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1.
Pancreatology ; 24(2): 271-278, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38286712

ABSTRACT

BACKGROUND: Germline BRCA mutations (gBRCAm) occur in 4%-8% patients with metastatic pancreatic cancer (mPC); guidelines recommend platinum-based chemotherapies and olaparib maintenance in this population. We evaluated, through modeling, the role of treatments and gBRCA testing on health outcomes of mPC patients. METHODS: A decision tree/partitioned survival model was developed to assess lifetime health outcomes for four strategies: 1) no testing; 2) early testing/no olaparib maintenance; 3) early testing (i.e., before 1L treatment)/olaparib maintenance; and 4) late testing/olaparib maintenance. Treatment patterns were assumed to follow current practice in the United States. Overall survival and progression-free survival curves were extrapolated from pivotal trials, including POLO trial for outcomes from olaparib maintenance after at least 16 weeks of platinum-based chemotherapy. RESULTS: Among patients with gBRCAm, almost twice as many patients received platinum-based regimens in strategies involving early testing compared to when early testing was not employed (78.7 % vs 40.2 %). Health outcomes were highest in the strategy with early testing and available olaparib treatment whether considering progression-free life years (PF LYs, 1.27 vs 0.55-0.87), LYs (1.82 vs 0.95-1.27) or quality adjusted life years (QALYs, 1.15 vs 0.73-0.92 for others). Consistent patterns of results were observed in the overall cohort of mPC patients (i.e., irrespective of gBRCAm). CONCLUSION: Patients with mPC achieved longest health outcomes (as measured by mean PF LYs, LYs and QALYs) with a scenario of early gBRCA testing and availability of olaparib maintenance. The results were primarily driven by improved health outcomes associated with higher efficacy of platinum-based chemotherapies and olaparib used in gBRCAm patients.


Subject(s)
Antineoplastic Agents , Pancreatic Neoplasms , Humans , United States , Antineoplastic Agents/therapeutic use , Progression-Free Survival , Germ-Line Mutation , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Pancreatic Neoplasms/diagnosis , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/genetics
2.
Expert Rev Hematol ; 14(12): 1137-1145, 2021 12.
Article in English | MEDLINE | ID: mdl-34465265

ABSTRACT

BACKGROUND: Patients with relapsed/refractory multiple myeloma (RRMM) require several lines of therapy, with typically shorter remission duration with each additional line. RESEARCH DESIGN AND METHODS: The cost-effectiveness of belantamab mafodotin (belamaf; DREAMM-2; NCT03525678) was compared with selinexor plus dexamethasone (SEL+DEX; STORM Part 2; NCT02336815) among patients with RRMM who have received at least four prior therapies. The base case used a US commercial payer's perspective over a 10-year time horizon. Efficacy data were based on parametric survival analysis of DREAMM-2 and matching-adjusted indirect treatment comparison between DREAMM-2 and STORM Part 2, which assessed relative treatment effects between belamaf and SEL+DEX. Cost inputs included drug treatment, concomitant medications, adverse event management, subsequent treatments, and disease management. RESULTS: Belamaf decreased total treatment costs per patient by $14,267 and increased patient life years by 0.74 and quality-adjusted life years (QALYs) by 0.49 versus SEL+DEX. Patients receiving belamaf accrued 0.12 fewer progression-free life years versus patients on SEL+DEX. CONCLUSIONS: From a US commercial payer's perspective, belamaf had lower costs, and increased QALYs and life-year gain, compared with SEL+DEX. Belamaf is therefore likely to be a cost-effective treatment option for patients with RRMM who have received four or more prior lines of therapy.


