Trehalose

Seelos Therapeutics, a small US biotech, provided trehalose (SLS-005) to the HEALEY trial. Seelos filed for Chapter 11 bankruptcy in November 2024, and GLD Partners bought its assets in October 2025. GLD said it plans to study trehalose in rare neurodegenerative and lysosomal disorders, not specifically ALS.

Cells clear out damaged and clumped proteins through a recycling process called autophagy. In ALS, this system may not keep up, letting harmful protein clumps build up in motor neurons. Trehalose was thought to switch on autophagy and help clear these clumps.

Trehalose was Regimen E of the HEALEY ALS Platform Trial. Results announced in March 2024 showed it missed its main goal. Seelos highlighted a possible signal in a subgroup of people not taking Relyvrio, which it said was planned in advance, but that result also fell short of the trial's bar for success, and the published paper found no benefit. The company went bankrupt later that year.

Topline results in March 2024 showed no meaningful slowing of ALS. The peer-reviewed paper in May 2025 confirmed this and also found more serious side effects on trehalose than placebo.

In the published results (120 people on trehalose, 205 on placebo), the disease rate ratio was 0.87, a possible 13% slowing, but the range of likely values included no effect and the result did not reach the trial's bar for success. Serious side effects were more common on trehalose than on the trial's own placebo group (16% versus 7%). The authors concluded it is unlikely to be effective.

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

The HEALEY trial enrolled adults with ALS at sites across the USA. People in this arm received trehalose (0.75 g per kg of body weight) or placebo as an intravenous infusion once a week for 24 weeks.

Trehalose (SLS-005) is not available as an ALS treatment and no ALS trials are recruiting. Trehalose sold as a food sugar is not the same as this intravenous medicine and should not be used to treat ALS.