This section highlights FDA-related milestones and regulatory updates for drugs developed by Mesoblast (MESO).
Over the past two years, Mesoblast has reported clinical trial outcomes, regulatory submissions, approvals, and other FDA events for drugs and therapies such as
Revascor, rexlemestrocel-L, and RYONCIL. For definitions of regulatory abbreviations such as NDA, BLA, or PDUFA, see the event status legend.
Revascor - FDA Regulatory Timeline and Events
Revascor is a drug developed by Mesoblast for the following indication: In the treatment of the congenital heart disease hypoplastic left heart syndrome (HLHS).
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- Revascor
- Announced Date:
- June 30, 2025
- Indication:
- In the treatment of the congenital heart disease hypoplastic left heart syndrome (HLHS).
Announcement
Mesoblast announced alignment with the United States Food and Drug Administration (FDA) on items required for filing a Biologics License Application (BLA) for Revascor® (rexlemestrocel-L) in the treatment of patients with ischemic heart failure with reduced ejection fraction (HFrEF) and inflammation.
AI Summary
Mesoblast announced that it has reached an agreement with the US Food and Drug Administration (FDA) on the key requirements for filing a Biologics License Application (BLA) for its therapy Revascor® (rexlemestrocel-L). The therapy is being developed to treat patients with ischemic heart failure with reduced ejection fraction (HFrEF) and inflammation.
During a meeting on June 3, 2025, the FDA and Mesoblast aligned on crucial elements needed for the BLA filing. The official meeting minutes detailed agreements on chemistry, manufacturing and controls (CMC), the potency assays required for releasing the commercial product, and the proposed design and primary endpoint for a confirmatory trial following approval.
This alignment with the FDA marks a significant milestone for Mesoblast as it prepares to move forward with its filing and accelerate the development of Revascor® for patients with severe heart conditions.
Read Announcement- Drug:
- Revascor
- Announced Date:
- June 11, 2025
- Indication:
- In the treatment of the congenital heart disease hypoplastic left heart syndrome (HLHS).
Announcement
Mesoblast today provided an update on continued momentum with United States Food and Drug Administration (FDA) regarding both accelerated approval pathway for Revascor® (rexlemestrocel-L) in the treatment of patients with ischemic chronic heart failure with reduced ejection fraction (HFrEF) and inflammation, and label extension for Ryoncil® (remestemcel-L-rknd) in adults with steroid refractory acute graft versus host disease (SR-aGvHD).
AI Summary
Mesoblast provided an update on its FDA interactions, highlighting progress for two key therapies. The company discussed the accelerated approval pathway for Revascor® (rexlemestrocel-L), designed for patients with ischemic chronic heart failure with reduced ejection fraction and inflammation. A recent Type B meeting under the RMAT designation with FDA covered important components such as chemistry, manufacturing controls, potency assays for product release, and the design for a confirmatory post-approval trial. The company is now waiting for the final meeting minutes to determine detailed timelines for the filing of a Biologics License Application.
Additionally, Mesoblast is preparing for an early July meeting about a pivotal trial for Ryoncil® (remestemcel-L-rknd) in adults with steroid refractory acute graft versus host disease (SR-aGvHD). This trial aims to secure a label extension, expanding approval from children to adults through collaboration with the BMT-CTN network.
Read Announcement- Drug:
- Revascor
- Announced Date:
- April 2, 2025
- Indication:
- In the treatment of the congenital heart disease hypoplastic left heart syndrome (HLHS).
Announcement
Mesoblast today provided an update on its plans to meet with the United States Food and Drug Administration (FDA) to discuss the accelerated approval pathway for Revascor® (rexlemestrocel-L) in the treatment of patients with ischemic chronic heart failure with reduced ejection fraction (HFrEF) and inflammation.
AI Summary
Mesoblast provided an update on its plans to meet with the FDA to discuss the accelerated approval pathway for Revascor® (rexlemestrocel-L) in treating patients with ischemic chronic heart failure with reduced ejection fraction (HFrEF) and inflammation. The company has requested a Type B meeting for this quarter, following its recent filing and previous guidance. The meeting, conducted under the Regenerative Medicines Advanced Therapy (RMAT) designation, will focus on securing FDA feedback concerning key issues. Mesoblast intends to discuss important topics such as the chemistry, manufacturing, and controls (CMC) for the product, alignment on potency assays needed for commercial release, and the design along with the primary endpoint for the confirmatory trial that will follow any accelerated approval. This update highlights Mesoblast’s ongoing efforts to advance Revascor® as a promising treatment option for patients suffering from HFrEF and associated inflammation.
