🧬 Aging Wiki

lonafarnib

Properties1
aliasesSCH-66336, Zokinvy, farnesyltransferase inhibitor HGPS

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Lonafarnib (Zokinvy)

The first and only FDA-approved disease-modifying therapy for Hutchinson-Gilford Progeria Syndrome (HGPS), approved November 2020 under the brand name Zokinvy. Lonafarnib is a non-peptidomimetic farnesyltransferase inhibitor (FTI) originally developed in the 1990s for oncology (Schering-Plough / SCH-66336), later rescued and repurposed for HGPS through the Progeria Research Foundation. Its mechanism — blocking farnesylation of progerin, the pathological truncated lamin A protein that causes HGPS — extends directly from the molecular lesion of the disease. Human survival benefit has been demonstrated in two matched-cohort analyses with HRs of 0.12 and 0.23 vs untreated contemporaneous controls, making lonafarnib one of the most robust pharmacological interventions with quantified survival benefit in a human progeroid syndrome.

Identity

FieldValue
PubChem CID148195
InChIKeyDHMTURDWPRKSOA-RUZDIDTESA-N
ChEMBL IDCHEMBL298734
DrugBank IDDB06105
CAS numbernot confirmed (#gap/needs-canonical-id)
Molecular formulaC27H31Br2ClN4O2
Molecular weight638.83 g/mol
Classnon-peptidomimetic farnesyltransferase inhibitor
Routeoral (twice-daily capsule)
Brand nameZokinvy (Eiger BioPharmaceuticals)
FDA approvalNovember 20, 2020 (accelerated approval; rare disease)
ATC codeA16AX20

Mechanism of action

Normal prelamin A maturation

Mature lamin A — a structural component of the nuclear lamina — is produced from prelamin A through sequential post-translational processing:

  1. Farnesylation: farnesyltransferase attaches a farnesyl isoprenoid group to the C-terminal CAAX motif of prelamin A.
  2. -AAX cleavage: The -AAX tripeptide is removed by RCE1/ZMPSTE24.
  3. Carboxymethylation: The exposed cysteine is carboxymethylated.
  4. Final ZMPSTE24 cleavage: zmpste24 removes the terminal 15 amino acids, including the farnesylated cysteine — the mature lamin A protein is not permanently farnesylated.

The progerin farnesylation trap

In HGPS, the de novo LMNA c.1824C>T mutation activates a cryptic splice site that deletes 50 amino acids (150 nt) from prelamin A, producing progerin (also Δ150 prelamin A). The 50-aa deletion removes the ZMPSTE24 recognition site for the final cleavage step. Progerin therefore:

  • Completes steps 1–3 (farnesylated, -AAX cleaved, carboxymethylated)
  • Cannot undergo step 4 (final ZMPSTE24 cleavage)
  • Retains its farnesyl group permanently, remaining anchored to the inner nuclear membrane 1

This permanent membrane anchoring is the root cause of HGPS nuclear pathology: nuclear blebbing, heterochromatin loss, DNA damage response activation, and premature cellular senescence.

Lonafarnib’s action

Lonafarnib competitively inhibits farnesyltransferase at the CAAX-binding pocket, preventing attachment of the farnesyl group to progerin’s CAAX motif 2. Without farnesylation:

  • Progerin cannot anchor to the inner nuclear membrane
  • Nuclear architecture is partially restored
  • Downstream progerin-driven pathology is attenuated

Not a cure: lonafarnib does not correct the LMNA splicing defect or eliminate progerin production — it reduces the toxicity of the progerin that is made. Some partially-processed, non-farnesylated progerin intermediates do accumulate, but these appear less toxic than the fully-farnesylated form 2.

Clinical evidence in HGPS

Gordon 2014 — first survival analysis

Gordon et al. (2014, Circulation) performed the first survival analysis in HGPS, combining treated patients from two ProLon clinical trial cohorts with the largest-assembled untreated natural history cohort 3:

  • n=43 treated (any farnesylation inhibitor regimen from ProLon1 and combination trials) vs n=161 untreated (natural history registry)
  • Untreated natural history: mean 14.6 yr, median 14.5 yr survival
  • Treatment effect: mean survival increase of 1.6 years (95% CI 0.8–2.4 yr; P<0.001)
  • HR for death 0.13 (95% CI 0.04–0.37) for treated vs contemporaneous untreated controls
  • Median follow-up in treated cohort: 5.3 years
DimensionStatus
Pathway conserved in humans?yes — human trial
Phenotype conserved in humans?yes — human trial
Replicated in humans?yes — this is the human trial

Gordon 2018 — JAMA matched-cohort study

Gordon et al. (2018, JAMA) — the pivotal study supporting FDA accelerated approval — compared lonafarnib-treated HGPS patients from two clinical trials (ProLon1 and ProLon2) against contemporaneous matched untreated controls from the natural history cohort 4:

