Effect of intracoronary administration of AAV1/SERCA2a on ventricular remodelling in patients with advanced systolic heart failure: results from the AGENT-HF randomized phase 2 trial.

AIMS: Restoration of sarco/endoplasmic reticulum Ca2+ ATPase (SERCA2a) activity through gene transfer improved cardiac function in experimental and pilot studies in humans with heart failure. The AGENT-HF (NCT01966887) trial investigated the impact of adeno-associated virus (AAV1)/SERCA2a on ventricular remodelling using multimodality non-invasive cardiac imaging. METHODS AND RESULTS: AGENT-HF was a single centre, randomized, double-blind, placebo-controlled trial in adult patients with NYHA class III-IV ischaemic or non-ischaemic heart failure and left ventricular ejection fraction ≤35%. Eligible patients were randomized to receive a single intracoronary infusion of either 1 × 1013 DNase-resistant particles of AAV1/SERCA2a or placebo. The primary endpoint was change in left ventricular end-systolic volume (LVESV), measured by cardiac computed tomography at 6 month follow-up. We planned to include 40 patients but the trial was terminated prematurely as the sponsor suspended further enrolment following neutral results of the CUPID-2 outcome trial. At the time of termination, nine patients were randomized with five patients infused with AAV1/SERCA2a and four with placebo. At 6 months, LVESV was increased in both groups compared with baseline: median (interquartile range) in AAV1/SERCA2a vs. placebo: 13 (13;14) mL vs. 3.5 (-36;36) mL, P = 0.74, with a mean difference between groups of 11.4 mL in favour of placebo. No safety issues were noted. CONCLUSION: AGENT-HF failed to demonstrate any improvement in ventricular remodelling in response to AAV1/SERCA2a at the dose studied. However, because of premature termination, the study was underpowered to demonstrate an effect of AAV1/SERCA2a and these data should be interpreted with caution.

Gene therapy for heart failure.

Heart failure is a major public health problem throughout the world and it is likely that its prevalence will continue to grow over the next several decades. Despite advances in the treatment of heart failure, morbidity and mortality remain unacceptably high. Gene transfer therapy provides a novel strategy for targeting abnormalities in cardiac cells that adversely affect cardiac function. New vectors for gene delivery, mainly adeno-associated viruses (AAVs) that are preferentially taken up by cardiomyocytes, can result in sustained transgene expression. The cardiac isoform of sarco(endo)plasmic reticulum Ca(2+)ATPase (SERCA2a) plays a major role in regulating calcium levels in cardiomyocytes. Abnormal calcium handling by the failing heart caused by a reduction in SERCA2a activity adversely affects both systolic and diastolic function. The Calcium Upregulation by Percutaneous Administration of Gene Therapy in Cardiac Disease (CUPID) study was a Phase 2a double-blind, randomized, placebo-controlled, dose-finding study that was performed in patients with advanced heart failure due to systolic dysfunction. Eligible patients received AAV/SERCA2a or placebo by direct antegrade infusion into the coronary circulation. At the end of 12 months, patients receiving high-dose therapy (i.e. 1×10(13) DNase Resistant Particles) had evidence of favorable changes in several clinically relevant domains compared to patients treated with placebo. There were no safety concerns at any dose of AAV/SERCA2a. Patients treated with AAV/SERCA2a exhibited a striking reduction in cardiovascular events that persisted through 36 months of follow-up compared to patients who received placebo. Transgene expression was detected in the myocardium of patients receiving AAV/SERCA2a gene therapy as long as 31 months after delivery. A second Phase 2b study, CUPID 2, designed to confirm this favorable effect on heart failure events, is currently underway with the results expected to be presented later in 2015. Additional studies using other vectors and targets are in planning or underway making gene transfer therapy one of the most exciting new approaches under development for treating heart failure.

Design of a phase 2b trial of intracoronary administration of AAV1/SERCA2a in patients with advanced heart failure: the CUPID 2 trial (calcium up-regulation by percutaneous administration of gene therapy in cardiac disease phase 2b).

