What happened

Shares of Mesoblast Limited (NASDAQ:MESO) were tumbling 19.6% lower as of 12:41 p.m. EST on Tuesday. The big drop came after the company announced Monday evening that its off-the-shelf cell therapy candidate rexlemestrocel-L (Revascor) failed to meet the primary endpoint of a late-stage clinical study targeting the treatment of advanced chronic heart failure.

So what

Mesoblast said that Revascor didn't achieve any reduction in recurrent non-fatal decompensated heart-failure events. Decompensated heart failure occurs when structural changes in the heart cause obvious symptoms. The problem was that this reduction was the primary endpoint of the company's late-stage study.

Electrocardiagram line

Image source: Getty Images.

However, Mesoblast did find some positives in its clinical trial. The Australia-based biotech stated that patients in the study achieved a 60% reduction in the incidence of heart attacks or strokes, as well as a 60% reduction in death from cardiac causes when treated early with Revascor in combination with other therapies.

Mesoblast CEO Silviu Itescu highlighted these positives, stating, "The reduction in mortality seen with rexlemestrocel-L in advanced chronic heart failure underlines the power of this technology and the commitment of Mesoblast to address diseases in patients with high unmet need which are refractory to existing therapies."

Now what

It's possible that the biotech stock could rebound from today's sell-off. Mesoblast now plans to meet with the U.S. Food and Drug Administration (FDA) about a possible path to approval for Revascor in treating advanced chronic heart failure based on mortality reduction.

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