Robert Hemmings

Adaptive clinical trial designs for European marketing authorization: a survey of scientific advice letters from the European Medicines Agency.

BackgroundSince the first methodological publications on adaptive study design approaches in the 1990s, the application of these approaches in drug development has raised increasing interest among academia, industry and regulators. The European Medicines Agency (EMA) as well as the Food and Drug Administration (FDA) have published guidance documents addressing the potentials and limitations of adaptive designs in the regulatory context. Since there is limited experience in the implementation and interpretation of adaptive clinical trials, early interaction with regulators is recommended. The EMA offers such interactions through scientific advice and protocol assistance procedures.MethodsWe performed a text search of scientific advice letters issued between 1 January 2007 and 8 May 2012 that contained relevant key terms. Letters containing questions related to adaptive clinical trials in phases II or III were selected for further analysis. From the selected letters, important characteristics of the proposed design and its context in the drug development program, as well as the responses of the Committee for Human Medicinal Products (CHMP)/Scientific Advice Working Party (SAWP), were extracted and categorized. For 41 more recent procedures (1 January 2009 to 8 May 2012), additional details of the trial design and the CHMP/SAWP responses were assessed. In addition, case studies are presented as examples.ResultsOver a range of 5½ years, 59 scientific advices were identified that address adaptive study designs in phase II and phase III clinical trials. Almost all were proposed as confirmatory phase III or phase II/III studies. The most frequently proposed adaptation was sample size reassessment, followed by dropping of treatment arms and population enrichment. While 12 (20%) of the 59 proposals for an adaptive clinical trial were not accepted, the great majority of proposals were accepted (15, 25%) or conditionally accepted (32, 54%). In the more recent 41 procedures, the most frequent concerns raised by CHMP/SAWP were insufficient justifications of the adaptation strategy, type I error rate control and bias.ConclusionsFor the majority of proposed adaptive clinical trials, an overall positive opinion was given albeit with critical comments. Type I error rate control, bias and the justification of the design are common issues raised by the CHMP/SAWP.

Cancer Drug Development and the Evolving Regulatory Framework for Companion Diagnostics in the European Union

The European Union (EU) legal framework for medical device regulation is currently under revision. The European Commission has proposed a new framework to ensure that medical devices serve the needs and ensure the safety of European citizens, aiming for a framework that is fit for purpose, more transparent, and better adapted to scientific and technological progress. The proposed new framework is described as an evolution of the current regime keeping the same legal approach. An important proposed change is that companion diagnostics will no longer be considered as low risk and subject to self-certification by the manufacturer. According to the new proposal, companion diagnostics will be classified as high individual risk or moderate public health risk (category C) and require conformity assessment by a notified body. It has also been proposed that evidence of the clinical utility of the device for the intended purpose should be required for companion diagnostics. In this article, we review the EU legal framework relevant for companion diagnostics, describe the proposed changes, and summarize the available scientific guidance from the European Medicines Agency and its regulatory experience with cancer drug development including companion diagnostics. See all articles in this CCR Focus section, “The Precision Medicine Conundrum: Approaches to Companion Diagnostic Co-development.” Clin Cancer Res; 20(6); 1458–68. ©2014 AACR.

The European Medicines Agency Review of Cabazitaxel (Jevtana®) for the Treatment of Hormone-Refractory Metastatic Prostate Cancer: Summary of the Scientific Assessment of the Committee for Medicinal Products for Human Use

On March 17, 2011 the European Commission issued a marketing authorization valid throughout the European Union for Jevtana® (Sanofi-Aventis, Paris, France) for the treatment of patients with hormone-refractory metastatic prostate cancer previously treated with a docetaxel-containing regimen. The active substance of Jevtana® is cabazitaxel acetone solvate, an antineoplastic agent that acts by disrupting the microtubular network in cells. The recommended dose of cabazitaxel is 25 mg/m2 administered as a 1-hour i.v. infusion every 3 weeks in combination with oral prednisone or prednisolone, 10 mg, administered daily throughout treatment. In the main study submitted for this application, a 2.4-month longer median overall survival time and a 30% lower risk for death were observed for cabazitaxel, compared with mitoxantrone. The most common side effects with cabazitaxel were anemia, leukopenia, neutropenia, thrombocytopenia, and diarrhea. This paper summarizes the scientific review of the application leading to approval in the European Union. The detailed scientific assessment report and product information, including the summary of product characteristics, are available on the European Medicines Agency Web site (http://www.ema.europa.eu).

