Exposure-response analyses of efzofitimod in patients with pulmonary sarcoidosis.

Background: Preliminary evidence for efficacy in pulmonary sarcoidosis has been shown for efzofitimod. Here we present supportive evidence of efficacy based on an exposure-response analysis. Methods: Data from two studies (Phase 1, N = 24, single dose in healthy volunteers, and Phase 1b/2a, N = 25, multiple doses over 24 weeks in participants with pulmonary sarcoidosis) were used to build a population pharmacokinetic model. Using this model, the relationship between efzofitimod exposure and three prespecified efficacy parameters [mean daily oral corticosteroid (OCS) dose, percent-predicted forced vital capacity (ppFVC) and King's Sarcoidosis Questionnaire-Lung (KSQ-Lung) score] was explored. Linear regression described the relationship of efzofitimod exposure and OCS reduction, ppFVC and KSQ-Lung score. Logistic regression related efzofitimod exposure to the probability of achieving a minimal clinically important difference for ppFVC and KSQ-Lung score. Due to the small study size, trends (not statistical significance) in relationships are reported. Results: In patients with pulmonary sarcoidosis, as efzofitimod exposure increased, the mean daily OCS dose decreased, and ppFVC and KSQ-Lung score improved over baseline. The slope for all the endpoints by both linear and logistic regression showed an improving trend with increased exposure. Conclusion: These preliminary findings of a positive exposure-response across multiple efficacy endpoints support the claim that proof of concept has been established for the use of efzofitimod in pulmonary sarcoidosis. Clinical Trial Registration: clinicaltrials.gov, identifier NCT03824392.

Efzofitimod for the Treatment of Pulmonary Sarcoidosis.

BACKGROUND: Pulmonary sarcoidosis is characterized by the accumulation of immune cells that form granulomas affecting the lungs. Efzofitimod (ATYR1923), a novel immunomodulator, selectively binds neuropilin 2, which is upregulated on immune cells in response to lung inflammation. RESEARCH QUESTION: What is the tolerability, safety, and effect on outcomes of efzofitimod in pulmonary sarcoidosis? STUDY DESIGN AND METHODS: In this randomized, double-blind, placebo-controlled study evaluating multiple ascending doses of efzofitimod administered intravenously every 4 weeks for 24 weeks, randomized patients (2:1) underwent a steroid taper to 5 mg/d by week 8 or < 5 mg/d after week 16. The primary end point was the incidence of adverse events (AEs); secondary end points included steroid reduction, change in lung function, and patient-reported outcomes on health-related quality-of-life scales. RESULTS: Thirty-seven patients received at least one dose of study medication. Efzofitimod was well tolerated at all doses, with no new or unexpected AEs and no dose-dependent AE incidence. Average daily steroid doses through end of study were 6.8 mg, 6.5 mg, and 5.6 mg for the 1 mg/kg, 3 mg/kg, and 5 mg/kg groups compared with 7.2 mg for placebo, resulting in a baseline-adjusted relative steroid reduction of 5%, 9%, and 22%, respectively. Clinically meaningful improvements were achieved across several patient-reported outcomes, several of which reached statistical significance in the 5 mg/kg dose arm. A dose-dependent but nonsignificant trend toward improved lung function also was observed for 3 and 5 mg/kg. INTERPRETATION: Efzofitimod was safe and well tolerated and was associated with dose-dependent improvements of several clinically relevant end points compared with placebo. The results of this study support further evaluation of efzofitimod in pulmonary sarcoidosis. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT03824392; URL: www. CLINICALTRIALS: gov.

Use of historical control data for assessing treatment effects in clinical trials.

Clinical trials rarely, if ever, occur in a vacuum. Generally, large amounts of clinical data are available prior to the start of a study, particularly on the current study's control arm. There is obvious appeal in using (i.e., 'borrowing') this information. With historical data providing information on the control arm, more trial resources can be devoted to the novel treatment while retaining accurate estimates of the current control arm parameters. This can result in more accurate point estimates, increased power, and reduced type I error in clinical trials, provided the historical information is sufficiently similar to the current control data. If this assumption of similarity is not satisfied, however, one can acquire increased mean square error of point estimates due to bias and either reduced power or increased type I error depending on the direction of the bias. In this manuscript, we review several methods for historical borrowing, illustrating how key parameters in each method affect borrowing behavior, and then, we compare these methods on the basis of mean square error, power and type I error. We emphasize two main themes. First, we discuss the idea of 'dynamic' (versus 'static') borrowing. Second, we emphasize the decision process involved in determining whether or not to include historical borrowing in terms of the perceived likelihood that the current control arm is sufficiently similar to the historical data. Our goal is to provide a clear review of the key issues involved in historical borrowing and provide a comparison of several methods useful for practitioners.

The current state of Bayesian methods in medical product development: survey results and recommendations from the DIA Bayesian Scientific Working Group.

Bayesian applications in medical product development have recently gained popularity. Despite many advances in Bayesian methodology and computations, increase in application across the various areas of medical product development has been modest. The DIA Bayesian Scientific Working Group (BSWG), which includes representatives from industry, regulatory agencies, and academia, has adopted the vision to ensure Bayesian methods are well understood, accepted more broadly, and appropriately utilized to improve decision making and enhance patient outcomes. As Bayesian applications in medical product development are wide ranging, several sub-teams were formed to focus on various topics such as patient safety, non-inferiority, prior specification, comparative effectiveness, joint modeling, program-wide decision making, analytical tools, and education. The focus of this paper is on the recent effort of the BSWG Education sub-team to administer a Bayesian survey to statisticians across 17 organizations involved in medical product development. We summarize results of this survey, from which we provide recommendations on how to accelerate progress in Bayesian applications throughout medical product development. The survey results support findings from the literature and provide additional insight on regulatory acceptance of Bayesian methods and information on the need for a Bayesian infrastructure within an organization. The survey findings support the claim that only modest progress in areas of education and implementation has been made recently, despite substantial progress in Bayesian statistical research and software availability.

Structured approach to the elicitation of expert beliefs for a Bayesian-designed clinical trial: a case study.

To quantify uncertainty in a formal manner, statisticians play a vital role in identifying a prior distribution for a Bayesian-designed clinical trial. However, when expert beliefs are to be used to form the prior, the literature is sparse on how feasible and how reliable it is to elicit beliefs from experts. For late-stage clinical trials, high importance is placed on reliability; however, feasibility may be equally important in early-stage trials. This article describes a case study to assess how feasible it is to conduct an elicitation session in a structured manner and to form a probability distribution that would be used in a hypothetical early-stage trial. The case study revealed that by using a structured approach to planning, training and conduct, it is feasible to elicit expert beliefs and form a probability distribution in a timely manner. We argue that by further increasing the published accounts of elicitation of expert beliefs in drug development, there will be increased confidence in the feasibility of conducting elicitation sessions. Furthermore, this will lead to wider dissemination of the pertinent issues on how to quantify uncertainty to both practicing statisticians and others involved with designing trials in a Bayesian manner.