Foselutoclax dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Foselutoclax is an eye shot that clears worn-out cells. In people with diabetic swelling in the eye, it kept up with the standard drug aflibercept on vision at 9 of 10 check points.
Evidence grade for Foselutoclax: 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, none stating how many people. A grade counts how much has been done to people, not whether it works.
- People given it
- 0
- 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, 0 people given it
2 effects reported, 1 unwanted, 1 wanted, by people using it, not a trial
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.
Foselutoclax is an eye shot from Unity Biotechnology. It kills worn-out cells by blocking a protein they need to survive. It is being tested for swelling at the back of the eye caused by diabetes. It is not approved.
What people take it for
- Better sight in diabetic eye swelling.
- Fewer eye shots than the usual drugs.
What studies in people showed
In an early study, one shot improved sight, and the gain held for 48 weeks. In a mid-stage study, it was put against aflibercept, the usual eye shot. Sight improved by 5 or more letters on the eye chart at weeks 24 and 36. It kept up with aflibercept at 9 of 10 check points. It did not clearly beat it. These are company figures.
What people report
Reports, not study results
The good
- In the studies on this page, one shot improved sight for close to a year.
The bad
- It kept up with the usual eye shot but did not clearly beat it. Investors called the result mixed.
- The studies on this page do not list side effects, and we have not collected user reports on this one yet.
Where these come from: Both lines are from the studies on this page. We have not collected forum or user reports for this drug yet.
My bottom line
If you have diabetes, get your eyes checked every year. This is not something you can take, and it is not an anti-ageing pill.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Nothing indexed yet
The 2 citations on this page do not report a result for any of the 36 goals indexed here. Most of what sits here is something else: a listing of a planned study, a study of how the body handles the drug, a safety report or a government record. None of those tests whether it works.
Show full evidence
What is Foselutoclax?
Foselutoclax is an eye shot that clears worn-out cells. In people with diabetic swelling in the eye, it kept up with the standard drug aflibercept on vision at 9 of 10 check points.
Foselutoclax, from Unity Biotechnology, kills worn-out cells by blocking BCL-xL, a protein those cells need to survive. It is given as a shot into the eye. In the earlier BEHOLD study, one shot improved sight in people with diabetic swelling at the back of the eye, and the gain held for 48 weeks. In the mid-stage ASPIRE study, sight improved by 5 or more letters on the eye chart at weeks 24 and 36. It kept up with aflibercept, the usual eye shot, at 9 of 10 check points. Investors called the result mixed. It is the clearest sign so far that clearing worn-out cells can change something doctors can measure in a patient.
How does Foselutoclax work?
It blocks BCL-xL, the survival signal worn-out cells depend on. Without it, those cells die off.
The evidence, in charts
Fig. 1a · how many people
2studies in people cited, but none says how many people took part
number of people not stated
We do not draw a total, because none of the studies in people on this page gives one. Read the sources below for what each study measured.
We read the number of people from the source lines on this page. Where a line gives no number, we count nothing for it. We do not guess.
Fig. 1b · evidence mix
All 2 sources here are studies in people.
- Study in people · done in people2100%
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
Every source here was published in 2025.
Too few different years on this page to draw a timeline.
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
- Small molecule
- Molecule weight
- 1,159.7 Da
- Half-life
- Stated in words, not a numbersee the exact wording below
- Chain length
- None on file
Half-life as stated on file: Not established (intravitreal; durable local effect)
No amino acid sequence is on file for Foselutoclax, which is expected: a small molecule is not built from amino acids.
The studies we cite
- Study in people2025UBX1325 in diabetic macular edema (BEHOLD)
One injection improved sight, and the gain held for close to a year. People with swelling at the back of the eye caused by diabetes got a single dose of foselutoclax, and their vision was still better at 48 weeks. That is unusual, because the standard drugs for this condition need repeat injections. This was an early trial in a small number of people, and a vision chart measures one part of the disease.
Vision gains sustained through 48 weeks after a single injection.
- Study in people2025UNITY announces complete 36-week results from the ASPIRE Phase 2b study
Put head to head against the standard drug, it mostly kept up and did not clearly win. Foselutoclax was compared with aflibercept, the injection normally used for this eye condition. Sight improved by five letters or more at weeks 24 and 36, and the senolytic matched aflibercept at nine of the ten times vision was measured. Matching is not beating. Investors read the result as mixed. These are company-reported figures from a mid-stage trial.
ASPIRE 36 week head to head against aflibercept, reported by press release rather than publication. Vision improved by five or more letters at weeks 24 and 36, and the drug was non-inferior to aflibercept at 9 of 10 timepoints. Read as mixed by investors. Sponsor reported, not peer reviewed, so no independent verification of the figures is possible.
Common questions
Has Foselutoclax been tested in people?
Yes. 0 people given it across 2 completed trials cited here, 0 of which found nothing. Foselutoclax is an eye shot that clears worn-out cells. In people with diabetic swelling in the eye, it kept up with the standard drug aflibercept on vision at 9 of 10 check points.
What is the Foselutoclax 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, 0 people given it
Is Foselutoclax FDA-approved?
Investigational; in mid-stage studies
Why is a senolytic being tested in the eye?
The eye is a closed space. A shot there can reach worn-out cells without the drug spreading through the body. That makes it a practical first place to test.
Can I take a senolytic like this?
No. Foselutoclax is an experimental shot used only in studies. Pills such as dasatinib plus quercetin, or fisetin, are a different and less proven group.
Latest reading on Foselutoclax
Blog posts about Foselutoclax, newest first.