An Ascending Dose Study of DKB903 in Participants With Rheumatoid Arthritis (RA) and Participants With Systemic Lupus Erythematosus (SLE)

Key Inclusion Criteria:

• Signed informed consent must be obtained prior to participation in the study.
• Able to communicate well with the Investigator, to understand the study and willing to comply with the requirements of the study.
• Immunization (primary or from vaccinations) against pneumococcus, influenza and COVID-19 at least 2 weeks prior to the first dosing.
• Male and female individuals, aged 18 to 75 years at screening, diagnosed with RA according to the 2010 American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) or 1987 ACR classification at least 12 weeks prior to screening.
• Male and female individuals, aged 18 to 75 years at screening, diagnosed with SLE according to the 2019 ACR/EULAR criteria at least 12 weeks prior to screening.

Key Exclusion Criteria:

• Body weight < 45 kg or > 145 kg and Body Mass Index (BMI) < 16 or > 39.
• Use of prohibited medication or inadequate wash-out as per protocol.
• Protocol-defined cardiac conditions or clinically significant ECG abnormalities or arrhythmia.
• Clinically significant active, opportunistic, chronic or recurrent infection (including Human Immunodeficiency Virus [HIV], Hepatitis B [HBV], Hepatitis C [HBC], and Tubercolosis [TB]) confirmed by clinical evidence, imaging, or positive laboratory tests (e.g., blood cultures, PCR for DNA/RNA) within one month prior to or during screening.
• Serious medical illness likely to interfere with participation in this clinical study.
• Women of childbearing potential (WOCBP), defined as all women physiologically capable of becoming pregnant from menarche until becoming post-menopausal, unless they are using highly effective methods of contraception (failure rate < 1% per year) from the time of enrollment until weeks after last DKB903 administration.

Other protocol-defined inclusion/exclusion criteria may apply.