Cost-effectiveness of dabrafenib and trametinib in combination as adjuvant treatment of BRAF V600E/K mutation-positive melanoma from a US healthcare payer perspective.

Objective: The COMBI-AD trial demonstrated the efficacy and safety of dabrafenib and trametinib in combination vs placebo as adjuvant treatment of patients with BRAF V600E/K mutation-positive resected Stage IIIA (lymph node metastasis >1 mm), IIIB, or IIIC melanoma. This analysis evaluated the cost-effectiveness of dabrafenib and trametinib vs observation from a US healthcare payer perspective.Methods: This evaluation employed a non-homogeneous, semi-Markov, cohort model with health states for relapse-free survival (RFS), post-locoregional recurrence (LR), post-distant recurrence (DR) receiving first-line treatment, and post-DR receiving second-line treatment. A 50-year modeling time horizon was used. Transition probabilities were estimated based on individual patient data (IPD) from the COMBI-AD trial. Health-state utilities were estimated using EuroQol (EQ-5D) index values from COMBI-AD and published sources. Direct medical costs associated with treatment of melanoma were considered, including costs of BRAF mutation testing, medication and administration costs for adjuvant and metastatic treatments, costs of treating recurrence, and costs of adverse events. Costs and quality-adjusted life-years (QALYs) were discounted at 3.0% annually.Results: Compared with observation, adjuvant dabrafenib and trametinib was estimated to result in a gain of 2.15 QALYs at an incremental cost of $74,518. The incremental cost-effectiveness ratio (ICER) was estimated to be $34,689 per QALY. In deterministic sensitivity analyses, the ICER was sensitive to the cost of dabrafenib and trametinib and the distribution used for projecting RFS beyond the end of follow-up in the COMBI-AD trial. At a cost-effectiveness threshold of $100,000 per QALY, the probability that dabrafenib and trametinib is cost-effective was estimated to be 92%.Conclusions: Given generally-accepted cost-effectiveness threshold values in the US, dabrafenib plus trametinib is likely to be a cost-effective adjuvant therapy for patients with BRAF mutation positive melanoma. These results may be useful for policy-makers in their deliberations regarding reimbursement and access to this treatment.

Custo-utilidade de terapias-alvo comparadas à dacarbazina para o tratamento de primeira linha do melanoma avançado não-cirúrgico e metastático no Sistema Único de Saúde do Brazil.

OBJECTIVE: To estimate the incremental cost-utility ratio (ICUR) of isolated and combined targeted therapy regimens compared to dacarbazine for first-line treatment of advanced and metastatic melanoma with BRAF V600 mutation. METHODS: A Markov model with three health states (no progression, progression and death), monthly duration cycle and 10-year time horizon was constructed to compare targeted therapy regimens (vemurafenib, dabrafenib, vemurafenib/cobimetinib and dabrafenib/trametinib) with dacarbazine chemotherapy under the Brazilian public health perspective. One-way and probabilistic sensitivity analyses were performed. RESULTS: Mean cost was R$5662.50 ($1490.13) for dacarbazine, R$175 937.18 (46 299.26) for vemurafenib, R$167 461.70 ($44 068.87) for dabrafenib, R$425 901 ($112 079.21) for vemurafenib/cobimetinib and R$411 799.81 ($108 368.37) for dabrafenib/trametinib, whereas QALY was 0.91 for dacarbazine, 1.08 for vemurafenib, 1.12 for dabrafenib, 1.64 for vemurafenib/cobimetinib and 1.56 for dabrafenib/trametinib. The ICUR was estimated from R$572 165.76 ($150 569.94) to R$1 012 524.56 ($266 453.83) per patient, and the most impactful parameters were risk of progression and death, and treatment cost. CONCLUSION: The incorporation of targeted therapies in the Brazilian public health system would produce an additional expenditure of at least 19 times the national GDP per capita to increase in one year the quality-adjusted survival of each patient with advanced/metastatic BRAF-mutant melanoma.

Analysis of survival of patients treated with vemurafenib, ipilimumab and dabrafenib for advanced skin melanoma in daily clinical practice (Real-World Data): retrospective analysis of patients treated under drug/reimbursement programmes in Poland in 2013-2016.