Subject(s)
Antibodies, Monoclonal, Humanized , Multiple Myeloma , Neoplasm Recurrence, Local , Antibodies, Monoclonal, Humanized/economics , Antibodies, Monoclonal, Humanized/therapeutic use , Cost-Benefit Analysis , Humans , Multiple Myeloma/drug therapy , Neoplasm Recurrence, Local/drug therapy , United States
3.
Clinicoecon Outcomes Res ; 13: 789-800, 2021.
Article in English | MEDLINE | ID: mdl-34531667

ABSTRACT

PURPOSE: Estimate the budget impact of belantamab mafodotin (belamaf) for patients with relapsed/refractory multiple myeloma (RRMM) who have received ≥4 prior therapies, including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent. METHODS: A budget impact analysis (BIA) was developed to estimate the cost difference between current (no belamaf) and projected (with belamaf) market scenarios over 3 years. Comparators were identified from a systematic literature review and included selinexor + dexamethasone or best supportive care. The number of treatment-eligible patients were estimated using an epidemiology model. Base-case analyses were conducted from a US commercial payer perspective (cost year: 2019). Model inputs included market share estimates, treatment duration, and costs of drug acquisition/administration, concomitant medications, adverse event (AE) management, treatment monitoring, and subsequent treatments based on published literature/cost databases. Budget impact, calculated as the difference in costs between current and projected scenarios over 3 years, was reported as cost per member per month (PMPM) and per member per year (PMPY). One-way sensitivity analysis assessed which key parameters most affected model outcomes. Alternative scenarios were tested (1- or 5-year time horizon; Medicare perspective; negligible cost of mental status change AE). RESULTS: In a hypothetical commercial payer health plan with 1 million members, 33 patients were identified as treatment-eligible over 3 years. Introducing belamaf for patients with RRMM resulted in an estimated budget-neutral PMPM cost of -$0.0003 and PMPY of -$0.004, based on n=9/33 patients receiving treatment. Sensitivity analyses showed that budget impact in the base case was most sensitive to changes in treatment duration and drug acquisition costs. Base-case results were consistent across all scenarios assessed. CONCLUSION: BIA indicates that adoption of belamaf in this patient population would be budget neutral for a US health plan.

4.
J Med Econ ; 24(1): 816-827, 2021.
Article in English | MEDLINE | ID: mdl-34126842

ABSTRACT

AIMS: To estimate the budget impact of adding tepotinib to United States (US) health plans for treating adult patients with metastatic non-small cell lung cancer (mNSCLC) harboring mesenchymal-epithelial transition exon 14 (METex14) skipping alterations. METHODS: The base-case analysis was conducted from the perspective of a hypothetical Medicare plan of 1 million members. Scenarios were analysed for other US health plans. Treatments included tepotinib, capmatinib, crizotinib, and standard of care (SoC). Patients eligible for tepotinib were estimated from published epidemiological data and literature, and real-world evidence. Clinical inputs were derived from the phase II VISION trial, US prescribing information, and published literature. Tepotinib uptake and projected testing rates for METex14 skipping alterations were based on market research. Unit costs (2020 US dollars (USD)) and resource utilization associated with drug acquisition and administration, treatment monitoring, disease and adverse event (AE) management, and subsequent treatment were derived primarily from public sources. RESULTS: In the base-case, 38-65 patients were eligible for tepotinib each year over the three-year time horizon. The cumulative net budgetary impact of tepotinib was -$692,541 (-2.6%); $26,531,670 in the scenario without tepotinib and $25,839,129 in the scenario with tepotinib. A negligible net budget impact was observed per member per month (PMPM) at $0.2457 and $0.2393, respectively, before and after tepotinib's introduction. Results were most sensitive to variability in unit costs of capmatinib and tepotinib and their corresponding median treatment durations. Sensitivity and scenario analyses support the conclusion that introducing tepotinib will have minimal budgetary impact for Medicare health plans. Similar results were obtained for other US health plans. LIMITATIONS: Assumptions and expert opinion were applied to address data gaps in key model inputs. CONCLUSIONS: The estimated budgetary impact of tepotinib for the treatment of adult patients with mNSCLC harboring METex14 skipping alterations is minimal from the perspective of US health plans.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Adult , Aged , Budgets , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/genetics , Exons , Humans , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Medicare , Piperidines , Pyridazines , Pyrimidines , United States
5.
Immunotherapy ; 12(1): 37-51, 2020 01.
Article in English | MEDLINE | ID: mdl-31992108

