Contributions
Abstract: P617
Type: Poster Sessions
Abstract Category: Therapy - Risk management for disease modifying treatments
Background: In clinical trials of disease-modifying therapies (DMTs) in patients with relapsing-remitting multiple sclerosis (RRMS), therapies such as dimethyl fumarate (DMF) and interferon beta-1a (IFN-b1a) have decreased total lymphocyte count (TLC) levels which, in real-world settings, are potentially associated with increased risk of infections. Data on these outcomes in older patients are lacking. This study compared infection rates and lymphocyte counts in RRMS patients ≥50 years old receiving subcutaneous (sc) IFN-b1a 44 mcg 3 times a week or DMF 240 mg twice daily.
Methods: A total of 36 RRMS patients ≥50 years old treated with IFNβ-1a sc (n=15) or DMF (n=21) were identified as having laboratory and clinical follow-up over 1 year with index date (baseline) between 1 January and 31 December 2015, by retrospective chart review at The Neurology Center of New England.
Results: Patients treated with IFNβ-1a sc and DMF had similar baseline characteristics (mean [SD]) including: duration of disease (14.7 [8.07] and 14.0 [12.52] years, respectively), number of prior DMTs (1.5 [0.99] and 2.0 [1.79], respectively) and number of relapses in prior 2 years (0.9 [1.03] and 1.0 [1.36], respectively). Only 1 patient in each group had a prior history of infection; 1 patient in each group had lymphopenia grade II at baseline, all others had normal TLC. The proportion of patients with ≥1 infection over 1 year was significantly lower for patients receiving IFNβ-1a sc than for those receiving DMF (33% vs. 71%, respectively; p=0.0409 by Fisher's exact test). Infection reports were also significantly fewer for patients receiving IFNβ-1a sc: 5 of 15 IFNβ-1a sc-treated patients had 7 total infections compared with 15 of 21 DMF treated patients, who had 43 infections over 1 year (rate ratio for IFNβ-1a sc vs. DMF=0.23; 95% confidence internal: 0.09-0.59; p=0.0023 by negative binomial regression). TLC from baseline to 1 year in DMF-treated patients decreased significantly compared with IFNβ-1a sc-treated patients (mean [SD] change: -686.4 [577.64] vs. 336.9 [1179.89] cells/µL, respectively; p=0.0459 by t-test). Further results on changes in CD4 and CD8 counts and CD4:CD8 ratio will be presented.
Conclusions: Significantly higher infection rates and more severe TLC reductions were seen in older RRMS patients receiving DMF compared with those receiving IFNβ-1a sc. Further evaluation of the effect of DMTs on lymphocyte levels and infection rates is warranted in a larger study.
Disclosure: BH and MG are employees of EMD Serono, Inc., Rockland, MA, USA (a business of Merck KGaA, Darmstadt, Germany). SC and SN are employees of the Neurology Center of New England and received grant support from EMD Serono, Inc. SA is an employee of Prometrika, LLC, which received funding from EMD Serono, Inc. to run the analysis.
Abstract: P617
Type: Poster Sessions
Abstract Category: Therapy - Risk management for disease modifying treatments
Background: In clinical trials of disease-modifying therapies (DMTs) in patients with relapsing-remitting multiple sclerosis (RRMS), therapies such as dimethyl fumarate (DMF) and interferon beta-1a (IFN-b1a) have decreased total lymphocyte count (TLC) levels which, in real-world settings, are potentially associated with increased risk of infections. Data on these outcomes in older patients are lacking. This study compared infection rates and lymphocyte counts in RRMS patients ≥50 years old receiving subcutaneous (sc) IFN-b1a 44 mcg 3 times a week or DMF 240 mg twice daily.
Methods: A total of 36 RRMS patients ≥50 years old treated with IFNβ-1a sc (n=15) or DMF (n=21) were identified as having laboratory and clinical follow-up over 1 year with index date (baseline) between 1 January and 31 December 2015, by retrospective chart review at The Neurology Center of New England.
Results: Patients treated with IFNβ-1a sc and DMF had similar baseline characteristics (mean [SD]) including: duration of disease (14.7 [8.07] and 14.0 [12.52] years, respectively), number of prior DMTs (1.5 [0.99] and 2.0 [1.79], respectively) and number of relapses in prior 2 years (0.9 [1.03] and 1.0 [1.36], respectively). Only 1 patient in each group had a prior history of infection; 1 patient in each group had lymphopenia grade II at baseline, all others had normal TLC. The proportion of patients with ≥1 infection over 1 year was significantly lower for patients receiving IFNβ-1a sc than for those receiving DMF (33% vs. 71%, respectively; p=0.0409 by Fisher's exact test). Infection reports were also significantly fewer for patients receiving IFNβ-1a sc: 5 of 15 IFNβ-1a sc-treated patients had 7 total infections compared with 15 of 21 DMF treated patients, who had 43 infections over 1 year (rate ratio for IFNβ-1a sc vs. DMF=0.23; 95% confidence internal: 0.09-0.59; p=0.0023 by negative binomial regression). TLC from baseline to 1 year in DMF-treated patients decreased significantly compared with IFNβ-1a sc-treated patients (mean [SD] change: -686.4 [577.64] vs. 336.9 [1179.89] cells/µL, respectively; p=0.0459 by t-test). Further results on changes in CD4 and CD8 counts and CD4:CD8 ratio will be presented.
Conclusions: Significantly higher infection rates and more severe TLC reductions were seen in older RRMS patients receiving DMF compared with those receiving IFNβ-1a sc. Further evaluation of the effect of DMTs on lymphocyte levels and infection rates is warranted in a larger study.
Disclosure: BH and MG are employees of EMD Serono, Inc., Rockland, MA, USA (a business of Merck KGaA, Darmstadt, Germany). SC and SN are employees of the Neurology Center of New England and received grant support from EMD Serono, Inc. SA is an employee of Prometrika, LLC, which received funding from EMD Serono, Inc. to run the analysis.