OBJECTIVES: Impaired cardiac isoform of sarco(endo)plasmic reticulum Ca(2+) ATPase (SERCA2a) activity is a key abnormality in heart failure patients with reduced ejection fraction. The CUPID 2 (Calcium Up-Regulation by Percutaneous Administration of Gene Therapy in Cardiac Disease Phase 2b) trial is designed to evaluate whether increasing SERCA2a activity via gene therapy improves clinical outcome in these patients. BACKGROUND: Intracoronary delivery of recombinant adeno-associated virus serotype 1 (AAV1)/SERCA2a improves intracellular Ca(2+) handling by increasing SERCA2a protein levels and, as a consequence, restores systolic and diastolic function. In a previous phase 2a trial, this therapy improved symptoms, functional status, biomarkers, and left ventricular function, and reduced cardiovascular events in advanced heart failure patients. METHODS: CUPID 2 is a phase 2b, double-blind, placebo-controlled, multinational, multicenter, randomized event-driven study in up to 250 patients with moderate-to-severe heart failure with reduced ejection fraction and New York Heart Association functional class II to IV symptoms despite optimal therapy. Enrolled patients will be at high risk for recurrent heart-failure hospitalizations by virtue of having elevated N-terminal pro-B-type natriuretic peptide/BNP (>1,200 pg/ml, or >1,600 pg/ml if atrial fibrillation is present) and/or recent heart failure hospitalization. The primary endpoint of time-to-recurrent event (heart failure-related hospitalizations in the presence of terminal events [all-cause death, heart transplant, left ventricular assist device implantation or ambulatory worsening heart failure]) will be assessed using the joint frailty model. This ongoing trial is expected to complete recruitment in 2014, with the required number of 186 recurrent events estimated to occur by mid 2015. RESULTS: Available data indicate that calcium up-regulation by AAV1/SERCA2a gene therapy is safe and of potential benefit in advanced heart failure patients. CONCLUSIONS: The CUPID 2 trial is designed to study the effects of this therapy on clinical outcome in these patients. (Calcium Up-Regulation by Percutaneous Administration of Gene Therapy in Cardiac Disease Phase 2b [CUPID-2b]; NCT01643330).

Cardiac surgical delivery of the sarcoplasmic reticulum calcium ATPase rescues myocytes in ischemic heart failure.

BACKGROUND: The sarcoplasmic reticulum calcium ATPase (SERCA2a) is an important molecular regulator of contractile dysfunction in heart failure. Gene transfer of SERCA2a mediated by molecular cardiac surgery with recirculating delivery (MCARD) is a novel and clinically translatable strategy. METHODS: Ischemic heart failure was induced by ligation of OM1 and OM2 in 14 sheep. Seven sheep underwent MCARD-mediated AAV1-SERCA2a delivery 4 weeks after myocardial infarction, and seven sheep served as untreated controls. Magnetic resonance imaging-based mechanoenergetic studies were performed at baseline, 3 weeks, and 12 weeks after infarction. Myocyte apoptosis was quantified by Tdt-mediated nick-end labeling assay. Myocyte cross-sectional area and caspase-8 and caspase-9 activity was measured with imaging software, specific fluorogenic peptides, and immunohistochemistry. RESULTS: MCARD-mediated AAV1-SERCA2a gene delivery resulted in robust cardiac-specific SERCA2a expression and stable improvements in global and regional contractility. There were significantly higher stroke volume index, left ventricular fractional thickening, and ejection fraction at 12 weeks in the MCARD group than in the control group (30 ± 3 vs 21 ± 2 mL/m(2); 12% ± 5% vs 3% ± 3%; and 43 ± 4 vs 32 ± 4, respectively, all p < 0.05). Apoptotic myocytes were observed more frequently in the control group than in the MCARD-SERCA2a group (0.57.2 ± 0.16 AU vs 0.32.4 ± 0.08 AU, p < 0.05). MCARD-SERCA2a also resulted in decreased caspase-8 and caspase-9 expression and decreased myocyte area in the border zone of transgenic sheep compared with control sheep (14.6% ± 1.2% vs 2.9% ± 0.7%; 18.2% ± 1.9% vs 8.6% ± 1.4%; and 102.1 ± 3.8 µm(2) vs 88.1 ± 3.6 µm(2), all p < 0.05). CONCLUSIONS: MCARD-mediated SERCA2a delivery results in robust cardiac specific gene expression, improved contractility, and a decrease in both myocyte apoptosis and myocyte hypertrophy.

Targeted sarcoplasmic reticulum Ca2+ ATPase 2a gene delivery to restore electrical stability in the failing heart.