ABSTRACT

Aim: To assess the cost-effectiveness of treatment sequences for patients with intermediate- to poor-risk advanced renal cell carcinoma. Patients & methods: A discrete event simulation model was developed to estimate patients' lifetime costs and survival. Efficacy inputs were derived from the CheckMate 214 and CheckMate 025 studies and network meta-analyses. Safety and cost data were obtained from the published literature. Results: The estimated average quality-adjusted life-years (QALYs) gained was the highest on nivolumab + ipilimumab-initiated sequences (3.6-5.3 QALYs) versus tyrosine kinase inhibitor (TKI)-initiated sequences (2.1-3.7 QALYs). Incremental cost per QALY gained for nivolumab + ipilimumab-initiated sequences was below the willingness-to-pay threshold of $150,000 versus other sequences. Conclusion: Immuno-oncology combination therapy followed by TKIs is cost-effective versus TKI sequences followed by immuno-oncology or sequencing TKIs.


Subject(s)
Antineoplastic Agents, Immunological/therapeutic use , Carcinoma, Renal Cell/drug therapy , Computer Simulation , Ipilimumab/therapeutic use , Kidney Neoplasms/drug therapy , Nivolumab/therapeutic use , Antineoplastic Protocols , Carcinoma, Renal Cell/economics , Carcinoma, Renal Cell/mortality , Cost-Benefit Analysis , Drug Therapy, Combination , Humans , Kidney Neoplasms/economics , Kidney Neoplasms/mortality , Models, Economic , Neoplasm Staging , Quality-Adjusted Life Years , Survival Analysis , Treatment Outcome
6.
Future Oncol ; 15(35): 4057-4067, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31687852

ABSTRACT

Aim: To conduct a value assessment of an immuno-oncology (IO) therapy for a rare cancer and evaluate whether existing frameworks consider challenges associated with valuing IOs for rare cancers. Materials & methods: Value frameworks developed by American Society of Clinical Oncologists, Memorial Sloan Kettering Cancer Center and National Comprehensive Cancer Network were used to estimate the value of an IO therapy in a rare cancer based on single-arm trial data and retrospective studies. Results: Paucity of direct evidence comparing rare cancer treatments and lack of acceptance of indirect comparisons hinder appropriate value assessment. Measurement of value based on short-term outcomes may not capture the value of IOs, where survival is often characterized by a plateau. Conclusion: Further work is required to factor in nuances associated with rare cancers and guide end users of the frameworks. To capture true value, multiple or more holistic value assessments are required.


Subject(s)
Antineoplastic Agents, Immunological/therapeutic use , Drug Approval , Medical Oncology , Neoplasms/drug therapy , Antineoplastic Agents, Immunological/pharmacology , Humans , Medical Oncology/methods , Neoplasms/immunology , Outcome Assessment, Health Care
7.
PLoS One ; 14(8): e0215761, 2019.
Article in English | MEDLINE | ID: mdl-31465470

ABSTRACT

OBJECTIVE: Advanced renal cell carcinoma (RCC) is commonly treated with vascular endothelial growth factor or mammalian target of rapamycin inhibitors. As new therapies emerge, interest grows in gaining a deeper understanding of treatment sequences. Recently, we developed a patient-level, discretely integrated condition event (DICE) simulation to estimate survival and lifetime costs for various cancer therapies, using a US payer perspective. Using this model, we explored the impact of treatments such as nivolumab and cabozantinib, and compared the clinical outcomes and cost consequences of commonly used treatment algorithms for patients with advanced RCC. METHODS: Included treatment sequences were pazopanib or sunitinib as first-line treatment, followed by nivolumab, cabozantinib, axitinib, pazopanib or everolimus. Efficacy inputs were derived from the CheckMate 025 trial and a network meta-analysis based on available literature. Safety and cost data were obtained from publicly available sources or literature. RESULTS: Based on our analysis, the average cost per life-year (LY) was lowest for sequences including nivolumab (sunitinib → nivolumab, $75,268/LY; pazopanib → nivolumab, $84,459/LY) versus axitinib, pazopanib, everolimus and cabozantinib as second-line treatments. Incremental costs per LY gained were $49,592, $73,927 and $30,534 for nivolumab versus axitinib, pazopanib and everolimus-containing sequences, respectively. The model suggests that nivolumab offers marginally higher life expectancy at a lower cost versus cabozantinib-including sequences. CONCLUSION: Treatment sequences using nivolumab in the second-line setting are less costly compared with sequential use of targeted agents. In addition to efficacy and safety data, cost considerations may be taken into account when considering treatment algorithms for patients with advanced RCC.