  • Total natural history cohort: n=258 patients
  • Treated: n=63 (ProLon1 n=27; ProLon2 n=36); lonafarnib monotherapy 150 mg/m² twice daily
  • Controls: matched untreated contemporaneous controls (age-, sex-, continent-matched from n=195 untreated patients)
  • Median treatment duration: 2.2 years

Primary analysis (ProLon1 vs matched controls):

  • 1 death (3.7%) in 27 treated vs 9 deaths (33.3%) in 27 matched untreated
  • HR 0.12 (95% CI 0.01–0.93; P=.04)

Combined secondary analysis (n=63 treated vs 63 matched untreated):

  • 4 deaths (6.3%) vs 17 deaths (27.0%)
  • HR 0.23 (95% CI 0.06–0.90; P=.04)

Untreated natural history (n=195): mean survival 14.5 yr, median 14.6 yr; primary cause of death in identified deaths: heart failure in 79.4%.

This mortality reduction supported FDA accelerated approval of lonafarnib (as Zokinvy) in November 2020 — the first and only drug approved for HGPS.

DimensionStatus
Pathway conserved in humans?yes — human trial
Phenotype conserved in humans?yes — human trial
Replicated in humans?yes (ProLon1 and ProLon2 arms both show benefit)

Pharmacokinetics

  • Route: oral, twice-daily capsule
  • Approved dose: initiated at 115 mg/m² twice daily; escalated to 150 mg/m² twice daily based on tolerability (per prescribing information)
  • Half-life: approximately 4 hours (moderate; supports twice-daily dosing) needs-canonical-id — precise PK parameters should be confirmed against FDA label or published PK study
  • Metabolism: primarily hepatic CYP3A4/5 substrate; significant first-pass effect
  • GI absorption: moderate oral bioavailability; lipophilic compound (haloaromatic structure with two bromines and one chlorine)
  • Dose-limiting toxicity: GI toxicity (nausea, vomiting, diarrhea, anorexia) — the primary side-effect profile managed by dose escalation schedules in clinical trials

dose-response-unclear — The optimal dose for maximum survival benefit vs tolerability in HGPS is not fully resolved. The approved dose (150 mg/m² BID) was the highest tolerated dose in ProLon1/2; whether higher exposure would confer greater benefit is unknown.

Side-effect profile

Lonafarnib’s main adverse effects in HGPS clinical trials:

EffectFrequency / Severity
Nausea / vomiting / diarrheaVery common; dose-dependent; managed by gradual escalation
FatigueCommon
Anorexia / weight lossCommon; especially early in treatment
Electrolyte disturbancesOccasional (secondary to GI losses)
HeadacheCommon
Elevated liver enzymesOccasional; monitor

GI toxicity is the primary safety signal and was the reason for the dose-titration schedule in ProLon trials. No black-box warning is issued for HGPS at approved doses, but standard monitoring is required.

Hypothesis: progerin accumulation in normal aging

The Scaffidi 2006 observation

Scaffidi and Misteli (2006, Science) demonstrated that normal human fibroblasts from older donors produce low levels of progerin via the same LMNA cryptic splice site activated in HGPS, and that aged cells display HGPS-like nuclear architectural defects partially reversible by antisense suppression of progerin 5. This was the first evidence that progerin is not exclusive to HGPS but may be a component of normal aging.

no-fulltext-access — Scaffidi 2006 PDF download failed in the academic archive (status: failed). Claims from this paper on this page have not been verified against the primary source.

Cao 2011 extension: telomere-progerin feedforward loop

Cao et al. (2011, J Clin Invest) showed that telomere shortening in normal cells causally activates the cryptic LMNA splice site, creating a feedforward loop: dysfunctional telomeres trigger progerin production, which further destabilizes the nucleus and accelerates cellular senescence 6. See progeria § Relationship to normal aging for detailed caveats.

Why this matters for lonafarnib

If low-level progerin contributes to nuclear dysfunction in normally aged cells, lonafarnib (or related FTIs) could theoretically reduce this burden. However, no human clinical evidence for lonafarnib benefit in non-HGPS aging exists. The hypothesis remains mechanistically plausible but experimentally untested.

DimensionStatus
Pathway conserved in humans?yes — cryptic LMNA splicing shown in human cells
Phenotype conserved in humans?partial — nuclear defects shown in aged fibroblasts in vitro; whole-organism in vivo relevance unclear
Replicated in humans?no — no interventional RCT in non-HGPS adults

needs-human-replication — No completed human trial has tested whether FTI treatment reduces progerin burden or aging phenotypes in non-HGPS older adults.

