8-K: Seelos Therapeutics Announces Top-Line Results from ALS Study, Shows Promise in Subgroup Analysis

Seelos Therapeutics reported top-line results from its Phase 2/3 ALS study, showing a potential signal of efficacy in a pre-specified subgroup despite not meeting statistical significance in the primary endpoint.

Summary

• Seelos Therapeutics announced top-line results from its Phase 2/3 HEALEY ALS Platform trial evaluating SLS-005 (IV trehalose) in patients with ALS.
• The study did not meet statistical significance in the primary and secondary endpoints in the Full Analysis Set (FAS).
• However, a pre-specified subgroup of patients not taking RELYVRIO (ERF) showed a 22% improvement in the 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 favored the SLS-005 treatment group versus placebo over 6 months (-0.80 and -1.07 points per month, respectively) in the ERF subgroup.
• A 25% slowing of Slow Vital Capacity (SVC) decline was observed in the SLS-005 group versus placebo (-11.5% and -15.4%, respectively) at 24 weeks in the ERF subgroup.
• The company plans to request a meeting with the FDA to discuss potential next steps for the program and will continue partner discussions.
• SLS-005 was generally well-tolerated with safety comparable to placebo, although there was an imbalance of deaths/death equivalents observed in the study, all considered unrelated to the study drug.
• The study included a Full Analysis Set (FAS) of 204 participants, an Efficacy Regimen Only (ERO) population of 161 participants, and an Efficacy RELYVRIO Free (ERF) population of 130 participants.

Sentiment

Score: 5

Explanation: The sentiment is neutral to slightly negative due to the study not meeting its primary endpoints, but there is a positive signal in a pre-specified subgroup. The company is also facing risks related to funding and regulatory approval.

Positives

• A pre-specified subgroup of patients not taking RELYVRIO (ERF) showed a 22% improvement in the slope of change in ALSFRS-R assessment adjusted for mortality.
• The ERF subgroup showed a 25% slowing of Slow Vital Capacity (SVC) decline with SLS-005 compared to placebo.
• The rate of decline in ALSFRS-R slope favored the SLS-005 treatment group versus placebo over 6 months in the ERF subgroup.
• SLS-005 was generally well-tolerated and comparable to placebo in safety.

Negatives

• The study did not meet statistical significance in the primary and secondary endpoints in the Full Analysis Set (FAS).
• There was an imbalance of deaths/death equivalents observed in the study, with more events seen in the SLS-005 group compared to placebo, although all were considered unrelated to the study drug.

Risks

• The study did not meet its primary endpoints, which could impact regulatory approval.
• The imbalance of deaths/death equivalents, although deemed unrelated to the drug, could raise concerns.
• The company's ability to secure FDA approval and commercialize SLS-005 is not guaranteed.
• The company is reliant on future capital raises to fund its development plans and ongoing operations.

Future Outlook

The company plans to request a meeting with the FDA to discuss potential next steps for the program and will continue partner discussions. They also plan to run additional analyses upon receiving the full dataset.

Management Comments

• Raj Mehra Ph.D., Chairman and Chief Executive Officer of Seelos, stated that the observed signal and success probability is competitive to other recently FDA-approved therapies for ALS.
• Management believes the HEALEY platform is designed to detect signals of efficacy.

Industry Context

The announcement is relevant to the broader ALS treatment landscape, where there is a high unmet need for effective therapies. The company is comparing its results to other recently approved ALS treatments, such as Relyvrio, Radicava and Qalsody.

Comparison to Industry Standards

• The company is comparing the results of SLS-005 to other recently approved ALS therapies, such as Relyvrio, Radicava and Qalsody, which also had challenges in meeting primary endpoints in initial trials.
• The 22% improvement in the slope of change in ALSFRS-R in the ERF subgroup is being presented as a competitive result compared to other approved therapies.
• The HEALEY platform trial is designed to detect signals of efficacy, and the company believes the observed signal is competitive to other recently FDA-approved therapies for ALS.

Stakeholder Impact

• Shareholders may react to the mixed results of the clinical trial.
• Patients with ALS and their families may be hopeful about the potential of SLS-005, but also cautious due to the study's limitations.
• Employees of Seelos Therapeutics will be focused on the next steps for the program and the company's future.

Next Steps

• The company plans to request a meeting with the FDA to discuss potential next steps for the program.
• Seelos will continue potential partner discussions.
• The company plans to run additional analyses, including biomarkers of neurodegeneration, neurofilament light chain (NfL), exploratory efficacy results, subgroups and post-hoc analyses, upon receiving the full dataset.

Key Dates

Keywords

ALS, Amyotrophic Lateral Sclerosis, SLS-005, Trehalose, Clinical Trial, HEALEY Platform, Neurodegenerative Disease, FDA, Biopharmaceutical, Rare Disease