Subject(s)
Carcinoma, Renal Cell/drug therapy , Carcinoma, Renal Cell/pathology , Cost-Benefit Analysis , Kidney Neoplasms/drug therapy , Kidney Neoplasms/pathology , Antineoplastic Agents/economics , Antineoplastic Agents/therapeutic use , Carcinoma, Renal Cell/economics , Humans , Kidney Neoplasms/economics , Models, Economic
8.
Adv Ther ; 36(9): 2327-2341, 2019 09.
Article in English | MEDLINE | ID: mdl-31350728

ABSTRACT

INTRODUCTION: Complex underlying risk functions associated with immuno-oncology treatments have led to exploration of different methods (parametric survival, spline, landmark, and cure-fraction models) to estimate long-term survival outcomes. The objective of this study was to examine differences in estimated short- and long-term survival in previously treated metastatic Merkel cell carcinoma (mMCC) patients receiving avelumab, when using alternative extrapolation approaches. METHODS: Efficacy data from the phase 2 JAVELIN Merkel 200 trial (part A) with at least 12 months of follow-up were analyzed. Standard parametric survival analyses and analyses of overall survival (OS) as a function of surrogate outcomes comprised of response (landmark analyses) and progression-free survival plus post-progression survival (PFS + PPS) were used to project OS. Overall survival throughout lifetime was projected and compared with the observed OS data with at least 24 months of follow-up. RESULTS: Estimated OS from all three approaches provided a good fit to the observed OS curve from at least 12 months of follow-up. However, performance compared with OS data from at least 24 months showed that the landmark approach followed by PFS + PPS provided a better fit to the data as compared to standard parametric analysis. Mean life expectancy estimated with avelumab was 2.48 years with best-fitting parametric function (a log-normal distribution), 3.15 years with the landmark approach, and 3.54 years with PFS + PPS. CONCLUSION: Although standard parametric survival analysis may provide a good fit to short-term survival, it appears to underestimate the long-term survival benefits associated with avelumab in mMCC. Extrapolations based on surrogate outcomes of response or progression predict OS outcomes from longer follow-up better and appear to provide more clinically plausible projections. FUNDING: EMD Serono Inc, Rockland, MA, a business of Merck KGaA, Darmstadt, Germany.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Carcinoma, Merkel Cell/drug therapy , Progression-Free Survival , Skin Neoplasms/drug therapy , Adult , Antibodies, Monoclonal, Humanized , Carcinoma, Merkel Cell/mortality , Disease-Free Survival , Female , Germany , Humans , Male , Middle Aged , Neoplasm Metastasis , Risk Assessment , Skin Neoplasms/mortality , Skin Neoplasms/pathology , Survival Analysis , Treatment Outcome
9.
Immunotherapy ; 11(4): 283-295, 2019 03.
Article in English | MEDLINE | ID: mdl-30563395

