Assess efficacy of cyclic rozanolixizumab treatment for generalized myasthenia gravis.

In the Phase 3 MycarinG (NCT03971422; MG0003) study, 1 cycle (6 weekly SC infusions) of the humanized IgG4 mAb FcRn inhibitor rozanolixizumab 7mg/kg or 10mg/kg significantly improved MG-ADL, MGC and QMG scores versus placebo. After MycarinG, patients could enrol in OLEs (MG0004 then MG0007, or directly in MG0007).

MG0004 (NCT04124965) was an OLE of up to 52 weeks of weekly rozanolixizumab infusions. In MG0007 (NCT04650854), after an initial cycle, subsequent cycles were administered on symptom worsening (investigator’s discretion; e.g. MG-ADL increase ≥2/QMG increase ≥3; “symptom-driven cycles”). Pooled data are reported across MycarinG, MG0004 (first 6 weeks) and MG0007 (interim analysis) for patients with ≥2 symptom-driven cycles (up to 6 cycles; efficacy) and with ≥1 cycle (safety).

127/196 (64.8%) patients received ≥2 symptom-driven cycles of rozanolixizumab (69 patients 7mg/kg and 58 patients 10mg/kg). Treatment response was consistent across cycles 1–6: Mean Day 43 CFB in MG-ADL score for all rozanolixizumab-treated patients was: Cycle 1 (n=127): −3.7; cycle 2 (n=127): −3.9; cycle 3 (n=98): −3.4; cycle 4 (n=75): −3.8; cycle 5 (n=51): −3.9; cycle 6 (n=32): −4.5. Mean Day 43 CFB in QMG score was: Cycle 1 (n=127): −5.4; cycle 2 (n=125): −4.7; cycle 3 (n=97): −4.7; cycle 4 (n=74): −5.1; cycle 5 (n=51): −4.5; cycle 6 (n=32): −6.3. MGC reductions were consistent across cycles. Patients with >1 year participation initiated a median of 4 cycles per year in the first year. 169/188 (89.9%) patients receiving ≥1 cycle of rozanolixizumab reported ≥1 TEAE, with 103 (77.4%) and 120 (91.6%) patients experiencing TEAEs with a rozanolixizumab dose of 7mg/kg and 10mg/kg, respectively (most were mild-to-moderate).

Rozanolixizumab efficacy was maintained over up to six 6-week treatment cycles across multiple MG-specific outcomes, with an acceptable safety profile following repeated cyclic treatment. Funding: UCB Pharma.