High Survival Rates With Ryoncil® in EIND Program Emphasize Importance of Earlier Use in Both Children and Adults With SR-aGvHD

Rhea-AI Summary

Mesoblast (Nasdaq: MESO) reported February 2026 EIND program data showing high survival with Ryoncil (remestemcel-L-rknd) in steroid‑refractory acute graft‑versus‑host disease (SR‑aGvHD) across children and adults and when used as second or third line.

Of 53 EIND patients treated ≥third line (89% grade III/IV), 15% died before completing treatment versus 2% in second‑line Phase 3 MSB‑GVHD001, underscoring earlier use after steroid resistance. A pivotal adult second‑line trial is expected to begin enrollment this quarter pending central IRB approval, aiming to support an adult label extension.

Positive

• Lower pre‑completion mortality in second‑line trial (2% vs 15%)
• High survival observed across children and adults in EIND
• Pivotal adult trial planned to start enrollment this quarter
• FDA‑approved MSC product for SR‑aGvHD including children under 12

Negative

• Higher pre‑completion mortality when used ≥third line (15%)
• Most ≥third‑line patients had severe disease (89% grade III/IV)

Key Figures

EIND patients treated: 53 patients Severe disease proportion: 89% grade III/IV Mortality ≥ third-line: 15% died +5 more

8 metrics

EIND patients treated 53 patients SR-aGvHD patients receiving Ryoncil® as ≥ third-line in EIND program

Severe disease proportion 89% grade III/IV Baseline severity among ≥ third-line EIND SR-aGvHD patients

Mortality ≥ third-line 15% died Patients dying before completing full Ryoncil® course in EIND program

Mortality second-line 2% died Patients dying before completing full Ryoncil® course in Phase 3 trial

Day 100 survival Day 100 survival Adult EIND patients had at least as favorable day 100 survival as children

Adult population size ≈3x pediatric Adult SR-aGvHD population versus pediatric SR-aGvHD population

Planned pivotal trial timing This quarter Adult second-line SR-aGvHD pivotal trial enrollment expected to commence

Treatment line Second or third line Ryoncil® use in SR-aGvHD across lines of therapy in presented data

Market Reality Check

Price: $18.30 Vol: Volume 212,232 is 1.06x t...

normal vol

$18.30 Last Close

Volume Volume 212,232 is 1.06x the 20-day average of 200,571. normal

Technical Price 18.3 is trading above the 200-day MA at 15.2.

Peers on Argus

MESO was up 1.72% while key biotech peers were mixed to down (e.g., DYN -2.51%, ...

MESO was up 1.72% while key biotech peers were mixed to down (e.g., DYN -2.51%, SRPT -1.8%, AUPH -0.62%, HRMY -1.32%, IMCR +0.7%), suggesting a stock-specific move tied to the Ryoncil® data.

Historical Context

5 past events · Latest: Jan 28 (Positive)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Jan 28	Quarter, financing update	Positive	-4.0%	Ryoncil® revenue growth, new credit facility, cash and pipeline updates.
Jan 26	Clinical outcomes data	Positive	+2.6%	Real‑world pediatric SR‑aGvHD survival and expanding commercial footprint.
Jan 18	FDA feedback CLBP	Positive	-3.5%	FDA feedback favoring rexlemestrocel‑L efficacy in chronic back pain.
Jan 08	Sales, financing update	Positive	+3.2%	Ryoncil® sales up 60% and new five‑year interest‑only facility.
Jan 01	Board leadership change	Neutral	+0.7%	Board role changes as company transitions to commercialization focus.

Pattern Detected

Recent news often positive, with mixed price reactions: both rallies and sell-offs have followed favorable Ryoncil® and pipeline updates.

Recent Company History

Over the past six weeks Mesoblast has reported multiple Ryoncil® milestones and financing developments. On Jan 8 and Jan 28, quarterly Ryoncil® sales rose to the mid‑US$30M range alongside a US$125M credit facility and improving cash metrics. Pediatric real‑world data on Jan 26 highlighted 84% survival after the 28‑day regimen, and a pivotal adult SR‑aGvHD trial was flagged. Today’s Tandem Meeting data and planned pivotal adult trial fit into this ongoing push to expand Ryoncil® use and label scope.