ABSTRACT

AIM: The cost-effectiveness of treatment sequences in BRAF-mutant advanced melanoma. MATERIALS & METHODS: A discrete event simulation model was developed to estimate total costs and health outcomes over a patient's lifetime (30 years). Efficacy was based on the CheckMate 067/069 trials and a matching-adjusted-indirect comparison between immuno-oncology and targeted therapies. Safety, cost (in US dollars; US third-party payer perspective) and health-related quality-of-life inputs were based on published literature. RESULTS: Estimated survival gain was higher for sequences initiating with anti-PD-1 + anti-CTLA-4 than for anti-PD-1 monotherapy or BRAF+MEK inhibitors. The incremental cost-effectiveness ratio per QALY gained for first-line anti-PD-1 + anti-CTLA-4 was US$54,273 versus first-line anti-PD-1 and $79,124 versus first-line BRAF+MEK inhibitors. CONCLUSION: Initiating treatment with anti-PD-1 + anti-CTLA-4 was more cost-effective than initiation with anti-PD-1 monotherapy or BRAF+MEK inhibitors.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Costs and Cost Analysis/statistics & numerical data , Immunotherapy/methods , Melanoma/drug therapy , Models, Economic , Skin Neoplasms/drug therapy , CTLA-4 Antigen/antagonists & inhibitors , Cost-Benefit Analysis , Humans , Melanoma/economics , Melanoma/mortality , Neoplasm Staging , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Protein Kinase Inhibitors/therapeutic use , Proto-Oncogene Proteins B-raf/genetics , Quality of Life , Skin Neoplasms/economics , Skin Neoplasms/mortality , Survival Analysis , Treatment Outcome
10.
Immunotherapy ; 10(14): 1241-1252, 2018 10.
Article in English | MEDLINE | ID: mdl-30175642

ABSTRACT

AIM: To evaluate the cost-effectiveness of treatment sequences with checkpoint inhibitors in patients with BRAF wild-type melanoma. MATERIALS & METHODS: Using a discrete event simulation model, cost and health outcomes were estimated. Pooled data from CheckMate 067/069 trials were used to calculate survival outcomes including treatment-free interval extrapolated over a patient's lifetime. Costs accounted for treatment, administration, toxicity, and disease management. RESULTS: First-line anti-PD-1 + anti-CTLA-4 initiating sequences had the highest estimated mean survival gain (7.6-7.7 years), driven by a longer estimated mean treatment-free interval (5.3 years). Incremental costs per incremental quality-adjusted life year gained for anti-PD-1 + anti-CTLA-4 followed by chemotherapy were US$30,955 versus anti-PD-1 initiating sequences, within the willingness-to-pay threshold. CONCLUSION: Anti-PD-1 + anti-CTLA-4 initiating sequences for BRAF wild-type melanoma are cost-effective versus anti-PD-1.


Subject(s)
Antibodies, Monoclonal/economics , Computer Simulation , Immunotherapy/economics , Ipilimumab/economics , Melanoma/drug therapy , Nivolumab/economics , Skin Neoplasms/drug therapy , Antibodies, Monoclonal/therapeutic use , CTLA-4 Antigen/antagonists & inhibitors , Clinical Trials as Topic , Cost-Benefit Analysis , Drug Therapy, Combination , Health Care Costs , Humans , Immunotherapy/methods , Ipilimumab/therapeutic use , Medicare , Melanoma/economics , Melanoma/mortality , Models, Economic , Mutation/genetics , Nivolumab/therapeutic use , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/genetics , Skin Neoplasms/economics , Skin Neoplasms/mortality , Survival Analysis , United States
11.
PLoS One ; 13(8): e0203406, 2018.
Article in English | MEDLINE | ID: mdl-30161244

ABSTRACT

OBJECTIVE: In oncology, extrapolation of clinical outcomes beyond trial duration is traditionally achieved by parametric survival analysis using population-level outcomes. This approach may not fully capture the benefit/risk profile of immunotherapies due to their unique mechanisms of action. We evaluated an alternative approach-dynamic modeling-to predict outcomes in patients with advanced renal cell carcinoma. We compared standard parametric fitting and dynamic modeling for survival estimation of nivolumab and everolimus using data from the phase III CheckMate 025 study. METHODS: We developed two statistical approaches to predict longer-term outcomes (progression, treatment discontinuation, and survival) for nivolumab and everolimus, then compared these predictions against follow-up clinical trial data to assess their proximity to observed outcomes. For the parametric survival analyses, we selected a probability distribution based on its fit to observed population-level outcomes at 14-month minimum follow-up and used it to predict longer-term outcomes. For dynamic modeling, we used a multivariate Cox regression based on patient-level data, which included risk scores, and probability and duration of response as predictors of longer-term outcomes. Both sets of predictions were compared against trial data with 26- and 38-month minimum follow-up. RESULTS: Both statistical approaches led to comparable fits to observed trial data for median progression, discontinuation, and survival. However, beyond the trial duration, mean survival predictions differed substantially between methods for nivolumab (30.8 and 51.5 months), but not everolimus (27.2 and 29.8 months). Longer-term follow-up data from CheckMate 025 and phase I/II studies resembled dynamic model predictions for nivolumab. CONCLUSIONS: Dynamic modeling can be a good alternative to parametric survival fitting for immunotherapies because it may help better capture the longer-term benefit/risk profile and support health-economic evaluations of immunotherapies.


