Combination of the Immune Modulator Fingolimod With Alteplase in Acute Ischemic Stroke: A Pilot Trial

Abstract

Background: Inflammatory and immune responses triggered by brain ischemia worsen clinical outcomes of stroke and contribute to hemorrhagic transformation, massive edema, and reperfusion injury associated with intravenous alteplase. We assessed whether a combination of the immune-modulator fingolimod and alteplase is safe and effective in attenuating reperfusion injury in patients with acute ischemic stroke treated within the first 4.5 hours of symptom onset.

Methods and results: In this multicenter trial, we randomly assigned 25 eligible patients with hemispheric ischemic stroke stemming from anterior or middle cerebral arterial occlusion to receive alteplase alone and 22 patients to receive alteplase plus oral fingolimod 0.5 mg daily for 3 consecutive days within 4.5 hours of the onset of ischemic stroke. Compared with patients who received alteplase alone, patients who received the combination of fingolimod with alteplase exhibited lower circulating lymphocytes, smaller lesion volumes (10.1 versus 34.3 mL; P=0.04), less hemorrhage (1.2 versus 4.4 mL; P=0.01), and attenuated neurological deficits in National Institute of Health Stroke Scales (4 versus 2; P=0.02) at day 1. Furthermore, restrained lesion growth from day 1 to 7 (-2.3 versus 12.1 mL; P<0.01) with a better recovery at day 90 (modified Rankin Scale score 0-1, 73% versus 32%; P<0.01) was evident in patients given fingolimod and alteplase. No serious adverse events were recorded in all patients.

Conclusions: In this pilot study, combination therapy of fingolimod and alteplase was well tolerated, attenuated reperfusion injury, and improved clinical outcomes in patients with acute ischemic stroke. These findings need to be tested in further clinical trials.

Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02002390.

Keywords: brain ischemia; edema; hemorrhage; inflammation; thrombolytic therapy.

Figure 1

Study flow chart. A total of 968 patients with stroke-like symptoms underwent screening within 4.5 hours after symptom onset. The 620 patients potentially eligible for intravenous thrombolysis were further screened for participation in the study. 47 patients were randomly assigned in a 1:1 ratio to the standard dose of alteplase (0.9 mg per kg, the first 10% administered as an initial bolus and the remainder over a 1-hour period, with a maximum dose of 90 mg); or to the standard dose of alteplase immediately following the 1^st dose of oral fingolimod (0.5 mg of FTY720 (Gilenya, Novartis). Fingolimod was administered once daily, for three consecutive days. Counts of circulating lymphocyte subsets were monitored by flow cytometry. Clinical assessments (NIHSS, mRS) were conducted at the indicated time points. Alterations of MRA status, lesion volume and hemorrhage volume were measured on MRI at the indicated time points.

Figure 2

Lymphocyte subset counts decreased after one day of fingolimod treatment. Blood was drawn from patients at the baseline (3.1 hours) and at day 1 after the first dose of alteplase with or without fingolimod (grey horizontal square depicts pooled data from patients who received alteplase only; lines with patient numbers depict those who received alteplase with fingolimod. Mononuclear cells were purified and stained with antibodies to individual cell types. Percentages of CD4⁺ T cells (A), CD8⁺ T cells (B),CD19⁺ B cells (C) and CD56⁺ NK cells (D) were determined by flow cytometry; absolute numbers were calculated, and are displayed as × 10⁶/ml of blood from patients. Each patient's mean ± SE is shown. Comparisons were performed with paired sample t-tests.

Figure 3

Lesion volume growth, hemorrhage volume and clinical status at day 1. Panel A: Lesion volume growth at day 1; lesion growth = lesion volume measured on Flair (day 1) minus lesion volumes measured on DWI (baseline); values are mean ± SE; comparisons were performed with independent t-tests. Panel B: Hemorrhage volume stemming from hemorrhagic transformation at day 1. Lesion volumes were measured on GRE at day 1; comparisons were performed using the Mann-Whitney test. Panel C: Changes in the NIHSS score at 24 hours. The horizontal line inside each box indicates the median, and the top and bottom of the box indicate the interquartile range. The error bars indicate the 5th and 95th percentiles. Comparisons were performed using the Mann-Whitney test. NIHSS = National Institutes of Health Stroke Scale. Panel D: Distribution of the type of hemorrhagic transformation at day 1; Chi-square test. HT = hemorrhagic transformation, HI = hemorrhagic infarction, PH = parenchymal hematoma, no-HT = no hemorrhagic transformation, Fin = fingolimod.

Figure 4

Lesion volume growth and clinical improvement from day 1 to day 7, as well as the probability of excellent recovery at 90 days. Panel A: Lesion volume growth from day 1 to day 7; lesion growth = Lesion volumes measured on Flair (day 7) minus Lesion volumes measured on Flair (day 1). Values are mean ± SE; comparisons were performed with independent t-tests. Panel B: Changes in the NIHSS score from day 1 to day 7; the horizontal line inside each box indicates the median, the top and bottom of the box indicate the interquartile range, the I bars indicate the 5th and 95th percentiles; comparisons were performed using the Mann-Whitney test; NIHSS = National Institutes of Health Stroke Scale. Panel C: Distribution of the degree of disability at day 90; comparisons were performed with Chi-squared test; mRS = modified Rankin Scale, Fin = fingolimod.

Figure 5

Representative MRI scans of a patient treated with alteplase plus fingolimod and a patient treated with only alteplase. Representative MRI scans show an acute left hemisphere infarct with the complete distal-first segment of middle cerebral artery occlusions in control (upper panel) and an acute left hemisphere infarct with complete mid-first segment of middle cerebral artery occlusions in fingolimod-treated patient (lower panel). At day 1, although the recanalization status of all their vessels was the same, striking differences were evident. The infarct volume was enlarged in the control patient on Flair imaging, and hemorrhagic transformation occurred with hypointense signaling on GRE. In contrast, the progression of infarct volume was restrained in our fingolimod-treated patient. At day 7, lesion volume in the control patients still increased, but to the contrary, lesion volume decreased in the fingolimod-treated patient. Fin = fingolimod.