Clinical Trial Finder

Inclusion Criteria:

• - Subprotocol A and B: Diagnosis of SLE according to 2019 European League Against Rheumatism and the American College of Rheumatology (ACR) classification criteria.

• - Subprotocol A and B: Participant must be positive for at least one of the following autoantibodies at screening (performed by central laboratory) or through documented history: 1.

Antinuclear antibodies (ANA) ≥ 1:80. 2. Anti-double stranded deoxyribonucleic acid (anti-dsDNA) antibodies elevated to above normal range (ie, positive results) 3. Anti-Smith antibodies elevated to above normal (ie, positive results).

• - Subprotocol A and B: Active, biopsy-proven, proliferative LN demonstrating class III or class IV with or without co-existing features of Class V LN according to 2018 International Society of Nephrology/Renal Pathology Society (ISN/RPS) criteria.

The local biopsy report will be used.

• - Subprotocol A and B: Inadequate response, loss of response or intolerance to at least 1 therapy (Subprotocol A) or 2 therapies (Subprotocol B) at the maximally tolerated doses as recommended by the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines (KDIGO, 2024).

Inadequate response is defined as: UPCR ≥ 1.0 mg/mg.

• - Subprotocol A and B: If receiving any of the following medications, participants must be on these doses prior to day 1: 1.

Prednisone dose ≤ 20 mg/day (or its equivalent in other corticosteroid forms) and at a stable dose for 5 days. 2. Hydroxychloroquine dose ≤ 400 mg/day and at a stable dose for 4 weeks. Other equivalent antimalarials (chloroquine, quinacrine) are also accepted at a stable dose for 4 weeks. 3. MMF dose ≤ 3 g/day or MPA dose ≤ 2160 mg/day and at a stable dose for 2 weeks. 4. AZA dose ≤ 2 mg/kg/day and at a stable dose for 2 weeks.

• - Subprotocol C: Diagnosis of RA according to the 2010 ACR/ European Alliance of Associations for Rheumatology (EULAR) classification criteria.

• - Subprotocol C: Active disease defined as having all the following criteria: 1.

DAS28-CRP > 3.2 at screening. 2. at least 6 tender joints at screening. 3. at least 6 swollen joints at screening.

• - Subprotocol C: Refractory disease defined as: - Moderate to severe active disease despite having received treatment with: 1.

at least 1 conventional synthetic disease-modifying antirheumatic drug (csDMARD), AND. 2. at least 2 biologic disease-modifying antirheumatic drugs (bDMARDs) of different mechanisms of action OR 1 bDMARD and at least 1 targeted synthetic disease-modifying antirheumatic drugs (tsDMARD).

• - Inadequate response or intolerance to csDMARDs, bDMARDs, and tsDMARDs should be defined as: 1.

Participant having active disease despite a minimum of 12 weeks of treatment with a csDMARD, bDMARD, or tsDMARD. 2. Intolerance to treatment as defined by participant having experienced an adverse effect from treatment with a csDMARD, bDMARD, or tsDMARD.

Exclusion Criteria:

• - Subprotocol A and B: Estimated glomerular filtration rate (eGFR) of < 30 mL per minute per 1.73 m^2 of body surface area (calculated using the Modification of Diet in Renal Disease [MDRD] formula, with screening laboratory results for serum creatinine value).

• - Subprotocol A and B: Significant likely irreversible organ damage related to SLE (eg, end-stage renal disease [ESRD]).

• - Subprotocol A and B: Any acute, severe lupus related flare during screening that needs immediate treatment.

• - Subprotocol A and B: A previous kidney transplant or planned transplant within study treatment period.

• - Subprotocol A and B: History of or current renal diseases (other than LN) that in the opinion of the investigator could interfere with the LN assessment and confound the disease activity assessment (eg, diabetic nephropathy).

• - Subprotocol A and B: Renal biopsy showing pure class V.

• - Subprotocol C: Prior history of current inflammatory joint disease other than RA including but not limited to systemic lupus erythematosus, mixed connective tissue disorder, scleroderma, polymyositis, or significant systemic involvement secondary to RA (eg, vasculitis, pulmonary fibrosis, or Felty's syndrome).

• - Subprotocol C: Functional Class IV as defined by the ACR classification of functional status in RA.

Arms

Experimental: Subprotocol A: Inebilizumab 3 Doses

Participants will receive 3 doses of inebilizumab administered via an intravenous (IV) infusion.

Experimental: Subprotocol A: Inebilizumab 4 Doses

Participants will receive 4 doses of inebilizumab administered via an IV infusion.

Experimental: Subprotocol B: Blinatumomab Low-dose

Participants will receive blinatumomab low-dose administered via SC injection.

Experimental: Subprotocol B: Blinatumomab Medium-dose

Participants will receive blinatumomab medium-dose administered via SC injection.

Experimental: Subprotocol B: Blinatumomab High-dose

Participants will receive blinatumomab high-dose administered via SC injection.

Experimental: Subprotocol C: Blinatumomab Low-dose

Participants will receive blinatumomab low-dose administered via SC injection.

Experimental: Subprotocol C: Blinatumomab Medium-dose

Participants will receive blinatumomab medium-dose administered via SC injection.

Experimental: Subprotocol C: Blinatumomab High-dose

Participants will receive blinatumomab high-dose administered via SC injection.

Interventions

Drug: - Inebilizumab

Intravenous (IV) Infusion

Drug: - Blinatumomab

SC Injection