FDA Accepts Resubmitted BLA for Remestemcel-L in Pediatric Steroid-Refractory Acute GVHD
核心洞察
The FDA has accepted Mesoblast's resubmitted Biologics License Application (BLA) for remestemcel-L (Ryoncil (搜索)) to treat pediatric steroid-refractory acute graft-vs-host disease (搜索) (SR-aGVHD).
The resubmission addresses chemistry, manufacturing, and control (CMC) issues, with the FDA considering prior clinical data from the Phase 3 MSB-GVHD001 trial as sufficient.
The PDUFA goal date for the FDA's decision on remestemcel-L is set for January 7, 2025, offering potential hope for children with limited treatment options.
Mesoblast Limited announced that the FDA has accepted the resubmission of its Biologics License Application (BLA) for remestemcel-L (Ryoncil (搜索)) for treating children with steroid-refractory acute graft-vs-host disease (搜索) (SR-aGVHD). The FDA considers this resubmission a complete response, setting the stage for a potential approval decision by January 7, 2025.
The resubmitted BLA addresses chemistry, manufacturing, and control (CMC) issues raised previously. The FDA indicated in March 2024 that clinical data from the Phase 3 MSB-GVHD001 trial were adequate to support the submission. This decision offers renewed hope for a potential treatment for a condition with limited options and high mortality rates.
Clinical Trial Data and Outcomes
The Phase 3 MSB-GVHD001 trial enrolled 54 pediatric patients with SR-aGVHD. The study met its primary endpoint, demonstrating a 70.4% overall response rate (ORR) at day 28, compared to a pre-specified ORR of 45% (P = .0003). Furthermore, patients achieving a response at day 28 had an 87% overall survival (OS) rate at day 100, compared to 47% for non-responders (P = .0001).
Compared to a matched control group from the Mount Sinai Acute GVHD International Consortium (MAGIC) database, remestemcel-L showed superior outcomes. The remestemcel-L group achieved a 70% ORR at day 28 and a 74% OS rate at day 100, compared to 43% and 57% respectively in the control group.
Long-Term Survival Benefits
A 4-year survival study by the Center for International Blood and Marrow Transplant Research (CIBMTR) on 51 patients from the Phase 3 trial showed durable survival benefits. The overall survival rates were 67% at 6 months, 63% at 1 year, 51% at 2 years, and 49% at 4 years. These results are particularly significant given that the expected 2-year survival rate with best available therapy is only 25-38%.
Addressing Unmet Needs in SR-aGVHD
Acute GVHD affects approximately 50% of patients undergoing allogeneic bone marrow transplants. SR-aGVHD is associated with mortality rates as high as 90%. There are currently no FDA-approved treatments for children under 12 with SR-aGVHD in the US, highlighting the urgent need for effective therapies.
Mechanism of Action
Remestemcel-L is an investigational therapy composed of culture-expanded mesenchymal stromal cells from unrelated donors. Administered intravenously, it modulates the immune system by inhibiting T-cell activation and proliferation, down-regulating pro-inflammatory cytokines, and promoting anti-inflammatory cell recruitment.