Tree-temporal scan statistics for safety signal detection in vaccine clinical trials

The evaluation of safety is critical in all clinical trials. However, the quantitative analysis of safety data in clinical trials poses statistical difficulties because of multiple potentially overlapping endpoints. Tree-temporal scan statistic approaches address this issue and have been widely employed in other data sources, but not to date in clinical trials. We evaluated the performance of three complementary scan statistical methods for routine quantitative safety signal detection: the self-controlled tree-temporal scan (SCTTS), a tree-temporal scan based on group comparison (BGTTS), and a log-rank based tree-temporal scan (LgRTTS). Each method was evaluated using data from two phase III clinical trials, and simulated data (simulation study). In the case study, the reference set was adverse events (AEs) in the Reference Safety Information of the evaluated vaccine. The SCTTS method had higher sensitivity than other methods, and after dose 1 detected 80 true positives (TP) with a positive predictive value (PPV) of 60%. The LgRTTS detected 49 TPs with 69% PPV. The BGTTS had 90% of PPV with 38 TPs. In the simulation study, with simulated reference sets of AEs, the SCTTS method had good sensitivity to detect transient effects. The LgRTTS method showed the best performance for the detection of persistent effects, with high sensitivity and expected probability of type I error. These three methods provide complementary approaches to safety signal detection in clinical trials or across clinical development programmes. All three methods formally adjust for multiple testing of large numbers of overlapping endpoints without being excessively conservative.

Co-administration of the adjuvanted recombinant zoster vaccine with other adult vaccines: An overview

BACKGROUND

The adjuvanted recombinant zoster vaccine (RZV; Shingrix®, GSK) is a subunit vaccine that has been approved for the prevention of herpes zoster in adults. Co-administration of two vaccines in a single visit is a strategy to improve overall vaccine coverage.

OBJECTIVES

This review aims to consolidate available clinical data on RZV co-administration, providing an overview of safety, reactogenicity and immunogenicity.

METHODS

RZV co-administration data were obtained from five randomised, open-label, phase III clinical trials with similar study designs. The co-administered vaccines included: quadrivalent seasonal inactivated influenza vaccine (IIV4; NCT01954251), 23-valent pneumococcal polysaccharide vaccine (PPSV23; NCT02045836), reduced-antigen-content diphtheria-tetanus-acellular pertussis vaccine (Tdap; NCT02052596), 13-valent pneumococcal conjugate vaccine (PCV13; NCT03439657) and COVID-19 mRNA-1273 booster (NCT05047770). Eligible participants were healthy adults aged ≥50 years.

RESULTS

A total of 3,974 participants were vaccinated (co-administration: 1,973; sequential: 2,001) across the five trials. Vaccine response rates to RZV were similar for co-administration (range: 95.8-99.1 %) and sequential groups (range: 95.1-99.1 %). Immune responses to RZV and the other vaccines (with the exception of pertactin) were non-inferior when the vaccines were co-administered compared with sequentially administered. Overall incidences of solicited local and general adverse events (AEs), unsolicited AEs, serious AEs or potential immune-mediated diseases were similar after co-administration or sequential administration. Myalgia was the most common solicited systemic AE (co-administration: 38-64 %; sequential: 30-59 %). Shivering and fever were more common after co-administration (16 % and 21 %, respectively) than after sequential administration (both 7 %) of RZV and PPSV23.

CONCLUSIONS

Co-administration of RZV with routine vaccines does not significantly alter the reactogenicity, immunogenicity or safety of RZV or the co-administered vaccine. Healthcare practitioners should consider routine co-administration of RZV with other adult vaccines to improve vaccination coverage.

