IDP-023 g-NK Cells Plus Ocrelizumab in Patients With Progressive Multiple Sclerosis

Key Inclusion Criteria: * Confirmed diagnosis of primary or non-active secondary progressive MS (SPMS) based on the 2017 revisions of the McDonald criteria. * Dosed with ocrelizumab within the prior 6 months. * Expanded Disability Status Scale (EDSS) at screening from 3.0 to 6.5 points. * Score of ≥2.0 on the Functional Systems (FS) scale for the pyramidal system that is due to lower extremity findings. * Disease duration from the onset of MS symptoms: * Less than 15 years in patients with an EDSS at screening \>5.0. * Less than 10 years in patients with an EDSS at screening ≤5.0. Key Exclusion Criteria: * Relapsing remitting MS at screening or active SPMS at screening. * Inability to complete an MRI. * Contraindication for gadolinium. * Known presence of other neurological disorders, including but not limited to the following: * History or known presence of CNS or spinal cord tumor (e.g., meningioma, glioma). * History or known presence of infectious causes of myelopathy (e.g., syphilis, Lyme disease, Human T-lymphotropic virus 1 \[HTLV-1\], herpes zoster myelopathy). * History or known presence of systemic autoimmune disorders potentially causing progressive neurologic disease (e.g., lupus, antiphospholipid antibody syndrome, Sjögren's syndrome, Behçet's disease). * Impaired cardiac function or history of clinical significant cardiac disease. * Human immunodeficiency virus (HIV) infection, active hepatitis B infection, or hepatitis C infection.