Long-Term VidoCa Has Favorable Safety Profile in Relapsing-Remitting MS

Long-term treatment with VidoCa has a favorable safety profile and no new safety signals reported among patients with relapsing-remitting MS.

Long-term treatment with vidofludimus calcium (VidoCa) in patients with relapsing-remitting multiple sclerosis (RRMS) has a favorable safety profile, according to study results presented at the 2023 Consortium of Multiple Sclerosis Centers (CMSC) Annual Meeting, held from May 31 to June 3 in Aurora, Colorado.

VidoCa is a highly selective, orally administered, second-generation dihydoorotate dehydrogenase inhibitor. In the phase 2, double-blind EMPhASIS trial (ClinicalTrials.gov Identifier: NCT03846219), which was conducted in patients with RRMS, VidoCa therapy was associated with a safety and tolerability profile that was comparable to that with placebo. Additionally, compared with placebo, treatment with VidoCa demonstrated a robust benefit in terms of magnetic resonance imaging (MRI) activity.

A phase 3 clinical trial with VidoCa is currently under way. Upon completion of the double-blind treatment portion of the study, participants are eligible to enter a long-term, open-label extension (OLE) period. Researchers sought to provide data on the initial interim analysis of the OLE period of EMPhASIS regarding the safety and tolerability of VidoCa in patients with RRMS.

Among 268 participants with RRMS who initiated the 24-week double-blind treatment period, 254 completed the blinded treatment portion and continued on to the OLE period. In the OLE portion of EMPhASIS, patients were treated with either once-daily VidoCa 30 mg or once-daily VidoCa 40 mg. The interim analysis utilized data from the October 16, 2022, data lock, which involved around 519 treatment years.

The OLE period of EMPhASIS experienced a very low discontinuation rate, low rates of AEs and SAEs, and no new safety signals.

The researchers found that as of October 16, 2022, a total of 209 patients continued on OLE therapy; some of these patients have undergone more than 180 weeks (approximately 4 years) of active treatment. Among these individuals, 193 received treatment in the OLE for ≥96 weeks (ie, approximately 2 years) and 144 underwent treatment in the OLE for ≥144 weeks (ie, approximately 3 years). An annualized discontinuation rate of 5.3% was reported.

The most frequently reported treatment-emergent adverse events (TEAEs) included the following:

  • COVID-19: 9.1%
  • Nasopharyngitis: 4.7%
  • Back pain: 2.8%
  • Urinary tract infection: 2.0%

Overall rates of renal TEAEs per treatment year were 0.023; overall rates of hepatic TEAEs per treatment year were 0.015. A total of 4 TEAEs were associated with treatment discontinuation. Further, a total of 14 serious adverse events (SAEs) were reported, which generated an SAE rate of 0.027 per patient per treatment year. None of the SAEs were considered to be associated with use of the investigational agent.

There were no new safety signals reported. No signal for modifications in hematology parameters was observed.

“The OLE period of EMPhASIS experienced a very low discontinuation rate, low rates of AEs and SAEs, and no new safety signals,” the researchers reported. “Overall, these data suggest a favorable safety profile in long-term treatment with VidoCa,” they concluded.

Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 


Fox RJ, Wolf C, Ondrus M, Sciacca V, Muehler A. Assessment of long-term safety and tolerability of vidofludimus calcium in patients with relapsing-remitting multiple sclerosis in the open-label extension period of the phase 2 trial (EMPhASIS). Abstract presented at: CMSC 2023; May 31-June 3, 2023; Aurora, CO. Abstract DMT51.