Baseline characteristics of patients with transthyretin amyloid cardiomyopathy enrolled in a tafamidis expanded access programme

Background

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive and ultimately fatal disease caused by the accumulation of amyloid fibrils in the heart muscle. Tafamidis, currently the only approved drug for the treatment of ATTR-CM, demonstrated reduced mortality and cardiovascular-related hospitalisations in the Tafamidis in Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT). Real-world data in patients with ATTR-CM, including patient characteristics, are scarce. Here we analysed the baseline characteristics of patients enrolled in an expanded access programme (EAP) for tafamidis. Initiated in 2018, this tafamidis EAP allows access to tafamidis for patients who have exhausted all standard-of-care options and are not eligible for a clinical trial.

Purpose

To examine baseline characteristics of patients with ATTR-CM enrolled in a tafamidis EAP.

Methods

All patients enrolled in this tafamidis EAP from the start (May 2018) until November 2020 were included. To be eligible for inclusion, patients had to have documentation of the following: genetic testing for transthyretin amyloidosis (TTR sequencing); ATTR-CM diagnosis, including the criteria used; exclusion of light chain amyloidosis; and current medical/cardiac status, including New York Heart Association (NYHA) functional classification. Patients were grouped for analysis purposes in the following NYHA classes: I–II, >II–III, and >III–IV.

Results

A total of 700 patients (88.7% male) from 20 countries were enrolled over 2.6 years. Mean age was 76.2 years in males and 76.6 years in females. Of 518 patients with a recorded genotype, 87.5% were wild-type (89.6% male) and 12.5% hereditary (73.8% male). In males and females, respectively, mean age was 77.0 and 79.4 years in wild-type patients, and 66.2 and 69.3 years in variant patients. The NYHA class distribution is shown in the Figure. The greatest proportion of patients was considered NYHA class I–II. The proportion of patients considered NYHA class I–II was lower in the first half of the data collection period (Months 0–15, 55.3%) compared with the latter half (Months 15–30, 59.4%). In 254 patients with baseline N-terminal pro-B-type natriuretic peptide (NT-proBNP) data, the median NT-proBNP level was 2784.5 pg/mL (NYHA class I–II, 2408.5 pg/mL; NYHA class >II–III, 3165.0 pg/mL).

Conclusions

These are the first multi-country, real-world data evaluating baseline characteristics of patients with ATTR-CM enrolled in an EAP. It is of interest that, compared with the ATTR-ACT population, this patient group was older and had a greater proportion of wild-type patients. As a higher percentage of patients with less severe disease was enrolled in the latter half of data collection, these data also suggest a potential shift over time to earlier diagnosis of ATTR-CM. This analysis provides insight into the characteristics of real-world patients with ATTR-CM.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Pfizer Figure 1. Baseline NYHA class distribution

Cost-effectiveness of potential infant vaccination against respiratory syncytial virus infection in The Netherlands

INTRODUCTION

Respiratory syncytial virus (RSV) infection is one of the major causes of respiratory illness in infants, infecting virtually every child before the age of 2 years. Currently, several Phase 1 trials with RSV vaccines in infants are ongoing or have been completed. As yet, no efficacy estimates are available for these vaccine candidates. Nevertheless, cost-effectiveness estimates might be informative to enable preliminary positioning of an RSV vaccine.

METHODS

A decision analysis model was developed in which a Dutch birth cohort was followed for 12 months. A number of potential vaccination strategies were reviewed such as vaccination at specific ages, a two- or three-dosing scheme and seasonal vaccination versus year-round vaccination. The impact of the assumptions made was explored in various sensitivity analyses, including probabilistic analysis. Outcome measures included the number of GP visits, hospitalizations and deaths, costs, quality-adjusted life years and incremental cost-effectiveness ratios (ICERs).

RESULTS

Currently, without vaccination, an annual number of 28,738 of RSV-related GP visits, 1623 hospitalizations, and 4.5 deaths are estimated in children in the age of 0-1 year. The total annual cost to society of RSV in the non-vaccination scenario is €7.7 million (95%CI: 1.7-16.7) and the annual disease burden is estimated at 597 QALYs (95%CI: 133-1319). In case all infants would be offered a potentially safe and effective 3-dose RSV vaccination scheme at the age of 0, 1 and 3 months, the total annual net costs were estimated to increase to €21.2 million, but 544 hospitalizations and 1.5 deaths would be averted. The ICER was estimated at €34,142 (95%CI: € 21,652-€ 87,766) per QALY gained. A reduced dose schedule, seasonal vaccination, and consideration of out-of-pocket expenses all resulted in more favorable ICER values, whereas a reduced vaccine efficacy or a delay in the timing of vaccination resulted in less favorable ICERs.

DISCUSSION

Our model used recently updated estimates on the burden of RSV disease in children and it included plausible utilities. However, due to the absence of clinical trial data, a number of crucial assumptions had to be made related to the characteristics of potential RSV vaccine. The outcomes of our modeling exercise show that vaccination of infants against RSV might be cost-effective. However, clinical trial data are warranted.

Cost-effectiveness estimates for antenatal HIV testing in the Netherlands

This paper provides an estimation of the lifetime health-care cost of HIV-infected children and an update of the cost-effectiveness of universal HIV-screening of pregnant women in Amsterdam (The Netherlands). During 2003-2005, we collected data concerning the prevalence of newly diagnosed HIV-infected pregnant women in Amsterdam. Also, data on resource utilization and HAART regimen for HIV-infected children was gathered from a national registry. Using Kaplan-Meier survival analysis, we estimated the life-expectancy of a vertically HIV-infected child at 19 years, with the corresponding lifetime health-care costs of 179,974 Euros. HIV-screening of pregnant women could prevent 2.4 HIV transmissions annually in Amsterdam, based on an estimated prevalence of nine yet undiagnosed HIV-positive pregnant women per 10,000 pregnancies. We show that universal HIV screening during pregnancy generates significant net cost savings and health benefits in most situations. Universal antenatal HIV screening is justified in Amsterdam from a health-economic point of view.

Excess drug prescriptions during influenza and RSV seasons in the Netherlands: potential implications for extended influenza vaccination

Influenza and respiratory syncytial virus (RSV) infections are responsible for considerable morbidity, mortality and health-care resource use. For the Netherlands, we estimated age and risk-group specific numbers of antibiotics, otologicals and cardiovascular prescriptions per 10,000 person-years during periods with elevated activity of influenza or RSV, and compared these with peri-season rates. Data were taken from the University of Groningen in-house prescription database (www.iadb.nl) and virological surveillance for the period 1998-2006. During influenza and RSV periods excess antibiotic prescriptions were estimated for all age groups. In the age groups 0-1 and 2-4 years, excess antibiotic prescriptions during periods with elevated RSV activity (65% and 59% of peri-seasonal rates) exceeded the surpluses estimated during the influenza-activity periods (24% and 34% of peri-seasonal rates) while for otologicals excess prescriptions were higher for influenza (22% and 27%) than for RSV (14% and 17%). Among persons of 50 years and older, notably those without medical high-risk conditions, excess prescriptions for cardiovascular medications were estimated during the influenza periods at approximately 10% (this was also already seen in persons aged 45-49). Our results may have implications for influenza vaccination policies. In particular, extension of influenza vaccination to groups of non-elderly adults and young children may lower excess prescriptions during these influenza periods for all three types of drug prescriptions investigated.