Author Of 2 Presentations
P0211 - Examination of fenebrutinib, a highly selective BTKi, on disease progression of multiple sclerosis (ID 1225)
Preventing multiple sclerosis (MS) disease progression is critical in preserving function and quality of life. Fenebrutinib is a potent, highly selective Bruton’s tyrosine kinase (BTK) inhibitor with a dual mechanism of action. Fenebrutinib targets acute and chronic aspects of MS by decreasing B-cell activation and limiting myeloid proinflammatory responses. This profile and studies of fenebrutinib in patients with other inflammatory diseases suggest a potentially favorable benefit-risk ratio, although there are no studies yet in patients with MS.
To describe the unique design aspects of the Phase III fenebrutinib clinical trial program as they relate to understanding disease progression across the MS spectrum.
We developed a Phase III program that will assess disease progression in two identical clinical trials in relapsing MS (RMS) and one trial in primary progressive MS (PPMS).
To understand the effects of fenebrutinib on disease progression, all three trials include 12-week composite Confirmed Disability Progression (cCDP12) as a primary endpoint; the RMS trials also include annualized relapse rate as a co-primary endpoint. The cCDP12 requires at least one of the following: (1) an increase in Expanded Disability Status Score (EDSS) score of ≥1.0 point from a baseline (BL) score of ≤5.5 points, or a ≥0.5 point increase from a BL score of >5.5 points; (2) a 20% increase from BL in time to complete the 9-Hole Peg Test; (3) a 20% increase from BL in the Timed 25-Foot Walk Test. The cCDP12 is a more sensitive assessment of disability than the EDSS, especially at early disease stages, as it provides a quantitative assessment of upper limb function. Comparator arms will include active disease-modifying treatments with known effects on disability progression (PPMS=ocrelizumab; RMS=teriflunomide). Treatment assignments will be 1:1, with estimated enrollment of 734 patients in each of the RMS trials and 946 in the PPMS trial. Study durations will be event driven, with the primary analysis occurring after a prespecified number of cCDP12 events (≥96 or ≥120 weeks in the RMS and PPMS trials, respectively).
Fenebrutinib will be investigated in RMS and PPMS and may offer a unique approach to slowing disease progression in MS. Furthermore, the use of the cCDP12 as a primary endpoint may provide a clearer, more complete picture of disability progression or improvement than the EDSS alone.
P0230 - Rationale and design of two Phase IIIb studies of ocrelizumab at higher than the approved dose in patients with RMS and PPMS (ID 971)
Ocrelizumab (OCR) is approved for the treatment of relapsing (RMS) and primary progressive multiple sclerosis (PPMS) at a dose of 600 mg iv twice yearly and showed significant benefit on disability progression (DP). Exposure-response (ER) analyses of the pivotal OCR Phase III studies in patients with RMS or PPMS showed that those with higher exposures (based on individual mean serum concentration [Cmean] exposure quartiles) had a greater benefit on DP vs patients with lower exposure, without an increase in adverse events. While doses of OCR of 1000–2000 mg were studied in a Phase II study, doses >600 mg have not been investigated in Phase III studies in RMS or PPMS patients.
To present the OCR higher dose selection rationale and design of two double-blind, parallel-group, randomized Phase IIIb studies (one in RMS and one in PPMS) aiming to explore if a higher dose of OCR will provide even higher benefits vs 600 mg on DP without adversely affecting the established favorable benefit-risk profile.
The higher dose of OCR in both studies is based on achieving a Cmean of at least that observed in the highest exposure quartile of the Phase III ER analyses while limiting Cmean below that observed with the highest OCR dose of 2000 mg in the Phase II study that had a similar safety profile, except for a slightly higher incidence of infusion-related reactions (pre-medication: methylprednisolone only; no mandatory antihistamine).
Modeling predicts that doses of 1200 mg (patients <75kg) or 1800 mg (patients ≥75kg) twice yearly would fulfill these criteria. Based on data from the pivotal trials, the expected risk reduction vs 600 mg in 12-week composite confirmed DP (cCDP; consisting of time to progression measured by the EDSS, Timed 25-Foot Walk or 9-Hole Peg Test) would be ≥35% in RMS and ≥27% in PPMS. Patients with RMS (EDSS score 0–5.5; N=786) or PPMS (EDSS score ≥3.0–6.5; N=699) will be randomized (2:1) to either the higher dose (above) or OCR 600 mg administered every 24 weeks (first dose divided into 2 infusions separated by 14 days) for ≥120 weeks (minimum 5 doses).
The primary outcome for both trials is risk reduction on cCDP. Immunoglobulin and oligoclonal bands in the CSF will be assessed in a sub-study of up to 288 patients.
These studies will test if higher-dose ocrelizumab provides an even higher benefit on cCDP vs the approved 600 mg dose without adversely affecting the established favorable benefit-risk profile.