Access and cost

  • Estimated US list price: ~$1.4M/year (as of 2024; extreme rare-disease pricing driven by ultra-small patient population)
  • Patient population: ~400 known HGPS cases ever recorded; ~150–200 alive at any given time globally
  • Orphan drug status: designated in the US and EU
  • Compassionate use / expanded access: available through the Progeria Research Foundation and Eiger BioPharmaceuticals for confirmed HGPS patients

Hallmark mapping

HallmarkLonafarnib’s relationship
genomic-instabilityProgerin causes persistent DNA damage response (DDR) activation; lonafarnib reduces progerin nuclear anchoring, thereby partially relieving DDR signaling in HGPS cells
loss-of-proteostasisFarnesylated progerin aggregates and resists autophagic clearance; blocking farnesylation produces less-toxic intermediates; also see autophagy and rapamycin as complementary strategy
cellular-senescenceHGPS cells are prematurely senescent; lonafarnib treatment partially restores replicative capacity and reduces senescence marker expression (P21 levels) in HGPS cell lines needs-replication
epigenetic-alterationsProgerin drives H3K27me3 and heterochromatin loss in HGPS nuclei; lonafarnib’s impact on epigenetic marks has not been independently quantified in human trials

Combination strategies (investigational)

Lonafarnib is also being studied in combination with pravastatin and zoledronate (HGPS combination trial NCT00916747). Both drugs additionally interfere with the farnesylation/isoprenylation pathway at upstream steps (HMG-CoA reductase; farnesyl-pyrophosphate synthesis), potentially providing additive reduction in progerin farnesylation. Pre-clinical mouse data showed combination superior to lonafarnib alone. Human combination trial data not yet mature as of 2026-05-05.

Emerging therapeutic landscape (R34 update 2026-05-08)

Pruthvi Raj et al. (Curr Gene Ther 2026) reviewed the broader therapeutic landscape for HGPS 7. Lonafarnib remains the only FDA-approved disease-modifying agent and continues to provide modest survival benefit. Investigational strategies under active development:

  • Gene editing approaches — CRISPR/Cas9 and base-editing for direct correction of the LMNA c.1824C>T mutation (Koblan et al. 2021 Nature established proof-of-principle in LAKI mice; clinical translation pending)
  • Antisense oligonucleotides (ASOs) — block use of the cryptic splice site, redirecting splicing toward wild-type lamin A
  • ICMT inhibitors — block the carboxymethylation step in prelamin A maturation, providing an alternative targeting node to FTI
  • Angiopoietin-2 modulation — newly proposed as a target for the vascular and skeletal complications that drive most HGPS mortality
  • Cardiovascular interventions — TAVR and ascending aortic constriction explored in high-risk HGPS patients

The review framing positions lonafarnib as foundational care providing modest benefit, with long-term HGPS management expected to depend on RNA-based and gene-editing approaches that address the upstream LMNA splicing defect rather than the downstream farnesylation step.

Cross-references

EntityRelationship
progeriaPrimary clinical indication; HGPS mechanism page (verified R11)
lmnaGene encoding lamin A/C; LMNA c.1824C>T produces progerin; lonafarnib targets the post-translational farnesylation step
farnesyltransferaseDirect molecular target; lonafarnib’s binding site
zmpste24The endoprotease whose cleavage site is absent in progerin; why progerin remains farnesylated
genomic-instabilityHallmark driven by progerin-induced nuclear pathology
loss-of-proteostasisHallmark: farnesylated progerin aggregates; lonafarnib reduces toxic species
cellular-senescenceProgerin drives premature senescence in HGPS cells
autophagyComplementary therapeutic approach — rapamycin-induced autophagy clears progerin by different mechanism
nuclear-laminaThe structural scaffold disrupted by permanently-farnesylated progerin
partial-reprogrammingOcampo 2016 tested cyclic OSKM in the LAKI progeria mouse model — an orthogonal approach to the same disease

Limitations and gaps

  • Not a cure: Lonafarnib suppresses progerin toxicity but does not correct the LMNA splicing mutation or eliminate progerin production. HGPS patients still die in early–mid adolescence despite treatment. long-term-unknown
  • Survival benefit is real but modest in absolute terms: HR 0.12–0.23 vs untreated controls is statistically strong; in absolute terms, mean survival gain ~1.6 yr from an already-short disease course. The disease remains fatal.
  • Non-HGPS aging — no human trial data: The hypothesis that lonafarnib might slow nuclear-lamina-driven aspects of normal aging is biologically plausible (low-level progerin in aged cells; telomere-progerin feedforward loop) but entirely untested in non-HGPS humans. needs-human-replication
  • Cost as translation barrier: ~$1.4M/yr is prohibitive for any aging-prevention application even if efficacy were demonstrated. A lower-cost FTI or alternative delivery would be required for population-scale use.
  • No biomarker endpoint for non-HGPS aging: If a trial were conducted in older adults, there is no validated circulating biomarker of progerin-related nuclear dysfunction to serve as a surrogate endpoint. no-mechanism
  • CAS number not confirmed: Lonafarnib CAS should be confirmed against PubChem or ChEMBL before citing in regulatory documents. needs-canonical-id
  • Scaffidi 2006 primary PDF unavailable: Claims about progerin in normal aging cells have not been verified against the primary source. no-fulltext-access

