A Phase 1 Trial to Evaluate the Safety, Tolerability, Pharmacodynamics, Pharmacokinetics, and Immunogenicity of VIS171 in Participants With Autoimmune Disease(s)

Inclusion criteria

• Estimated glomerular filtration rate (eGFR) >30 milliliters/minute/1.73 square meters (mL/min/1.73 m^2) at the screening visit.

For SLE participants:

• Participant has a confirmed diagnosis of SLE according to European League Against Rheumatism/American College of Rheumatology SLE classification criteria ≥ 24 weeks prior to signing the informed consent form (ICF).

For AA participants:

• Current scalp involvement between 25% and 95%, inclusive (Severity of Alopecia Tool [SALT] score between 25 and 95, inclusive), at screening.
• Current episode of AA is of duration > 24 weeks (without evidence of spontaneous terminal hair regrowth at the time of screening and first treatment, i.e., no more than 10% regrowth), but ≤ 5 years from onset of current episode of severe scalp hair loss.

For FSGS participants:

• Prior biopsy (no time limit) showing histologic minimal change disease (MCD), FSGS, or MCD/FSGS spectrum.
• History of at least one prior episode of nephrotic syndrome, defined as 24-hour urine protein > 3.5 grams per day (g/day) and serum albumin < 3.5 grams per deciliter (g/dL).
• History of steroid responsive nephrotic syndrome, including participants who achieved complete remission, partial remission, had a course of steroid dependent nephrotic syndrome or relapsing nephrotic syndrome (all defined as per the managing physician at the time of the episode).

Exclusion criteria

• Receipt of high-dose corticosteroid therapy within 4 weeks prior to screening as either (a) intravenous (IV) pulse corticosteroid therapy or (b) daily oral corticosteroid therapy of ≥ 1 milligrams per kilogram (mg/kg) or up to 40 milligrams per day (mg/day) prednisone (or equivalent).
• Receipt of blood products within 6 months prior to screening.
• Previous exposure to VIS171 or any other drug targeting interleukins (IL)-2 or the IL-2 receptor or T regulatory cells.
• History of or current diagnosis of catastrophic or severe anti-phospholipid syndrome (APS) within 1 year prior to signing ICF. SLE participants with APS adequately controlled by anticoagulant are eligible. SLE participants who are found to be triple positive for anti-phospholipid antibodies at screening (without clinical APS) will be excluded unless they are on stable anti-thrombotic therapy.
• Known primary immunodeficiency disorder.
• Participant has a history of Class V lupus nephritis.
• Receipt of anifrolumab, tumor necrosis factor-alpha monoclonal antibodies ([TNF]-α mAb), immunoglobulins (IV/SC) plasmapheresis, or any other immunosuppressants (calcineurin inhibitors, Janus kinase [JAK] inhibitors or other kinase inhibitors), other than hydroxychloroquine, mycophenolic acid (MPA)/mycophenolate mofetil (MMF) and corticosteroids, within 6 months prior to screening.
• Participant has concomitant hair loss of another form, including but not limited to traction alopecia, central centrifugal cicatricial alopecia, lichen planopilaris, frontal fibrosing alopecia, or androgenetic alopecia.
• Participant has received (1) Within 12 weeks prior to Day 1: Systemic therapies (oral or injection), such as corticosteroids, JAK inhibitors, methotrexate, calcineurin inhibitors, oral minoxidil, low-dose IL-2 and topical immunotherapies such as psoralen plus UVA (PUVA) , diphenylcyclopropenone (DPCP), dinitrochlorobenzene (DNCB), intralesional steroids or (2) Within 4 weeks prior to Day 1: Other topical therapies, such as topical minoxidil, clobetasol etc. These therapies will also not be allowed during this trial.
• Steroid resistant nephrotic syndrome defined as absence of history of at least 1 episode of complete or partial remission following at least 12 weeks of full dose corticosteroid therapy.
• Receipt of anifrolumab, TNF-α mAb, immunoglobulins (IV/SC) plasmapheresis, or any other immunosuppressants (JAK inhibitors or other kinase inhibitors).

Note: Other protocol-specified Inclusion/Exclusion criteria may apply.