The value of novel antihyperlipidemic treatments in the U.S. healthcare system: Reducing the burden of cardiovascular diseases and filling the gap of low adherence in statins

2018-07-26The studies presented in this dissertation discuss the potential value of PCSK9 inhibitors from the U.S. healthcare system perspective and propose an innovative drug pricing strategy to address the current health outcome lost due to the access barriers of this new drug. We also identified the trend of suboptimal use of statins in a national representative elderly population, which is helpful guide the policy makers for prioritizing the access to the PCSK9 inhibitors. ❧ To forecast the long-term benefit of PCSK9 inhibitors in a real-world U.S. population instead of a synthetic cohort, the first paper of my dissertation estimates the net monetary value of PCSK9 inhibitors in the older Americans (age 51 and older) under the FDA-approved eligibility when comparing with the status quo scenario -- the scenario of the current treatment strategies to manage hypercholesterolemia without the introduction of PCSK9 inhibitors. We also consider an extended eligibility scenario which includes patients with no pre-existing cardiovascular disease (CVD) but at high-risk, to inform the potential value when the patients gain greater access to this new therapy. We conducted simulations using the Future Elderly Model (FEM), an established dynamic microsimulation model, to project the lifetime outcomes for the U.S. population aged 51 or older. Efficacy estimates of Drugs from published meta-analysis studies of the early Phase III clinical trials were used to project changes in life expectancy, quality-adjusted life-years, and lifetime medical spending resulting from use of PCSK9 inhibitors. ❧ While PCSK9 could add a substantial societal value in a long run, there is still a paramount concern that the high prices of innovative prescription drugs like PCSK9, which places economic burden under a short-term budget impact model. Utilization restriction by payers results in a slow adoption of PCSK9 inhibitors, which creates barriers for patients who could benefit from the new therapy and lead to worse clinical outcomes for patients. Therefore, the outcome-based pricing for prescription drugs has been recently taken hold in the U.S. to ensure the prices we pay for the new drugs reflect the benefits we receive. The payers must find new ways to achieve cost control without limiting access to beneficial services and at the same time ensure enough incentives to the innovation for the manufacturers. While substantial manufacturer discounts could address the dilemma, it is unclear whether those would be flexible enough to reflect real-world outcomes, especially if the therapy’s long-term effectiveness is better than initially expected or larger absolute risk reductions in major ASCVD event rates given the higher baseline event rate in the real world. Therefore, we propose a payment model -- a three-part pricing model -- incorporating the real-world evidence to encourage payers to pay for services that provide expected or better outcomes. The aim of our second paper is to compare the value of our three-part pricing model comparing with the current one-price model (status quo) by using PCSK9 inhibitors as an example. The FEM is used to estimate the numbers of averted cardiovascular events in each year in those with existing CVD and/or FH and elevated LDL-C. We use the effectiveness estimates from a recently published clinical trial (FOURIER study) which focused on long-term cardiovascular outcomes in high risk patients. Among the eligible population, two PCSK9 uptake functions are used to estimate the numbers of patients actually be treated. To make the manufacturers be indifferent between the two pricing models, the drug price for our three-part pricing model will be calibrated to ensure the overall revenue during the patent protection period will be the same as the status quo. ❧ Given the access expansion of PCSK9 inhibitors is challenging and the hurdle of pricing strategy for this novel class of drugs hasn’t been solved, on the other hand it would be important to understand the societal value of improving the adherence to statins. The third paper of this dissertation aim to evaluate the longitudinal trends of statin adherence in the U.S elderly population and identify the factors which are associated with the better statin adherence