Read Announcement- Drug:
- Revascor
- Announced Date:
- December 4, 2024
- Indication:
- In the treatment of the congenital heart disease hypoplastic left heart syndrome (HLHS).
Announcement
Mesoblast Limited announced the United States Food and Drug Administration (FDA) has granted its second generation allogeneic, STRO3-immunoselected, and industrially manufactured stromal cell therapy Revascor® (rexlemestrocel-L) Regenerative Medicine Advanced Therapy (RMAT) designation following submission of results from the randomized controlled trial in children with hypoplastic left heart syndrome (HLHS), a potentially life threatening congenital heart condition.
AI Summary
Mesoblast Limited announced that the U.S. FDA has granted its second-generation stromal cell therapy, Revascor® (rexlemestrocel-L), the Regenerative Medicine Advanced Therapy (RMAT) designation. This decision followed the submission of results from a randomized controlled trial in children with hypoplastic left heart syndrome (HLHS), a severe congenital condition where the left side of the heart does not develop properly. The trial showed that a single injection of Revascor during surgery led to significant growth in the left ventricle, which is key to achieving a full biventricular repair and reducing the risk of complications like heart failure. Under the RMAT designation, Mesoblast plans to work closely with the FDA to explore an accelerated approval pathway, potentially bringing this life-saving therapy to children with HLHS sooner.
Read Announcement
rexlemestrocel-L - FDA Regulatory Timeline and Events
rexlemestrocel-L is a drug developed by Mesoblast for the following indication: For Chronic Low Back Pain.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- rexlemestrocel-L
- Announced Date:
- July 21, 2024
- Indication:
- For Chronic Low Back Pain
Announcement
Mesoblast Limited announced that the confirmatory Phase 3 trial of its allogeneic, immunoselected, and industrially manufactured stromal cell product rexlemestrocel-L in patients with chronic low back pain (CLBP) due to inflammatory degenerative disc disease of less than five years duration has commenced enrollment at multiple sites across the United States.
AI Summary
Mesoblast Limited has begun enrolling patients in a confirmatory Phase 3 trial in the United States. The trial is testing rexlemestrocel-L, an allogeneic, immunoselected, and industrially manufactured stromal cell product, for chronic low back pain caused by inflammatory degenerative disc disease of less than five years duration. It is a randomized, placebo-controlled study that will enroll 300 patients to determine if the treatment significantly reduces pain over 12 months. The trial’s key secondary endpoints will measure improvements in quality of life, functionality, and a reduction in opioid use. This study represents an important step in confirming the promising pain relief outcomes seen in earlier research and could offer a durable treatment option for patients who suffer from chronic low back pain.
Read Announcement
RYONCIL - FDA Regulatory Timeline and Events
RYONCIL is a drug developed by Mesoblast for the following indication: For the treatment of severe and life-threatening inflammatory conditions.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- RYONCIL
- Announced Date:
- May 14, 2025
- Indication:
- For the treatment of severe and life-threatening inflammatory conditions.
Announcement
Mesoblast announced that it has received seven years of orphan-drug exclusive approval from U.S. Food and Drug Administration (FDA) for Ryoncil® (remestemcel-L) for treatment of steroid-refractory acute graft versus host disease (SR-aGvHD) in pediatric patients 2 months of age and older.
AI Summary
Mesoblast has received seven years of orphan-drug exclusive approval from the U.S. Food and Drug Administration for its product Ryoncil® (remestemcel-L). This approval is specifically for treating steroid-refractory acute graft versus host disease (SR-aGvHD) in pediatric patients aged 2 months and older. With this status, the FDA will not allow any other mesenchymal stromal or stem cell products to be approved for this use during the seven-year period. This exclusivity boosts Mesoblast’s ability to secure a strong market position with Ryoncil® and prevents competitors from entering the field with similar treatments for this serious condition.
The decision highlights Mesoblast’s commitment to developing innovative cellular therapies for severe inflammatory diseases, offering hope to young patients with limited treatment options.
Read Announcement- Drug:
- RYONCIL
- Announced Date:
- February 13, 2025
- Indication:
- For the treatment of severe and life-threatening inflammatory conditions.
Announcement
Mesoblast Limited announced that its recently approved product Ryoncil® (remestemcel-L) is being highlighted at the 2025 Transplantation & Cellular Therapy Tandem Meetings of the American Society for Transplantation and Cellular Therapy (ASTCT) and the Center for Blood and Marrow Transplant Research (CIBMTR), the industry's premier conference taking place this week in Honolulu, HI.
