Traditional first-line treatment failure rates in neuromyelitis optica spectrum disorder patients included in the Argentinean registry (RelevarEM)

• Published in: Multiple sclerosis and related disorders 2024-09, Vol.89, p.105771, Article 105771
• Main Authors: Carnero Contentti, Edgar, Lopez, Pablo A, Patrucco, Liliana, Cristiano, Edgardo, Miguez, Jimena, Silva, Berenice, Liwacki, Susana, Tkachuk, Verónica, Balbuena, María E, Vrech, Carlos, Deri, Norma, Correale, Jorge, Marrodan, Mariano, Ysrraelit, María C, Fiol, Marcela, Leguizamon, Felisa, Luetic, Geraldine, Tavolini, Darío, Mainella, Carolina, Zanga, Gisela, Burgos, Marcos, Hryb, Javier, Barboza, Andrés, Lazaro, Luciana, Alonso, Ricardo, Fernández Liguori, Nora, Nadur, Débora, Martinez, Alejandra, Steinberg, Judith, Carrá, Adriana, Alonso Serena, Marina, Rojas, Juan I
• Format: Article
• Language: English
• Subjects: Adult; Argentina; Azathioprine - therapeutic use; Female; Humans; Immunosuppressive Agents - therapeutic use; LATAM; Longitudinal Studies; Male; Middle Aged; Mycophenolic Acid - therapeutic use; Neuromyelitis Optica - drug therapy; NMOSD; Registries; Retrospective Studies; Rituximab - administration & dosage; Rituximab - therapeutic use; Treatment; Treatment Failure
• ISSN: 2211-0348; 2211-0356; 2211-0356
• DOI: 10.1016/j.msard.2024.105771

•We studied 139 NMOSD patients from Argentina on AZA (n = 105), MMF (n = 5), or RTX (n = 29).•The annualized relapse rate decreased post-treatment in 51.1 %, 48.4 %, and 79.1 % of cases.•RTX showed a significantly lower risk compared to AZA (HR= 1.67, 95 %CI 1.34–3.54, p = 0.01) and MMF (HR= 2.01, 95 %CI 1.86–4.43, p = 0.008).•49/105 (46.6 %) on AZA, 2/5 (40 %) on MMF, and 4/29 (13.8 %) on RTX switched therapies due to treatment failure.•Higher neurological disability and longer time to treatment initiation increased relapse risk with traditional first-line IST. Immunosuppressive therapies as azathioprine (AZA), mycophenolate mofetil (MMF) and rituximab (RTX) are widely prescribed as first-line treatment to prevent relapses in NMOSD. However, the rate of response to these traditional therapies is unknown in Argentina. We aimed to describe and compare treatment failure rates in NMOSD patients included in the Argentinean MS and NMOSD registry (RelevarEM, NCT 03375177). A retrospective cohort study was conducted in NMOSD patients included in RelevarEM (a nationwide, longitudinal, observational, non-mandatory registry of MS and NMOSD in Argentina). NMOSD patients were defined based on validate diagnostic criteria. Only NMOSD patients who received AZA or MMF for at least 6 months or RTX for at least 1 month were included. Patients who were receiving AZA, MMF, or RTX and then switched to another 1 of these 3 therapies were included if the above-mentioned criteria for each drug were fulfilled. Data on patient demographics, clinical, neuroradiological findings, and treatments administered were collected. Treatment failure was defined as any new attack/relapse that occurred despite immunosuppressive treatment. We included 139 NMOSD patients who were receiving AZA (n = 105), MMF (n = 5) or RTX (n = 29) with a mean follow-up time of 41.3 ± 11.4 months and median of EDSS at treatment initiation of 3. We observed a reduction in the annualized relapse rate from pre-treatment to post-treatment of 51.1 %, 48.4 %, and 79.1 % respectively with a Hazard Risk relative to RTX (95 % CI) of 1.67 (1.34–3.54, p = 0.01) for AZA and 2.01 (1.86–4.43, p = 0.008) for MMF. AZA, MMF and RTX failure was observed in 45/105 (42.8 %), 2/5 (40 %) and 3/29 (10.3 %) patients, respectively. Treatment failure rates were higher for AZA and MMF than RTX in Argentinean NMOSD patients in a real-world setting. High-efficacy treatment increases the opportunity to prevent attacks of NMOSD.