The European Medicines Agency approval of ingenol mebutate (Picato) for the cutaneous treatment of non-hyperkeratotic, non-hypertrophic actinic keratosis in adults: Summary of the scientific assessment of the Committee for Medicinal Products for Human Use (CHMP)

BackgroundThe European Commission has recently issued a marketing authorisation valid throughout the European Union for ingenol mebutate (Picato) in the cutaneous treatment of non-hyperkeratotic, non-hypertrophic actinic keratosis in adults.ObjectivesThe objective of this paper is to summarise the scientific review of the application leading to regulatory approval in the EU. The full scientific assessment report and product information, including the summary of product characteristics, are available on the EMA website (www.ema.europa.eu).Material & MethodsThe application was supported by 25 clinical studies, of which 18 were performed in patients with actinic keratosis.ResultsThe active substance is a pure ingenol angelate obtained from the aerial parts of the plant species Euphorbia peplus by extraction and purification. One tube of ingenol mebutate 150 mcg/g gel or 500 mcg/g gel should be applied once daily to the affected area for 3 or 2 consecutive days on the ‘face and scalp’ or ‘trunk and extremities’, respectively. Complete response rate is 42.2% on the ‘face and scalp’ and 34.1% on the ‘trunk and extremities’. The most common side effects are local skin responses including erythema, flaking/scaling, crusting, swelling, vesiculation/pustulation and erosion/ulceration at the application site.ConclusionsThe benefits of ingenol mebutate are its ability to improve the complete response rate of actinic keratosis, the short duration of treatment and the ease of self-application.

The European Medicines Agency Review of Pomalidomide in Combination With Low-Dose Dexamethasone for the Treatment of Adult Patients With Multiple Myeloma: Summary of the Scientific Assessment of the Committee for Medicinal Products for Human Use

On August 5, 2013, a marketing authorization valid throughout the European Union (EU) was issued for pomalidomide in combination with dexamethasone for the treatment of adult patients with relapsed and refractory multiple myeloma (MM) who have received at least two prior treatment regimens, including both lenalidomide and bortezomib, and have demonstrated disease progression on the last therapy. Pomalidomide is an immunomodulating agent. The recommended starting dose of pomalidomide is 4 mg once daily taken on days 1-21 of repeated 28-day cycles. The main evidence of efficacy for pomalidomide in MM was based on a phase III multicenter, randomized, open-label study (CC-4047-MM-003) in which pomalidomide plus low-dose dexamethasone therapy (POM+LoDEX) was compared with high-dose dexamethasone alone (HiDEX) in previously treated adult patients with relapsed and refractory multiple myeloma who had received at least two prior treatment regimens, including both lenalidomide and bortezomib, and had demonstrated disease progression on the last therapy. For the intent-to-treat population, median progression-free survival based on International Myeloma Working Group criteria was 15.7 weeks (95% confidence interval [CI]: 13.0-20.1) in the POM+LoDEX group versus 8.0 weeks (95% CI: 7.0-9.0) in the HiDEX group (log-rank p value <.001). Overall survival (secondary endpoint) was also different in the two treatment groups (hazard ratio 0.53 [95% CI: 0.37-0.74]). The most commonly reported adverse reactions to pomalidomide in clinical studies were anemia (45.7%), neutropenia (45.3%) and thrombocytopenia (27%), fatigue (28.3%), pyrexia (21%), peripheral edema (13%), and infections including pneumonia (10.7%). Peripheral neuropathy adverse reactions were reported in 12.3% of patients, and venous embolic or thrombotic (VTE) adverse reactions were reported in 3.3% of patients. Pomalidomide is expected to be teratogenic. This paper summarizes the scientific review of the application leading to approval in the EU. The detailed scientific assessment report and product information, including the summary of product characteristics, are available on the EMA website (http://www.ema.europa.eu).

Regulatory watch: Impact of scientific advice from the European Medicines Agency

18/28 16/18 2/10 87/118 74/88 13/30 Scientific advice (SA) provided by the European Medicines Agency (EMA) was initiated in 1996 as a tool to improve communication between sponsors and regulators throughout drug development. Its aim is to support sponsors to provide adequate data for benefit–risk assessment at the time of marketing authorization application (MAA), and thereby to facilitate the introduction of new, safe and effective medicines. SA is voluntary and non‐binding, and may be given on all aspects of drug development programmes by the Scientific Advice Working Party (SAWP) of the EMA’s Committee for Medicinal Products for Human Use (CHMP). Compliance with SA recommendations on clinical trial design has previously been shown to correlate with MAA success R E G U L ATO RY WAT C H

Regulatory perspectives on data safety monitoring boards: protecting the integrity of data.

