Equivalence tests for interchangeability based on two one-sided probabilities

Use of tolerance intervals for assessing biosimilarity

A biosimilar is a biological product that is highly similar to an existing approved reference drug and has no clinically meaningful difference from it. Biosimilars are composed of or derived from living cells or organisms. Therefore, they are often sensitive to slight variations in the manufacturing process. Consequently, in demonstrating biosimilarity, it might be inappropriate to focus solely on the mean difference, or ratio of means, while ignoring the variabilities associated with the test and reference products. It is important to account for the entire population of clinical outcomes. Thus, we propose using the concept of tolerance intervals and related hypothesis testing for assessing biosimilarity. Our approach has the advantage of considering entire populations associated with both groups. A real example is used to illustrate our proposed method, and our approach is more stringent than those that employ confidence intervals. This is specifically the case when the mean difference of two drugs is not sufficiently large, but the biosimilar has a higher variability than that in the reference drug.

A Handheld and Textile-Enabled Bioimpedance System for Ubiquitous Body Composition Analysis. An Initial Functional Validation

In recent years, many efforts have been made to promote a healthcare paradigm shift from the traditional reactive hospital-centered healthcare approach towards a proactive, patient-oriented, and self-managed approach that could improve service quality and help reduce costs while contributing to sustainability. Managing and caring for patients with chronic diseases accounts over 75% of healthcare costs in developed countries. One of the most resource demanding diseases is chronic kidney disease (CKD), which often leads to a gradual and irreparable loss of renal function, with up to 12% of the population showing signs of different stages of this disease. Peritoneal dialysis and home haemodialysis are life-saving home-based renal replacement treatments that, compared to conventional in-center hemodialysis, provide similar long-term patient survival, less restrictions of life-style, such as a more flexible diet, and better flexibility in terms of treatment options and locations. Bioimpedance has been largely used clinically for decades in nutrition for assessing body fluid distributions. Moreover, bioimpedance methods are used to assess the overhydratation state of CKD patients, allowing clinicians to estimate the amount of fluid that should be removed by ultrafiltration. In this work, the initial validation of a handheld bioimpedance system for the assessment of body fluid status that could be used to assist the patient in home-based CKD treatments is presented. The body fluid monitoring system comprises a custom-made handheld tetrapolar bioimpedance spectrometer and a textile-based electrode garment for total body fluid assessment. The system performance was evaluated against the same measurements acquired using a commercial bioimpedance spectrometer for medical use on several voluntary subjects. The analysis of the measurement results and the comparison of the fluid estimations indicated that both devices are equivalent from a measurement performance perspective, allowing for its use on ubiquitous e-healthcare dialysis solutions.

Investigation into the interchangeability of generic formulations using immunosuppressants and a broad selection of medicines

Purpose

To date, the interchangeability of generic drugs has only been investigated for a limited number of medicines. The objective of this study was to investigate generic-generic drug interchangeability in a large subset of generic formulations in order to cover a broad spectrum of drugs.

Methods

Orally administered drugs for investigation in this study were selected using strict, predefined criteria, with the purpose to avoid bias. This selection procedure yielded atorvastatin, bicalutamide, naratriptan, olanzapine, perindopril, and venlafaxine. Further, ciclosporin, tacrolimus, and mycophenolate mofetil were investigated as test immunosuppressants. Adjusted indirect comparisons were conducted between generic drugs containing the same active substance, and the 90 % confidence interval (CI) for AUC and C_max was calculated.

Results

In total, 120 bioequivalence studies were identified in the Dutch medicine regulatory agency’s database, allowing 292 indirect comparisons between generic drugs. The indirect comparison results indicated that in the vast majority of cases, i.e., 80.5 %, the 90 % CIs for both AUC_t and C_max fell within the bioequivalence criteria (in 90.1 and 87.0 % for AUC_t and C_max, respectively). In 1 % of the 292 indirect comparison for AUC_t and 3 % for C_max, a wider range of 75–133 % (or 80–125 %) was exceeded.

Conclusions

Overall, our study suggests that exposure-related risks associated with the exchange of different generic drugs in clinical practice are not increased to a relevant extent compared to the situation in which a generic is exchanged with the innovator.

Electronic supplementary material

The online version of this article (doi:10.1007/s00228-015-1878-z) contains supplementary material, which is available to authorized users.