Seelos Therapeutics, Inc. provided an update on top-line data of the Phase 2/3 HEALEY ALS Platform trial. This study was performed in collaboration with The Sean M. Healey and AMG Center, which is viewed as an influential force in ALS research and in caring for the ALS community. Their unique and innovative approach continues to be a benefit to the ALS community and its contributions have helped bring the last two FDA approved therapies for ALS to market.

The study was designed to evaluate SLS-005 (IV trehalose), a low molecular weight disaccharide that stabilizes misfolded proteins and activates autophagy, in decreasing the slope of the ALS Functional Rating Scale (ALSFRS-R) and separation from placebo in Function and Mortality in an all-comers population of Persons with ALS (PALS). While the study did not meet statistical significance in the primary and secondary endpoint in the Full Analysis Set (FAS)2, by showing a 13% improvement in Function and Mortality with an 88% success probability (versus the pre-specified 98%), it showed a potential signal of efficacy in a pre-specified subgroup (ERF). In the pre-specified subgroup of PALS treated with SLS-005, without RELYVRIO®, the top-line data favored SLS-005 versus placebo in efficacy measures in the Efficacy RELYVRIO® Free (ERF)1 data set (n=130), including: a 22% improvement in slope of change in ALSFRS-R assessment adjusted for mortality, with an 89% success probability, at 24 weeks, the rate of decline in ALSFRS-R slope (points per month) also favored the SLS-005 treatment group versus placebo over 6 months (-0.80 and -1.07 points per month, respectively), a 25% slowing of Slow Vital Capacity (SVC) decline versus placebo (-11.5% for SLS-005 and -15.4% for placebo) at 24 weeks.

Seelos has not yet received the full dataset and upon receiving it in the near future, Seelos plans to run additional analyses, including biomarkers of neurodegeneration, neurofilament light chain (NfL), exploratory efficacy results, subgroups and post-hoc analyses. SLS-005 was generally well-tolerated and comparable to placebo in safety. There was an imbalance of deaths/death equivalents observed in the study, with more events seen in the SLS-005 group compared to placebo, all were considered unrelated to the study drug.

Seelos received top-line results for Regimen E (RGE). This included a Full Analysis Set (FAS), an Efficacy Regimen Only (ERO) population and an Efficacy RELYVRIO® Free (ERF) population. FAS includes shared placebo from all regimens, including RGE (n=204) and the RGE SLS-005 participants (n=120).

The Efficacy Regimen Only (ERO) population includes 120 RGE SLS-005 and 41 RGE placebo participants. 31 participants in the ERO population received RELYVRIO® during the SLS-005 RGE study, thus confounding results from this population. The ERF analyses exclude participants who initiated RELYVRIO® during the study.

ERF represents the participants who followed the protocol as envisioned (n=130, i.e., the ERF population comprises 81% of ERO/RGE participants). SLS-005 is a low molecular weight disaccharide (0.342 kDa) that crosses the blood brain barrier and is thought to stabilize proteins and activate autophagy through the activation of Transcription Factor EB (TFEB), a key factor in lysosomal and autophagy gene expression. The activation of TFEB is an emerging therapeutic target for a number of diseases with pathologic accumulation of storage material.

In animal models of several diseases associated with abnormal cellular protein aggregation or storage of pathologic material, SLS-005 has been shown to reduce aggregation of misfolded proteins and reduce accumulation of pathologic material. SLS-005 has previously received Orphan Drug Designation for the treatment of ALS from the U.S. Food and Drug Administration and from the European Medicines Agency in the EU. SLS-005 is an investigational treatment and is not currently approved by any health authority for medicinal use.

According to the National Institute of Neurological Disorders and Stroke, amyotrophic lateral sclerosis (ALS) is a group of rare neurological diseases that mainly involve the nerve cells (neurons) responsible for controlling voluntary muscle movement. In ALS, both the upper motor neurons and the lower motor neurons degenerate or die and stop sending messages to the muscles. Unable to function, the muscles gradually weaken, start to twitch (called fasciculations), and waste away (called atrophy).

Eventually, the brain loses its ability to initiate and control voluntary movements. The disease is progressive, meaning the symptoms get worse over time. The majority of ALS cases (90% or more) are considered sporadic.

This means the disease seems to occur at random with no clearly associated risk factors and no family history of the disease. Although family members of people with sporadic ALS are at an increased risk for the disease, the overall risk is very low, and most will not develop ALS. Most people with ALS eventually die from respiratory failure, usually within 3 to 5 years from when the symptoms first appear.

However, about 10% of people with ALS survive for 10 or more years. Currently, there is no cure for ALS and no effective treatment to halt or reverse the progression of the disease. A 1-point change in the ALSFRS-R score can indicate a meaningful difference in a person's ability to function independently with activities of daily living (ADL's), including eating, bathing, dressing or walking.