Mesoblast gets FDA approval for cell therapy batch test
TIBA will be added to the testing matrix for every new commercial RYONCIL batch alongside existing potency assays.
Rhea-AI Filing Summary
Mesoblast Limited (MESO) received FDA approval to implement its T-cell Proliferation Inhibition BioAssay (TIBA) for release and stability monitoring of all new commercial RYONCIL product lots. TIBA will be used in a batch-release matrix alongside the existing IL-2Rα inhibition and Cell Adhesion and Proliferation (CAP) assays. Mesoblast said the assay will provide sensitivity to detect potency shifts that could arise from manufacturing-process changes or production at new facilities.
RYONCIL is approved for steroid-refractory acute graft versus host disease in patients aged 2 months or older. Mesoblast describes it as the first industrially manufactured allogeneic MSC product approved by the FDA for any indication.
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Key Figures
Minimum patient age for RYONCIL indication: 2 months or older
Granted patents or patent applications: Over 1,000
Commercial protection through: At least 2044
3 metrics
Minimum patient age for RYONCIL indication
2 months or older
Patients with steroid-refractory acute graft versus host disease
Granted patents or patent applications
Over 1,000
Mesoblast intellectual property portfolio
Commercial protection through
At least 2044
All major markets
Key Terms
T-cell Proliferation Inhibition BioAssay (TIBA), Biologics License, Cell Adhesion and Proliferation (CAP), mesenchymal stromal cell (MSC), +1 more
5 terms
T-cell Proliferation Inhibition BioAssay (TIBA) technical
"T-cell Proliferation Inhibition BioAssay (TIBA)"
Biologics License regulatory
"as per the product's Biologics License"
Cell Adhesion and Proliferation (CAP) technical
"CAP (Cell Adhesion and Proliferation)"
mesenchymal stromal cell (MSC) medical
"mesenchymal stromal cell (MSC) product"
Mesenchymal stromal cells (MSCs) are versatile, adult-derived cells found in bone marrow, fat and other tissues that can help repair damaged tissue and calm excessive immune reactions; think of them as a handyman and emergency crew that can both patch structural damage and coordinate healing. They matter to investors because companies developing MSC-based therapies face scientific, manufacturing and regulatory hurdles but also the potential for sizable markets in regenerative medicine and immune-related diseases.
steroid-refractory acute graft versus host disease (SR-aGvHD) medical
"steroid-refractory acute graft versus host disease (SR-aGvHD)"
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
What did the FDA approve for Mesoblast (MESO)?
The FDA approved Mesoblast’s implementation of the T-cell Proliferation Inhibition BioAssay (TIBA) for release and stability monitoring of all new commercial RYONCIL product lots. TIBA will be used with the existing IL-2Rα inhibition and Cell Adhesion and Proliferation assays in the batch-release matrix.
How many patents and patent applications does Mesoblast (MESO) report?
Mesoblast reports over 1,000 granted patents or patent applications covering cell compositions, manufacturing methods and indications. The company says this intellectual property provides commercial protection through at least 2044 in all major markets.
AI-generated analysis. How Rhea-AI works. Not financial advice.
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
Form 6-K
Report of Foreign Private Issuer
Pursuant to Rule 13a-16 or 15d-16 under the Securities Exchange Act of 1934
Pursuant to Rule 13a-16 or 15d-16 under the Securities Exchange Act of 1934
For the month of September 2026
Commission File Number 001-37626
Mesoblast Limited
(Exact name of Registrant as specified in its charter)
Not Applicable
(Translation of Registrant’s name into English)
Australia
(Jurisdiction of incorporation or organization)
(Jurisdiction of incorporation or organization)
Silviu Itescu
Chief Executive Officer and Executive Director
Level 38
55 Collins Street
Melbourne 3000
Australia
(Address of principal executive offices)
Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F:
Form 20-F ☑ Form 40-F ☐
INFORMATION CONTAINED ON THIS REPORT ON FORM 6-K
On September 24, 2026, Mesoblast Limited filed with the Australian Securities Exchange a new release announcement, which is attached hereto as Exhibit 99.1, and is incorporated herein by reference.
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly organized.
