (Ovid), PREMEDLINE In-Process & Other Non-Indexed Citations. Bibliographies of related papers were assessed and experts were contacted to identify additional references and the manufacturer's submission to NICE was also searched. Two reviewers independently screened titles and abstracts for eligibility. Inclusion criteria were applied to the full text of retrieved papers using a standard form. For the clinical effectiveness review, the studies were randomised controlled trials (RCTs), which included adult participants with relapsed SCLC who responded to first-line treatment and for whom re-treatment with first-line therapy was inappropriate. The treatment was topotecan (oral or intravenous, i.v.) compared with one another, best supportive care (BSC) or other chemotherapy regimens. Outcomes included measures of response or disease progression and measures of survival. For the cost-effectiveness review studies were eligible for inclusion if they reported cost-effectiveness, cost-utility, cost-benefit or cost-consequence analyses. Data extraction and quality assessment of included studies was undertaken by one reviewer and checked by a second. Studies were synthesised through a narrative review with full tabulation of results. An independent economic model estimated the cost-effectiveness of topotecan (oral or i.v.) compared with BSC. The model used survival analysis methods to derive estimates of mean survival for patients treated with topotecan or receiving BSC alone. These were combined with quality of life (QoL) weights to derive estimates of mean quality-adjusted life expectancy for patients receiving BSC alone or topotecan plus BSC. Categories of costs included in the model included drug use, chemotherapy administration and on-treatment monitoring, management of adverse events, monitoring for disease progression and palliative care. A total of 434 references were identified of which five were included in the clinical effectiveness review. In these trials topotecan was compared with BSC, CAV [cyclophosphamide, Adriamycin (doxorubicin) and vincristine] or amrubicin, or oral topotecan was compared with i.v. topotecan. No economic evaluations were identified. There were no statistically significant differences between groups when i.v. topotecan was compared with either CAV or oral topotecan for overall response rate (ORR). Response rate was significantly better in participants receiving i.v. amrubicin than in those receiving a low dose of i.v. topotecan (38% versus 13%, respectively, p = 0.039). There was a statistically significant benefit in favour of oral topotecan compared with BSC (HR 0.61, 95% CI 0.43 to 0.87, p = 0.01). Drug acquisition costs for four cycles of treatment were estimated at 2550 pounds for oral topotecan and 5979 pounds for i.v. topotecan. Non-drug treatment costs accounted for an additional 1097 pounds for oral topotecan and 4289 pounds for i.v. topotecan. Total costs for the modelled time horizon of 5 years were 4854 pounds for BSC, 11,048 pounds for oral topotecan and between 16,914 pounds and 17,369 pounds for i.v. topotecan (depending on assumptions regarding time progression). Life expectancy was 0.4735, 0.7984 and 0.7784 years for BSC, oral topotecan and i.v. topotecan respectively. Total quality-adjusted life-years (QALYs) were 0.2247 and 0.4077, for BSC and oral topotecan respectively, resulting in an incremental cost-effectiveness ratio (ICER) of 33,851 pounds per QALY gained. Total QALYs for i.v. topotecan were between 0.3875 and 0.4157 (depending on assumptions regarding time progression) resulting in an ICER between 74,074 pounds and 65,507 pounds per QALY gained. Topotecan appeared to be better than BSC alone in terms of improved survival, and was as effective as CAV and less favourable than i.v. amrubicin in terms of response. Oral topotecan and i.v. topotecan were similar in efficacy. Topotecan offers additional benefit over BSC, but at increased cost. ICERs for i.v. topotecan, compared with BSC, were high and suggest that it is unlikely to be a cost-effective option. The ICER for oral topotecan is at the upper extreme of the range conventionally regarded as cost-effective from an NHS decision-making perspective. Further research into the QoL of patients with relapsed SCLC could identify the impacts of disease progression and treatment response.