Biosimilars: Where We Were and Where We Are

BOB: Bayesian optimal design for biosimilar trials with co-primary endpoints

For regulatory approval of a biosimilar product, extensive evaluations should be performed by rigorous clinical trials to establish the similarity between the reference product and the proposed biosimilar in terms of both efficacy and safety. Existing designs for biosimilar trials often use a single primary efficacy endpoint in trial monitoring, and then separately evaluate the safety of the biosimilar product in a secondary analysis at the trial completion. However, ignoring the safety endpoint and the correlation between safety and efficacy in trial monitoring may lead to a high false positive rate, or it may delay the termination of the trial when dissimilarity in safety is early detected. We propose a Bayesian optimal design for biosimilar trials by incorporating both safety and efficacy endpoints in a unified framework. Based on a Bayesian joint safety and efficacy model, we sequentially use a so-called Bayesian biosimilar probability to make go/no-go decisions. We calibrate the Bayesian design to maximize the statistical power while maintaining the frequentist type I error rate at the nominal level. We carry out extensive simulation studies to show that the design has desirable performance in terms of the false positive rate and the average sample size. We also apply the proposed design to a biosimilar trial evaluating a ranibizumab product.

An overview of developing TNF-α targeted therapy for the treatment of psoriasis

INTRODUCTION

Three biologic drugs targeting TNF-α are approved to treat moderate-to-severe cutaneous psoriasis. These are adalimumab, etanercept and infliximab. These drugs are given by subcutaneous injection or intravenous infusion, and while generally safe and effective, they are expensive with potential for side effects. Thus, numerous new drug candidates are under development that also target TNF-α.

AREAS COVERED

In this review, the authors detail several drugs under development that target TNF-α, focusing on those drugs in preclinical, Phase I and II trials. The authors describe emerging biologic psoriasis therapies, including biosimilars and novel biologics, in addition to several synthetic and naturally derived small-molecule drug candidates.

EXPERT OPINION

The currently approved TNF-α antagonists benefit from over 10 years of safety and efficacy data. The expense and method of administration of these biologics, however, can be cumbersome, and less expensive alternatives have the potential to benefit patients with psoriasis. It is inevitable, despite the introduction of new anti-IL-17 therapies, that established TNF-α targeted therapies, as well as newcomers targeting TNF-α, will continue to play an important role in the lifelong management of psoriasis.