Natalizumab (NTZ) is an effective therapy for patients with relapsing MS (RMS). However, it is associated with a risk of progressive multifocal leukoencephalopathy (PML) in patients infected with John Cunningham virus (JCV). Ocrelizumab (OCR) has demonstrated efficacy, yet its safety in patients previously treated with NTZ is unclear.
To present interim data from OCTAVE, a prospective, observational study to evaluate the efficacy and safety of OCR in RMS patients previously treated with NTZ.
Clinically and radiologically stable RMS patients, aged 18-65 treated with a stable dose of NTZ for ≥ 12 months, were started on OCR 4-6 weeks after last dose of NTZ and followed for 12 months. Relapse assessment, Expanded Disability Status Scale (EDSS), and MRI were performed prior to starting OCR and at months 3, 6, 9 (no MRI), and 12.
Thirty-seven patients, 75.7% female with mean age of 43.8 (± 10.97) and a median of 33.5 [IQR = 63.2] NTZ infusions prior to starting OCR have been enrolled between August 9th, 2017 and February 3rd, 2020. 23 patients have completed the study duration of 12 months. Thirty-one subjects switched to OCR due to potential PML risk. One patient had a clinical relapse reported at month 12 although no MRI correlate. However, EDSS at baseline was 4.0 and at month 12 the score was 5.5. At month 3, one patient had one enhancing lesion, and one patient had 3 enhancing lesions. At months 6 and 12, there were no enhancing or new/enlarging T2 lesions. There were no significant changes in the EDSS, physical MSIS-29, and psychological MSIS-29 from baseline to months 6 and 12, though there was an increasing trend for EDSS. Median EDSS [IQR] was 3.00 [2.0] at baseline and median EDSS [IQR] was 4.00 [2.50] at month 12. Infusion reactions were seen in 40.5% of patients with the first dose (includes both 300mg infusions) and 13.5 % with the second dose (600mg infusion). Eight serious adverse events (SAEs) have been reported with three possibly related to OCR, breast cancer, urinary tract infection, and acute cystitis. No cases of PML have been reported.
The transition from NTZ to OCR resulted in limited disease activity. In 2 patients, MRI activity was present at 3 months, but no MRI changes were seen at months 6 and 12. One patient was reported to have a clinical relapse at month 12; however, there were no MRI changes. The trend in increasing EDSS is concerning.