Amgen and Cytokinetics: approaching acute heart failure from a different angle

After the recent failures of two high profile acute heart failure (HF) therapies, Cardiorentis’ ularitide and Novartis’ serelaxin, the strategy of treating patients in the acute setting and expecting long term improvements has come under intense scrutiny.

To combat this, several drug developers are beginning to target patients in the post-acute setting. A clear leader in this field is Amgen and Cytokinetics’ omecamtiv mecarbil (OM), a novel therapy that directly activates cardiac myosin. Targeting this group of patients is a strategic move for the companies as these patients are at an extremely high risk of death or re-hospitalization. Thus if further studies of OM prove that the drug is efficacious at reducing these outcomes, then payers will have less leverage to deny access to the drug if it gains regulatory approval.

A theory that has been tested several times with novel drugs, is that early administration of intravenous therapies in the acute setting can not only help relieve short term symptoms, such as dyspnea, but also improve long term outcomes. This was recently tested by Cardiorentis with their drug ularitide in the large Phase III TRUE-AHF study. Despite improving short term outcomes, no long term benefits were seen in the treatment group compared to placebo.

A direct competitor to ularitide was Novartis’ serelaxin, similarly it was hoped that IV infusion of the drug would improve both short- and long-term outcomes. However in what can be viewed as the final nail in the coffin for this theory, Novartis announced no benefit with serelaxin treatment.

Potentially in response to these failures, as well as the struggle the new chronic HF medication, Entresto, has experienced, Amgen and Cytokinetics have altered their development strategy for OM. The companies were initially developing OM as a twice daily oral therapy for chronic HF with reduced ejection fraction (HF-REF), as well as an IV-administered treatment for acute HF.

Interestingly the Phase II chronic HF-REF study, COSMIC-HF, excluded any patients who had been hospitalized for HF within 30 days prior to enrollment. Whilst the Phase II acute HF-REF study, ATOMIC-AHF, assessed the drug as an IV therapy administered within 48h from initial hospitalization, treating patients in the acute setting. Based on positive results the orally administered form of OM was moved into Phase III studies, no update on the IV form is available as of yet.

Amgen and Cytokinetics are currently enrolling patients into their Phase III GALACTIC-HF study, and a key inclusion criterion is that patients must be currently hospitalized for HF, but stable, or have been hospitalized for HF within the past 12 months. The drug will be given as a twice daily oral pill on top of standard of care and the primary outcome will assess CV death or time to first HF event through to study completion (up to 208 weeks). This change in strategy clearly points to Amgen and Cytokinetics recognizing and targeting areas of high unmet need, whilst reacting to developments within the acute HF space.

Although this therapeutic area is relatively high risk, if results from GALACTIC-HF are positive, the companies are set to reap lucrative rewards.