Phase 1b/2a Study to Evaluate Safety and Efficacy of KPG-818 in SLE

The clinical trial is titled "A Phase 1b/2a Multicenter Study to Assess the Safety and Tolerability, Pharmacokinetics, and Preliminary Efficacy of KPG-818 in Patients with Systemic Lupus Erythematosus". This study was designed to address the following key questions: * Phase 1b: Assess safety and PK of KPG-818 in SLE patients over 14 days. * Phase 2a: Assess safety, efficacy, PD biomarkers, and PK of KPG-818 in SLE patients over 12 weeks. The study design comprises eight Cohorts, which are outlined below: * Phase 1b dose levels: Cohort A (0.15 mg/day), B (0.6 mg/day), C (2 mg/day), and D (5 mg/day). * Phase 2a dose levels: Cohort E (0.15 mg/day), F (0.6 mg/day), G (2 mg/day) and H (placebo).

1. Male or female of 18 years of age or older at the time of signing the ICF. 2. BMI between 18 and 40 kg/m2. 3. Able and was willing to adhere to the visit schedule and other protocol requirements. 4. Diagnosed with SLE according to the 2019 EULAR/ACR criteria for SLE. 5. Met SLE activity requirements as described below: * For the Phase 1b part of the study, patients with or without active SLE were enrolled if, in the opinion of the Investigator, the disease activity was stable and there was no need for change or increase in SLE therapy anticipated for the study duration. If patients were on stable standard care of SLE treatment, this was to comply with inclusion criteria No. 11. * For the Phase 2a part of the study, patients must have had a SLEDAI-2K score of ≥ 6 points at the screening visit with a SLEDAI-2K clinical score ≥ 4 points at the baseline visit. The "clinical" score was the SLEDAI-2K assessment score without the inclusion of points attributable to any urine or blood laboratory results, including immunologic measures. Neurologic descriptors of the SLEDAI-2K were not counted towards the SLEDAI study entry criteria. In addition, the patient must have been on stable standard care of SLE treatment with at least 1 of the followings: OCS, anti malarial, or immunosuppressant (see inclusion criteria No. 11 for allowed medications and doses). 6. Documented history or presence at screening of positive autoantibodies associated with SLE, which must have included at least 1 of the following: * Positive ANA test with a titer of 1:80 or greater. * Anti-dsDNA antibodies elevated to above normal. * Anti-Smith antibody elevated to above normal. 7. WOCBP must: * Have had 2 negative serum pregnancy tests as verified by the Investigator prior to starting study therapy, 1 at screening and again within 3 days before taking the first dose of KPG-818, then have a negative urine pregnancy test at baseline before dosing. WOCBP must have agreed to ongoing pregnancy testing during the course of the study, and after the end of IMP. This applied even if the patient practiced true abstinence from heterosexual contact. * Either commit to true abstinence from heterosexual contact (which was reviewed on a monthly basis and source documented) or agreed to use 2 forms of reliable contraception simultaneously. One must have been a highly effective method and 1 additional effective (barrier) method and both must have been practiced without interruption, at least 28 days before starting IMP, during the study therapy (including dose interruptions), and for 28 days after discontinuation of study therapy. 8. Male patients must: Have practiced true abstinence or agreed to use a barrier contraception (male latex condom or non-latex condom NOT made out of natural \[animal\] membrane \[for example, polyurethane\]) during sexual contact with a WOCBP while participating in the study, and for at least 90 days after IMP discontinuation, even if he had undergone a successful vasectomy. Male patients had to agree not to donate semen or sperm during the treatment period and for at least 90 days after the discontinuation of KPG-818. 9. Female patients who were postmenopausal must have demonstrated a FSH blood level of equal to or greater than 40 mIU/mL at the screening visit. Women aged \> 60 years old whose FSH values were not equal to or greater than 40 mIU/mL were included at the discretion of the Investigator and in consultation with the Sponsor. 10. All patients must: * Understand that KPG-818 could have potential teratogenic risk. * Agreed not to share KPG-818 with another person. * Be counseled about pregnancy precautions and risks of fetal exposure as described in the Pregnancy Prevention Plan. 11. In the Phase 2a part of the study, the patient must have been on stable standard-of-care SLE treatment with at least 1 of the followings: OCS, antimalarial, or immunosuppressant: 1. If was taking OCS, must be on-treatment for ≥ 4 weeks before the screening visit, and maintained on a stable dose of ≤ 20 mg/day of prednisone or equivalent for at least 4 weeks before the baseline visit. 2. If was taking an antimalarial agent (hydroxychloroquine, chloroquine, or quinacrine), must be on-treatment for ≥ 8 weeks before the screening visit and be on a stable dose for ≥ 4 weeks before the screening visit. Antimalarials at the following doses were allowed: * Hydroxychloroquine (≤ 400 mg/day) * Chloroquine (≤ 500 mg/day) * Quinacrine (≤ 200 mg/day) 3. If was taking allowed immunosuppressants, must be on-treatment for ≥ 8 weeks prior to the screening visit and be on a stable dose for ≥ 4 weeks before the screening visit. Only 1 of the immunosuppressants below was allowed at the indicated doses: * Mycophenolate mofetil (≤ 2 g/day) or mycophenolic acid (≤ 1.44 g/day) * Azathioprine (≤ 200 mg/day) * Methotrexate (≤ 20 mg/week) * Leflunomide (≤ 20 mg/day) 4. If was taking NSAIDs or other regularly administered analgesics, these were allowed if treatment started ≥ 4 weeks before the baseline visit and dosing had not been changed within the last 2 weeks before the baseline visit. 5. If immunosuppressants, antimalarial, or OCS were discontinued, the last dose must have been more than 4 weeks prior to the screening visit. 12. Patients had to agree not to donate blood (or any component of blood) from 3 months before screening until 3 months after the last dose of KPG-818. 13. Patients had to be willing to comply with precautions to reduce the risk of COVID 19 infection in accordance with recommendations from the applicable medical associations and the Investigator for the duration of the study and to undergo COVID 19 polymerase chain reaction test as required based on Investigator judgment and/or local requirements.