Fremanezumab
Fremanezumab, a biologic. Humanised IgG2a/κ mAb binding both α- and β-isoforms of the CGRP ligand → prevents engagement of the CLR/RAMP1… Subcutaneous half-life 31 d.
Humanised IgG2a/κ mAb binding both α- and β-isoforms of the CGRP ligand → prevents engagement of the CLR/RAMP1 canonical receptor and the AMY1 receptor. Unique among CGRP mAbs in offering a validated quarterly SC dosing option. Reduces monthly migraine days by ~3–4 vs placebo in episodic migraine.
PK: ABSORPTION RATE AUTHORED FROM A VERBATIM PEAK TIME. This row carried no ka, so the solver substituted 1.0/h and the modelled peak landed at 7.0 h — for a slowly-absorbed subcutaneous product that is wrong by design, not by a little. Source: "Median Tmax (range 5-11 days) and mean half-lives (range 31-39 days) were similar across doses for both ethnicities". RANGE: shorter endpoint taken. With the stored half-life fixing ke, Tmax solves uniquely for ka by inverting the model own definition, ln(ka/ke)/(ka-ke) = Tmax — ARITHMETIC, NOT AN ESTIMATE — giving 0.02981/h, which reproduces 120 h on substitution. EXPOSURE IS UNCHANGED: the absorption rate cancels out of AUC entirely, so only the shape moves.
Pharmacokinetics
- Subcutaneous — t½ 31.0 d · F 60% · ka 0.02981 h⁻¹ · Vd 4.2 L
Sources: PMID:31418911, PMID:29667896