Contributions
Abstract: P677
Type: Poster Sessions
Abstract Category: Clinical aspects of MS - Epidemiology
Background: Long-term efficacy of disease-modifying therapies (DMT) remains a key question in Multiple Sclerosis (MS). Few real-world studies have confirmed the long-term efficacy of DMT on disability progression, especially when given early. Moreover, the possibility of cumulative effects of past DMT use has not been investigated so far.
Objective: To explore the relationship of mild disability risk, measured by irreversible DSS between 3 and 5 with current and prior DMT use in patients with relapsing-remitting MS (RRMS).
Methods: 2,117 patients with RRMS, at least one relapse between 1996 and 2002 and less than five years from MS onset, naïve of any DMT and above 18 years-old were included from four OFSEP centers. The baseline date was defined as the date of the relapse. Association between the use of DMT and risk of irreversible DSS was assessed using a novel weighted cumulative exposure model correlating DMT exposure to the current risk of disability. That model assigns to each drug use taken in the past a weight that represents the importance of this use. Several baseline confounders were considered: sex, duration of disease, time since last relapse, period, irreversible DSS (0, 1 or 2), semiology of relapse and centers. Age and cumulative number of relapses were considered as time-dependant covariates.
Results: At baseline, patients were 33.1 +/- 8.8 years-old and 75.9% were women. The median duration of follow-up was 14.9 years (interquartile range: 7.8-17.5). 78.2% of patients were treated during their follow-up and 57.2% of the DMT were interferon or glatiramer acetate. Current and recent use of DMT has the highest impact on current risk of disability with increased risk while DMT taken between 2 and 10 years ago are associated with a decreased risk. The 'remote' uses had relatively low weights with little effect but, if taken for a long time, could lead to an important cumulative effect. Uninterrupted use of DMT in the past 20 years was associated with a decreased risk of irreversible DSS [3-5] compared to uninterrupted use in the past 2 years (HR=0.57, 95% CI: 0.42-0.83). Past use for 8 years, stopped 2 years ago had a 41% decreased risk of irreversible DSS compared to DMT use in the past 2 years (HR=0.59, 95% CI: 0.46-0.76).
Conclusion: Mechanisms affecting the long-term risk of mild disability may include cumulative effects of DMT use in the previous years. Early use of DMT has a beneficial cumulative impact on the occurrence of mild disability.
Disclosure: FR: nothing to disclose
RC: nothing to disclose
MD: nothing to disclose
GE: Personal honoraria for lectures or consulting from Bayer, Biogen, LFB, Merck, Novartis, Roche, Sanofi. Research support from Bayer, Biogen, Genzyme, Merck, Novartis, Roche and Teva Pharma
SW: nothing to disclose
EL: Consulting and lecture fees or travel grants from Biogen, Genzyme, MedDay Pharmaceuticals, Merck Serono Novartis, and Roche
SV: Consulting and lecture fees, travel grants and research support from Biogen, Geneuro, Genzyme, Novartis, Merck Serono, Roche, Sanofi Aventis and Teva Pharm
DAL: Honoraria and consulting fees from Biogen, Sanofi-Genzyme, Bayer, Novartis, Teva, Merck-Serono, Roche and Medday. Research supports from Biogen, Novartis, Sanofi-Genzyme, Roche and Medday
Abstract: P677
Type: Poster Sessions
Abstract Category: Clinical aspects of MS - Epidemiology
Background: Long-term efficacy of disease-modifying therapies (DMT) remains a key question in Multiple Sclerosis (MS). Few real-world studies have confirmed the long-term efficacy of DMT on disability progression, especially when given early. Moreover, the possibility of cumulative effects of past DMT use has not been investigated so far.
Objective: To explore the relationship of mild disability risk, measured by irreversible DSS between 3 and 5 with current and prior DMT use in patients with relapsing-remitting MS (RRMS).
Methods: 2,117 patients with RRMS, at least one relapse between 1996 and 2002 and less than five years from MS onset, naïve of any DMT and above 18 years-old were included from four OFSEP centers. The baseline date was defined as the date of the relapse. Association between the use of DMT and risk of irreversible DSS was assessed using a novel weighted cumulative exposure model correlating DMT exposure to the current risk of disability. That model assigns to each drug use taken in the past a weight that represents the importance of this use. Several baseline confounders were considered: sex, duration of disease, time since last relapse, period, irreversible DSS (0, 1 or 2), semiology of relapse and centers. Age and cumulative number of relapses were considered as time-dependant covariates.
Results: At baseline, patients were 33.1 +/- 8.8 years-old and 75.9% were women. The median duration of follow-up was 14.9 years (interquartile range: 7.8-17.5). 78.2% of patients were treated during their follow-up and 57.2% of the DMT were interferon or glatiramer acetate. Current and recent use of DMT has the highest impact on current risk of disability with increased risk while DMT taken between 2 and 10 years ago are associated with a decreased risk. The 'remote' uses had relatively low weights with little effect but, if taken for a long time, could lead to an important cumulative effect. Uninterrupted use of DMT in the past 20 years was associated with a decreased risk of irreversible DSS [3-5] compared to uninterrupted use in the past 2 years (HR=0.57, 95% CI: 0.42-0.83). Past use for 8 years, stopped 2 years ago had a 41% decreased risk of irreversible DSS compared to DMT use in the past 2 years (HR=0.59, 95% CI: 0.46-0.76).
Conclusion: Mechanisms affecting the long-term risk of mild disability may include cumulative effects of DMT use in the previous years. Early use of DMT has a beneficial cumulative impact on the occurrence of mild disability.
Disclosure: FR: nothing to disclose
RC: nothing to disclose
MD: nothing to disclose
GE: Personal honoraria for lectures or consulting from Bayer, Biogen, LFB, Merck, Novartis, Roche, Sanofi. Research support from Bayer, Biogen, Genzyme, Merck, Novartis, Roche and Teva Pharma
SW: nothing to disclose
EL: Consulting and lecture fees or travel grants from Biogen, Genzyme, MedDay Pharmaceuticals, Merck Serono Novartis, and Roche
SV: Consulting and lecture fees, travel grants and research support from Biogen, Geneuro, Genzyme, Novartis, Merck Serono, Roche, Sanofi Aventis and Teva Pharm
DAL: Honoraria and consulting fees from Biogen, Sanofi-Genzyme, Bayer, Novartis, Teva, Merck-Serono, Roche and Medday. Research supports from Biogen, Novartis, Sanofi-Genzyme, Roche and Medday