A drug that clears aged cells beats a sham treatment in a controlled trial
Clearing aged cells (cells that have stopped dividing but will not die, and inflame their neighbours) from a person is one thing; making a person measurably better is another. This leaf is the second: a controlled trial in which people given such a drug do better on the trial's main measure than people given a sham or placebo. The first such result came in a small trial in the eye: in 2022 the company Unity Biotechnology reported that a single injection of its drug UBX1325 into the eyes of people with diabetic macular oedema (swelling at the back of the eye) improved their vision over twenty-four weeks compared with a sham injection, and the trial was published in a peer-reviewed journal in 2025. The follow-on trial against the standard drug missed its main goal in 2025 and the company let its staff go, so the result stands but nothing is approved. A second controlled result came on 2026-10-01: in a phase 2 trial in Amsterdam, 31 people with scarred fatty liver were given a by-mouth course of two drugs that clear aged cells (dasatinib and quercetin) or a placebo, and 47 per cent of those treated, against 7 per cent on placebo, had at least one stage less scarring on biopsy without the disease worsening.
What would count
A controlled trial in people, with a placebo or sham group, in which a drug meant to kill aged cells improves the trial's pre-stated main measure (vision, walking, joint function, disease progression) by a statistically significant margin, in a peer-reviewed report or a trial registry's posted results. For the clinic rung: a regulator approves such a drug for an age-related condition on the strength of such a trial.
Who settles it: A peer-reviewed trial report or the trial registry's posted results for the first-human rung; a regulator's approval record for the clinic rung.
Where it stands
First human. Reached 2022, on the record of clinicaltrials.gov. Next rung within 5 to 20 years.
When it reaches the clinic: the project's estimate
This is the one thing on this page that is a judgment rather than a record. The project's estimate of the year it reaches the clinic is 2037, no earlier than 2031 and no later than 2065; the model draws from that range every run, with the likely year the most probable draw. Set 16 October 2026, a first pass awaiting an outside review.
| Rung | No earlier than | Most likely | No later than | |
|---|---|---|---|---|
| In clinical use | 2031 | 2037 | 2065 | feeds the year at the top |
| In wide use | 2035 | 2045 | 2085 |
Why. One positive controlled trial exists, small and in one eye condition, and the company that ran it has no staff. Reaching the clinic needs a sponsor to carry a drug of this class through a large trial and an approval; several academic and company programmes in the knee, the lung and the eye are at early stages. The likely year assumes one of them reads out positive in the early 2030s and approval follows in two or three years; the earliest assumes the UBX1325 asset is picked up and a confirmatory trial starts within two years; the latest allows for the whole first generation failing on safety or effect and a second generation starting over. [Note 2026-10-17, from the weekly reading of that date: the reasoning above counts one positive controlled trial. Two now exist, the 2022 eye trial and the 2026-10-01 liver trial (koning-2026), each small and in a single organ. The years are unchanged; John may want to weigh the second trial at the next review of the ranges.]
Changes to this record
- 17 October 2026, description: peer-reviewed journal in 2025. The follow-on trial against the standard drug missed its main goal in 2025 and the company let its staff go, so the result stands but nothing is approved. became peer-reviewed journal in 2025. The follow-on trial against the standard drug missed its main goal in 2025 and the company let its staff go, so the result stands but nothing is approved. A second controlled result came on 2026-10-01: in a phase 2 trial in Amsterdam, 31 people with scarred fatty liver were given a by-mouth course of two drugs that clear aged cells (dasatinib and quercetin) or a placebo, and 47 per cent of those treated, against 7 per cent on placebo, had at least one stage less scarring on biopsy without the disease worsening.. [reading 2026-10-17] Adds the Amsterdam liver trial (Nature Metabolism, 2026-10-01), a second controlled result for the class that the description of 2026-10-16 did not know. The stage was already first human, so it does not move. Source: Koning and 12 others, 1 October 2026.
