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Calcium Up-Regulation by Percutaneous Administration of Gene Therapy in Cardiac Disease Phase 2b (CUPID 2): a Randomised, Multinational, Double-Blind, Placebo-controlled Trial
Barry Greenberg, Javed Butler, G. Michael Felker, Piotr Ponikowski, Adriaan A. Voors, Akshay S. Desai, Denise Barnard, MD; Alain Bouchard, Brian Jaski, Alexander R. Lyon, MD, PhD; Janice M. Pogoda, Jeffrey J. Rudy, Krisztina M. Zsebo
Affiliations: UCSD Sulpizio Cardiovascular Center, La Jolla, CA, USA (Prof B Greenberg MD, Prof D Barnard MD); Stony Brook University, Stony Brook, NY, USA (Prof J Butler MD); Duke University School of Medicine, Durham, NC, USA (Prof G M Felker MD); Wroclaw Medical University and Military Hospital, Wroclaw, Poland (Prof P Ponikowski MD); University of Groningen, Groningen, Netherlands (Prof A A Voors MD); Cardiovascular Division, Brigham and Women’s Hospital, Boston, MA, USA (A S Desai MD); Cardiology, PC, Birmingham, AL, USA (A Bouchard MD); San Diego Cardiac Center, Sharp Memorial Hospital, San Diego, CA, USA (B Jaski MD); Royal Brompton Hospital and Imperial College London, London, UK (A R Lyon MD); Celladon Corporation, San Diego, CA, USA (J M Pogoda PhD, J J Rudy BS); Santa Barbara, CA, USA (K M Zsebo PhD)
Corresponding Author:
Barry Greenberg, MD
Distinguished Professor of Medicine
Director Advanced Heart Failure Treatment Program
UCSD Sulpizio Cardiovascular Center
9444 Medical Center Dr., #7411
La Jolla, CA 92037-7411
Phone: 858-657-5267
Email:
Key Words: Gene transfer therapy, heart failure, SERCA2a
Funding statement: The clinical study, data analyses, and manuscript support were funded by Celladon Corporation.
Summary
Background Sarco/endoplasmic reticulum Ca2+ ATPase (SERCA2a) activity is deficient in the failing heart. Correction of this abnormality by gene transfer may improve cardiac function. CUPID 2 investigated the clinical benefits and safety of gene therapy through infusion of adeno-associated virus 1 (AAV1)/SERCA2a in heart failure patients with reduced ejection fraction.
Methods CUPID 2 was a phase 2b, multinational, double-blind, placebo-controlled study of high-risk ambulatory patients with New York Heart Association class II-IV symptoms, ischemic or non-ischemic aetiology, and left ventricular ejection fraction ≤0·35. The study was conducted at 67 clinical centres and hospitals in the United States, Europe, and Israel. Patients were randomised 1:1 via an interactive voice and web response system to receive a single intracoronary infusion of 1x1013 DNase-resistant particles of AAV1/SERCA2a or placebo. Randomisation was stratified by country and by 6 minute walk test distance. Patients were followed for ≥12 months. The primary efficacy endpoint was time to recurrent events (hospitalization, ambulatory worsening heart failure treatment) analysed using a joint frailty model to account for multiple, correlated events within subjects. Primary efficacy endpoint analyses and safety analyses were performed on all treated patients. The trial was registered with clinicaltrials.gov, number NCT01643330, and is now closed.
Findings Between July 9, 2012 and February 5, 2014, 1558 patients were screened and 250 were enrolled; 121 were infused with AAV1/SERCA2a and 122 with placebo. Compared with placebo, AAV1/SERCA2a did not improve the primary endpoint (128 recurrent events versus 104 recurrent events; hazard ratio 0·93; 95% CI 0·53—1·65; p=0·81). No safety issues were noted.
Interpretation CUPID 2 was the largest gene transfer study performed in heart failure patients to date. Despite promising results from earlier studies, a single intracoronary infusion of AAV1/SERCA2a at the dose tested did not improve the clinical course of heart failure patients with reduced ejection fraction.
Funding Celladon Corporation.
