Nomlabofusp dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
A replacement for frataxin, the protein people with Friedreich ataxia are missing.
Evidence grade for Nomlabofusp: Limited. The rule: people have taken it in a published study, but fewer than 100 of them. The sum on this page: 2 completed trials, 28 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 28
- Human studies
- 2
- Found nothing
- 0
Dose
No human dose established
Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose.
2 completed trials, 28 people given it
No first-hand reports gathered yet. That is a gap in what we have collected, not a finding that nothing has been reported.
Goal pages: Ageing and longevity
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
Nomlabofusp is a shot that tries to replace frataxin. People with Friedreich ataxia, a rare inherited nerve disease, do not make enough of this protein. A short peptide carries it into cells. It is still being tested and is not approved anywhere.
What people take it for
- Treating Friedreich ataxia by putting the missing protein back.
- Some catalogues list it as a mitochondria peptide. It is a full protein built for one disease.
What studies in people showed
In 55 adults with Friedreich ataxia, it raised frataxin in cheek cells, skin and blood platelets. Doses went up to 100 mg a day for 13 days. Side effects were mostly mild, and nothing serious happened. No study has measured whether patients got better. A final-stage trial of about 150 people started in August 2026 to test that. Results are due in 2029. In mice, rats and monkeys, the protein reached the heart, muscle and nerves.
What people report
Reports, not study results
The good
- Side effects in the 55 adults were mostly mild, with nothing serious.
The bad
- Nobody knows yet if it slows the disease.
- The longest anyone has taken it next to a dummy group is 13 days.
Where these come from: From the studies on this page. We have not collected user reports on this one yet.
My bottom line
My opinion: a serious drug for a serious rare disease, and the real answer comes in 2029. It has no use for anyone without Friedreich ataxia.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Nomlabofusp has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Living longer28 people · 1 study
35 of the 36 indexed goals have no study of any kind behind Nomlabofusp
No study in people, animals or cells on this page reports a result for these. That does not prove Nomlabofusp does nothing for them. It does mean anything you have heard about Nomlabofusp and one of these did not come from a study cited here.
Show full evidence
What is Nomlabofusp?
A replacement for frataxin, the protein people with Friedreich ataxia are missing. It is joined to a short peptide that helps it get into cells, and given as a shot under the skin. In 55 adults across two short safety studies, it raised frataxin in cheek cells, skin and blood platelets. Whether that changes the disease is the question for a 150 person final-stage trial. That trial began in August 2026 and reports in 2029.
Friedreich ataxia is caused by too little frataxin, a protein that works inside the cell's power plants, the mitochondria. Nomlabofusp is an attempt to put the protein back. It is lab made human frataxin joined to a short peptide from an HIV protein called TAT. The peptide carries it through cell walls. Once inside the mitochondria, the cell cuts off the carrier and leaves normal frataxin behind. Larimar Therapeutics is developing it, under the earlier code CTI-1601. It is a full protein, not a peptide. The peptide is just the delivery truck.
What has been measured in people is how the drug behaves, not whether it helps. Two early studies compared it with a dummy shot in 55 adults with Friedreich ataxia, aged 19 to 69. In one, 28 people got a single dose of 25 to 100 mg. In the other, 27 people got up to 100 mg a day for 13 days. Blood levels peaked 15 minutes after the shot. Side effects were mostly mild, and nothing serious happened. Frataxin rose in cheek cells, skin and platelets, more with bigger and more frequent doses. A 2026 paper measured frataxin in patients and in animals. In patients, only easy to reach tissues could be checked. In mice, rats and monkeys, levels in skin and cheek cells tracked levels in the heart, muscle and nerve clusters next to the spine. That is the case for sampling skin and cheek cells instead. A study where everyone gets the drug (NCT06447025, about 85 people) is recruiting, with first results due January 2027. A final-stage trial (NCT07778836, about 150 people) started on 5 August 2026 and should finish in July 2029. A children's study (NCT06681766) was stopped after 18 people for a paperwork reason, so children could move straight into the longer study. It was not a safety stop.
No study has yet tested whether nomlabofusp slows or reverses the nerve damage of Friedreich ataxia. Nomlabofusp is not approved anywhere.
How does Nomlabofusp work?
In people, three things are known. A shot under the skin is absorbed fast. Daily doses raise frataxin in cheek cells, skin and platelets by an amount you can measure. And levels in those tissues rise and fall together. Nobody has measured whether frataxin reaches the tissues that matter most in a person. Those are the nerve clusters next to the spine, the cerebellum and the heart. That link comes from animals. In cells and animals, the TAT piece carries the protein through the outer wall of the cell. A tag on frataxin itself steers it into the mitochondria. There the carrier is cut off and normal frataxin is left. A 2025 paper shows this freed frataxin works in cells that lack it. In mice, rats and monkeys, a shot under the skin gets frataxin into the heart, muscle, spinal nerve clusters and brain.
What have studies in people found about Nomlabofusp?
