β1EC2-CP prevented and almost fully reversed antibody-induced cardiac damage in a rat model of immune-mediated heart failure, showing superior efficacy to bisoprolol mono-therapy.
Does a novel cyclic peptide mimicking β1EC2 (β1EC2-CP) prevent or treat antibody-induced cardiomyopathy in a human-analogous rat model?
A novel cyclic peptide mimicking β1EC2 prevents and reverses antibody-induced cardiomyopathy in a rat model, offering a potential new therapeutic strategy for immune-mediated heart failure.
Despite recent therapeutic advances the prognosis of heart failure remains poor. Recent research suggests that heart failure is a heterogeneous syndrome and that many patients have stimulating auto-antibodies directed against the second extracellular loop of the β1 adrenergic receptor (β1EC2). In a human-analogous rat model such antibodies cause myocyte damage and heart failure. Here we used this model to test a novel antibody-directed strategy aiming to prevent and/or treat antibody-induced cardiomyopathy. To generate heart failure, we immunised n = 76/114 rats with a fusion protein containing the human β1EC2 (amino-acids 195-225) every 4 weeks; n = 38/114 rats were control-injected with 0.9% NaCl. Intravenous application of a novel cyclic peptide mimicking β1EC2 (β1EC2-CP, 1.0 mg/kg every 4 weeks) or administration of the β1-blocker bisoprolol (15 mg/kg/day orally) was initiated either 6 weeks (cardiac function still normal, prevention-study, n = 24 (16 treated vs. 8 untreated)) or 8.5 months after the 1st immunisation (onset of cardiomyopathy, therapy-study, n = 52 (40 treated vs. 12 untreated)); n = 8/52 rats from the therapy-study received β1EC2-CP/bisoprolol co-treatment. We found that β1EC2-CP prevented and (alone or as add-on drug) treated antibody-induced cardiac damage in the rat, and that its efficacy was superior to mono-treatment with bisoprolol, a standard drug in heart failure. While bisoprolol mono-therapy was able to stop disease-progression, β1EC2-CP mono-therapy -or as an add-on to bisoprolol- almost fully reversed antibody-induced cardiac damage. The cyclo¬peptide acted both by scavenging free anti-β1EC2-antibodies and by targeting β1EC2-specific memory B-cells involved in antibody-production. Our model provides the basis for the clinical translation of a novel double-acting therapeutic strategy that scavenges harmful anti-β1EC2-antibodies and also selectively depletes memory B-cells involved in the production of such antibodies. Treatment with immuno-modulating cyclopeptides alone or as an add-on to β1-blockade represents a promising new therapeutic option in immune-mediated heart failure.
Boivin et al. (Fri,) conducted a other in Immune-mediated heart failure (n=114). β1EC2-CP vs. Bisoprolol, untreated, or 0.9% NaCl was evaluated on Cardiac function and morphology (LV end-diastolic diameter, cardiac index). β1EC2-CP prevented and almost fully reversed antibody-induced cardiac damage in a rat model of immune-mediated heart failure, showing superior efficacy to bisoprolol mono-therapy.