Patients with relapsing-remitting multiple sclerosis (RRMS) often experience disease activity despite receiving a disease-modifying therapy (DMT). The Phase IIIb CASTING study (NCT02861014) of ocrelizumab evaluated the efficacy/safety in patients with RRMS who had a prior suboptimal response to one or two DMTs (primary endpoint: 2-year no evidence of disease activity [NEDA] rate).
To evaluate CASTING 2-year NEDA outcomes by inclusion criteria, baseline characteristics and prior DMT.
Patients (Expanded Disability Status Scale [EDSS] score ≤4.0; discontinued prior DMT of ≥6 months’ duration due to suboptimal disease control) received intravenous ocrelizumab 600 mg every 24 weeks for 96 weeks. The primary endpoint of NEDA (with prespecified MRI re-baselining at Week 8) was defined as absence of: protocol-defined relapses, 24-week confirmed disability progression, T1‑weighted contrast-enhancing and new/enlarging T2-weighted lesions over 2 years.
A total of 680 patients were evaluated (female, 64%; mean [SD] baseline EDSS score, 2.1 [1.1]; pretreated with one or two DMTs, including orals and injectables, n=411 [60.4%]/n=269 [39.6%]; enrolled due to activity of: MRI only, n=167 [24.6%]; relapse only, n=238 [35.0%]; MRI and relapse, n=275 [40.4%]). After 2 years, 74.8% (n/N=492/658) of patients had NEDA (with MRI re-baselined at Week 8). The NEDA rate was highest among patients enrolled due to MRI activity alone (80.6%) versus enrollment for relapse (75.1%) or relapse with MRI (70.5%). NEDA rates across disease-related subgroups were highest in the subgroups of baseline EDSS score <2.5 (77.2%), ≤1 relapse prior to enrollment (78.2%) and the event leading to enrollment occurring ≥6 months prior to study entry (75.8%) versus the counterpart subgroups of EDSS score ≥2.5 (70.8%), >1 relapse prior to enrollment (66.3%) and the event leading to enrollment occurring <6 months prior to entry (71.0%). The NEDA rate did not vary by baseline age (≤40 years, 74.7%; >40 years, 75.0%). NEDA rates were higher in patients receiving one prior DMT (77.6%) versus two prior DMTs (70.3%) and remained generally high when stratified by the last prior DMT received before enrollment: interferons, 81.1%; glatiramer acetate, 73.9%; dimethyl fumarate, 73.8%; teriflunomide 69.8%; fingolimod, 68.9%.
The NEDA rate was high overall and across a wide range of disease-related and demographic subgroups, regardless of prior treatment background.