Mesoblast Limited | ||||||||||||||
| /s/ Niva Sivakumar | ||||||||||||||
| Niva Sivakumar | ||||||||||||||
| Company Secretary | ||||||||||||||
Dated: September 24, 2026
INDEX TO EXHIBITS
| Item | ||||||||
99.1 | Press release of Mesoblast Ltd, dated September 24, 2026. | |||||||
MESOBLAST RECEIVES FDA APPROVAL FOR NEW POTENCY ASSAY TO RELEASE COMMERCIAL RYONCIL PRODUCT New York, USA: September 24 and Melbourne, Australia: September 23, 2026: Mesoblast Limited (ASX:MSB; Nasdaq:MESO), global leader in allogeneic cellular medicines for inflammatory diseases, today announced that it has received approval from the United States Food and Drug Administration (FDA) to implement a new potency assay, T-cell Proliferation Inhibition BioAssay (TIBA), for release and stability monitoring of all new commercial product lots of its FDA-approved mesenchymal stromal cell (MSC) product Ryoncil® (remestemcel-L-rknd). The TIBA assay will ensure sufficient sensitivity to detect any shifts in potency of the commercial product that could arise during changes in manufacturing processes or production in new facilities. This assay will be used as part of a matrix to release each commercial batch of RYONCIL in conjunction with the existing potency assays which determine IL-2Rα inhibition and CAP (Cell Adhesion and Proliferation), as per the product's Biologics License. Together these assays ensure that the RYONCIL product is consistent, potent, and clinically effective. RYONCIL is the first industrially-manufactured allogeneic MSC product approved by FDA for any indication, and the only MSC product to be approved for patients with steroid-refractory acute graft versus host disease (SR-aGvHD) aged 2 months or older.1 Mesoblast and FDA have been working closely together since RYONCIL was approved for commercial use to ensure alignment on continued advancements to the product’s manufacturing processes and implementation of assays measuring the product’s ongoing quality control. About Mesoblast Mesoblast (the Company) is a world leader in developing allogeneic (off-the-shelf) cellular medicines for the treatment of severe and life-threatening inflammatory conditions. The therapies from the Company’s proprietary mesenchymal lineage cell therapy technology platform respond to severe inflammation by releasing anti-inflammatory factors that counter and modulate multiple effector arms of the immune system, resulting in significant reduction of the damaging inflammatory process. Mesoblast’s Ryoncil® (remestemcel-L-rknd) for the treatment of steroid-refractory acute graft versus host disease (SR-aGvHD) in pediatric patients 2 months and older is the first FDA-approved mesenchymal stromal cell (MSC) therapy. Please see the full Prescribing Information at www.ryoncil.com. Mesoblast is committed to developing additional cell therapies for distinct indications based on its remestemcel-L and rexlemestrocel-L allogeneic stromal cell technology platforms. Ryoncil® is being developed for additional inflammatory diseases including SR-aGvHD in adults and biologic-resistant inflammatory bowel disease. Rexlemestrocel-L is being developed for heart failure and chronic low back pain. The Company has established commercial partnerships in Japan, Europe and China. About Mesoblast intellectual property: Mesoblast has a strong and extensive global intellectual property portfolio, with over 1,000 granted patents or patent applications covering mesenchymal stromal cell compositions of matter, methods of manufacturing and indications. These granted patents and patent applications provide commercial protection extending through to at least 2044 in all major markets. About Mesoblast manufacturing: The Company’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. Mesoblast has locations in Australia, the United States and Singapore and is listed on the Australian Securities Exchange (MSB) and on the Nasdaq (MESO). For more information, please see www.mesoblast.com, LinkedIn: Mesoblast Limited and X: @Mesoblast Exhibit 99.1
Footnotes / References 1. Please see the full Prescribing Information at www.ryoncil.com Forward-Looking Statements This press release includes forward-looking statements that relate to future events or our future financial performance and involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to differ materially from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. We make such forward-looking statements pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 and other federal securities laws. Forward-looking statements should not be read as a guarantee of future performance or results, and actual results may differ from the results anticipated in these forward-looking statements, and the differences may be material and adverse. Forward-looking statements include, but are not limited to, statements about: the initiation, timing, progress and results of Mesoblast’s preclinical and clinical studies, and Mesoblast’s research and development programs; Mesoblast’s ability to advance product candidates into, enroll and successfully complete, clinical studies, including multi-national clinical trials; Mesoblast’s ability to advance its manufacturing capabilities; the timing or likelihood of regulatory filings and approvals, manufacturing activities and product marketing activities, if any; the commercialization of Mesoblast’s RYONCIL for pediatric SR-aGVHD and any other product candidates, if approved; regulatory or public perceptions and market acceptance surrounding the use of stem-cell based therapies; the potential for Mesoblast’s product candidates, if any are approved, to be withdrawn from the market due to patient adverse events or deaths; the potential benefits of strategic collaboration agreements and Mesoblast’s ability to enter into and maintain established strategic collaborations; Mesoblast’s ability to establish and maintain intellectual property on its product candidates and Mesoblast’s ability to successfully defend these in cases of alleged infringement; the scope of protection Mesoblast is able to establish and maintain for intellectual property rights covering its product candidates and technology; estimates of Mesoblast’s expenses, future revenues, capital requirements and its needs for additional financing; Mesoblast’s financial performance; developments relating to Mesoblast’s competitors and industry; and the pricing and reimbursement of Mesoblast’s product candidates, if approved. You should read this press release together with our risk factors, in our most recently filed reports with the SEC or on our website. Uncertainties and risks that may cause Mesoblast’s actual results, performance or achievements to be materially different from those which may be expressed or implied by such statements, and accordingly, you should not place undue reliance on these forward-looking statements. We do not undertake any obligations to publicly update or revise any forward-looking statements, whether as a result of new information, future developments or otherwise. Release authorized by the Chief Executive. For more information, please contact: Corporate Communications / Investors Paul Hughes T: +61 3 9639 6036 Media – Global Media – Australia Rubenstein BlueDot Media Caroline Nelson Steve Dabkowski T: +1 703 489 3037 T: +61 419 880 486 E: cnelson@rubenstein.com E: steve@bluedot.net.au