globaldataWhile the overall level of unmet need in the atrial fibrillation market is generally considered moderate, the need for safer antiarrhythmic drugs for the maintenance of sinus rhythm is still a major issue in the treatment space, according to research and consulting firm GlobalData.

The company’s report states that despite the restoration and maintenance of sinus rhythm being a common practice in the management of atrial fibrillation, the available antiarrhythmic drugs are of modest efficacy and have unfavourable safety profiles. For example, amiodarone is a widely used generic antiarrhythmic drug, and despite being considered an effective agent available for heart rhythm control, it has a number of side-effects including proarrhythmia, and thyroid, liver, skin, and pulmonary complications.

Jesus Cuaron, PhD, PPM, GlobaData’s senior analyst covering cardiovascular and metabolic disorders, explains: “Antiarrhythmic drug development has been very slow and there are presently no late-stage drug candidates that are expected to address this unmet need by 2025. In addition, most antiarrhythmic drugs are already genericized and more will follow, contributing to a rapid decline in market value from 2022.”

Two of the more promising antiarrhythmic drugs that had just entered, or were expected to enter, Phase III clinical trials, recently had their development discontinued, namely Gilead’s fixed-dose combination of ranolazine/dronedarone and Laguna Pharmaceuticals’ vanoxerine. In the early-stage antiarrhythmic drug pipeline, there are only three drug candidates in Phase II and one drug in Phase I development for atrial fibrillation.

Cuaron explains: “Part of the reason for the low level of activity in the pipeline is because to the high risk involved in developing an antiarrhythmic drug. Large and costly clinical trials are required to demonstrate that a drug is safe and effective, and the track record for those antiarrhythmic drugs that have reached the market in the past decade has been disappointing.”

“It is also expected that the availability of cheaper generic alternatives and the continuing cost constraints faced by national health authorities will make it difficult for drugs to obtain reimbursement and subsequent addition to hospital formularies. With continued advances in technology, it is expected that there will be a move towards using procedural technologies, such as catheter ablation, as the preferred treatment option for rhythm control,” he concluded.