The use of interim analyses and data safety monitoring boards (DSMBs) can assist greatly in the timely determination of whether or not a medicine has an acceptable benefit-risk profile. Regulatory authorities regard the appropriate use of interim analyses favourably, but will consider the extent to which the conduct of interim analyses and the involvement of DSMBs may have compromised the evidence of efficacy and safety from a clinical trial. Issues of particular concern, which may potentially introduce bias, include the dissemination of interim data and the rules by which a trial might be terminated early. If data from trials which employ a DSMB are to be considered reliable and scientifically valid, it is the responsibility of the trial sponsor to demonstrate that the DSMB is set up and run appropriately and to verify that any bias introduced has had no important effect on the conclusions.

An Overview of Statistical and Regulatory Issues in the Planning, Analysis, and Interpretation of Subgroup Analyses in Confirmatory Clinical Trials

Whether confirmatory or exploratory in nature, the investigation of subgroups poses statistical and interpretational challenges, yet these investigations can have important consequences for product licensing, labeling, reimbursement, and prescribing decisions. This article provides a high-level, nontechnical summary of key statistical issues in the analysis of subgroups, with a focus on the regulatory context in which drug development and licensing decisions are made. References to specific aspects of regulatory processes are based on the system in Europe, though it is hoped that the principles outlined can be generally applied to other regulatory regions. This article challenges the common assumption that a clinical trial population should be assumed to be homogeneous, with homogeneous response to treatment, and asks whether commonly employed strategies for handling and identifying potential heterogeneity are sufficient. Investigations into subgroups are unavoidable, yet subgroup analyses suffer from fundamental complications and limitations of which those planning and interpreting clinical trials must be aware. Some areas for further methodological work and an improved methodological framework for the conduct of exploratory subgroup analyses are discussed. Above all, the need for an integrated scientific approach is highlighted.

The European Medicines Agency Review of Abiraterone for the Treatment of Metastatic Castration-Resistant Prostate Cancer in Adult Men After Docetaxel Chemotherapy and in Chemotherapy-Naïve Disease: Summary of the Scientific Assessment of the Committee for Medicinal Products for Human Use

On September 5, 2011, abiraterone was approved in the European Union in combination with prednisone or prednisolone for the treatment of metastatic castration-resistant prostate cancer (CRPC) in adult men whose disease has progressed on or after a docetaxel-based chemotherapy regimen. On December 18, 2012, the therapeutic indication was extended to include the use of abiraterone in combination with prednisone or prednisolone for the treatment of metastatic CRPC in adult men who are asymptomatic or mildly symptomatic after failure of androgen deprivation therapy in whom chemotherapy is not yet clinically indicated. Abiraterone is a selective, irreversible inhibitor of cytochrome P450 17α, an enzyme that is key in the production of androgens. Inhibition of androgen biosynthesis deprives prostate cancer cells from important signals for growth, even in cases of resistance to castration. At the time of European Union approval and in a phase III trial in CRPC patients who had failed at least one docetaxel-based chemotherapy regimen, median overall survival for patients treated with abiraterone was 14.8 months versus 10.9 months for those receiving placebo (hazard ratio, 0.65; 95% confidence interval 0.54-0.77; p < .0001). In a subsequent phase III trial in a similar but chemotherapy-naïve patient population, median radiographic progression-free survival was 16.5 months for patients in the abiraterone treatment arm versus 8.3 months for patients in the placebo arm (hazard ratio, 0.53; 95% confidence interval, 0.45-0.62; p < .0001). Abiraterone was most commonly associated with adverse reactions resulting from increased or excessive mineralocorticoid activity. These were generally manageable with basic medical interventions. The most common side effects (affecting more than 10% of patients) were urinary tract infection, hypokalemia, hypertension, and peripheral edema.

Seeking harmony: estimands and sensitivity analyses for confirmatory clinical trials

In October 2014, the Steering Committee of the International Conference on Harmonization endorsed the formation of an expert working group to develop an addendum to the International Conference on Harmonization E9 guideline (“Statistical Principles for Clinical Trials”). The addendum will focus on two topics involving randomized confirmatory clinical trials: estimands and sensitivity analyses. Both topics are motivated, in part, by the need to improve the precision with which scientific questions of interest are formulated and addressed by clinical trialists and regulators, specifically in the context of post-randomization events such as use of rescue medication or missing data resulting from dropouts. Given the importance of these topics for the statistical and medical community, we articulate the reasons for the planned addendum. The resulting “ICH E9/R1” guideline will include a framework for improved trial planning, conduct, analysis, and interpretation; a draft is expected to be ready for public comment in the second half of 2016.