A Study of OL-108 in Relapsed/Refractory Autoimmune Diseases

Inclusion Criteria:

• General:

• Adults aged 18-65 years old

• ECOG 0-2

• Adequate organ function

• Females of childbearing potential (FCBP) must have a negative pregnancy test atscreening and must agree to use a highly effective contraceptive method startingfrom the time of lymphodepletion and for 2 years after dosing of the IMP

• SLE specific: a) Fulfilling the 1997 ACE SLE criteria/ 2012 SLICC criteria/ 2019 ACR/EULARclassification criteria of SLE; b) A positive ANA titer (≥ 1:80) and/or presence ofanti-dsDNA, or anti-Sm antibodies; c) Active disease at screening, defined asSLEDAI-2K≥8 AND clinical SLEDAI-2K≥6, AND ≥1 organ system with a British Isles LupusAssessment (BILAG) A score (severe disease activity) or ≥2 organ systems with aBILAG B score (moderate disease activity), AND PGA≥ 1; OR biopsy proven 2003 ISN/RPSclass III/IV +/- class V lupus nephritis; d) relapsed or refractory to at least oneimmunosuppressant or biologic.

• IIM specific: a) Fulfilling the 2017 ACR/EULAR classification criteria for DM, PM, ADM, ASS andIMNM; b) Active disease as defined by at least one of the following criteria: atleast one muscle enzyme > ULN in the past 4 weeks, active disease by EMG/musclebiopsy/MRI in the past 3 months, active DM rash; c)MMT < 142 and 2 of the followingcriteria: VAS patients Global ≥ 2 cm, VAS physician Global ≥ 2 cm, HAQ > 0.25, atleast one muscle enzyme > 1.5x ULN, MDAAT ≥ 2 ; d) CDASI ≥14 if with skininvolvement; e) At least one myositis-specific or associated antibody positive;f)relapsed or refractory to at least one immunosuppressant or biologic.

• SSc specific: a)Fulfilling the 2013 ACR/EULAR classification criteria of SSc; b) Active disease asdefined by one of following: new or progressing skin manifestation/vital organinvolvement within 6 months prior to screening, CRP≥6 mg/L, ESR≥28 mm/h, platelet ≥330 × 10⁹/L; c) mRSS score >10; d)relapsed or refractory to at least oneimmunosuppressant or biologic.

• AAV specific:

1. Fulfilling the 2022 ACR/EULAR classification criteria for MPA/GPA; b) Presenceof ANCA to either proteinase 3 or myeloperoxidase; c)At least one major orthree non-major items or at least two renal items of hematuria and proteinuriaon the BVAS; d)relapsed or refractory to at least one immunosuppressant orbiologic.

Exclusion Criteria:

• Active uncontrolled infection

• Serologic evidence of chronic hepatitis B virus (HBV) infection and unable orunwilling to receive standard prophylactic antiviral therapy or with detectable HBVviral load

• Serologic evidence of hepatitis C virus (HCV) infection without completion ofcurative treatment or with detectable HCV viral load

• HIV antibody positive

• Syphilis antibody positive

• Active tuberculosis, untreated or inadequately treated latent tuberculosis infection (LTBI)

• History of serious infection within 3 months prior to screening (defined asrequiring hospitalization or intravenous antimicrobial therapy), or history of oralantimicrobial therapy within 1 month prior to screening (e.g., viral infections,opportunistic infections, including but not limited to severe cytomegalovirus orherpes virus infections)

• Congenital long QT syndrome or a corrected QTcF interval of ≥480 ms at screening (unless secondary to pacemaker or bundle branch block)

• Uncontrolled hypertension (blood pressure ≥160/100 mm Hg repeatedly), unstableangina, congestive heart failure (greater than New York Heart Association class II),electrocardiographic evidence of acute ischemia, coronary angioplasty or myocardialinfarction within 6 months prior to screening, uncontrolled atrial or ventricularcardiac arrhythmia, poorly controlled diabetes or other endocrine diseases, severechronic pulmonary disease, or other serious medical condition which is likely tosignificantly impair the patient's ability to tolerate the study treatment

• history of organ transplant

• Pregnancy or lactating women

• Use of any other experimental medication within 4 weeks or 5 half-lives prior tostart of study drug

• Use of biologics within 3 months, stem cell transplant or CAR-T within 6 monthsprior to the start of study drug

• Received live or attenuated vaccine within 4 weeks of Cycle 1 Day 1

• Presence of other autoimmune or auto-inflammatory diseases that may affect studyassessments, such as rheumatoid arthritis, gout, or active fibromyalgia syndrome.

• Limited to patients diagnosed with SLE: patients with active neuropsychatric SLE

• Limited to patients diagnosed with IIM: Severe involvement of respiratory musclesaffecting ventilatory function; permanent muscle weakness related to IIM; otherinflammatory or non-inflammatory myopathy: inclusion body myositis, infectiousmyopathy, metabolic myopathy, muscular dystrophy or a family history of musculardystrophy, drug-induced or endocrine-induced myositis, and juvenile myositis

• Limited to patients diagnosed with SSc: at risk for scleroderma renal crisis;SSc-associated gastric antral vascular ectasia; Severe gastrointestinal involvementleading to malabsorption or intestinal failure

• Limited to patients diagnosed with AAV: Central nervous system vasculitis; Alveolarhemorrhage requiring invasive pulmonary ventilation