Rallybio Corporation announced new biomarker analyses and manufacturing process enhancements for RLYB116, its investigational once-weekly, subcutaneous C5 inhibitor for complement-mediated diseases. These findings suggest RLYB116 achieved greater complement inhibition in a Phase 1 study than originally reported, potentially positioning it as a best-in-class therapy. A confirmatory clinical pharmacokinetic/pharmacodynamic (PK/PD) study is planned for the second quarter of 2025.
Post-Phase 1 study analyses revealed the assay used to measure free C5 overestimated levels by approximately ten-fold. This indicates RLYB116 provided more substantial complement inhibition than initially indicated. Furthermore, manufacturing process enhancements completed in the third quarter of 2024, utilizing advanced analytical techniques like mass spectrometry, further purified the RLYB116 drug substance. This is anticipated to improve tolerability at doses matching or exceeding those in the Phase 1 study.
The upcoming confirmatory PK/PD study, scheduled for the second quarter of 2025, aims to demonstrate this improved tolerability and sustained complement inhibition. This single-blind, multiple ascending dose study will involve two cohorts of eight participants each. Cohort 1 will receive 150 mg weekly doses, while Cohort 2 will receive 225 mg weekly doses. The treatment duration is four weeks, followed by a ten-week follow-up period.
RLYB116 is designed as a convenient, once-weekly, small volume, subcutaneous injection. The prior Phase 1 single- and multiple-ascending dose (SAD/MAD) study in healthy participants, completed in the fourth quarter of 2023, evaluated safety, tolerability, pharmacokinetics, and pharmacodynamics. The MAD portion employed an adaptive single-blind design with a four-week treatment period and ten-week follow-up. Four cohorts were included, exploring different dosing regimens: Cohort 1 (100 mg weekly), Cohort 2 (three 100 mg doses the first week, followed by weekly dosing), Cohort 3 (150 mg weekly, reduced to 125 mg weekly), and Cohort 4 (75 mg twice weekly initially, then 100 mg twice weekly).
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
