Riulvy is the trade name for tegomil fumarate, an oral disease-modifying therapy (DMT) approved in 2025 in the European Union for the treatment of relapsing-remitting multiple sclerosis (RRMS). It is classified as a hybrid medicinal product, referencing the already approved dimethyl fumarate (Tecfidera). Both agents are prodrugs that produce the same active metabolite — monomethyl fumarate, responsible for the therapeutic effect.

Riulvy is developed to offer an equivalent alternative to Tecfidera, with potential benefits in manufacturing, access, or tolerability, depending on regional healthcare systems.

Indications and Usage

Riulvy is indicated for:

• Adults and adolescents aged 13 years and older
• Diagnosed with relapsing-remitting multiple sclerosis
• With at least one documented clinical relapse or MRI activity in the recent past

Treatment initiation and monitoring should be performed by physicians experienced in the diagnosis and management of MS.

Mechanism of Action

Tegomil fumarate is a fumaric acid ester prodrug that, after oral administration, is rapidly converted to its active metabolite monomethyl fumarate (MMF) in the gastrointestinal tract.

Monomethyl fumarate activates the Nrf2 (nuclear factor erythroid 2-related factor 2) pathway, which:

• Reduces oxidative stress in neurons and glial cells
• Modulates the immune response
• Decreases the migration of pro-inflammatory cells across the blood-brain barrier
• Supports neuroprotection and reduces axonal damage

This immunomodulatory mechanism is considered central to the long-term disease-modifying effects of Riulvy.

Dosage and Administration

Riulvy is administered orally as gastro-resistant hard capsules, available in 174 mg and 348 mg strengths. The capsules must be swallowed whole, with or without food. They should not be crushed, chewed, or opened.

Standard Adult Dosing:

Dose titration is advised to minimize the occurrence of flushing and gastrointestinal side effects during initiation.

Clinical Efficacy

As a hybrid product, Riulvy was approved based on bioequivalence and therapeutic equivalence to dimethyl fumarate. Direct comparative trials were not required; instead, the manufacturer provided analytical, pharmacokinetic, and pharmacodynamic data showing that tegomil fumarate results in similar systemic exposure to MMF.

Expected clinical benefits, inferred from Tecfidera’s pivotal studies, include:

• Reduced annualized relapse rate (ARR)
• Fewer new or enlarging T2 lesions on MRI
• Prolonged time to confirmed disability progression

Summary Table – Clinical Outcomes Expected

These expectations are based on the assumption of similar exposure to MMF, the active metabolite in both formulations.

Safety and Adverse Effects

Riulvy’s safety profile is expected to closely resemble that of dimethyl fumarate, as both share the same active compound.

Common Adverse Events

Laboratory Monitoring

• Complete blood count with differential, including absolute lymphocyte count: before treatment, every 3–6 months during treatment
• Liver function tests: prior to treatment and periodically
• Urinalysis and renal function: at baseline and if clinically indicated

Warnings and Precautions

• Lymphopenia: Persistent reduction in lymphocyte count may increase the risk of opportunistic infections, including progressive multifocal leukoencephalopathy (PML).
• Flushing and GI effects: Can be reduced with dose titration and administration with food. Consider symptomatic treatment if needed.
• Hepatic effects: Monitor transaminases, especially in patients with known hepatic impairment.
• Pregnancy and lactation: Use only if the potential benefit justifies the potential risk to the fetus. No adequate human data are available.

Contraindications

Riulvy is contraindicated in:

• Patients with known hypersensitivity to tegomil fumarate, MMF, dimethyl fumarate, or any excipients
• Patients with a history of severe allergic or anaphylactic reactions to fumaric acid esters

Drug Interactions

Tegomil fumarate does not significantly interact with cytochrome P450 enzymes or major drug transporter systems. However:

• Concomitant use with other immunosuppressive agents or corticosteroids may increase the risk of infection.
• Use caution when co-administering with hepatotoxic medications due to potential additive hepatic effects.

No formal drug-drug interaction studies have been conducted as of the 2025 approval.

Use in Specific Populations

• Pediatric use: Approved for use in patients aged 13 years and older. Safety and efficacy in children under 13 have not been established.
• Geriatric use: Clinical data in patients ≥65 years are limited. Monitor for increased susceptibility to adverse effects.
• Renal or hepatic impairment: No dose adjustment is required for mild to moderate impairment. Riulvy has not been formally studied in patients with severe renal or hepatic dysfunction.

Storage and Handling

• Store Riulvy capsules at room temperature (15–25°C) in a dry place, away from moisture and direct sunlight.
• Do not use if the capsule is damaged or altered.
• Keep out of reach of children.
• No special handling or hazardous drug precautions are required.

Regulatory Status

Riulvy received marketing authorization in the European Union in 2025 as a hybrid medicinal product referencing Tecfidera. The approval was based on analytical comparability, pharmacokinetics, and safety data. The decision reflects confidence in Riulvy as a cost-effective, equivalent alternative to existing fumarate therapies for MS.

At the time of writing, Riulvy has not been approved by the U.S. FDA. Its availability outside the EU depends on ongoing regulatory submissions.

Riulvy (tegomil fumarate) is a newly approved oral therapy for relapsing-remitting multiple sclerosis in patients 13 years and older. As a hybrid version of dimethyl fumarate, it provides equivalent delivery of monomethyl fumarate, offering the same mechanism of action via Nrf2 pathway activation. Clinical benefits include relapse reduction, reduced MRI lesion activity, and favorable safety when properly monitored. Its approval expands options for MS patients and may improve access to fumarate-based treatment through alternative sourcing and cost structures.

Frequently Asked Questions (FAQ)