A Swiss biopharmaceutical company developing treatments for rare and ultra-rare conditions where patients have no approved options.
Rarivia Therapeutics AG is a Swiss biopharmaceutical company dedicated to developing and delivering treatments for rare and ultra-rare diseases where no approved therapies exist.
We believe every patient deserves access to effective medicine, regardless of how rare their condition. We focus on diseases where strong scientific rationale exists but no company has brought an approved treatment to market.
Headquartered in Zurich, we operate at the intersection of Swiss precision and global ambition. We are pursuing regulatory approval in the United States and Europe to bring our lead program to patients worldwide.
Our initial focus is on cerebral creatine deficiency syndromes — specifically GAMT deficiency. We target conditions with established clinical evidence and a clear unmet medical need for patients and families.
We work closely with the patient and caregiver community, clinical experts, and advocacy organizations. Patients and families are at the center of everything we do.
Guanidinoacetate methyltransferase (GAMT) deficiency is an ultra-rare, autosomal recessive inborn error of creatine metabolism. Loss of GAMT function causes a dual pathology: cerebral creatine depletion (energy failure) and toxic accumulation of guanidinoacetate (GAA).
In healthy individuals, the GAMT enzyme converts guanidinoacetate (GAA) into creatine. In GAMT deficiency, this step is blocked — leading to toxic GAA accumulation and creatine depletion in the brain.
Proton magnetic resonance spectroscopy (MRS) demonstrates restoration of the cerebral creatine peak in every treated patient — providing objective, measurable confirmation of target engagement. Brain MRS is the gold-standard biomarker for monitoring treatment response in GAMT deficiency.
On January 4, 2023, the US Secretary of Health and Human Services added GAMT deficiency to the Recommended Uniform Screening Panel (RUSP). The evidence review found that 7 of 8 infants treated before 6 months achieved normal developmental outcomes. Seven states are currently screening, with 14+ in planning.
We are developing pharmaceutical-grade creatine monohydrate as the first FDA-approved treatment for GAMT deficiency — bringing standardized dosing, cGMP manufacturing, and insurance coverage to patients who today rely on unregulated sports supplements.
There is no FDA-approved drug for GAMT deficiency. Parents of newborns identified through screening are directed to purchase sports nutrition supplements for their infants — without standardized pediatric dosing, pharmaceutical-grade manufacturing, or insurance coverage. FDA has approved pharmaceutical-grade formulations for comparable rare diseases when patients previously relied on supplements.
A validated GAMT-deficient mouse model confirms the human disease phenotype of cerebral creatine depletion, elevated GAA, and neurological impairment (Renema et al. 2003). Creatine supplementation in this model restores brain creatine levels detectable by MRS, mirroring the human treatment response. Mechanistic studies have elucidated multiple pathological pathways of GAA neurotoxicity including GABA(A) receptor agonism, mitochondrial respiratory chain inhibition, and oxidative stress — providing robust scientific rationale for treatment. Gene delivery approaches (AAV9-GAMT) have demonstrated proof-of-concept in preclinical models (Binsfeld et al. 2026), though pharmacological creatine replacement remains the only established therapeutic approach.
| Drug | Disease | Type | Year |
|---|---|---|---|
| Cystadane (betaine) | Homocystinuria | Amino acid derivative | 1996 |
| Carnitor (levocarnitine) | Carnitine deficiency | Endogenous nutrient | 1999 |
| Kuvan (sapropterin) | Phenylketonuria | Cofactor replacement | 2007 |
| Zycubo (copper histidinate) | Menkes disease | Essential mineral | 2026 |
| Creatine monohydrate | GAMT deficiency | Metabolite replacement | — In development |
Decades of published clinical literature and independent government validation (RUSP) support the efficacy of creatine supplementation in GAMT deficiency.
Pursuing the first approved pharmaceutical-grade creatine product for patients with GAMT deficiency.
Unlike supplement-grade products, our creatine monohydrate will be manufactured under cGMP conditions with rigorous quality controls, ensuring consistent potency, purity, and safety.
Giving patients and healthcare providers confidence in a standardized, approved therapy — and enabling insurance reimbursement for families.
Interested in learning more about our programs?