Subject(s)
Carcinoma, Renal Cell/mortality , Kidney Neoplasms/mortality , Antineoplastic Agents/therapeutic use , Carcinoma, Renal Cell/drug therapy , Everolimus/therapeutic use , Humans , Kidney Neoplasms/drug therapy , Models, Statistical , Nivolumab/therapeutic use , Proportional Hazards Models , Survival Analysis , Treatment Outcome
13.
PLoS One ; 12(11): e0187662, 2017.
Article in English | MEDLINE | ID: mdl-29121105

ABSTRACT

BACKGROUND: The 1-hour (h) algorithm triages patients presenting with suspected acute myocardial infarction (AMI) to the emergency department (ED) towards "rule-out," "rule-in," or "observation," depending on baseline and 1-h levels of high-sensitivity cardiac troponin (hs-cTn). The economic consequences of applying the accelerated 1-h algorithm are unknown. METHODS AND FINDINGS: We performed a post-hoc economic analysis in a large, diagnostic, multicenter study of hs-cTnT using central adjudication of the final diagnosis by two independent cardiologists. Length of stay (LoS), resource utilization (RU), and predicted diagnostic accuracy of the 1-h algorithm compared to standard of care (SoC) in the ED were estimated. The ED LoS, RU, and accuracy of the 1-h algorithm was compared to that achieved by the SoC at ED discharge. Expert opinion was sought to characterize clinical implementation of the 1-h algorithm, which required blood draws at ED presentation and 1h, after which "rule-in" patients were transferred for coronary angiography, "rule-out" patients underwent outpatient stress testing, and "observation" patients received SoC. Unit costs were for the United Kingdom, Switzerland, and Germany. The sensitivity and specificity for the 1-h algorithm were 87% and 96%, respectively, compared to 69% and 98% for SoC. The mean ED LoS for the 1-h algorithm was 4.3h-it was 6.5h for SoC, which is a reduction of 33%. The 1-h algorithm was associated with reductions in RU, driven largely by the shorter LoS in the ED for patients with a diagnosis other than AMI. The estimated total costs per patient were £2,480 for the 1-h algorithm compared to £4,561 for SoC, a reduction of up to 46%. CONCLUSIONS: The analysis shows that the use of 1-h algorithm is associated with reduction in overall AMI diagnostic costs, provided it is carefully implemented in clinical practice. These results need to be prospectively validated in the future.


Subject(s)
Algorithms , Blood Chemical Analysis , Emergency Service, Hospital/economics , Myocardial Infarction/blood , Myocardial Infarction/diagnosis , Triage/economics , Troponin T/blood , Acute Disease , Aged , Humans , Longevity , Sensitivity and Specificity
15.
J Med Econ ; 19(5): 445-61, 2016.
Article in English | MEDLINE | ID: mdl-26613118

