FDA ACCEPTS MESOBLAST’S BIOLOGICS LICENCE APPLICATION FOR RYONCIL™ AND AGREES TO PRIORITY REVIEW

Melbourne, Australia; April 1, 2020; and New York, USA; March 31, 2020: Mesoblast Limited (ASX:MSB; Nasdaq: MESO), global leader in cellular medicines for inflammatory diseases, today announced that the United States Food and Drug Administration (FDA) has accepted for priority review the Company’s Biologics License Application (BLA) filing for RYONCILTM (remestemcel-L), its allogeneic cell therapy for the treatment of children with steroid-refractory acute graft versus host disease (SR-aGVHD). The FDA has set a Prescription Drug User Fee Act (PDUFA) action date of September 30, 2020, and if approved, Mesoblast will make RYONCIL immediately available in the United States. A Priority Review designation will direct overall attention and resources to the evaluation of applications for drugs that, if approved, would be significant improvements in the safety or effectiveness of the treatment, diagnosis, or prevention of serious conditions when compared to standard applications.

The FDA has advised that they are planning to hold an Advisory Committee Meeting to discuss this application. Mesoblast Chief Executive Dr Silviu Itescu stated: “There is a critical need to improve survival outcomes in children suffering from the more advanced stages of this devastating disease. The acceptance of the BLA represents an important milestone for the Company.

Mesoblast is on track in its preparation for the potential launch of RYONCIL, including meeting its target inventory build and commercial team roll-out.”

About Acute GVHD Acute

GVHD occurs in approximately 50% of patients who receive an allogeneic bone marrow transplant (BMT). Over 30,000 patients worldwide undergo an allogeneic BMT annually, primarily during treatment for blood cancers, and these numbers are increasing.1 In patients with the most severe form of acute GVHD (Grade C/D or III/IV) mortality is as high as 90% despite optimal institutional standard of care.2,3. There are currently no FDA-approved treatments in the US for children under 12 with SR-aGVHD.

About RYONCILTM

Mesoblast’s lead product candidate, RYONCIL (remestemcel-L), is an investigational therapy comprising cultureexpanded mesenchymal stem cells derived from the bone marrow of an unrelated donor. It is administered to patients in a series of intravenous infusions.

RYONCIL is believed to have immunomodulatory properties to counteract the inflammatory processes that are implicated in SR- aGVHD by down-regulating the production of pro-inflammatory cytokines, increasing production of anti-inflammatory cytokines, and enabling recruitment of naturally occurring anti-inflammatory cells to involved tissues.

References 1. Niederwieser D, Baldomero H, Szer J. (2016) Hematopoietic stem cell transplantation activity worldwide in 2012 and a SWOT analysis of the Worldwide Network for Blood and Marrow Transplantation Group including the global survey. 2. Westin, J., Saliba, RM., Lima, M. (2011) Steroid-refractory acute GVHD: predictors and outcomes. Advances in Hematology. 3. Axt L, Naumann A, Toennies J (2019) Retrospective single center analysis of outcome, risk factors and therapy in steroid refractory graft-versus-host disease after allogeneic hematopoietic cell transplantation. Bone Marrow Transplantation.

About Mesoblast

Mesoblast Limited (ASX: MSB; Nasdaq: MESO) is a world leader in developing allogeneic (off-the-shelf) cellular medicines. The Company has leveraged its proprietary mesenchymal lineage cell therapy technology platform to establish a broad portfolio of commercial products and late-stage product candidates. Mesoblast’s proprietary manufacturing processes yield industrial-scale, cryopreserved, off-the-shelf, cellular medicines. These cell therapies, with defined pharmaceutical release criteria, are planned to be readily available to patients worldwide.