Comparative efficacy of vericiguat to sacubitril/valsartan for patients with heart failure reduced ejection fraction: Systematic review and network meta-analysis

BACKGROUND

Despite the established efficacy of vericiguat compared to placebo, uncertainties remain regarding its comparative efficacy to sacubitril/valsartan for patients with heart failure reduced ejection fraction (HFrEF). This study aimed to assess the relative efficacy of vericiguat and sacubitril/valsartan through a systematic review, network meta-analysis, and non-inferiority tests.

METHODS

A systematic review was conducted to identify the randomized phase 3 clinical trials involving vericiguat and sacubitril/valsartan. The hazard ratios (HRs) with 95% confidence intervals (CI) for cardiovascular death (CVD) and hospitalization due to HF (hHF) were extracted from these trials and synthesized via network meta-analysis. Non-inferiority testing of vericiguat was performed using a fixed-margin method with a predefined non-inferiority margin (1.24). Sensitivity analyses explored the impact of the time from hHF to screening.

RESULTS

Among the 1366 studies, two trials (VICTORIA and PARADIGM-HF) met the inclusion criteria. Network meta-analysis demonstrated that the HR for CVD or hHF with vericiguat did not significantly differ from that for sacubitril/valsartan (HR: 0.88, 95% CI:0.62-1.23). The upper limit of the 95% CI was less than the predefined margin of 1.24, confirming vericiguat's non-inferiority to sacubitril/valsartan. Sensitivity analyses affirmed the robustness of the base-case results.

CONCLUSION

Vericiguat exhibited a comparable risk of CVD or hHF when contrasted with sacubitril/valsartan. Importantly, in patients with HFrEF, vericiguat's efficacy was not statistically inferior to that of sacubitril/valsartan. These findings reinforce the potential of vericiguat as a viable treatment option for this patient population.

Conducting the non-inferiority test for the means with unknown coefficient of variation in a three-arm trial

BACKGROUND

The non-inferiority test is a reasonable approach to assessing a new treatment in a three-arm trial. The three-arm trial consists of a placebo, reference, and an experimental treatment. The non-inferiority is often measured by the mean differences between the experimental and the placebo groups relative to the mean differences between the reference and the placebo groups.

METHODS

To cope with possible estimation distortion due to the allowance of heteroskedasticity, we adjust the measurement of non-inferiority by the incorporation of coefficient of variation (CV) of the experimental, the reference and the placebo groups. In this research, we propose a generalized [Formula: see text]-value based method (GPV-based method) to facilitate non-inferiority tests for the means with unknown coefficient of variation in a three-arm trial.

RESULTS

The simulation results show that the GPV-based method can not only adequately control type I error rate at nominal level better but also provide power higher than those from Delta method and the empirical bootstrap method, which verifies the feasibility of our adjustment.

CONCLUSIONS

We revise the measurement of non-inferiority by deducting the CV of each kind of treatment from the average effect of trials. CVs are included in the non-inferiority explicitly to help prevent possible estimating distortion if heteroskedasticity is allowed. Through the simulation study, the performance of GPV-based method for facilitating non-inferiority tests for the means with unknown CV in a three-arm trial is better than those from empirical bootstrap method and Delta method for small, medium and large sample sizes. Hence, the GPV-based method is recommended to be used to conduct the non-inferiority test for the means with unknown CV in a three-arm trial. The GPV-based method still performs well in non-normality cases.

A note on the determination of non-inferiority margins with application in oncology clinical trials

The goal of a non-inferiority trial is to evaluate whether the effect of an experimental treatment is not inferior to that of the active control. Determination of an appropriate non-inferiority margin is critical to the demonstration of non-inferiority. A commonly used method is called the fixed-margin approach recommended by the FDA. The fixed-margin approach consists of two steps: first the lower limit of the 1 - α * two-sided confidence interval (CI) of the active-control effect versus placebo is calculated from relevant historical trials or meta-analysis; second, the non-inferiority margin is obtained as a fraction of the lower confidence limit of the control effect to preserve partial control effect. An alternative method is to use the point estimate, instead of the lower confidence limit, of the active-control effect. The fixed-margin approach based on the lower limit may be ultra-conservative with unconditional Type 1 error rate much smaller than target α / 2 level, while the margin based on the point estimate is liberal. We derive the Type 1 error rate as a function of variances of the effect estimates in the historical and the current non-inferiority trials. We also propose an alternative approach for the non-inferiority margin that maintains the target Type 1 error rate. For the endpoint of landmark survival, we conduct simulations to compare the fixed-margin methods and the proposed method. For illustration, we apply the proposed method to an oncology non-inferiority clinical trial to determine an alternative non-inferiority margin.

Non-inferiority tests for binary endpoints with variable margins

Non-inferiority comparison between binary response rates of test and reference treatments is often performed in clinical studies. The most common approach to assess non-inferiority is to compare the difference between the estimated response rates with some margin. Previous methods use a variety of margins, including fixed margin, step-wise constant margin, and piece-wise smooth margin, where the latter two are functions of the reference response rate. The fixed margin approach assumes that the margin can be determined from historical trials with the consistent difference between the reference treatment and placebo, which may not be available. The step-wise constant margin approach suffers discontinuity in the power function which can cause trouble in sample size determination. Furthermore, many methods ignore the variability in margins dependent on the estimated reference response rate, leading to poor type I error control and power function approximation. In this study, we propose a variable margin approach to overcome the difficulties in fixed and step-wise constant margin approaches. We discuss several test statistics and evaluate their performance through simulation studies.

