New drug for chronic heart failure tested in early study
An early clinical study shows that a new oral drug is safe and well-tolerated in patients with chronic heart failure. The study, led by researchers at Karolinska Institutet, has been published in the scientific journal The Lancet.
Heart failure with reduced pumping capacity means that the heart struggles to pump blood effectively around the body. Despite current treatments, many patients’ condition worsens over time, and existing drugs that strengthen the heart’s contractions can cause serious side effects, such as heart rhythm disturbances and changes in blood pressure.
In the study, researchers investigated a new drug, AC01, which targets the body’s ghrelin receptor. Ghrelin is a hormone that influences metabolism and growth hormone release, and its receptor is also found in heart muscle. AC01 is intended to strengthen the heart’s pumping ability through a different biological mechanism from traditional heart‑stimulating drugs, thereby reducing the risk of side effects.
The study was a randomised, placebo‑controlled phase 1b/2a trial involving 58 patients with stable, chronic heart failure with reduced pumping capacity. Participants received different doses of AC01 or placebo for either seven or 28 days. The main aim was to assess safety and tolerability.
The drug was well tolerated
The results show that the drug was well tolerated. No serious side effects linked to AC01 were reported. The researchers also found no signs of harmful effects on heart rhythm or blood pressure. Exploratory analyses additionally indicated signs of improved heart function, such as increased stroke volume and cardiac output.
“This is an early study with a limited number of patients, but the results suggest that AC01 can be administered safely to people with heart failure. The findings now justify further studies to investigate whether the signals of improved heart function that we have observed can lead to clinical benefit in larger and longer studies,” says Lars Lund, first author and professor at the Department of Medicine, Solna, Karolinska Institutet, and senior consultant cardiologist at Karolinska University Hospital.
The study was conducted in collaboration with researchers and clinicians in several European countries. The research was funded by the pharmaceutical company AnaCardio AB. Several of the researchers, including the principal investigator, have ties to the company, which are disclosed in the scientific article.
Publication
“Safety, tolerability, and haemodynamic effects of the ghrelin receptor agonist AC01 in patients with chronic heart failure: a randomised, double-blind, placebo-controlled, phase 1b/2a study”, Lars H Lund, Arantxa Barandiaran Aizpurua, Entela Bollano, Oscar Braun, Jan Leendert P Brouwer, Jan W Buikema, Antonio Cannata, Roy S Gardner, M Louis Handoko, Chim C Lang, Marco Metra, Gianfranco Sinagra, Tonje Thorvaldsen, Robert MA van der Boon, Bart J van Essen, Sanjiv J Shah, Adriaan A Voors, Carolyn SP Lam, Bertram Pitt, Scott D Solomon, Camilla Hage, Marcus Stahlberg, Alberto Bernareggi, Allan Gordon, Marianna Del Sole, Elin Rosendahl, Patrik Strömberg, Göran Westerberg, Robert Edfors, Mark C Petrie, The Lancet, online June 25, 2026, doi: 10.1016/S0140-6736(26)00904-9