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Early pipeline

ACE-2223

Bottom line

Very early: the first safety test in healthy volunteers began in September 2026. It looked promising in mice, but most drugs at this stage never become approved treatments.

Very early. This drug is in its first safety trial in people and has not been tested for whether it helps in ALS. Most drugs at this stage never reach approval. More about early drugs

ACE-2223 is an experimental drug taken by mouth that is meant to break up clumps of a protein called TDP-43, which build up in the nerve cells of almost everyone with ALS. Its first-ever human trial, in healthy volunteers in Melbourne, Australia, started dosing in September 2026. It has not been given to anyone with ALS yet.

Information checked 5 Nov 2026

Evidence: Results pending

Studies: 1 running

Trials are running, but there are no efficacy results yet.

How we decide the overall verdict: How to read this site.

At a glance

CompanyAcelotExplanation and sources

Acelot is a small private biotech in South San Francisco. It finds drug candidates with a computer-modelling platform it calls RESOLUTE. ACE-2223 is its lead programme and its first drug to reach human testing. The Australian trial is run by a contract research company, Avance Clinical.

Sources

  1. Acelot Announces Initiation of Dosing in Phase Ia Clinical Trial of ACE-2223, a First-in-Class Oral Small Molecule Targeting Aggregated TDP-43 in ALSAcelot · 17 Sept 2026 · Company press release
  2. Acelot newsAcelot · Company website
  3. First-in-human study of ACE-2223 in healthy adults (ACTRN12626000231347)ANZCTR · Trial registry
How it worksDrug taken by mouth, meant to break up harmful TDP-43 clumpsAggregated TDP-43 (small-molecule disaggregator)Explanation and sources

TDP-43 normally helps nerve cells read their genes correctly. In ALS it leaves its usual place in the cell and forms clumps. Acelot says these clumps are found in about 97% of people with sporadic ALS. ACE-2223 is designed to bind the clumped form and pull it apart, so that TDP-43 can work normally again.

Sources

  1. Acelot Announces Initiation of Dosing in Phase Ia Clinical Trial of ACE-2223, a First-in-Class Oral Small Molecule Targeting Aggregated TDP-43 in ALSAcelot · 17 Sept 2026 · Company press release
  2. First participant dosed in clinical trial of experimental ALS treatmentALS News Today · 21 Sept 2026 · News
StagePhase 1Phase 1a in healthy volunteers, up to 96 people · Dosing: healthy volunteersExplanation and sources

The trial (ACE2223-101) is the first time the drug has been given to people. Healthy adults aged 18 to 65 get a single dose, or doses for 7 days, of ACE-2223 or placebo, with doses rising step by step to check safety and how the body handles the drug. Acelot announced the first dose in September 2026. It has not said when people with ALS will be included.

Sources

  1. Acelot Announces Initiation of Dosing in Phase Ia Clinical Trial of ACE-2223, a First-in-Class Oral Small Molecule Targeting Aggregated TDP-43 in ALSAcelot · 17 Sept 2026 · Company press release
  2. First-in-human study of ACE-2223 in healthy adults (ACTRN12626000231347)ANZCTR · Trial registry
Best reported effectNo ALS data yetSafety and drug levels in healthy volunteersExplanation and sources

No one with ALS has taken ACE-2223, so there is no evidence it helps people. Acelot reports that in lab tests and two ALS mouse models it reduced TDP-43 damage, lowered the nerve-damage marker NfL and helped the mice live longer. These are lab and mouse results; most drugs that work in mice do not work in people.

This is the most favourable result reported. See all key studies for the full picture.

Sources

  1. Acelot Announces Initiation of Dosing in Phase Ia Clinical Trial of ACE-2223, a First-in-Class Oral Small Molecule Targeting Aggregated TDP-43 in ALSAcelot · 17 Sept 2026 · Company press release
  2. Acelot to Present on TDP-43 Targeting in ALS at 2026 NEALS MeetingAcelot · 26 Oct 2026 · Company press release
Who it's forAimed at sporadic ALS with TDP-43 clumps; trial is in healthy adultsSporadic · By mouth (liquid in this trial)Explanation and sources

Acelot is developing ACE-2223 for sporadic ALS, the common non-inherited form, where TDP-43 clumps are almost always present. The current trial only takes healthy adults aged 18 to 65, who drink the drug as a liquid and stay in a clinical unit.