Sustainable use of tainted boar meat: Blending is a strategy for processed products

While forming mixtures is a widely used approach for other raw materials in food industry, it has not yet been systematically analyzed for boar tainted meat. That is why we simultaneously studied four factors relevant for the production of emulsion-type sausages: percentage boar meat (skatole concentrations up to 0.3 μg/g, androstenone up to 3.8 μg/g in melted backfat), duration of traditional smoke and concentration levels of two spices. 16 variants of Frankfurters were produced in two independent studies and evaluated by in total 211 consumers. A linear mixed effects model revealed that increased levels of boar tainted meat significantly reduced consumer acceptance which could not be compensated by increased smoke or spice levels. We propose a non-inferiority test to identify the mixture which is similarly accepted as the reference made without boar tainted meat. Up to 33% tainted boar meat is proposed, assuming a liking drop of 0.5 on a 9 point liking scale as benchmark for an inferior product.

Comparison of oral and intravenous lansoprazole for the prevention of bleeding from artificial ulcers after endoscopic submucosal dissection for gastric tumors: a prospective randomized phase II study (KDOG 0802)

BACKGROUND

Very few studies have evaluated the effectiveness of oral proton-pump inhibitors for the prevention of bleeding after endoscopic submucosal dissection (ESD) for gastric tumors. The aim of our study was to establish the non-inferiority of lansoprazole orally disintegrating (OD) tablets to intravenous lansoprazole for the prevention of bleeding from artificial ulcers after ESD.

PATIENTS AND METHODS

Consecutive patients who underwent ESD for gastric tumors were randomly assigned to receive lansoprazole OD tablets (OD group) or intravenous lansoprazole (IV group). In the OD group, lansoprazole OD tablets (30 mg) were given orally once daily for 8 weeks (56 days), starting on the day before ESD. In the IV group, lansoprazole (30 mg) was given as a continuous intravenous infusion twice daily for 3 days, starting on the day before ESD, and lansoprazole OD tablets (30 mg) were given orally once daily on days 4-56. The primary endpoint was the incidence of bleeding events within 8 weeks after ESD.

RESULTS

Among 310 enrolled patients, 304 patients (152 in the OD group and 152 in the IV group) were included in the analysis. Endoscopic hemostasis was performed in 38 patients (19 in the OD group and 19 in the IV group). The incidence of bleeding events within 8 weeks after ESD did not differ significantly between the groups (p = 0.487). Endoscopic hemostasis was performed at second-look endoscopy in 17 patients (11.2%) in the OD group and 19 patients (12.5%) in the IV group (difference, 1.3 percentage points; 90% confidence interval, - 4.8-7.4%; non-inferiority, p < 0.001).

CONCLUSIONS

The effectiveness of lansoprazole OD tablets for the prevention of bleeding from artificial ulcers after ESD was similar to that of intravenous lansoprazole. Lansoprazole OD tablets are thus considered a treatment option in patients who undergo ESD.

Validation of Milliflex® Quantum for Bioburden Testing of Pharmaceutical Products

This article reports the validation strategy used to demonstrate that the Milliflex^® Quantum yielded non-inferior results to the traditional bioburden method. It was validated according to USP <1223>, European Pharmacopoeia 5.1.6, and Parenteral Drug Association Technical Report No. 33 and comprised the validation parameters robustness, ruggedness, repeatability, specificity, limit of detection and quantification, accuracy, precision, linearity, range, and equivalence in routine operation. For the validation, a combination of pharmacopeial ATCC strains as well as a broad selection of in-house isolates were used. In-house isolates were used in stressed state. Results were statistically evaluated regarding the pharmacopeial acceptance criterion of ≥70% recovery compared to the traditional method. Post-hoc test power calculations verified the appropriateness of the used sample size to detect such a difference. Furthermore, equivalence tests verified non-inferiority of the rapid method as compared to the traditional method. In conclusion, the rapid bioburden on basis of the Milliflex^® Quantum was successfully validated as alternative method to the traditional bioburden test.LAY ABSTRACT: Pharmaceutical drug products must fulfill specified quality criteria regarding their microbial content in order to ensure patient safety. Drugs that are delivered into the body via injection, infusion, or implantation must be sterile (i.e., devoid of living microorganisms). Bioburden testing measures the levels of microbes present in the bulk solution of a drug before sterilization, and thus it provides important information for manufacturing a safe product. In general, bioburden testing has to be performed using the methods described in the pharmacopoeias (membrane filtration or plate count). These methods are well established and validated regarding their effectiveness; however, the incubation time required to visually identify microbial colonies is long. Thus, alternative methods that detect microbial contamination faster will improve control over the manufacturing process and speed up product release. Before alternative methods may be used, they must undergo a side-by-side comparison with pharmacopeial methods. In this comparison, referred to as validation, it must be shown in a statistically verified manner that the effectiveness of the alternative method is at least equivalent to that of the pharmacopeial methods. Here we describe the successful validation of an alternative bioburden testing method based on fluorescent staining of growing microorganisms applying the Milliflex^® Quantum system by MilliporeSigma.