- 17 October 2026, notes: 2022 eye result is the first controlled human result in the drug class, and it is a small trial of one dose. became 2022 eye result was the first controlled human result in the drug class, a small trial of one dose; the 2026 liver result (koning-2026) is a second, with a by-mouth two-drug course in a different organ. It too is small (31 people) and in one condition, run by an academic group, with two of its authors holding patents on drugs of this class.. [reading 2026-10-17] Replaces 'the first controlled human result in the drug class' with the two controlled results now on record. Source: Koning and 12 others, 1 October 2026.
- 17 October 2026, estimate.why: (nothing; a dated note added at the end of the reasoning; no year changed) became [Note 2026-10-17, from the weekly reading of that date: the reasoning above counts one positive controlled trial. Two now exist, the 2022 eye trial and the 2026-10-01 liver trial (koning-2026), each small and in a single organ. The years are unchanged; John may want to weigh the second trial at the next review of the ranges.]. [reading 2026-10-17] A dated note that the premise 'one positive controlled trial exists' is out of date; the years are John's and were not changed. Source: Koning and 12 others, 1 October 2026.
The last readings
- 17 October 2026 Left for the author
Nothing dated in the window bears on the test, and nothing new was found on Unity Biotechnology or its eye drug UBX1325 (the company wound down in 2025 and the search returned no 2026 partner or asset sale). Just before the window, on 2026-10-01 by the search summary, Nature Metabolism published a phase 2, double-blind, placebo-controlled trial of dasatinib plus quercetin in 31 people with scarred liver from fatty liver disease (MASH), in which 47 per cent of treated people met the pre-stated main measure (one stage less scarring on paired liver biopsies without the disease worsening) against 7 per cent on placebo, P = 0.02; the record, written 2026-10-16, does not know it. Rubedo Life Sciences' topical drug RLS-1496 reported a vehicle-controlled phase 1 in skin conditions in 2026-03 and an uncontrolled lesion-count result in 2026-05, neither of which meets the test and neither of which is in the window. Left for the author, resolved on 17 October 2026: The change I would make: the description says the 2022 eye result is the first controlled human result in the drug class and that nothing else stands; the Nature Metabolism liver trial is a second controlled result, with an oral two-drug course rather than an injection, and it belongs in the description and the notes, and in the publications log. The stage does not change: the leaf is already at first-human, and the next rung needs a regulator's approval. It is not mine to make because the paper is dated before the window (2026-10-01 by the search summary, which I could not confirm on the journal's page), so the entry as written on 2026-10-16 missed it, and correcting an entry is the author's. The estimate's reasoning ("one positive controlled trial exists") would also want a look, since the trial is small (31 people) and in a single liver condition. To log in the publications log once its page has been read, as the reading's rule asks: Senolytics dasatinib and quercetin in metabolic dysfunction-associated steatohepatitis: a proof-of-principle randomized, controlled trial (Nature Metabolism (2026), 2026-10-01; https://www.nature.com/articles/s42255-026-01643-4).source 1, source 2, source 3, source 4
What the story so far says about it
On the record
- 2 November 2011Clearance of p16Ink4a-positive senescent cells delays ageing-associated disorders
- 1 October 2026Senolytics dasatinib and quercetin in metabolic dysfunction-associated steatohepatitis: a proof-of-principle randomized, controlled trial
Notes
The animal record is shared with the aged-cell leaf that is the worked example: the 2011 Mayo Clinic report in which clearing such cells from mice delayed several age-related conditions. The knee osteoarthritis trial of Unity's earlier drug UBX0101 failed its main measure in 2020; the 2022 eye result was the first controlled human result in the drug class, a small trial of one dose; the 2026 liver result (koning-2026) is a second, with a by-mouth two-drug course in a different organ. It too is small (31 people) and in one condition, run by an academic group, with two of its authors holding patents on drugs of this class. Two other leaves on this branch hold the measurement result (fewer aged cells in a tissue sample) and the knee result; this one holds the clinical benefit.