Efficacy and safety of a bodyweight-adjusted higher dose of ocrelizumab in relapsing (MUSETTE) and primary progressive (GAVOTTE) multiple sclerosis: two multicentre, randomised, double-blind, parallel-group phase 3b trials

Abstract

Background: Ocrelizumab is a humanised anti-CD20 monoclonal antibody approved for people with relapsing (RMS) or primary progressive multiple sclerosis (PPMS). In a post-hoc analysis of phase 3 trials in RMS and PPMS using a 600 mg dose, higher exposure to ocrelizumab was associated with greater B-cell depletion and lower risk of confirmed disability progression. Here, we prospectively assessed the efficacy and safety of a high dose of ocrelizumab in patients with RMS or PPMS.

Methods: Two multicentre, double-blind, phase 3 controlled trials were conducted to compare high-dose ocrelizumab with the approved 600 mg dose of the drug in patients with RMS (MUSETTE) and PPMS (GAVOTTE) aged 18-56 years. MUSETTE involved 122 centres in 21 countries and GAVOTTE involved 149 centres in 22 countries. Participants were randomly assigned 2:1, with a permuted-block randomisation method, to high-dose ocrelizumab (1200 mg or 1800 mg for baseline body weight <75 kg or ≥75 kg, respectively) or 600 mg ocrelizumab. Patients, investigators, and the sponsor were blinded to treatment allocation. Patients received ocrelizumab infusions every 24 weeks for a minimum 120 weeks and until a prespecified minimum number of confirmed disability events (MUSETTE, 205; GAVOTTE, 357) had occurred. In both trials, the primary endpoint was time to onset of 12-week composite confirmed disability progression (cCDP), assessed by prespecified increases in Expanded Disability Status Scale, Timed 25-Foot Walk Test, or 9-Hole Peg Test scores. Efficacy endpoints were evaluated in all randomised participants and safety endpoints were evaluated in participants who received at least one ocrelizumab infusion. These studies are registered with ClinicalTrials.gov: MUSETTE, NCT04544436; GAVOTTE, NCT04548999.

Findings: Participants in MUSETTE were enrolled between Nov 26, 2020, and Aug 30, 2022; participants in GAVOTTE were enrolled between Dec 3, 2020, and May 15, 2023. In MUSETTE, 860 patients were randomly assigned (high-dose ocrelizumab, n=577; 600 mg ocrelizumab, n=283) and had median overall treatment duration of 184·4 weeks. In GAVOTTE, 753 patients were randomly assigned (high-dose ocrelizumab, n=500; 600 mg ocrelizumab, n=253) and had median overall treatment duration of 174·1 weeks. In MUSETTE, the percentage of patients with 12-week cCDP was 34% (198 of 577) with high-dose ocrelizumab versus 37% (104 of 283) with 600 mg ocrelizumab (hazard ratio [HR] 0·93 [95% CI 0·73-1·18]; p=0·53). In GAVOTTE, the percentage of patients with 12-week cCDP was 47% (235 of 500) with high-dose ocrelizumab versus 49% (124 of 253) with 600 mg ocrelizumab (HR 0·95 [95% CI 0·76-1·18]; p=0·64). Safety profiles were similar for the high-dose ocrelizumab and 600 mg ocrelizumab; in MUSETTE, rates of adverse events (552 [96%] of 577 and 267 [94%] of 283), serious adverse events (77 [13%] of 577 and 34 [12%] of 283), and fatalities (four [1%] of 577 and one [<1%] of 283) were comparable, as were rates of adverse events (447 [90%] of 499 and 230 [91%] of 254), serious adverse events (61 [12%] of 499 and 29 [11%] of 254), and fatalities (two [<1%] of 499 and three [1%] of 254) in GAVOTTE.

Interpretation: In both studies, high-dose ocrelizumab did not further improve control of disability progression in either RMS or PPMS, and no new safety concerns were identified.

Funding: F Hoffmann-La Roche.