Vemurafenib, ipilimumab and dabrafenib were registered for the treatment of advanced skin melanoma pursuant to the results of randomized phase III clinical trials. Real-world data on survival time for patients treated with those drugs in daily clinical practice are so far limited. Patients with advanced skin melanoma treated under reimbursement programmes (drug programmes), for which they were qualified pursuant to uniform inclusion criteria in force in all oncology centres in Poland. Data were obtained from the electronic databases of the national payer (NFZ) responsible for the implementation and monitoring of reimbursement (drug) programmes. The analysis included all patients included for treatment with vemurafenib (since March of 2013), ipilimumab (since March of 2014) and dabrafenib (since July of 2015) until December 2016. The end date of the observation was set to 31 December 2016. The total survival analysis was performed using the Kaplan-Meier estimator. Until 31 December 2016, 759 patients were treated with vemurafenib, 370 with ipilimumab and 181 with dabrafenib. The overall survival (OS) median was 9.8 months for patients treated with vemurafenib (95% confidence interval: 8.8-10.6) and 6.9 months for patients treated with ipilimumab (95% confidence interval: 5.7-9.2). For patients treated with dabrafenib, the OS median was not reached because of an overly short observation period. The probability of surviving 12 months in the group of patients treated with vemurafenib was 40.5%, ipilimumab was 35.1% and dabrafenib was 60.7%. The probability of surviving 24 and 36 months in the group of patients treated with vemurafenib or ipilimumab amounted to, respectively, 20.1, 15.4 and 21, 18.8%. OS of patients with advanced melanoma treated in daily clinical practice may be comparable to the ones achieved in registration trials. The use of appropriate treatment inclusion criteria may affect the obtained OS.

A cost-effectiveness analysis of trametinib plus dabrafenib as first-line therapy for metastatic BRAF V600-mutated melanoma in the Swiss setting.

BACKGROUND: The treatment of patients with metastatic melanomas that harbour BRAF V600E or V600K mutations with trametinib plus dabrafenib appears to be superior to treatment with vemurafenib alone. This treatment regimen is likely to become available in Switzerland in the near future. OBJECTIVES: To determine the cost-effectiveness of trametinib plus dabrafenib. METHODS: A Markov cohort simulation was conducted to model the clinical course of typical patients with metastatic melanoma. Information on response rates, clinical condition and follow-up treatments were derived and transition probabilities estimated based on the results of a clinical trial that compared treatment with trametinib plus dabrafenib vs. vemurafenib alone. RESULTS: Treatment with trametinib plus dabrafenib was estimated to cost an additional CHF199 647 (Swiss francs) on average and yield a gain of 0·52 quality-adjusted life years (QALYs), resulting in an incremental cost-effectiveness ratio of CHF385 603 per QALY. Probabilistic sensitivity analyses showed that a willingness-to-pay threshold of CHF100 000 per QALY would not be reached at the current US price of trametinib. CONCLUSIONS: The introduction of trametinib in Switzerland at US market prices for the treatment of metastatic BRAF V600-mutated melanoma with trametinib plus dabrafenib is unlikely to be cost-effective compared with vemurafenib monotherapy. A reduction in the total price of the combination therapy is required to achieve an acceptable cost-effectiveness ratio for this clinically promising treatment.

Dabrafenib for Treating Unresectable, Advanced or Metastatic BRAF V600 Mutation-Positive Melanoma: An Evidence Review Group Perspective.

The National Institute for Health and Care Excellence (NICE) invited GlaxoSmithKline, the manufacturer of dabrafenib, to submit evidence for the clinical and cost effectiveness of dabrafenib for the treatment of unresectable, advanced or metastatic BRAF V600 mutation-positive melanoma in accordance with the Institute's Single Technology Appraisal (STA) process. The Liverpool Reviews and Implementation Group (LRiG) at the University of Liverpool was commissioned to act as the Evidence Review Group (ERG). This article summarizes the ERG's review of the evidence submitted by the company and provides a summary of the Appraisal Committee's (AC) final decision in October 2014. The clinical evidence for dabrafenib was derived from an ongoing phase III, randomized, double-blind, placebo-controlled, international, multicentre clinical trial (BREAK-3) involving 230 patients randomized 2:1 to receive either dabrafenib or dacarbazine. A significant improvement in median progression-free survival (PFS) but not overall survival (OS) was reported in the dabrafenib arm compared with dacarbazine. Vemurafenib is considered a more appropriate comparator than is dacarbazine. The clinical evidence for vemurafenib was derived from a completed phase III, randomized, double-blind, placebo-controlled, international, multicentre clinical trial (BRIM-3) involving 675 patients randomized 1:1 to receive either vemurafenib or dacarbazine. A significant improvement in median PFS and OS was reported in the vemurafenib arm compared with dacarbazine. As there is no direct evidence comparing dabrafenib versus vemurafenib, the company presented an indirect treatment comparison (ITC) that demonstrated no statistical differences between dabrafenib and vemurafenib for PFS or OS. The ERG expressed concerns with the ITC, mainly in relation to the validity of the assumptions underpinning the methodology; the ERG concluded this resulted in findings that are unlikely to be robust or reliable. Dabrafenib and vemurafenib are both available to patients treated by the National Health Service (NHS) in England via a Patient Access Scheme (PAS) in which the costs of the drugs are discounted. Using these discounted costs, the incremental cost-effectiveness ratios (ICERs) generated by the company were £60,980 per quality-adjusted life-year (QALY) for dabrafenib versus dacarbazine and £11,046 per QALY gained for dabrafenib versus vemurafenib. The ERG considered the economic model structure developed by the company to derive the ICERs to be overly complex and based on unsubstantiated assumptions, most importantly in relation to the projection of OS. Applying the latest OS data from BREAK-3 to a less complex model structure increased the estimated ICER for dabrafenib compared with dacarbazine from £60,980 to £112,727 per QALY gained. Since the results from the ITC were considered by the ERG to be neither reliable nor robust, the ERG also considered a cost-effectiveness comparison to be inappropriate due to a lack of meaningful or reliable data. In spite of limitations in the data, the AC took the view that dabrafenib and vemurafenib were "likely" of similar clinical effectiveness. Since the overall costs of these two drugs were similar, the AC recommended the use of dabrafenib in patients with unresectable, advanced or metastatic BRAF V600 mutation-positive melanoma.

