Mesoblast gets BLA filing number for rexlemestrocel-L in LVAD patients

Mesoblast Limited announced on July 1, 2026 that it received a Biologics License Application filing number from the FDA and asked for a modular review of its BLA covering rexlemestrocel-L, aimed at preventing serious gastrointestinal bleeding linked to right ventricular dysfunction in end-stage heart failure patients who have a left ventricular assist device (LVAD)¹.

The company said rexlemestrocel-L already carries Orphan Drug Designation for stopping major mucosal bleeding events in this setting, along with Regenerative Medicine Advanced Therapy (RMAT) status, both of which allow for rolling and priority review of the BLA¹.

Mesoblast also pointed to recent regulatory context, noting the FDA's new leadership recently gave added guidance on regulatory flexibility for orphan diseases marked by high mortality and irreversible harm, including a new draft guidance called "Demonstrating Substantial Evidence of Effectiveness for Human Drug and Biological Products," which describes FDA's flexible view on proving effectiveness¹. That follows an earlier May guidance titled "Chemistry, Manufacturing, and Controls Flexibilities for Developing Human Cellular and Gene Therapy Products for a Biologics License Application"¹.

On the clinical background, the company said rexlemestrocel-L has been tested in two large placebo-controlled randomized studies in chronic heart failure, one enrolling 565 patients with NYHA class II/III HFrEF and another enrolling 159 patients with end-stage HFrEF who had an LVAD implanted¹.

CEO Silviu Itescu said the company looks forward to working with FDA to bring rexlemestrocel-L to end-stage heart failure patients on mechanical devices who face high risk of life-threatening GI bleeding from progressive right heart failure¹. The filing did not specify a target review timeline beyond the modular review request.