Treatment of Type 1 Diabetes With Anti-OX40L Bispecific With Anti-TNF Activity In a Single Nanobody® Molecule

Inclusion Criteria:

1. Participant must be 18 to 35 y.o. inclusive, at the time of signing the informedconsent in order to be enrolled in Part A. Participant must be 12 to 21 y.o.inclusive, at the time of signing the informed consent in order to be enrolled inPart B.

2. Participants who meet the criteria of T1D according to American Diabetes Association (ADA 2024).

3. Initiated exogenous insulin replacement therapy not longer than 90 days prior toScreening visit at which random C-peptide will be assessed.

4. Receiving insulin hormone replacement therapy:

5. Participants must be positive for at least 1 of the following T1D autoantibodiesconfirmed by medical history and/or obtained at study Screening:

• Glutamic acid decarboxylase (GAD-65)

• Insulinoma Antigen-2 (IA-2)

• Zinc-transporter 8 (ZnT8) or

• Insulin (if obtained not later than 10 days after exogenous insulin therapyinitiation)

6. Have random C-peptide levels ≥0.2 nmol/L determined at Screening.

Exclusion Criteria:

Participants are excluded from the study if any of the following criteria apply:

1. Serious systemic viral, bacterial or fungal infection (eg, pneumonia,pyelonephritis), infection requiring hospitalization or intravenous (IV) antibioticsor significant chronic viral (including history of recurrent or active herpeszoster, acute or active cytomegalovirus [CMV], Epstein-Barr Virus [EBV] asdetermined at Screening), bacterial, or fungal infection (eg, osteomyelitis) 30 daysbefore and during Screening.

2. History of invasive opportunistic infections, such as, but not limited tohistoplasmosis, listeriosis, coccidioidomycosis, candidiasis, pneumocystisjirovecii, and aspergillosis, regardless of resolution.

3. Evidence of active or latent tuberculosis (TB) as documented by medical history andexamination, chest X-rays (posterior anterior and lateral), and/or TB testing.

4. Evidence of any clinically significant, severe or unstable, acute or, chronicallyprogressive, uncontrolled infection, medical or surgical condition (eg, but notlimited to, cerebral, cardiac, pulmonary, renal, hepatic, gastrointestinal,neurologic, or any known immune deficiency), or any condition that may affectparticipant safety in the judgment of the Investigator (including vaccinations whichare not updated based on local regulation).

5. History of a systemic hypersensitivity reaction or significant allergies, other thanlocalized injection site reaction, to any humanized mAb. Clinically significantmultiple or severe drug allergies, intolerance to topical corticosteroids, or severepost-treatment hypersensitivity reactions (including, but not limited to, erythemamultiforme major, linear IgA dermatosis, toxic epidermal necrolysis, and exfoliativedermatitis).

6. History of moderate to severe congestive heart failure (New York Health Association [NYHA] Class III or IV), or recent cerebrovascular accident, or any other conditionwhich, in the opinion of the Investigator, would put the participant at risk byparticipation in the protocol.

7. History of demyelinating disease (including myelitis) or neurologic symptomssuggestive of demyelinating disease.

8. Has other autoimmune or inflammatory conditions

9. Diabetes of forms other than autoimmune T1D that include but are not limited togenetic forms of diabetes, maturity-onset diabetes of the young (MODY), latentautoimmune diabetes of the adult (LADA), secondary to medications or surgery, type 2diabetes by judgment of the investigator.

10. History of malignancy or lymphoproliferative disease other than adequately treatedlocalized carcinoma in situ of the cervix or nonmetastatic squamous cell carcinoma,or nonmetastatic basal cell carcinoma of the skin that was excised and completelycured or any family history in two or more relatives (immediate family) of samecancer (ie, rare cancers, those manifesting at a young age in a parent or sibling,certain genetic-based inheritable cancers).

11. Systemic corticosteroids (duration >7 days), adrenocorticotropic hormone 1 monthprior to Screening.

12. Any IV, intramuscular (IM) or SC administered biologic treatments (mono- orpolyclonal antibodies affecting function of immune system), <3 months or <5half-lives (whichever is longer), prior to randomization.

13. Any live (attenuated or viral-vector) vaccine (including but not limited tovaricella zoster, oral polio, nasal influenza, rabies) within 3 months prior torandomization or is scheduled in expected period of study (78 weeks afterrandomization) if this vaccination cannot be safely postponed.

14. Any non-live (inactivated, mRNA, recombinant, conjugate, toxoid) vaccineadministered less than 14 days prior to randomization.

15. Any immunosuppressive therapy within 12 weeks prior to randomization and through 78weeks after randomization

16. Course of Thymoglobulin®, teplizumab or other immunomodulatory treatments at anytime

17. Any drugs that may be used for treatment of T1D and type 2 diabetes other thaninsulin including but not limited to metformin, glucagon-like peptide 1 (GLP-1)agonists, sodium-glucose co-transporter-2 and 1 (SGLT2/1) inhibitor, and verapamilwithin 2 weeks prior to Screening.

18. Abnormal laboratory test(s) at Screening

19. Participants who have impaired renal function with estimated glomerular filtrationrate (eGFR) (using the Modification of Diet in Renal Disease [MDRD] formula) <60mL/min/1.73 m2, or using the bedside Schwartz equation in the participants under theage of 18 y.o.