Assessment of the drug interaction potential and single- and repeat-dose pharmacokinetics of the BRAF inhibitor dabrafenib.

The induction of CYP2C9 by dabrafenib using S-warfarin as a probe and the effects of a CYP3A inhibitor (ketoconazole) and a CYP2C8 inhibitor (gemfibrozil) on dabrafenib pharmacokinetics were evaluated in patients with BRAF V600 mutation-positive tumors. Dabrafenib single- and repeat-dose pharmacokinetics were also evaluated. S-warfarin AUC(0- ∞) decreased 37% and Cmax increased 18% with dabrafenib. Dabrafenib AUC(0- τ) and C(max) increased 71% and 33%, respectively, with ketoconazole. Hydroxy- and desmethyl-dabrafenib AUC(0-τ) increased 82% and 68%, respectively, and AUC for carboxy-dabrafenib decreased 16%. Dabrafenib AUC(0-τ) increased 47%, with no change in C(max), after gemfibrozil co-administration. Gemfibrozil did not affect systemic exposure to dabrafenib metabolites. Single- and repeat-dose dabrafenib pharmacokinetics were consistent with previous reports. All cohorts used the commercial capsules. More-frequent monitoring of international normalized ratios is recommended in patients receiving warfarin during initiation or discontinuation of dabrafenib. Substitution of strong inhibitors or strong inducers of CYP3A or CYP2C8 is recommended during treatment with dabrafenib.

Cost effectiveness of dabrafenib as a first-line treatment in patients with BRAF V600 mutation-positive unresectable or metastatic melanoma in Canada.

OBJECTIVE: To evaluate the cost effectiveness of dabrafenib versus dacarbazine and vemurafenib as first-line treatments in patients with BRAF V600 mutation-positive unresectable or metastatic melanoma from a Canadian healthcare system perspective. METHODS: A partitioned-survival analysis model with three mutually exclusive health states (pre-progression, post-progression, and dead) was used. The proportion of patients in each state was calculated using survival distributions for progression-free and overall survival derived from pivotal trials of dabrafenib and vemurafenib. For each treatment, expected progression-free, post-progression, overall, and quality-adjusted life-years (QALYs), and costs were calculated. Costs were based on list prices, a clinician survey, and published sources. A 5-year time horizon was used in the base case. Costs (in 2012 Canadian dollars [CA$]) and QALYs were discounted at 5% annually. Deterministic and probabilistic sensitivity analyses were conducted. RESULTS: Dabrafenib was estimated to yield 0.2055 more QALYs at higher cost than dacarbazine. The incremental cost-effectiveness ratio was CA$363,136/QALY. In probabilistic sensitivity analyses, at a threshold of CA$200,000/QALY, there was an 8.2% probability that dabrafenib is cost effective versus dacarbazine. In deterministic sensitivity analyses, cost effectiveness was sensitive to survival distributions, utilities, and time horizon, with the hazard ratio for overall survival for dabrafenib versus dacarbazine being the most sensitive parameter. Assuming a class effect for efficacy of BRAF inhibitors, dabrafenib was dominant versus vemurafenib (less costly, equally effective), reflecting its assumed lower daily cost. Assuming no class effect, dabrafenib yielded 0.0486 more QALYs than vemurafenib. CONCLUSIONS: At a threshold of CA$200,000/QALY, dabrafenib is unlikely to be cost effective compared with dacarbazine. It is not possible to make reliable conclusions regarding the relative cost effectiveness of dabrafenib versus vemurafenib based on available information.

Efficacy assessment of a combined anticholinergic and oxime treatment against topical sarin-induced miosis and visual impairment in rats.