Market Pulse Summary

This announcement highlights high survival outcomes with Ryoncil® in SR-aGvHD when used earlier, acr...

Analysis

This announcement highlights high survival outcomes with Ryoncil® in SR-aGvHD when used earlier, across both children and adults, and underscores the impact of completing the full treatment course. It also flags an upcoming pivotal adult second-line trial in a population roughly three times the pediatric market. In context of recent sales growth and prior pediatric data, investors may watch enrollment progress, adult survival data, and future regulatory interactions as key milestones.

Key Terms

steroid-refractory acute graft-versus-host disease, sr-agvhd, mesenchymal stromal cell, emergency investigational new drug, +2 more

6 terms

steroid-refractory acute graft-versus-host disease medical

"The study results showed that Ryoncil® ... in steroid-refractory acute graft-versus-host disease"

A severe condition that can follow a stem cell or bone marrow transplant in which the donor immune cells attack the patient’s organs and tissues; “steroid-refractory” means it does not improve after standard steroid treatment. Investors pay attention because it represents an urgent unmet medical need that drives demand for new drugs, influences clinical trial success and regulatory approvals, and can materially affect the commercial prospects and valuation of companies developing effective therapies — like a fire that the usual extinguisher cannot put out.

sr-agvhd medical

"children or adults With SR-aGvHD ... with steroid-refractory acute graft-versus-host disease"

Steroid-refractory acute graft-versus-host disease (sr‑aGVHD) is a severe immune reaction that can occur after a patient receives a donor stem cell or bone marrow transplant; it means the inflammation did not improve after standard steroid therapy. For investors, it signals a high medical need and potential market opportunity for new therapies because affected patients face worse outcomes, longer hospital stays and higher costs, similar to a fire that keeps flaring up despite the usual extinguisher.

mesenchymal stromal cell medical

"Ryoncil® is the first mesenchymal stromal cell (MSC) product approved by the U.S."

Mesenchymal stromal cells are a type of adult cell found in bone marrow, fat and other tissues that can act like a repair crew, supporting tissue healing, reducing inflammation and helping other cells grow. Investors care because these cells are the basis for many experimental therapies and diagnostics; clinical success, manufacturing scale-up, safety and regulatory approval determine commercial potential and can strongly affect a company’s valuation.

emergency investigational new drug regulatory

"treatment under the Emergency Investigational New Drug (EIND) program (89% grade III/IV"

An emergency investigational new drug is a regulatory pathway that lets a patient access an unapproved, experimental medication or treatment immediately when no approved option exists and waiting for full approval would be dangerous. For investors, an emergency access authorization can signal urgent clinical need, potential early real‑world use and reputational or regulatory risk, much like allowing a prototype car onto the road for a single, urgent trip.

phase 3 medical

"second-line in the Phase 3 trial MSB-GVHD001."

Phase 3 is the late-stage clinical testing step for a new drug or medical treatment, where the product is given to large groups of patients to confirm effectiveness, monitor side effects, and compare it to standard care. Successful Phase 3 results are often the final scientific hurdle before regulators decide on approval and market launch—like passing a final exam before graduation—and can sharply change a company's valuation and future revenue prospects.

institutional review board regulatory

"after protocol approval by the trial's central Institutional Review Board (IRB)."

An institutional review board is an independent committee that reviews and approves research involving people to make sure studies are safe, ethical, and protect participants’ rights and privacy. For investors, IRB approval is a gatekeeper: it can determine whether a clinical trial can start or continue, affecting timelines, regulatory risk, cost and the credibility of trial results—similar to a safety inspector whose sign-off is required before work can proceed.

AI-generated analysis. Not financial advice.

