Task Order 10: RSA E: TREHALOSE S-005

REGIMEN-SPECIFIC APPENDIX SUMMARY Regimen-Specific Appendix E For SLS-005, also known as Trehalose injection, 90.5 mg/mL for intravenous infusion. Rationale and RSA Design Trehalose is a disaccharide that is well known for its protein-stabilizing properties (Elbein 2003, Emanuele 2014) and its ability to activate autophagy. Because of its known ability to reduce abnormal protein aggregations, trehalose was studied in several cellular and animal models of hereditary neurologic and muscular disorders. Three in vivo studies (Castillo et al (2013), Zhang et al (2014) and Li Y et al (2015)) demonstrated that trehalose is a potential protective agent in ALS. These studies were performed using the SOD1 mouse model with the G93T mutation or the G86R mutation. In mice, trehalose can be used orally because they lack intestinal trehalase, the enzyme that catalyzes conversion of trehalose to two glucose molecules. Treatment with trehalose both oral and intraperitoneal delayed onset of disease, prolonged survival, preserved motor function and motor neurons in the spinal cord. When trehalose is taken orally in humans, trehalase enzymes in the brush border of the gut actively cleave trehalose into 2 glucose molecules. The most effective way to ensure that adequate amounts of trehalose reaches the primary therapeutic target organs, brain and muscle cells, is to circumvent the extensive gut metabolism in humans by administering trehalose via IV infusion. This is a randomized double-blind placebo-controlled trial. Participants who qualify will be randomized 3:1 to receive weekly infusions of Trehalose Injection, 90.5 mg/mL for intravenous infusion at a dose of 0.75g/kg or placebo (sodium chloride injection, 0.9%, USP) intravenous infusion at an equivalent weight-based volume. Allocation to Treatment Regimens Participants must first be screened and determined to be eligible under the Master Protocol before they are randomized to a treatment regimen. As soon as pre-defined criteria for futility for the regimen are met, or the target number of randomized participants has been reached, enrollment will stop in the regimen. Number of Planned Participants and Treatment Groups The number of planned participants for this regimen is approximately 160. There are 2 treatment groups for this regimen, active and placebo. Participants will be randomized in a 3:1 ratio to active treatment or placebo (i.e., 120 active: 40 placebo). Planned Number of Sites Research participants will be enrolled from approximately 80 centers in the US. Treatment Duration The maximum duration of the placebo-controlled treatment period is 24 weeks. Follow-up Duration At the conclusion of the 24-week placebo-controlled treatment period of the study, all participants will either schedule a 28-day follow up phone call and end their participation in the HEALEY ALS Platform Trial Regimen-Specific Appendix E, Trehalose Version 2.0 12/03/2021 CONFIDENTIAL Page 8 of 51 regimen or have the option to receive intravenous infusions of trehalose in the Open Label Extension (OLE) period of the study. The duration of the OLE period is planned for 52 weeks. Total Planned Trial Duration For participants completing the placebo-controlled treatment period of the study, the planned amount of time for a participant in the trial is up to 34 weeks, or about 8 months. This duration assumes a 6-week screening window, a 24-week placebo-controlled treatment period, and a 4-week safety follow-up period for those participants who do not enter the OLE. Participants will complete approximately 10 study visits during the placebo-controlled treatment period of the study, in addition to weekly infusions outside of these visits. If the participant opts into the subsequent OLE, the total planned amount of time for a participant in the trial is approximately 86 weeks. This duration assumes a 6-week screening window, 24-week placebo-controlled treatment period, a 52-week OLE period, and a 4-week safety follow-up period. Participants will complete 10 study visits across the planned