Introduction
Despite advances in treatment, morbidity and mortality remain unacceptably high for patients with heart failure (HF)1 and new approaches for improving outcomes are needed. Identification of derangements in key pathways that regulate cardiac function has provided potential novel targets for gene therapy, and evidence that vectors such as adeno-associated viruses (AAVs) can deliver genes of interest to cardiomyocytes, resulting in sustained transgene expression in the heart, has stimulated interest in gene transfer as a strategy for treating HF. The sarco/endoplasmic reticulum Ca2+ ATPase (SERCA2a) regulates cardiomyocyte contraction and relaxation by transporting Ca2+ from the cytosol into the sarcoplasmic reticulum during diastole.2,3 A deficiency of SERCA2a is related to HF progression.4,5 Correction of this deficiency has been shown to favourably affect calcium flux and improve the function of cardiomyocytes derived from failing hearts. Gene transfer of SERCA2a has also been shown to improve cardiac performance and survival in experimental models of HF.4,5 Recently, we reported that a single intracoronary infusion of recombinant AAV serotype 1 (AAV1) delivering the SERCA2a gene to the heart had favourable effects in patients with advanced HF in a pilot study.6,7 On the basis of these promising results, the Calcium Up-Regulation by Percutaneous Administration of Gene Therapy in Cardiac Disease Phase 2b (CUPID 2) study was designed to further assess the effects of AAV1/SERCA2a therapy on clinical outcomes in a larger group of patients with moderate to severe HF and reduced ejection fraction.8
METHODS
Study design
The CUPID Phase 2b trial (CUPID 2; NCT01643330) was a multinational, double-blind, placebo-controlled, randomised study designed to investigate whether gene transfer therapy with SERCA2a improved outcomes in patients with HF and reduced ejection fraction. The study design has been published.8 The study was conducted at 67 centres and hospitals in the United States (US), Europe, and Israel according to the principles of the International Conference on Harmonisation Guideline on Good Clinical Practice and the principles of the World Medical Association Declaration of Helsinki. All relevant Institutional Review Board and Institutional Bio-Safety Committee approvals were obtained at each site. Manufacturing information is provided in the Appendix (p 4).
Participants
Eligible patients were between 18 and 80 years of age with a diagnosis of stable New York Heart Association (NYHA) class II-IV chronic HF due to ischemic or non-ischemic cardiomyopathy and left ventricular ejection fraction ≤0·35 on optimal tolerated stable medical therapy for at least 30 days prior to randomisation. In response to a lower than anticipated pooled event rate during the early period of the trial, a protocol amendment designed to increase risk for future HF events was initiated after enrolment of 101 patients. This amendment required eligible patients to have elevated N-terminal pro–B-type natriuretic peptide (NT-proBNP) (>1,200 pg/mL, or >1,600 pg/mL if atrial fibrillation was present) or HF-related hospitalization within 6 months of enrolment into the study. Patients were required to have <1:2 or equivocal anti-AAV1 neutralizing antibody (NAb) titres at screening.
Exclusion criteria included cardiac surgery, percutaneous coronary intervention, valvuloplasty, or intravenous (IV) therapy for HF within 30 days prior to screening. A comprehensive list of exclusion criteria has been published.8 All patients provided written informed consent.
Randomisation and masking
Following screening, patients were randomised in parallel in a 1:1 ratio to receive either 1x1013 DNase resistant particles (DRP) AAV1/SERCA2a or placebo. Randomisation was conducted through a fully validated and controlled interactive voice and web response system provided by Almac Clinical Technologies. Randomisation was stratified by country and the ability to walk between 150 and 425 meters or outside of these distances on the 6 minute walk test (6MWT). A blinded kit was shipped to the investigative site following randomisation. All patients and physicians were blinded to treatment assignment, and the company that conducted randomisation was not involved with other facets of the trial.
Procedures
Drug was administered a single time to each patient. On day 0, before infusion of the investigational product, coronary angiography was performed to determine the strategy for administering AAV1/SERCA2a and to confirm that at least one coronary artery had Thrombolysis in Myocardial Infarction (TIMI) flow grade 3. Infusion of the investigational product was tailored to the patient and multiple infusion scenarios were possible depending on the extent and distribution of coronary artery stenosis, collateralization patterns, and anatomic variations. During the single administration of drug, operators were instructed to provide delivery using at most three infusions according to the distribution of left ventricular blood flow.8 The overall goal was to achieve homogeneous delivery to the myocardium with two-thirds of the dose to the anterolateral and one-third to the posterolateral myocardium. It was recognized that multiple coronary infusion scenarios were possible based on occlusive disease and collateralization patterns and investigators received instruction regarding perfusion options at the time their sites were activated. An IV nitroglycerin infusion was started 10 to 25 minutes prior to infusion of the investigational product to enhance uptake of AAV1/SERCA2a in cardiomyocytes by increasing vasodilation of the capillary bed.9
During the 12-month active observation period, assessments of efficacy, safety, and quality of life were undertaken at months 1, 3, 6, 9, and 12. Data collection on clinical endpoints continued until the primary analysis data cutoff was reached, which was when all patients completed the 12-month active observation period and at least 186 adjudicated HF-related recurrent events had occurred.
Outcomes
The primary efficacy endpoint was time to recurrent events, defined as hospitalizations due to HF or ambulatory treatment for worsening HF. The secondary efficacy endpoint was time to first terminal event, defined as all-cause death, heart transplant, or durable mechanical circulatory support device (MCSD) implantation. All primary and secondary endpoints were reviewed by a blinded clinical endpoints committee (Appendix p 3) and adjudicated according to standardized definitions. Adjudication criteria for these events, as well as detailed statistical methods, have been previously described.8 Exploratory analyses included the effect of the investigational product on change from baseline in NYHA class, exercise ability as assessed by the 6MWT, quality of life as assessed by the Kansas City Cardiomyopathy Questionnaire (KCCQ), and NT-proBNP.
