Delaying generic competition--corporate payoffs and the future of Plavix

Mortality and adverse events with brand and generic clopidogrel in the US Food and Drug Administration Adverse Event Reporting System

Aims

Clopidogrel is commonly used even after expiring patents. The brand clopidogrel (BC) was dealt by single company, while numerous manufacturers produce generic clopidogrel (GC). There are no convincing data to compare the safety of different formulations. Therefore, the data yielded from international, uniform, government-mandated registries may be useful.

Methods and results

We assessed primary causative adverse events (PCAE) after BC and GC in the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS). The outcomes were divided into death, cardiac, thrombotic/embolic, haemorrhagic, and rash/dermal complications. These primary endpoints were then examined by proportional reporting ratios (PRR) and chi-square (χ2). Among total FAERS (n = 9 466 679) reports, overall BC (n = 88 863) cases were more common than after GC (n = 36 559). When triaged by PCAE role, BC (n = 18 328) was also more abundant than GC (n = 3987). The reported death rates were more than doubled after BC [18.4% vs. 7.0%; PRR = 0.38; 95% confidence interval (95% CI) 0.32–0.43; χ2=369.7; P<0.0001] for total FAERS, and consistent for late 2010–2017 (17.6% vs. 7.0% PRR = 0.40; 95% CI 0.37–0.45; χ2=286.2; P<0.004) PCAE cases. In contrast, GC trended to co-report more cardiac (14.6% vs. 13.3%; PRR = 1.12; 95% CI 1.0–1.25; χ2=3.5; P<0.06). The haemorrhagic (40.9% vs. 32.3%; PRR = 1.45; 95% CI 1.33–1.57; χ2=75.8; P<0.0001), and rash/dermal (5.4% vs. 4.6%; PRR = 1.20; 95% CI 1.0–1.44; χ2=3.75; P<0.05) events were also more common for GC. Thrombotic/embolic events were reported equally (at 7.0%) after each formulation.

Conclusion

The PCAE profiles differ with BC and GC in FAERS. While deaths reports were higher, the rates of cardiac, haemorrhagic, and skin complications were less common for BC. Despite expected reporting bias, this may indicate that the manufacturers of GC are reluctant to report deaths to the FDA. However, the overall adverse event profile suggests potentially better safety of BC over GC formulations.

Branded versus generic clopidogrel in cardiovascular diseases: a systematic review

In the United States, patent for branded Plavix has recently expired. Some studies have compared branded and generic clopidogrel in terms of pharmacokinetic parameters in healthy volunteers, but data on patients and clinical outcomes are scarce. We aimed to review efficacy and safety data from studies comparing Plavix with generic clopidogrel in patients with cardiovascular disease. Electronic databases were searched (from inception to May 2012) for prospective studies evaluating branded versus generic clopidogrel in patients with cardiovascular diseases. Studies' characteristics and data estimates were retrieved. Pooled risk ratio (RR) and 95% confidence intervals (95% CIs) were estimated through a random-effects model. Three studies evaluating 760 patients were included: 2 randomized controlled trials and 1 cohort study. The RR for major cardiovascular events was 1.01 (95% CI, 0.67-1.52). Incidence of adverse events was similar between Plavix and generic (RR 0.85; 95% CI, 0.49-1.48). The risks of mortality, bleeding, and drug discontinuation were also not different between groups. There are a limited number of studies comparing Plavix and generic clopidogrel in patients with cardiovascular diseases and reporting hard clinical end points. The available evidence is therefore limited and does not support the existence of differences in efficacy or safety between branded and generic clopidogrel.

Dabigatran - a case history demonstrating the need for comprehensive approaches to optimize the use of new drugs

BACKGROUND

There are potential conflicts between authorities and companies to fund new premium priced drugs especially where there are safety and/or budget concerns. Dabigatran, a new oral anticoagulant for the prevention of stroke in patients with non-valvular atrial fibrillation (AF), exemplifies this issue. Whilst new effective treatments are needed, there are issues in the elderly with dabigatran due to variable drug concentrations, no known antidote and dependence on renal elimination. Published studies have shown dabigatran to be cost-effective but there are budget concerns given the prevalence of AF. There are also issues with potentially re-designing anticoagulant services. This has resulted in activities across countries to better manage its use.