BACKGROUND: Recently, we reported that sarcoplasmic reticulum Ca(2+) ATPase 2a (SERCA2a), the pump responsible for reuptake of cytosolic calcium during diastole, plays a central role in the molecular mechanism of cardiac alternans. Heart failure (HF) is associated with impaired myocardial calcium handling, deficient SERCA2a, and increased susceptibility to cardiac alternans. Therefore, we hypothesized that restoring deficient SERCA2a by gene transfer will significantly reduce arrhythmogenic cardiac alternans in the failing heart. METHODS AND RESULTS: Adult guinea pigs were divided into 3 groups: control, HF, and HF+AAV9.SERCA2a gene transfer. HF resulted in a decrease in left ventricular fractional shortening compared with controls (P<0.001). As expected, isolated HF myocytes demonstrated slower sarcoplasmic reticulum calcium uptake, decreased Ca(2+) release, and increased diastolic Ca(2+) (P<0.05) compared with controls. Moreover, SERCA2a, cardiac ryanodine receptor 2, and sodium-calcium exchanger protein expression was decreased in HF compared with control (P<0.05). As predicted, HF increased susceptibility to cardiac alternans, as evidenced by decreased heart rate thresholds for both V(m) alternans and Ca alternans compared with controls (P<0.01). Interestingly, in vivo gene transfer of AAV9.SERCA2a in the failing heart improved left ventricular contractile function (P<0.01), suppressed cardiac alternans (P<0.01), and reduced ryanodine receptor 2 P(o) secondary to reduction of ryanodine receptor 2-P(S2814) (P<0.01). This ultimately resulted in a decreased incidence of inducible ventricular arrhythmias (P=0.05). CONCLUSIONS: These data show that SERCA2a gene transfer in the failing heart not only improves contractile function but also directly restores electric stability through the amelioration of key arrhythmogenic substrate (ie, cardiac alternans) and triggers (ie, sarcoplasmic reticulum Ca(2+) leak).

Calcium upregulation by percutaneous administration of gene therapy in cardiac disease (CUPID Trial), a first-in-human phase 1/2 clinical trial.

BACKGROUND: SERCA2a deficiency is commonly seen in advanced heart failure (HF). This study is designed to investigate safety and biological effects of enzyme replacement using gene transfer in patients with advanced HF. METHODS AND RESULTS: A total of 9 patients with advanced HF (New York Heart Association [NYHA] Class III/IV, ejection fraction [EF] < or = 30%, maximal oxygen uptake [VO2 max] <16 mL.kg.min, with maximal pharmacological and device therapy) received a single intracoronary infusion of AAV1/SERCA2a in the open-label portion of this ongoing study. Doses administered ranged from 1.4 x 10(11) to 3 x 10(12) DNase resistant particles per patient. We present 6- to 12-month follow-up data for these patients. AAV1/SERCA2a demonstrated an acceptable safety profile in this advanced HF population. Of the 9 patients treated, several demonstrated improvements from baseline to month 6 across a number of parameters important in HF, including symptomatic (NYHA and Minnesota Living with Heart Failure Questionnaire, 5 patients), functional (6-minute walk test and VO2 max, 4 patients), biomarker (NT-ProBNP, 2 patients), and LV function/remodeling (EF and end-systolic volume, 5 patients). Of note, 2 patients who failed to improve had preexisting anti-AAV1 neutralizing antibodies. CONCLUSIONS: Quantitative evidence of biological activity across a number of parameters important for assessing HF status could be detected in several patients without preexisting neutralizing antibodies in this open-label study, although the number of patients in each cohort is too small to conduct statistical analyses. These findings support the initiation of the Phase 2 double-blind, placebo-controlled portion of this study.

Design of a phase 1/2 trial of intracoronary administration of AAV1/SERCA2a in patients with heart failure.

BACKGROUND: Heart failure (HF) remains a major cause of morbidity and mortality in North America. With an aging population and an unmet clinical need by current pharmacologic and device-related therapeutic strategies, novel treatment options for HF are being explored. One such promising strategy is gene therapy to target underlying molecular anomalies in the dysfunctional cardiomyocyte. Prior animal and human studies have documented decreased expression of SERCA2a, a major cardiac calcium cycling protein, as a major defect found in HF. METHODS AND RESULTS: We hypothesize that increasing the activity of SERCA2a in patients with moderate to severe HF will improve their cardiac function, disease status, and quality of life. Gene transfer of SERCA2a will be performed via an adeno-associated viral (AAV) vector, derived from a nonpathogenic virus with long-term transgene expression as well as a clinically established favorable safety profile. CONCLUSIONS: We describe the design of a phase 1 clinical trial of antegrade epicardial coronary artery infusion (AECAI) administration of AAVI/SERCA2a (MYDICAR) to subjects with HF divided into 2 stages: in Stage 1, subjects will be assigned open-label MYDICAR in one of up to 4 sequential dose escalation cohorts; in Stage 2, subjects will be randomized in parallel to 2 or 3 doses of MYDICAR or placebo in a double-blinded manner.