CellProthera, a regenerative cell therapy developer focused on ischemic diseases, has announced a significant step forward in its ProtheraCytes cell therapy program for acute myocardial infarction (AMI). Following a pre-Investigational New Drug (IND) meeting with the US Food and Drug Administration (FDA), the company has reached an agreement with regulators on the design of a planned pivotal Phase III trial.
Phase III Trial Design and Objectives
Building on the success of its Phase II trial conducted in the UK and France, CellProthera is now advancing ProtheraCytes into the final phase of clinical development. The Phase III trial will be conducted across the US and Europe, involving a larger patient population. A key aspect of the trial is the two-year long-term follow-up, which aims to monitor the ability of ProtheraCytes to prevent subsequent heart diseases in patients treated post-AMI.
The trial is designed as a randomized, concurrent-controlled, open-label study, with standard-of-care post-AMI treatment serving as the control. The primary endpoint will be a composite measure based on findings from the Phase II EXCELLENT study. This approach received positive feedback from the FDA, paving the way for the pivotal trial.
Promising Phase II Results
The Phase II EXCELLENT study demonstrated that ProtheraCytes improved left ventricular (LV) volumes and viability of myocardial segments at 6 months following treatment. These results are considered strong indicators of the therapy's potential efficacy, which the Phase III trial seeks to confirm through long-term follow-up.
According to CellProthera's CEO, Matthieu de Kalbermatten, the positive feedback from FDA regulators positions the company favorably to launch a pivotal Phase III trial in the US after a successful IND filing. This trial will run in parallel with the recently launched PERFECT study, which will provide additional long-term safety and efficacy data by following patients from the Phase II study over an additional ten years.
Addressing Unmet Needs in AMI Treatment
Despite advancements in guideline-directed therapies, the prevention of mortality and hospitalization for heart failure in AMI patients with large necrosis remains a significant challenge. ProtheraCytes works by differentiating into endothelial cells and releasing paracrine factors that support angiogenesis and enhance the proliferation of resident cardiomyocytes, thereby attenuating adverse remodeling effects.
Mechanism of Action and Cell Delivery
ProtheraCytes is derived from CD34+ cells harvested from the patient's peripheral blood. These cells are known for their ability to stimulate new blood vessel formation. CellProthera has developed a technology that enables the implantation of larger quantities of cells back into the patient via intramyocardial injection, facilitating more successful cell grafting. This platform can inject 50 million cells directly into the heart tissue, surpassing the capabilities of other approaches like intracoronary catheters.
Market Opportunity
While the majority of heart attack patients respond well to current treatments, a significant minority (5%-10%) who experience severe infarction do not recover cardiovascular health and may progress to long-term heart failure. This patient group, numbering around 50,000-100,000 annually, represents the target population for ProtheraCytes, which aims to regenerate tissue and revascularize the heart.
