Mesoblast clears FDA path as Ryoncil growth funds new clinical milestones

FDA opens route to heart-failure filing

Mesoblast Limited (ASX:MSB; Nasdaq:MESO) has cleared a significant regulatory hurdle for rexlemestrocel-L, with the U.S. Food and Drug Administration confirming that the company may proceed with a Biologics License Application for preventing life-threatening gastrointestinal bleeding in end-stage heart failure patients supported by left ventricular assist devices.

The planned filing would use the therapy’s Regenerative Medicine Advanced Therapy and Orphan Drug designations. Formal minutes from the FDA meeting are still expected, so the announcement establishes a path to filing rather than an approval of the therapy or its proposed use.

The regulatory update arrived alongside completion of treatment in Mesoblast’s 350-patient Phase 3 trial of rexlemestrocel-L for chronic inflammatory low back pain caused by degenerative disc disease. The trial’s primary endpoint is durable pain reduction at 12 months, with the readout expected next year. The result will therefore depend on follow-up data, not simply the completion of dosing, after the 350-patient Phase 3 trial reached its treatment milestone earlier in the year.

Ryoncil sales improve while cash use contracts

Commercially, Ryoncil continued to provide the quarter’s clearest financial momentum. Net revenue reached US$28 million in the three months to September 30, up 44% from the prior-year period, with September recording the highest monthly number of new patient starts. Mesoblast said the revenue figure remains subject to completion of financial close procedures and audit.

The cash-flow picture improved even more sharply on the company’s measure of operating use. Net cash used in operating activities was US$2.128 million, compared with US$14.9 million in the prior-year quarter. Cash and cash equivalents stood at US$98.545 million at quarter-end, which the Appendix 4C mechanically translates into 46.3 quarters of funding at the quarter’s operating cash-use rate. That calculation does not remove the uncertainty created by future trial, manufacturing, commercial and financing requirements.

Adult Ryoncil expansion adds a manufacturing test

Mesoblast has also begun enrolling the registration trial intended to expand Ryoncil’s use to adults with steroid-refractory acute graft-versus-host disease. The company expects up to 40 US sites to be activated this year, representing about 60% of the estimated 8,500 annual US allogeneic adult bone marrow transplant population.

As it scales inventory for potential adult demand, Mesoblast has implemented an FDA-approved additional potency assay, the T-cell Proliferation Inhibition BioAssay. The assay is intended to provide further assurance around product potency and consistency as manufacturing expands, following the FDA-approved potency assay disclosed in September.

US$125 million facility remains fully drawn

The stronger operating cash position sits alongside a heavily drawn capital structure. Mesoblast had US$125 million outstanding under a five-year credit-line facility from an existing shareholder and director, carrying a fixed 8% annual interest rate and secured solely against the Temcell royalty. The company reported no unused financing facilities at September 30.

That combination gives Mesoblast substantial reported cash but leaves the next phase of the story tied to execution: the formal FDA minutes and timing of any BLA, the 12-month low-back-pain data, adult trial enrolment, and whether Ryoncil’s September demand can be sustained beyond seasonal treatment scheduling.