Sources

  1. Acelot Announces Initiation of Dosing in Phase Ia Clinical Trial of ACE-2223, a First-in-Class Oral Small Molecule Targeting Aggregated TDP-43 in ALSAcelot · 17 Sept 2026 · Company press release
  2. First-in-human study of ACE-2223 in healthy adults (ACTRN12626000231347)ANZCTR · Trial registry
What's nextSafety results from the healthy-volunteer trialExplanation and sources

Acelot has not given a date for results or for a first trial in people with ALS. The trial registry dates for enrolment have already passed and do not show when results will come.

Sources

  1. Acelot Announces Initiation of Dosing in Phase Ia Clinical Trial of ACE-2223, a First-in-Class Oral Small Molecule Targeting Aggregated TDP-43 in ALSAcelot · 17 Sept 2026 · Company press release
  2. First-in-human study of ACE-2223 in healthy adults (ACTRN12626000231347)ANZCTR · Trial registry
Can I join?Healthy volunteers only; people with ALS can't join yetExplanation and sources

The only trial is for healthy adults at the Nucleus Network unit in Melbourne. People with ALS cannot join it. We found no expanded access programme.

Sources

  1. First-in-human study of ACE-2223 in healthy adults (ACTRN12626000231347)ANZCTR · Trial registry
  2. First participant dosed in clinical trial of experimental ALS treatmentALS News Today · 21 Sept 2026 · News

Signal: Steady

Signal measures how often, and how reliably, Acelot tells the public about this drug. It says nothing about whether the drug works. A quiet company isn't necessarily a bad sign, but regular, on-time updates help patients plan.

Last company update26 Oct 2026 (10 days ago)40 / 40
Company updates in the last 12 months212 / 35
Promises keptNot enough history yet (neutral score)12.5 / 25
Signal score65 / 100 · Steady

70 or more is Active, 45 or more is Steady, 20 or more is Quiet, below 20 is Silent. Full method.

Timeline

5 events, newest first. Company updates are marked; independent news and regulator decisions are shown too.

2026

  1. Press releaseFrom the companyAcelot

    Acelot to present ALS mouse data at NEALS

    Acelot said it would present lab and mouse data on ACE-2223 at the NEALS annual meeting on October 30, 2026. No human results were announced.

  2. NewsThe Business Journals

    Business press profiles Acelot's ALS programme

    The Business Journals profiled Acelot as a start-up taking on ALS with ACE-2223.

  3. NewsALS News Today

    ALS News Today reports the first dose of ACE-2223

    Independent coverage of the start of the healthy-volunteer trial, with background on the TDP-43 approach and the mouse results.

  4. Press releaseFrom the companyAcelot

    First healthy volunteer dosed with ACE-2223

    Acelot announced the first dose in its Phase 1a trial in healthy volunteers in Melbourne, the first time the drug has been given to a person.

  5. Trial registryANZCTR

    First-in-human trial of ACE-2223 registered in Australia

    The Phase 1a trial in up to 96 healthy adults was registered on the Australian New Zealand Clinical Trials Registry, with ALS named as the target disease.

All sources for this page

  1. First-in-human study of ACE-2223 in healthy adults (ACTRN12626000231347)ANZCTR · Trial registry
  2. Acelot Announces Initiation of Dosing in Phase Ia Clinical Trial of ACE-2223, a First-in-Class Oral Small Molecule Targeting Aggregated TDP-43 in ALSAcelot · 17 Sept 2026 · Company press release
  3. First participant dosed in clinical trial of experimental ALS treatmentALS News Today · 21 Sept 2026 · News
  4. Acelot to Present on TDP-43 Targeting in ALS at 2026 NEALS MeetingAcelot · 26 Oct 2026 · Company press release
  5. Acelot newsAcelot · Company website