Objective:

We here aimed to assess the impact of CLAD on serum neurofilament light chain (sNfL), a biomarker for neuroaxonal damage. Moreover, we investigated whether sNfL at baseline and at 12 months from CLAD start can predict treatment response.

Background:

Cladribine (CLAD) acts as semi-selective immune reconstitution therapy (IRT) for patients with multiple sclerosis (MS). As such, short treatment cycles in year one and two promise long-term disease control. 

Design/Methods:

We included 14 patients with MS about to start CLAD and assessed sNfL values at baseline (BL) and at the end of the first treatment year (12 months from BL). Long-term clinical and radiological data were extracted from medical records. Disease activity was classified according to relapses, MRI activity and EDSS progression. We also calculated a time to loss of "no evidence of disease activity (NEDA)" analysis to evaluate the predictive value of sNfL.

 

Results:

Patients (12/14 female, mean age 35 ± 9 years, median EDSS 1.75 range 0 - 3.5) were followed-up for 39 (± 9) months after CLAD start. A breakthrough disease was recorded in 36% (5/14) while 64% had no or mild disease activity. The sNfL was significantly reduced by CLAD therapy (mean: 24,72 pg/ml to 8,75 pg/ml, p = 0.0008) and increased in only one patient (from 4,63 pg/ml to 5,55 pg/ml). SNfL values at BL and 12 months did not correlate with long-term disease control.

Conclusions:

CLAD therapy prevents neuroaxonal damage as reflected by sNfL. Most patients had no or only mild disease progression on long-term outcome. SNfL at the end of the first treatment cycle appears no suitable marker to predict long-term treatment response.