55 adults took part in two early studies that compared it with a dummy shot. 18 children and teens were in a children's study that was stopped for a paperwork reason. A study where everyone gets the drug is still recruiting. Every human result so far is about safety, how the body handles the drug, or frataxin levels in easy to reach tissue. No study has yet reported whether patients got better.
- Single dose study: 28 adults, 25 to 100 mg or a dummy shot. Well tolerated, nothing serious.
- Daily dose study: 27 adults, up to 100 mg a day for 13 days or a dummy shot. Frataxin rose in cheek cells, skin and platelets, more with bigger and more frequent doses. Nothing serious.
- Tissue link (2026): in patients, frataxin levels in skin and cheek cells rose and fell together. The link to heart and nerve tissue comes from animals.
- NCT07778836: final-stage trial, about 150 people expected, started 5 August 2026, due July 2029.
- NCT06447025: everyone gets the drug, about 85 people expected, recruiting, first results due January 2027.
- NCT06681766: children's early study, 18 joined, stopped for a paperwork reason. The children moved straight into the longer study.
What this does not tell you: Raising frataxin in skin is not the same as slowing the disease. Frataxin level is a stand-in measure for a disease caused by missing frataxin. It is a sensible one. But the link between frataxin in skin and frataxin in the heart and nerves, which are what fail in Friedreich ataxia, has only been shown in animals. The longest anyone took it next to a dummy group is 13 days, in 27 people. The long term study has no comparison group, so it cannot show whether the drug works. The final-stage trial that can will not report before 2029.
The state of the research
This is a rare disease programme run by one small company. The evidence is exactly as far along as the programme. There is careful data on how the drug behaves, a clean but short safety record, and a question about whether it helps that has been asked but not answered. Larimar paid for every study and employs most of the authors of the human papers. That is normal for a company at this stage, and it is said here because the company is the only source of data. A patient group, the Friedreich's Ataxia Research Alliance, also has people among the authors. Nomlabofusp shows up in peptide catalogues because of its TAT delivery peptide. But the active part is a full human protein, and it has no use outside the disease it is built for.
The thing to watch is the stand-in measure. A protein replacement for a rare disease can seek approval based on a lab marker, with follow up studies afterwards. The 2026 paper is building the case that frataxin in skin and cheek cells can stand in for tissues that cannot be sampled. Animal data and links between easy to reach tissues in patients back that up. Whether regulators accept it is one question. Whether it means slower disease is another, and that is what the 2029 trial result is for.
The evidence, in charts
Fig. 1a · how many people
28people, across 1 study in people cited here
| Study | People | Share |
|---|---|---|
| Annals of Clinical and Translational Neurology 2024 | 28 | 100% |
The whole total is one study of 28. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 4 more studies in people give no headcount and are not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
5 of 7 sources here are studies in people. The rest are not.
- Study in people · done in people571%
- Animal study · done in animals114%
- Lab (cells in a dish) · cells or tissue114%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 3 different years, 2024 to 2026, counted from the list of sources on this page.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 4 · how much does what
Nobody has tested different amounts in people
This chart would show how the effect changes as the amount goes up. For this compound, nobody has measured that in people. So we leave it empty. We will not borrow an animal chart and pretend it works the same in people.
Fig. 5 · what the molecule is
- Kind of compound
- Biologic
- Molecule weight
- Not on file
- Half-life
- None on file
- Chain length
- None on file
No amino acid sequence is on file for Nomlabofusp, so none is drawn rather than guessed from a name.
The studies we cite
- Study in people2024Safety, pharmacokinetics, and pharmacodynamics of nomlabofusp (CTI-1601) in Friedreich's ataxia
The drug got the missing protein into the body, which is not the same as helping anyone. Fifty five adults with Friedreich ataxia took part across two short safety studies, some getting one shot and some getting daily shots for under two weeks. Nobody involved knew who got the real thing. Side effects were mostly mild and nobody was seriously harmed. Levels of the protein rose in skin, cheek cells and platelets. No symptom or daily ability was measured. The maker paid and most authors work there.
Two double blind placebo controlled phase 1 trials in adults aged 19 to 69 with Friedreich ataxia: single ascending dose 25 to 100 mg (28 participants) and multiple ascending dose up to 100 mg daily for 13 days (27 participants). Mostly mild adverse events, no serious adverse events or deaths; peak plasma levels at 15 minutes; frataxin rose in buccal cells, skin and platelets with higher and more frequent dosing. Funded by Larimar Therapeutics; most authors are or were Larimar employees.
- Study in people2026Nomlabofusp Treatment Produces Frataxin Levels That Correlate Across Peripheral Tissues: Preclinical and Clinical Support for Surrogate Tissue Sampling
This work is about where to take samples, not about whether patients get better. Levels of the replacement protein were measured in mice, rats, monkeys and people after a shot under the skin. In animals, levels in skin and cheek cells tracked levels in the heart, muscle and nerve tissue. In people only the easy to reach tissues could be sampled, so the link to heart and nerve is assumed from the animals. Nothing here is a measure of health. The maker paid.