NEW YORK, Feb. 11, 2026 (GLOBE NEWSWIRE) -- Mesoblast Limited (Nasdaq:MESO; ASX:MSB), global leader in allogeneic cellular medicines for inflammatory diseases, today provided data presented at the February 2026 Tandem Meetings of the American Society for Transplantation and Cellular Therapy (ASTCT) and the Center for Blood and Marrow Transplant Research (CIBMTR) in Salt Lake City, Utah.

The study results showed that Ryoncil^® (remestemcel-L-rknd) achieved similarly high survival outcomes in steroid-refractory acute graft-versus-host disease (SR-aGvHD) irrespective whether used in children or adults, as second or third line, and in ruxolitinib naive or resistant patients.¹ Ryoncil^® is the first mesenchymal stromal cell (MSC) product approved by the U.S. Food and Drug Administration (FDA) for any indication, and the only product approved for children under age 12 with steroid-refractory acute graft-versus-host disease (SR-aGvHD).²

Importantly, of the 53 patients with SR-aGvHD who received Ryoncil^® as ≥ third line treatment under the Emergency Investigational New Drug (EIND) program (89% grade III/IV disease), 15% died before being able to complete a full treatment course of Ryoncil^® compared with only 2% of patients who received Ryoncil^® as second-line in the Phase 3 trial MSB-GVHD001. These results emphasize the importance of using Ryoncil^® as early as possible after steroid resistance in acute GVHD in order to complete a full treatment course and maximize survival.

Additionally, adult patients in the EIND program of Ryoncil^® had at least as favorable day 100 survival as children in the EIND program, providing strong support and rationale for the planned pivotal trial of early use of Ryoncil^® as part of the second-line treatment regimen in adults with severe SR-aGvHD. The trial is expected to commence enrollment this quarter after protocol approval by the trial's central Institutional Review Board (IRB). If successful, the trial will support label extension of Ryoncil^® for use in adults - a population approximately three times the size of the pediatric SR-aGvHD population.

“Treatment initiation as early as possible is essential in order to give Ryoncil^® the best chance to save as many precious lives as possible,” said Mesoblast Chief Executive Dr. Silviu Itescu. "The Phase 3 trial in adults with SR-aGvHD will position Ryoncil^® as the earliest treatment regimen for severe disease after steroid resistance."

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 Twitter: @Mesoblast

References / Footnotes

1. Kurtzberg J, et al. Remestemcel-L-rknd (Ryoncil) Improves Survival After Failure of Second-Line Treatment for SR-aGVHD [Poster presentation]. 2026 Transplantation & Cellular Therapy Tandem Meetings
2. 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
Allison Worldwide	BlueDot Media
Emma Neal	Steve Dabkowski
T: +1 603 545 4843	T: +61 419 880 486
E: emma.neal@allisonworldwide.com	E: steve@bluedot.net.au

FAQ

What did Mesoblast (MESO) report about Ryoncil survival in the February 2026 EIND program?

Ryoncil showed similarly high survival in children and adults across second and third line use. According to the company, EIND data showed comparable day‑100 survival and supports earlier treatment after steroid resistance to maximize completion and outcomes.

How did mortality before completing Ryoncil differ between ≥third‑line EIND and second‑line Phase 3 (MESO‑GVHD001)?

Pre‑completion mortality was higher in ≥third‑line EIND patients at 15% versus 2% in second‑line Phase 3. According to the company, this contrast supports administering Ryoncil earlier after steroid resistance to improve chances of completing therapy.

When will Mesoblast begin the pivotal adult second‑line trial of Ryoncil (MESO)?

The pivotal adult second‑line trial is expected to begin enrollment this quarter after central IRB protocol approval. According to the company, the trial aims to evaluate earlier use in adults and support a potential adult label extension.

Why does Mesoblast say early use of Ryoncil matters for adults with SR‑aGvHD (MESO)?

Early use increases likelihood of completing a full treatment course and may maximize survival benefits. According to the company, higher pre‑completion deaths in later lines highlight the importance of initiating Ryoncil soon after steroid resistance.