| Therapy type | Mechanism | Development stage | Key findings |
|---|---|---|---|
| Conventional management: dietary protein restriction, carnitine supplementation, metronidazole/other antibiotics | Reduces propiogenic substrate load from isoleucine, valine, methionine, threonine and lowers gut microbiota-derived propionate; carnitine promotes formation/excretion of propionylcarnitine and helps maintain carnitine pools | Standard of care / established clinical management | Current treatment is mainly supportive rather than curative. Dietary restriction, carnitine, and metronidazole/antibiotics are widely used and have improved survival, but many patients still develop chronic complications including neurologic and cardiac disease despite metabolic management (pqac-00000010, pqac-00000034) |
| Liver transplantation | Provides a major new source of functional hepatic PCC activity, increasing systemic propionyl-CoA clearance and reducing recurrent metabolic instability | Established option for selected severe patients | Considered for severe disease; can stabilize metabolic control and may improve or reverse cardiomyopathy in some patients, but does not fully cure extrahepatic disease and is limited by transplant eligibility and risks (pqac-00000008, pqac-00000014) |
| mRNA-3927 dual mRNA-LNP therapy (encodes PCCA and PCCB) | Intravenous lipid nanoparticle delivery of therapeutic mRNAs to liver cells, enabling translation of both PCC subunits and reconstitution of active PCC enzyme | Clinical; first-in-human Phase 1/2 with interim results published in *Nature* (2024) | In 16 participants across 5 dose cohorts, 346 IV doses were administered over 15.69 person-years with no dose-limiting toxicities. Among 8 participants with pretreatment metabolic decompensation events, treatment was associated with a 70% reduction in risk; biomarkers including 3-HP, 2-MC, propionylcarnitine, and n-propionylglycine generally decreased after treatment (pqac-00000024, pqac-00000025, pqac-00000026) |
| Antisense oligonucleotide therapy targeting PCCA pseudoexon | Splice-switching ASOs suppress aberrant pseudoexon inclusion in mutant PCCA pre-mRNA to restore normal splicing and rescue enzyme expression/activity | Preclinical / experimental personalized RNA therapy | Recent work demonstrated modulation of PCCA pseudoexon splicing as a plausible mutation-specific rescue strategy, highlighting pseudoexon activation as a therapeutically actionable mechanism in propionic acidemia (pqac-00000011) |
| Metabolic rerouting approaches | Diverts upstream propiogenic flux away from propionyl-CoA production, for example by genetically or pharmacologically reducing valine/isoleucine catabolic steps that feed propionate metabolism | Preclinical proof-of-concept | In zebrafish models of disorders of propionyl-CoA metabolism, proximal interruption of valine/isoleucine oxidation improved survival and reduced propionate-derived toxic metabolites, supporting metabolic rerouting as a candidate strategy for PA (pqac-00000011) |


*Table: This table summarizes current and emerging therapeutic approaches for propionic acidemia associated with PCCA deficiency, spanning standard management, transplantation, RNA therapeutics, and experimental metabolic strategies. It is useful for comparing mechanism, maturity, and evidence across interventions.*