Cost-Effectiveness Analysis of Second-Line Chemotherapy Agents for Advanced Gastric Cancer.

STUDY OBJECTIVE: Gastric cancer is the fifth most common malignancy and second leading cause of cancer-related mortality. Chemotherapy options for patients who fail first-line treatment are limited. Thus the objective of this study was to assess the cost-effectiveness of second-line treatment options for patients with advanced or metastatic gastric cancer. DESIGN: Cost-effectiveness analysis using a Markov model to compare the cost-effectiveness of six possible second-line treatment options for patients with advanced gastric cancer who have failed previous chemotherapy: irinotecan, docetaxel, paclitaxel, ramucirumab, paclitaxel plus ramucirumab, and palliative care. MEASUREMENTS AND MAIN RESULTS: The model was performed from a third-party payer's perspective to compare lifetime costs and health benefits associated with studied second-line therapies. Costs included only relevant direct medical costs. The model assumed chemotherapy cycle lengths of 30 days and a maximum number of 24 cycles. Systematic review of literature was performed to identify clinical data sources and utility and cost data. Quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) were calculated. The primary outcome measure for this analysis was the ICER between different therapies, where the incremental cost was divided by the number of QALYs saved. The ICER was compared with a willingness-to-pay (WTP) threshold that was set at $50,000/QALY gained, and an exploratory analysis using $160,000/QALY gained was also used. The model's robustness was tested by using 1-way sensitivity analyses and a 10,000 Monte Carlo simulation probabilistic sensitivity analysis (PSA). Irinotecan had the lowest lifetime cost and was associated with a QALY gain of 0.35 year. Docetaxel, ramucirumab alone, and palliative care were dominated strategies. Paclitaxel and the combination of paclitaxel plus ramucirumab led to higher QALYs gained, at an incremental cost of $86,815 and $1,056,125 per QALY gained, respectively. Based on our prespecified WTP threshold, our base case analysis demonstrated that irinotecan alone is the most cost-effective regimen, and both paclitaxel alone and the combination of paclitaxel and ramucirumab were not cost-effective (ICER more than $50,000). Both 1-way sensitivity analyses and PSA demonstrated the model's robustness. PSA illustrated that paclitaxel plus ramucirumab was extremely unlikely to be cost-effective at a WTP threshold less than $400,000/QALY gained. CONCLUSION: Irinotecan alone appears to be the most cost-effective second-line regimen for patients with gastric cancer. Paclitaxel may be cost-effective if the WTP threshold was set at $160,000/QALY gained.

Single 4.5 mg fixed-dose of rasburicase for hyperuricemia associated with tumor lysis syndrome.

Rasburicase is a recombinant urate oxidase enzyme administered for treatment of hyperuricemia associated with tumor lysis syndrome. Studies demonstrate effectiveness of single fixed-dose rasburicase as compared to the FDA-approved dose of 0.2 mg/kg intravenously daily for up to five days. Doses in these studies range from 1.5 mg to 7.5 mg. Our study evaluated outcomes in patients who received single 4.5 mg fixed-dose rasburicase. This retrospective, IRB-approved chart review evaluated adult oncology subjects who received fixed-dose rasburicase between January 2007 and April 2014. The primary outcome was percentage of patients with normalization of uric acid (level <8 mg/dL within 24 h) after a single 4.5 mg fixed-dose of rasburicase. Secondary objectives were incidence of initial failure of fixed-dose rasburicase and normalization of uric acid in overweight (body mass index ≥25 kg/m2) versus non-overweight patients. Initial failure was defined as need for additional doses or progression to dialysis within one week of the initial fixed-dose. In the 128 patients included, the mean baseline uric acid level was 14.84 mg/dL. Of the 112 patients with a follow-up uric acid level, 68% achieved normalization within 24 h of rasburicase administration. Thirty-eight patients received additional treatment: 10 received additional dose(s) and 28 underwent dialysis. Normalization of uric acid in overweight versus non-overweight patients was 66% and 73%, respectively. Overall, a single 4.5 mg fixed-dose of rasburicase effectively normalized uric acid in 68% of patients within 24 h. Further studies are needed to determine the optimal single fixed-dose necessary for treatment response across all patients.

Use of atropine-diphenoxylate compared with hyoscyamine to decrease rates of irinotecan-related cholinergic syndrome.

BACKGROUND: Cholinergic syndrome is a well established acute adverse reaction associated with irinotecan. Cholinergic side effects can be ameliorated or prevented with anticholinergic agents. To date, no formal studies have compared atropine-diphenoxylate and hyoscyamine as premedications for prophylaxis of the cholinergic syndrome with irinotecan infusion. OBJECTIVES: To compare the incidence of cholinergic syndrome with irinotecan using atropine-diphenoxylate or hyoscyamine as premedication. METHODS: We conducted a retrospective, single-center, nonrandomized, cohort study of adult patients treated with atropine-diphenoxylate or hyoscyamine as premedication before receiving irinotecan. For all irinotecan infusions, intravenous atropine was administered for patients experiencing any cholinergic reaction. RESULTS: A total of 532 irinotecan cycles (354 cycles for atropine-diphenoxylate group; 178 cycles for hyoscyamine group) were analyzed in 80 patients. Overall incidence of cholinergic syndrome did not differ between atropine-diphenoxylate (8.2%) and hyoscyamine (9.0%) groups (P = .76). The incidence of cholinergic syndrome after the £rst cycle of irinotecan was similar between the 2 arms, atropine-diphenoxylate (14.6%) and hyoscyamine (10.7%), with P = .74. The most common cholinergic symptoms documented were abdominal pain or cramping, and diarrhea. LIMITATIONS: This study was subjected to vulnerabilities to bias and random error because of its observational retrospective design and small number of participants. CONCLUSIONS: Lack of difference in the incidence of cholinergic syndrome observed in irinotecan-treated patients suggests atropinediphenoxylate and hyoscyamine may both be effective prophylactic options. The findings support the need for a larger, randomized study to assess and compare these agents with other potential premedications such as scopolamine and atropine in prevention of irinotecan-related cholinergic syndrome.