BACKGROUND AND PURPOSE: Eye exposure to the organophosphorus (OP) irreversible cholinesterase inhibitor sarin results in long-term miosis and impaired visual function. We have previously shown that tropicamide is better at ameliorating this insult than topical atropine or cyclopentolate. However, to minimize side effects associated with repeated tropicamide applications and high treatment doses, we evaluated the effects of oximes (ChE re-activators) alone and combined with tropicamide at ameliorating OP-induced ocular impairments. EXPERIMENTAL APPROACH: Rats were topically exposed to sarin, followed by topical treatment with various oximes alone or in combination with tropicamide. Pupil width and light reflex were measured by an infrared-based digital photograph system, while visual performance was assessed by employing the cueing version of the Morris water maze (MWM). KEY RESULTS: Oxime treatment following sarin ocular exposure induced a slow persistent pupil widening with efficacy in the order of HLö-7 > HI-6 > obidoxime = TMB-4 = MMB-4. In the light reflex test, the ability of the iris to contract following oxime treatment was mostly impaired at 1 h and was back to normal at 4 h following sarin exposure. All oxime treatments ameliorated the sarin-induced visual impairment as tested in the visual task (MWM). The combined topical treatment of tropicamide with an oxime induced a rapid improvement in pupil widening, light reflex and visual performance, and enabled a reduction in tropicamide dose. CONCLUSIONS AND IMPLICATIONS: The use of tropicamide combined with an oxime should be considered as the topical treatment of choice against the toxic effects of ocular OP exposure.

Usefulness of administration of non-organophosphate cholinesterase inhibitors before acute exposure to organophosphates: assessment using paraoxon.

Reversible acetylcholinesterase (AChE) inhibitors can protect against the lethal effects of irreversible organophosphorus AChE inhibitors (OPCs), when administered before OPC exposure. We have assessed in vivo the mortality-reducing efficacy of a group of known AChE inhibitors, when given in equitoxic dosage before exposure to the OPC paraoxon. Protection was quantified in rats by determining the relative risk (RR) of death. Best in vivo protection from paraoxon-induced mortality was observed after prophylactic administration of physostigmine (RR = 0.30) or the oxime K-27 (RR = 0.34); both treatments were significantly superior to the pre-treatment with all other tested compounds, including the established substance pyridostigmine. Tacrine (RR = 0.67), ranitidine (RR = 0.72), pyridostigmine (RR = 0.76), tiapride (RR = 0.80) and 7-MEOTA (RR = 0.86) also significantly reduced the relative risk of paraoxon-induced death, but to a lesser degree. Methylene blue, amiloride and metoclopramide had an unfavorable effect (RR ≥ 1), significantly increasing mortality. When CNS penetration by prophylactic is undesirable K-27 is a promising alternative to pyridostigmine.

Asoxime (HI-6) impact on dogs after one and tenfold therapeutic doses: assessment of adverse effects, distribution, and oxidative stress.

Asoxime (HI-6) is a well known oxime reactivator used for counteracting intoxication by nerve agents. It is able to reactivate acetylcholinesterase (AChE) inhibited even by sarin or soman. The present experiment was aimed to determine markers of oxidative stress represented by thiobarbituric acid reactive substances and antioxidants represented by ferric reducing antioxidant power, reduced and oxidized glutathione in a Beagle dog model. Two groups of dogs were intramuscularly exposed to single (11.4 mg/kg.b.wt.) or tenfold (114 mg/kg.b.wt.) human therapeutically doses of HI-6. HI-6 affinity for AChE in vitro was evaluated in a separate experiment. Complete serum biochemistry and pharmacokinetics were also performed with significant alteration in blood urea nitrogen, creatine phosphokinase, glucose and triglycerides. Blood samples were collected before HI-6 application and after 30, 60, and 120 min. The overall HI-6 impact on organism is discussed.

Performance of tiloronoxim and tilorone determination in human blood by HPLC-MS/MS: method validation, uncertainty assessment and its application to a pharmacokinetic study.

A highly sensitive and selective HPLC-MS/MS method is presented for the quantitative determination of tiloronoxim and its metabolite tilorone in human blood. An aliquot of 200 microl human blood was extracted with a mixture of chloroform/ethyl ether (1/2, v/v), using metoprolol as the internal standard (the IS). Separation was achieved on an Xterra MS C18 column (50 mm x 2.1 mm, 5 microm) with a gradient mobile phase of methanol/water containing 15 mM ammonium bicarbonate (pH 10.5). Detection was performed using positive MRM mode on a TurboIonSpray source. The mass transitions monitored were m/z 426.3-->100.0, m/z 411.3-->100.0 and m/z 268.3-->116.1 for tiloronoxim, tilorone and the IS, respectively. The method was fully validated using total error theory, which is based on beta-expectation tolerance intervals and include trueness and intermediate precision. The method was found to be accurate over a concentration range of 1-100 ng/ml for both compounds. The measurement uncertainty based on beta-expectation tolerance intervals was assessed at each concentration level of the validation standards. This method was successively applied to a pharmacokinetic study of tiloronoxim in healthy volunteers.