Evaluation of frequency, severity, and independent risk factors for recurrence of disease activity after fingolimod discontinuation in a large real-world cohort of patients with multiple sclerosis

Antiviral therapy with tenofovir in MS

Infection by the Epstein-Barr virus (EBV) is implicated as the leading cause of multiple sclerosis (MS). We have previously published a case description of a person with MS (pwMS) who was also HIV positive and treated with a combination of antiretrovirals (ART) containing tenofovir, a potent inhibitor of EBV replication. In the years following this publication, the patient had no new relapses, even though she did not use any MS disease-modifying therapy for nearly five years. After switching to another ART with no known efficacy against EBV, her MS-disease activity gradually re-emerged. This finding further emphasizes that targeting EBV lytic reactivation should be explored further in clinical trials as a potential treatment option for MS.

Risk of T2 lesions when discontinuing fingolimod: a nationwide predictive and comparative study

Fingolimod is a frequently used disease-modifying therapy in relapsing-remitting multiple sclerosis. However, case reports and small observational studies indicate a highly increased risk of disease reactivation after discontinuation. We aimed to investigate the risk of radiological disease reactivation in patients discontinuing fingolimod. We performed a nationwide cohort study in Denmark, including patients who discontinued fingolimod between January 2014 and January 2023. Eligibility was a diagnosis with relapsing-remitting multiple sclerosis and two MRIs performed respectively within 1 year before and after discontinuing fingolimod. The included patients were compared with those discontinuing dimethyl fumarate with the same eligibility criteria in an unadjusted and matched propensity score analysis. Matching was done on age, sex, Expanded Disability Status Scale, MRI data, cause for treatment discontinuation, treatment duration and relapse rate. The main outcome was the presence of new T2 lesions on the first MRI after treatment discontinuation. To identify high-risk patients among those discontinuing fingolimod, we made a predictive model assessing risk factors for obtaining new T2 lesions. Of 1324 patients discontinuing fingolimod in the study period, 752 were eligible for inclusion [mean age (standard deviation), years, 41 (10); 552 females (73%); median Expanded Disability Status Scale (Q1-Q3), 2.5 (2.0-3.5); mean disease duration (standard deviation), years, 12 (8)]. Of 2044 patients discontinuing dimethyl fumarate in the study period, 957 were eligible for inclusion, presenting similar baseline characteristics. Among patients discontinuing fingolimod, 127 (17%) had 1-2 new T2 lesions, and 124 (17%) had ≥3 new T2 lesions compared with 114 (12%) and 45 (5%), respectively, for those discontinuing dimethyl fumarate, corresponding to odds ratios (95% confidence interval) of 1.8 (1.3-2.3) and 4.4 (3.1-6.3). The predictive model, including 509 of the 752 patients discontinuing fingolimod, showed a highly increased risk of new T2 lesions among those with disease activity during fingolimod treatment and among females under 40 years. This nationwide study suggests that discontinuing fingolimod in some cases carries a risk of developing new T2 lesions, emphasizing the importance of clinical awareness. If feasible, clinicians should prioritize the prompt initiation of new disease-modifying therapies, particularly among young females.

Frequency and risk factors of rebound after fingolimod discontinuation - A retrospective study

BACKGROUND

Fingolimod (FTY) rebound, a phenomenon of unexpectedly severe disease activity following FTY discontinuation, has been reported to occur in 5-43 % of patients. Only a few larger cohorts have been analyzed. We aimed to determine the frequency and risk factors of FTY rebound in our hospital district in Southern Finland with a population of 1.7 million.

METHODS

We searched the Finnish MS-register for patients who were previous or current users of FTY for at least 6 months by November 2020. We assessed medical records and collected basic demographic data for the whole cohort. Criteria for a rebound were: (i) the most severe relapse in patient's history and an increase of at least 2 EDSS points during the relapse occurring within 6 months from FTY cessation, or (ii) more than one relapse within 6 months after FTY discontinuation, this being the highest relapse rate observed during the patient's lifetime.

RESULTS

Among 3496 MS patients, we found 331 patients ever starting FTY and 283 of them had used FTY for at least 6 months. Among these 283 patients we discovered a total of 114 discontinuation events in 110 patients. Of the discontinuations, 32 (28 %) were followed by a relapse: 20 (17.5 %) were ordinary relapses not fulfilling rebound criteria, and 12 (10.5 %) were rebounds. The median time to an ordinary relapse and rebound were similar: 8.5 weeks (range 1.3-23) and 9.9 weeks (range 5.9-15.9), respectively. The rebound group was younger at diagnosis (p = 0.034) and had used FTY for a longer time (p = 0.048) before discontinuation compared to the group without a relapse. After discontinuation, rebound group had lower lymphocyte values as compared to both ordinary relapse group (p = 0.027) and no-relapse group (p = 0.006) and neutrophil to lymphocyte ratio (NLR) was increased compared to the no-relapse group (p = 0.019).

CONCLUSION

In this study, 10.5 % of patients experienced a rebound, which is similar to the frequencies (10.3-12.5 %) obtained in other larger studies with >100 discontinuations. Relapses of any severity occurred in 28 % of patients discontinuing FTY, and therefore initiation of subsequent disease modifying therapies should occur promptly after discontinuation. Younger age at diagnosis, longer exposure to FTY and lower lymphocyte count as well as higher NLR after discontinuation were identified as risk factors for a rebound. The differences in blood leukocytes indicate that rebound might be a distinct pathophysiological phenomenon compared to an ordinary relapse.