FGFR3-targeted therapeutics (vosoritide / infigratinib / sotuletinib)
FGFR3 is a fibroblast growth factor receptor whose constitutively active mutation causes achondroplasia (most common dwarfism). | Compound
Aliases (5)
▸ Overview TL;DR
FGFR3 is a fibroblast growth factor receptor whose constitutively active mutation causes achondroplasia (most common dwarfism). The queue entry "fgfr3 — sotuletinib for achondroplasia?" most plausibly refers to vosoritide (Voxzogo) — the FDA-approved CNP analog for pediatric achondroplasia — and the small-molecule FGFR3 kinase inhibitors in trial (infigratinib repurposed; recifercept; sotuletinib/TAS-120 is actually a pan-FGFR oncology drug). Not relevant for Dylan, who has normal stature and no skeletal dysplasia.
▸ Mechanism of action
Vosoritide (BMN 111, Voxzogo): Modified 39-aa C-type natriuretic peptide analog. Binds NPR-B (natriuretic peptide receptor B) on chondrocytes → cGMP rise → inhibits MAPK signaling downstream of mutant FGFR3 → restores chondrocyte proliferation and differentiation in growth-plate cartilage. Daily SC injection, half-life ~28 minutes (long enough due to receptor occupancy / signaling persistence).
Infigratinib (Truseltiq): Oral small-molecule pan-FGFR1-3 ATP-competitive TKI. Originally approved for FGFR2-fusion cholangiocarcinoma; being repurposed at low dose (PROPEL3) to inhibit mutant FGFR3 kinase activity in achondroplasia chondrocytes.
Sotuletinib (TAS-120 / futibatinib): Irreversible covalent pan-FGFR1-4 inhibitor — actually marketed as Lytgobi for FGFR2-fusion cholangiocarcinoma. Sometimes mis-cited in achondroplasia context; not in achondroplasia development as of 2025.
Recifercept: Soluble FGFR3 decoy receptor — sequesters FGF ligands. Phase 2 (Pfizer).
▸ Pharmacokinetics Approximate
Approximate decay curve drawn from the half-life mention(s) in the source notes. Real PK data not yet ingested per compound.
▸ What to expect Generic
- 1Week 1Tolerability and dose-response.
- 2Week 2-4Early effect window.
- 3Week 4-8Peak benefit assessment.
- 4Week 8+Cycle decision point.
▸ Side effects + safety
- Common (>10%): Vosoritide — injection site reaction, transient mild hypotension, dizziness. TKIs — hyperphosphatemia, GI upset, retinal pigment epithelial detachment.
- Less common (1-10%): Vomiting, fatigue (vosoritide). TKIs — hand-foot syndrome, nail toxicity, transaminitis.
- Rare-serious (<1%): TKIs in oncology dose — serous retinal detachment, severe hyperphosphatemia, cardiotoxicity.
- Specific watch periods: Vosoritide — first 30 min post-injection for symptomatic hypotension; long-term — joint growth proportions monitored.
▸References5 sources
Savarirayan R, et al. (2020) — Once-daily, subcutaneous vosoritide therapy in children with achondroplasia: a randomised, double-blind, phase 3, placebo-controlled, multicentre trial. Lancet
2020PMID 32945803, vosoritide pivotal trial
Savarirayan R, et al. (2022) — Vosoritide for children with achondroplasia: a 30-month update from an ongoing extension study. Genetics in Medicine
2022PMID 35305862, long-term extension
Komla-Ebri D, et al. (2016) — Tyrosine kinase inhibitor NVP-BGJ398 functionally improves FGFR3-related dwarfism in mouse model. J Clin Invest
2016PMID 27348590, infigratinib mechanism in achondroplasia model
Goyal L, et al. (2023) — Futibatinib for FGFR2-rearranged intrahepatic cholangiocarcinoma. NEJM
2023PMID 36534649, futibatinib (sotuletinib alias) oncology pivotal — confirms it is NOT an achondroplasia drug
Foreman PK, et al. (2020) — Birth prevalence of achondroplasia: a systematic literature review. Am J Med Genet A
2020PMID 32243066, epidemiologic context