Footnotes

Footnotes

  1. doi:10.1038/nature01629 · Eriksson M et al. · Nature 2003;423(6937):293–298 · n=20 unrelated HGPS patients + controls · observational/genetic · model: human · identified LMNA c.1824C>T silent mutation activating cryptic splice site; showed permanent farnesylation of progerin underlies nuclear anchoring defect · see progeria for full footnote ↩

  2. doi:10.1073/pnas.0506001102 · Capell BC, Erdos MR, Madigan JP et al. · PNAS 2005;102(36):12879–12884 · n=HeLa, HEK293, NIH3T3 cells transiently transfected with progerin construct + primary HGPS patient fibroblasts · in-vitro · model: human cell lines + mouse NIH3T3 · download status: pending (bronze OA) · 380 citations; citation_percentile=100 · demonstrated that FTI treatment restored normal nuclear architecture in progerin-expressing cells and reduced nuclear blebbing in HGPS patient fibroblasts; foundational mechanism paper for the FTI therapeutic strategy in HGPS. Note: DOI corrected from user-submitted 10.1073/pnas.0506152102 to confirmed 10.1073/pnas.0506001102 (verified via PubMed PMID 16129833). ↩ ↩2

  3. gordon-2014-lonafarnib-progeria-survival · doi:10.1161/CIRCULATIONAHA.113.008285 · Gordon LB, Massaro J, D’Agostino RB Sr et al. · Circulation 2014;130(1):27–34 · n=43 treated, n=161 untreated (total n=204) · observational survival analysis · model: human · local PDF available · 234 citations; citation_percentile=100 · first survival analysis in HGPS; treatment with any farnesylation inhibitor regimen associated with mean survival increase of 1.6 yr (95% CI 0.8–2.4 yr; P<0.001; HR 0.13, 95% CI 0.04–0.37); median follow-up 5.3 yr ↩

  4. gordon-2018-lonafarnib-jama · doi:10.1001/jama.2018.3264 · Gordon LB, Shappell H, Massaro J et al. · JAMA 2018;319(16):1687–1695 · n=258 total; 63 treated (ProLon1 n=27, ProLon2 n=36) vs contemporaneous matched untreated controls · observational matched cohort · model: human · local PDF available · 210 citations; citation_percentile=100 · lonafarnib monotherapy 150 mg/m² twice daily; primary analysis (ProLon1) HR 0.12 (95% CI 0.01–0.93; P=.04); combined analysis HR 0.23 (95% CI 0.06–0.90; P=.04); median treatment duration 2.2 yr; primary cause of death heart failure 79.4%; supported FDA accelerated approval Nov 2020 ↩

  5. doi:10.1126/science.1127168 · Scaffidi P, Misteli T · Science 2006;312(5776):1059–1063 · n=normal human fibroblasts from donors aged 0–96 yr · in-vitro/observational · model: human (primary cells) · download status: failed no-fulltext-access · 1185 citations; citation_percentile=100 · low-level progerin production via cryptic LMNA splice site detected in normally-aged fibroblasts; older donors produced more progerin; antisense suppression of progerin reversed nuclear defects in aged cells; UNVERIFIED against primary PDF ↩

  6. doi:10.1172/JCI43578 · Cao K, Blair CD, Faddah DA et al. · J Clin Invest 2011;121(7):2833–2844 · n=6 primary fibroblast lines + immortalized lines · in-vitro · model: human (primary cells) · local PDF available · 297 citations; citation_percentile=100 · telomere shortening activates the cryptic LMNA splice site causally; telomerase overexpression suppressed progerin production 3–10-fold; feedforward loop between telomere dysfunction and progerin production established ↩

  7. doi:10.2174/0115665232415170251130041834 · pmid:42099136 · review · Pruthvi Raj R, Swetha BR, Thomas J · Curr Gene Ther 2026 May 5 (online ahead of print) · therapeutic landscape review of HGPS — confirms lonafarnib as the only FDA-approved disease-modifying agent providing modest survival benefit; emerging strategies = gene editing, antisense oligonucleotides, ICMT inhibitors, angiopoietin-2 modulation, TAVR/aortic constriction in high-risk patients ↩

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