AI Summary
Mesoblast Limited announced that its newly approved product, Ryoncil® (remestemcel-L), will be featured at the 2025 Transplantation & Cellular Therapy Tandem Meetings hosted by the American Society for Transplantation and Cellular Therapy (ASTCT) and the Center for Blood and Marrow Transplant Research (CIBMTR). This annual event, held in Honolulu, HI, is one of the industry's most important gatherings for experts in transplantation and cell therapy. Mesoblast has set up an information hub at the conference to educate healthcare providers about the science and clinical results of Ryoncil®. In addition, the company will highlight key data through presentations and advisory panel meetings led by investigators. The focus at the conference is to engage with the healthcare community and discuss the promising advances and real-world impact of Ryoncil® in treating transplant-related conditions.
Read Announcement- Drug:
- RYONCIL
- Announced Date:
- July 23, 2024
- Indication:
- For the treatment of severe and life-threatening inflammatory conditions.
Announcement
Mesoblast Limited announced that the United States Food and Drug Administration (FDA) has accepted its Biologics License Application (BLA) resubmission for Ryoncil® (remestemcel-L) in the treatment of children with steroid-refractory acute graft versus host disease (SR-aGVHD).
AI Summary
Mesoblast Limited announced that the U.S. FDA has accepted its resubmitted Biologics License Application (BLA) for Ryoncil® (remestemcel-L), a treatment for children suffering from steroid-refractory acute graft versus host disease (SR-aGVHD). The decision by the FDA supports the completeness of the resubmission, which addressed key Chemistry, Manufacturing, and Control (CMC) issues. Mesoblast now looks forward to an FDA decision on or before the Prescription Drug User Fee Act goal date of January 7, 2025. Ryoncil® is an investigational therapy made from mesenchymal stromal cells derived from bone marrow, designed to reduce harmful inflammation by regulating the immune system. This acceptance marks a significant step forward in providing a much-needed treatment option for children with SR-aGVHD, a condition that currently has no approved therapies for patients under 12 years old.
Read Announcement- Drug:
- RYONCIL
- Announced Date:
- July 8, 2024
- Indication:
- For the treatment of severe and life-threatening inflammatory conditions.
Announcement
Mesoblst Limited announced it has resubmitted its BLA for approval of Ryoncil® (remestemcel-L) in the treatment of children with SR-aGVHD.
AI Summary
Mesoblast Limited has resubmitted its Biologics License Application (BLA) for Ryoncil® (remestemcel-L), a treatment targeting children with steroid‐refractory acute graft versus host disease (SR-aGVHD). The resubmission comes after the FDA indicated that the clinical data from the Phase 3 study MSB-GVHD001 is strong enough to support the filing. This application addresses the remaining Chemistry, Manufacturing, and Control (CMC) items needed for approval. Mesoblast’s CEO, Dr. Silviu Itescu, highlighted that close collaboration with the FDA has been essential in preparing the resubmission, which could potentially help improve the very low survival rates seen in children suffering from SR-aGVHD. Once accepted, the FDA review is expected to take between two to six months, paving the way for a much-needed therapy for this serious condition.
Read Announcement- Drug:
- RYONCIL
- Announced Date:
- July 1, 2024
- Indication:
- For the treatment of severe and life-threatening inflammatory conditions.
Announcement
Mesoblast Limited confirmed that it will file its Biologics License Application (BLA) for approval of Ryoncil® (remestemcel-L) in the treatment of children with steroid-refractory acute graft versus host disease (SR-aGVHD) with the U.S. Food and Drug Administration (FDA) next week.
AI Summary
Mesoblast Limited announced that it will file a Biologics License Application (BLA) with the U.S. Food and Drug Administration (FDA) next week for Ryoncil® (remestemcel-L). This application is for the treatment of children with steroid‐refractory acute graft versus host disease (SR‑aGVHD), a severe and life‐threatening condition. The filing represents an important step in advancing this off‑the‑shelf cellular therapy, developed using Mesoblast’s proprietary mesenchymal cell platform that aims to reduce damaging inflammation by releasing anti‑inflammatory factors.
By moving forward with this regulatory submission, Mesoblast reinforces its commitment to providing new treatment options for young patients facing limited alternatives. The decision is closely watched by the medical community, as success could offer a significant advancement in the management of SR‑aGVHD in children.
Read Announcement