Safety was assessed in all patients who received treatment with AAV1/SERCA2a or placebo. Safety parameters included incidence and severity of adverse events and time to cardiovascular-related death.
Post-treatment tissue and serum processing
During follow-up of patients enrolled in the study, participating centres were instructed to try to obtain tissue samples from treated patients at the time of cardiac transplantation, implantation of a MCSD, or at autopsy. The levels of AAV1/SERCA2a were determined using methods previously described.7 In addition, AAV1 NAb testing was performed in study patients using serum collected at the 6 month follow-up visit.
Statistical analysis
Monte Carlo simulation using background rates and correlations similar to those observed in CUPID 1 estimated that 186 recurrent events in 250 patients with a median follow-up time of 18 months would provide 80% power at the 0·05 two-sided significance level to detect a recurrent event hazard ratio (HR) of 0·55 using a joint frailty model.
The intention-to-treat (ITT) analysis population was defined as all randomised subjects.10 A modified ITT (mITT) analysis population was also pre-specified, comprising only randomised patients who received study medication.10,11 The primary analysis of the primary and secondary endpoints was done at the primary analysis data cutoff using the mITT population ; secondary analyses were done using the ITT population (all randomised patients) and additional pre-specified populations (Appendix p 5). Treatment effects on the primary and secondary endpoints were estimated simultaneously by a semi-parametric joint frailty model12 implemented using the NLMIXED procedure13 in SAS (SAS Institute, Inc., Cary, NC). This model accounts for correlated recurrent events within patients and the correlation between recurrent and terminal events (i.e., informative censoring). The reference time point was randomisation date for the ITT population and treatment date for the mITT population and for the additional pre-specified populations (e.g. excluding patients who had major protocol deviations and excluding patients who were positive or equivocal for neutralizing antibodies). Primary and secondary endpoints were graphically depicted using the mean cumulative function14 and the survival function (estimated by the PHREG procedure in SAS), respectively. Sensitivity analyses using alternative models for both endpoints were also performed.
The trial was registered with clinicaltrials.gov, number NCT01643330.
Role of the funding source
This trial, including patient management, data collection, and data analysis, was funded by Celladon Corporation. Celladon also provided funding for manuscript and graphics support. The corresponding author had full access to all data in the study and, with the support of the full author group, had final responsibility for the decision to submit for publication.
Results
From July 9, 2012 through February 5, 2014, 1558 patients at 67 centres in the US, Europe, and Israel underwent NAb prescreening for CUPID 2 (Figure 1). Of these patients, 921 (59·1%) were NAb positive and 284 (18·2%) were considered ineligible for other reasons, leaving 353 (22·7%) with a qualifying NAb titre (<1:2 or equivocal) who were eligible for further screening. Of these patients, 103 (29·2%) were excluded for reasons summarized in Figure 1, and 250 patients were enrolled into the study and randomised. Two of 123 patients allocated to receive AAV1/SERCA2a and five of 127 patients allocated to placebo did not receive study drug infusion (Figure 1). The remaining 121 patients who received AAV1/SERCA2a and 122 patients who received placebo constituted the mITT population that was the pre-specified population for the primary efficacy analysis. Over the course of the study, 5 patients (3 in mITT) withdrew consent and 1 (in mITT) was lost to follow-up.
The participants were predominantly white and male with two-thirds from the US (Table 1). A total of 135/250 (55·6%) patients had coronary artery disease and HF was ascribed to an ischemic aetiology in 125/250 (51·4%) patients. Patients had moderate to severe HF as evidenced by NYHA Functional Class, ejection fraction, 6MWT distance, KCCQ score, and NT-proBNP level. Baseline characteristics were balanced between groups.
Median follow-up was 17·5 months since the study extended over 30 months in order to allow all randomised patients to be followed for at least 12 months. At the time the last patient had been followed for 12 months, a total of 232 recurrent and 65 terminal events had occurred in the mITT population. Of the 232 recurrent events that qualified as primary endpoints, 128 were in the placebo group and 104 were in the AAV1/SERCA2a group; most were HF hospitalizations. Treatment with AAV1/SERCA2a failed to improve the rate of recurrent events (HR, 0·93; 95% confidence interval [CI] 0·53 to 1·65; p=0·81; Figure 2A and Table 2). Of the 65 terminal events that qualified as secondary endpoints, 29 were in the placebo group and 36 were in the AAV1/SERCA2a group; most were deaths (Table 2). AAV1/SERCA2a administration failed to improve time to first terminal event (HR, 1·27; 95% CI 0·72 to 2·24; p=0·40; Figure 2B). AAV1/SERCA2a treatment also did not improve time to all-cause death (Figure 2C).