ABSTRACT

AIM: A cost-effectiveness analysis was performed for sequential treatments of chronic myelogenous leukemia (CML) with tyrosine kinase inhibitors (TKIs) after failure of 1st line imatinib, from a commercial payer perspective in the US. METHODS: A Markov model was developed to simulate lifetime treatment costs and health outcomes for TKI sequences for treatment of patients resistant or intolerant to 1st-line imatinib. Five health states were included, chronic phase 2nd-line TKI, chronic phase 3rd-line TKI, chronic phase post-TKI, advanced phases, and death. Efficacy (response achievement, loss of response, transformation, death) and safety (adverse events incidence, discontinuation) data are based on clinical trials. Resource utilization, costs, and utilities were based on product labels and publically available data. Uncertainty analyses were conducted for key inputs. RESULTS: In patients failing imatinib, dasatinib-initiating treatment sequences provide the most survival (ΔLYs = 0.2-2.0), QALYs (ΔQALYs = 0.2-1.9), and accrue highest CML-related costs (ΔCosts = $64,000-$222,000). The average ICER per QALY for dasatinib- vs imatinib-initiating sequences is $100,000 for an imatinib-resistant population. The average ICER per QALY for dasatinib- vs nilotinib-initiating sequences is $170,000 for an imatinib-resistant population, and $160,000 for an imatinib-intolerant population. CONCLUSIONS: This analysis suggests that dasatinib is associated with increased survival and quality of life compared to high dose imatinib and to a smaller extent with nilotinib, among patients resistant or intolerant to 1st-line imatinib, primarily based on higher cytogenetic response rates observed in clinical studies of dasatinib. Head-to-head studies of sequential use of dasatinib and nilotinib are needed to validate the model findings of improved survival (LYs) with better quality-of-life (QALYs) for patients initiating dasatinib in 2nd-line. However, the model findings (in light of higher cytogenetic response rates with dasatinib) are supported by other studies showing improved quality-of-life for responders, and improved survival for patients achieving cytogenetic response.


Subject(s)
Dasatinib/economics , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Protein Kinase Inhibitors/economics , Pyrimidines/economics , Aged , Aged, 80 and over , Cost-Benefit Analysis , Dasatinib/therapeutic use , Disease Progression , Drug Resistance, Neoplasm , Health Services/economics , Health Services/statistics & numerical data , Humans , Imatinib Mesylate/therapeutic use , Markov Chains , Middle Aged , Models, Econometric , Protein Kinase Inhibitors/therapeutic use , Pyrimidines/therapeutic use , Quality of Life , Quality-Adjusted Life Years , Survival Analysis
16.
J Neurosci ; 30(18): 6466-76, 2010 May 05.
Article in English | MEDLINE | ID: mdl-20445073

ABSTRACT

In vertebrates, sialylated glycans participate in a wide range of biological processes and affect the development and function of the nervous system. While the complexity of glycosylation and the functional redundancy among sialyltransferases provide obstacles for revealing biological roles of sialylation in mammals, Drosophila possesses a sole vertebrate-type sialyltransferase, Drosophila sialyltransferase (DSiaT), with significant homology to its mammalian counterparts, suggesting that Drosophila could be a suitable model to investigate the function of sialylation. To explore this possibility and investigate the role of sialylation in Drosophila, we inactivated DSiaT in vivo by gene targeting and analyzed phenotypes of DSiaT mutants using a combination of behavioral, immunolabeling, electrophysiological, and pharmacological approaches. Our experiments demonstrated that DSiaT expression is restricted to a subset of CNS neurons throughout development. We found that DSiaT mutations result in significantly decreased life span, locomotor abnormalities, temperature-sensitive paralysis, and defects of neuromuscular junctions. Our results indicate that DSiaT regulates neuronal excitability and affects the function of a voltage-gated sodium channel. Finally, we showed that sialyltransferase activity is required for DSiaT function in vivo, which suggests that DSiaT mutant phenotypes result from a defect in sialylation of N-glycans. This work provided the first evidence that sialylation has an important biological function in protostomes, while also revealing a novel, nervous system-specific function of alpha2,6-sialylation. Thus, our data shed light on one of the most ancient functions of sialic acids in metazoan organisms and suggest a possibility that this function is evolutionarily conserved between flies and mammals.


Subject(s)
Behavior, Animal/physiology , Central Nervous System/physiology , Drosophila , Sialyltransferases/physiology , Animals , Central Nervous System/anatomy & histology , Central Nervous System/growth & development , Central Nervous System/metabolism , Drosophila/enzymology , Drosophila/physiology , Gait Disorders, Neurologic/genetics , Gene Expression Regulation, Developmental , Genes, Insect/physiology , Longevity/genetics , Mutation , Neuromuscular Junction/genetics , Neuromuscular Junction/physiology , Neurons/metabolism , Neurons/physiology , Sialyltransferases/genetics , Sodium Channels/genetics , Sodium Channels/physiology , Synaptic Potentials/genetics , Synaptic Potentials/physiology
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