Evaluation of Donor-Derived B Cell Infusions in Patients With Amyotrophic Lateral Sclerosis (ALS)

This is a phase 1, non-randomized, open-label study to assess the safety and pharmacokinetics of up to 2 doses of donor B cells. Up to 10 recipients will each receive 2 infusions of donor B cells at doses of ≥ 2.0 x 10\^8 and ≤ 1.0 x 10\^9 donor B cells delivered at least 60 days apart. The first three participants will receive infusions as inpatients in a staggered fashion 30 days apart. After completion of a 30-day observation of the third participant after the second infusion, study investigators will determine whether the infusions are safe and well-tolerated and that there are no indications of significant immune rejection of the donor B cells. In such a case the remaining participants will receive 2 infusions in an outpatient setting with no mandatory staggering interval. Each participant will be followed for six months after the second infusion. Donors. Each subject will be consented along with a relative meeting the HLA matching requirements to serve as a donor. The patient and potential donor will be HLA (A, B and DR- B1) tested and the potential donor will be a haploidentical match to the recipient, will have cleared all medical and infectious diseases screening tests, and will have agreed to be the B cell donor for this study. Each donor will undergo one or more leukapheresis procedures each yielding up to 1.5 mL of a concentrated white cell fraction. Purified B cells will be derived from these cells for a target final yield of between 2.0 x 108 and 1.0 x 109 B cells. Purified donor B cells will be stored in liquid nitrogen and thawed at bedside for infusion into participant. Recipients. Prior to infusion, each enrolled subject will have a pre-infusion visit (study Day -50 to -40) where medical history will be taken, vitals and ALS-related measurements will be taken and a blood sample drawn to establish baseline blood counts, chemistry, and immunologic profile. Treatment. All participants will receive up to 2 infusions of ≥ 2.0 x 10\^8 and ≤ 1.0 x 10\^9 donor B cells with the second infusion no less than 60 days after the first infusion. Participants will receive infusions with no preparatory treatment. Donor B cells in a concentration of 1.0 x 10\^7 donor B cells/mL in a volume of up to 100 mL will be delivered over a 2-hour period through a peripheral line pre-incubated with a 4% solution of human serum albumin. Evaluation. The first three participants will receive infusions as inpatients to carefully monitor responses to infusions for up to 24 hours. These participants will be staggered 30 days apart. If infusions of inpatient participants appear to be well tolerated and safe, the remaining participants will receive infusions as outpatients with no staggering. Safety monitoring will include periodic measurement of vital signs and specific blood tests, monitoring of changes in medical history, reports of AEs, evaluation of ALS status through ALSFRS-R and grip strength, and assessment of Columbia Suicide Severity Rating Scale. Blood tests will be taken periodically to monitor for changes in CBC, including ESR and CRP, and a metabolic panel that includes an expanded range of kidney function tests as well as ferritin. Study investigators will evaluate blood markers of immune rejection at time points up to the first four weeks after each infusion. During the study, blood tests will be taken periodically to monitor other immunologic markers including flow cytometry using an established antibody panel developed for the previously-conducted expanded access studies.