Drug derived frataxin measured after subcutaneous dosing in mice, rats, primates and patients with Friedreich ataxia. Levels in skin and buccal cells correlated with levels in heart, skeletal muscle and dorsal root ganglia across species, supporting those accessible tissues as surrogates for exposure. Tissue level correlations in animals; peripheral tissues only in patients. Funded by Larimar.
- Study in people2026A Study to Evaluate the Efficacy and Safety of Subcutaneous Nomlabofusp in Subjects With Friedreich's Ataxia (NCT07778836)
The first trial that will actually ask whether this drug helps patients is still recruiting. About one hundred and fifty people with Friedreich ataxia are expected. It opened in August 2026 and answers are not due until 2029. Everything published so far measured protein levels and safety, not symptoms. Until this finishes, nobody can say whether the drug changes how anyone lives. The record shows a trial in progress and no results. The maker is paying for it.
Phase 3, estimated 150 participants, started 5 August 2026, recruiting, primary completion projected July 2029. The first trial designed to measure clinical efficacy. Sponsor funded.
- Study in people2024An Open-Label Study of CTI-1601 in Subjects With Friedreich's Ataxia (NCT06447025)
This study is still running and everyone in it gets the drug. About eighty five people with Friedreich ataxia are expected, and it has been recruiting since January 2024. There is no comparison group, so whatever is seen cannot be set against what would have happened anyway. First results are due in 2027. Nothing has been reported yet, and that is simply what the record shows. The maker is paying for it.
Phase 2, open label, estimated 85 participants, recruiting since January 2024, primary completion expected January 2027. Uncontrolled long term dosing study. Sponsor funded.
- Study in people2024A Study to Assess Nomlabofusp in Adolescents and Children With Friedreich's Ataxia (NCT06681766)
This children's study was stopped early, and not because anything went wrong. Eighteen young people had taken part. Once the first group's results were reviewed, children could join the longer study directly without a break in dosing, so the separate study was no longer needed. The record gives that as the reason. It was not stopped for safety and it was not stopped because the drug failed.
Phase 1 paediatric pharmacokinetic study, terminated after 18 participants. Sponsor's stated reason: review of cohort 1 data allowed direct enrolment into the open label study and removed a pause in dosing. An administrative termination, not a safety or efficacy stop.
- Animal study2025Pharmacokinetics and Pharmacodynamics of Nomlabofusp in Non-clinical Studies of Friedreich's Ataxia
In animals. After a shot under the skin, the drug carried frataxin to the heart, muscle and nerve tissue. This is animal data on where the drug goes. Industry and the US National Institutes of Health paid.
Non-clinical pharmacokinetics and tissue distribution after subcutaneous dosing in animals, including delivery of frataxin to heart, muscle and nervous tissue. Animal data. Industry and NIH intramural support.
- Lab (cells in a dish)2025Nomlabofusp, a Fusion Protein of Human Frataxin and a Cell Penetrant Peptide, Delivers Mature and Functional Frataxin into Mitochondria
In a dish. The drug got into cells, and the cell cut it down to normal frataxin. That freed frataxin worked in cells that were short of it. This shows how the drug is meant to work. It does not show it helps anyone. Industry paid.
Shows that the fusion protein enters cells, is processed by mitochondrial peptidase to mature frataxin, and that the released frataxin is functional in frataxin deficient cells. Mechanistic; industry funded.
Common questions
Has Nomlabofusp been tested in people?
Yes. 28 people given it across 2 completed trials cited here, 0 of which found nothing. A replacement for frataxin, the protein people with Friedreich ataxia are missing.
What is the Nomlabofusp dosage?
No human dose established. Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose. 2 completed trials, 28 people given it
Is Nomlabofusp FDA-approved?
Not FDA approved. A mid-stage study, where everyone knows they are getting the drug, is signing people up. A final-stage study (NCT07778836, 150 people) started 5 August 2026, with its main results expected by July 2029.
Does nomlabofusp treat Friedreich ataxia?
Not shown yet. In 55 adults it raised frataxin in cheek cells, skin and platelets over up to 13 days, with mostly mild side effects. No study has yet measured whether that changes nerve function or slows the disease. The final-stage trial built to test that began in August 2026 and should finish in July 2029.
Is nomlabofusp a peptide?
It is a joined protein. Full length human frataxin is attached to a short peptide from the HIV TAT protein that helps it get into cells. The peptide is the delivery truck. Once inside the mitochondria, the carrier is cut off, and the frataxin left behind is the same as the body's own.
Was the paediatric trial stopped for safety?
No. NCT06681766 was stopped after 18 people. In the company's words, a review of the first group's data let children join the longer study directly, without a break in dosing. That is a paperwork reason.
Is it approved anywhere?
No. It is a test drug everywhere. The study where everyone gets the drug is recruiting, and the final-stage trial started in August 2026.