OBJECTIVE

To (i) review authority activities in over 30 countries and regions, (ii) use the findings to develop new models to better manage the entry of new drugs, and (iii) review the implications for all major stakeholder groups.

METHODOLOGY

Descriptive review and appraisal of activities regarding dabigatran and the development of guidance for groups through an iterative process.

RESULTS

There has been a plethora of activities among authorities to manage the prescribing of dabigatran including extensive pre-launch activities, risk sharing arrangements, prescribing restrictions, and monitoring of prescribing post-launch. Reimbursement has been denied in some countries due to concerns with its budget impact and/or excessive bleeding. Development of a new model and future guidance is proposed to better manage the entry of new drugs, centering on three pillars of pre-, peri-, and post-launch activities.

CONCLUSION

Models for introducing new drugs are essential to optimize their prescribing especially where there are concerns. Without such models, new drugs may be withdrawn prematurely and/or struggle for funding.

Upper gastrointestinal bleeding and the changing use of COX-2 non-steroidal anti-inflammatory drugs and low-dose aspirin

BACKGROUND

Rofecoxib was withdrawn in 2004.

AIM

To assess the incidence of upper gastrointestinal bleeding in the context of the changing use of cyclo-oxygenase-2 non-steroidal anti-inflammatory drugs and low-dose aspirin.

METHODS

We examined the characteristics of patients developing upper gastrointestinal bleeding in a defined population in south-west Scotland. The primary comparisons were made between two calendar years, preceding and following the withdrawal of rofecoxib.

RESULTS

The overall incidence of upper gastrointestinal bleeding rose from 98.7 in 2002 to 143 per 10(5) of the population per annum in 2005 (chi(2) = 21.1; P < 0.001). The rise in the incidence was associated with using low-dose aspirin, from 26.6 to 38.4 per 10(5) (chi(2) = 5.4; P = 0.02), other antithrombotic drugs, from 12.1 to 30.2 per 10(5) (chi(2) = 19.6; P < 0.001), and excess alcohol, from 23.5 to 36.4 per 10(5) (chi(2) = 7.1; P = 0.008), but insignificantly with using non-steroidal anti-inflammatory drugs, from 13.3 to 16.1 per 10(5) (chi(2) = 0.64; P = 0.4). After adjustment for the concomitant use of these drugs, there was no significant trend in the incidence of upper gastrointestinal bleeding associated with non-steroidal anti-inflammatory drugs over the period of 1996-2005.

CONCLUSION

The rise in the incidence of upper gastrointestinal bleeding was weakly related to the change in use of non-steroidal anti-inflammatory drugs. Instead, it probably reflected the increasing use of low-dose aspirin, other antithrombotic drugs and alcohol.

Intellectual property policy in the pharmaceutical sciences: the effect of inappropriate patents and market exclusivity extensions on the health care system

Though patents are effective tools for promoting innovation and protecting intellectual property in the pharmaceutical sciences, there has been growing concern about 2 important ways that patents in this field can have a negative effect on patient care and the practice of medicine. First, inventors can seek and receive patents on pharmaceutical products or research tools that stretch the statutory requirements for patenting. Second, patent holders in the pharmaceutical market can use legal loopholes or aspects of the patent registration system to extend exclusivity for inventions beyond what was anticipated by the Patent Act or subsequent legislation. The monopoly control bestowed by such inappropriate patents or manipulation of the patent system can limit options available to patients, increase the cost of health care delivery, and make cooperative research more difficult. In response, several different government and market-based efforts have emerged to promote more equitable patent policy in health care that encourages dissemination of ideas while still supporting the development of innovative products.