A Model for Monitoring Spontaneously Reported Medication Errors Using the Adjuvanted Recombinant Zoster Vaccine as an Example

A European legislation was put in place for the reporting of medication errors, and guidelines were drafted to help stakeholders in the reporting, evaluation, and, ultimately, minimization of these errors. As part of pharmacovigilance reporting, a proper classification of medication errors is needed. However, this process can be tedious, time-consuming, and resource-intensive. To fulfill this obligation regarding medication errors, we developed an algorithm that classifies the reported errors in an automated way into four categories: potential medication errors, intercepted medication errors, medication errors without harm (i.e., not associated with adverse reaction(s)), and medication errors with harm (i.e., associated with adverse reaction(s)). A fifth category ("conflicting category") was created for reported cases that could not be unambiguously classified as either potential or intercepted medication errors. Our algorithm defines medication error categories based on internationally accepted terminology using the Medical Dictionary for Regulatory Activities (MedDRA®) preferred terms. We present the algorithm and the strengths of this automated way of reporting medication errors. We also give examples of visualizations using spontaneously reported vaccination error data associated with the adjuvanted recombinant zoster vaccine. For this purpose, we used a customized web-based platform that uses visualizations to support safety signal detection. The use of the algorithm facilitates and ensures a consistent way of categorizing medication errors with MedDRA® terms, thereby saving time and resources and avoiding the risk of potential mistakes versus manual classification. This allows further assessment and potential prevention of medication errors. In addition, the algorithm is easy to implement and can be used to categorize medication errors from different databases.

Effectiveness and safety of recombinant zoster vaccine: A review of real-world evidence

The recombinant zoster vaccine (RZV) was licensed in the US for prevention of herpes zoster (HZ) in 2017. We conducted a literature search (January 1, 2017-August 1, 2023) using PubMed, Embase, and Scopus to consolidate the real-world evidence related to RZV. Overall, RZV effectiveness against HZ was high across the studied populations in real-world settings, including adults aged ≥ 50 years and patients aged ≥ 18 years with immunodeficiency or immunosuppression. Effectiveness was higher with two doses versus one dose, especially in elderly people and immunocompromised individuals. The safety profile of RZV was broadly consistent with that established in clinical trials. RZV does not appear to increase the risk of disease flares in patients with immune-mediated diseases. Approximately two-thirds of individuals received a second RZV dose within 2-6 months after the first dose. Collectively, RZV effectiveness against HZ was high, and these real-world studies reaffirm its favorable benefit-risk profile.

Recombinant Zoster Vaccine Is Efficacious and Safe in Frail Individuals

BACKGROUND/OBJECTIVES

Frail participants are often under-represented in randomized trials, raising questions about outcomes of interventions in real-world settings. Frailty is strongly associated with vulnerability to illness and adverse health outcomes. We studied the impact of frailty on recombinant zoster vaccine (RZV) clinical outcomes.

DESIGN/SETTING

Data from two previously conducted phase III randomized trials of RZV were pooled. These two parent trials were conducted concurrently at the same study sites using the same methods.

PARTICIPANTS/INTERVENTION

In the two parent studies, participants aged ≥50 years (ZOE-50 study) and ≥70 years (ZOE-70 study), respectively, were randomized 1:1 to receive two doses of RZV or placebo.

MEASUREMENTS

In the current ZOE-Frailty study (NCT03563183), a frailty index was created using previously validated methods. Clinical outcomes assessed by frailty status included vaccine efficacy, immunogenicity, reactogenicity, and safety.

RESULTS

Of 29,305 participants from the pooled ZOE-50 and ZOE-70 total vaccinated cohort, 92% were included in this study. Mean age was 68.8 years; 58.1% were women; 45.6% were pre-frail and 11.3% frail. The percentage of frail participants increased with age from 5.7% aged 50-59 years to 22.7% aged ≥80 years. RZV vaccine efficacy against herpes zoster was >90% for all frailty subgroups (non-frail: 95.8% (95% confidence interval = 91.6-98.2), pre-frail: 90.4% (84.4-94.4), frail: 90.2% (75.4-97.0)). The RZV group demonstrated robust anti-gE antibody and gE-specific CD4²⁺ responses, with mean concentrations remaining above pre-vaccination levels at least 3 years post-dose two, in all frailty subgroups. In the RZV group, the percentage of participants reporting solicited adverse events tended to decrease with increasing frailty.

CONCLUSION

The relatively nonrestrictive inclusion/exclusion criteria in the parent ZOE studies resulted in a range of participants that included frail and pre-frail older adults. RZV significantly reduced the risk of herpes zoster across all frailty subgroups.